the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 08 Sep 2022
Excess radiation exacerbates drought stress impacts on canopy conductance along aridity gradients
Jing Wang
Xuefa Wen
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- Final revised paper (published on 08 Sep 2022)
- Supplement to the final revised paper
- Preprint (discussion started on 15 Mar 2022)
- Supplement to the preprint
Interactive discussion
Status: closed
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CC1: 'Comment on bg-2022-50', Yakun Tang, 29 Apr 2022
Stomatal conductance (gs) of all co-existing species plays a significant role in transpiration and carbon uptake photosynthesis at ecosystem level. This study investigates the interactive effect of environmental stressors and biotic factors on canopy gs, through an experiment conducted through three plateaus in China. Bulk leaf δ18O organic matter is affected by gs based in steady-state leaf water 18O enrichment and is widely used by plant eco-physiologists to infer the spatial and temporal variation in gs. The manuscript is well rewritten and the topic is useful for canopy gc simulating at different scales.
The author should clarify why the radiation exhibited negative effect on gs, however, temperature exhibited positive or no effect on gs in different regions. Generally, radiation may influence plant gs through its influence air temperature, thus, the consistent effect of radiation and temperature on gs may be more reasonable.
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AC1: 'Reply on CC1', Xue-Fa Wen, 14 Jul 2022
Response to reviews of manuscript “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” bg-2022-50
Response to community comment #1
Dear Yakun Tang,
We would like to thank you for the thoughtful and valuable comments and suggestions on our manuscript entitled “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” (bg-2022-50). We have carefully revised our manuscript to take account of your comment. Meanwhile, we have rephrased our manuscript title as “Excess radiation exacerbates drought stress impacts on canopy conductance along aridity gradients”.Here are the point-to-point responses (responses in upright Roman in black front) to the comments (original queries in Italic in blue front).
General comments:
The author should clarify why the radiation exhibited negative effect on gs, however, temperature exhibited positive or no effect on gs in different regions. Generally, radiation may influence plant gs through its influence air temperature, thus, the consistent effect of radiation and temperature on gs may be more reasonable.
Response: Thank you very much for your comment. We respond this comment from three aspects.
(1) We corrected the structure equation method result about the effect of temperature on gs in Losses Plateau: “Tempmax in LP did not exist significant effect on community 1/△18O (P>0.05).”
(2) We rephrased the discussion about the negative effect of solar radiation on canopy conductance (Gs, presented by community 1/△18O) via drought stress: “Solar radiation and temperature regulated variability in Gs within transect via drought stress (Fig.4). Solar radiation exhibited consistently negative effects on Gs, because it increased with increasing aridity within three transects (Fig.1h, Table S1). These results were consistent with those of Fu et al. (2006), who demonstrated that the net CO2 exchange of grassland in MP and shrubland in TP was significantly reduced by high solar radiation. In this study, solar radiation exhibited negative effect on Gs via drought stressors (Fig.4 a-c). On one hand, increasing solar radiation would decrease SM by increasing energy partitioning in evaporation and transpiration (Zhang et al. 2019). Solar radiation had negative effects on SM in the three transects in this study (Table S5). On the other hand, increasing solar radiation can increase VPD by increasing temperatures (Grossiord et al. 2020). However, a positive relationship between temperature and VPD was observed only in TP (Table S2).”
(3) We rephrased the discussion about the negative effect of temperature on Gs via drought stress: “The drought stress on Gs within transect was exacerbated by higher temperatures in TP (Fig.4c). In TP, temperature increased with increasing aridity (Table S1), and was negatively related to SM and positively to VPD (Table S5, Fig.4c). As with solar radiation, increases in temperature tend to increase evaporation and transpiration rates ultimately reducing SM, while VPD always increased with increasing temperatures (Grossiord et al. 2020; Oren et al. 1999). Consequently, increasing temperature exacerbate soil and atmospheric drought, ultimately reducing Gs along an aridity gradient in TP. In LP, the temperature exhibited negative correlations with community 1/△18O, while did not exhibited significantly effect on community 1/△18O (Fig.4a). The reason was that temperature was significantly correlated with SM in LP (Table S5). ”
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AC1: 'Reply on CC1', Xue-Fa Wen, 14 Jul 2022
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CC2: 'Comment on bg-2022-50', Zhaoguo Wang, 29 Apr 2022
This study of the impacts of stress factors and plant traits on stomatal conductance along aridity gradients is critical and timely. It represents a lot of work and will make a good addition to the literature, but there are some aspects that can be improved.
1 There are expressions like “drought”, “dryness”, “low soil moisture” and “soil moisture stress” in this manuscript. I don’t think these have the same meaning. Please check and use it properly. Similarly, this manuscript focused on gs, but sometimes there are expressions like “canopy gs”.2 I think hypothesis should be based on the information provided in the introduction. In terms of the hypothesis 2 “excess solar radiation and low temperatures will result in differences in gs among transects”, I don’t understand how low temperatures will affect gs according to the information in introduction.
3 The last paragraph should be the last but one paragraph or in the methods.
4 There may be interspecific difference in gs, so information on plant species and species composition of the three study sites should be provided.
5 The headline of the first part in the discussion should be changed, because the patterns of gs among the tree transects are similar, but differ in magnitude. In addition, the authors attribute this difference to the temperature-induced changes in photosynthesis, which I don’t agree. Indeed, gs and photosynthesis are closely correlated, for example, to maximize carbon gain and minimize water loss according to the optimal stomatal behaviour. However, in my opinion, the correlation between gs and photosynthesis is regulated by stomatal behaviour.
6 line 25 delete “at leaf level”.
7 line 24 change “in one” and “in the other” into (1) and (2), respectively.
8 I suggest that “interaction effects” may be changed into “interactive effects”.
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AC2: 'Reply on CC2', Xue-Fa Wen, 14 Jul 2022
Response to reviews of manuscript “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” bg-2022-50
Response to community comment #2
Dear Zhaoguo Wang,
We would like to thank you for the thoughtful and valuable comments and suggestions on our manuscript entitled “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” (bg-2022-50). We have carefully revised our manuscript to take account of your comments and suggestions. Meanwhile, we have rephrased our manuscript title as “Excess radiation exacerbates drought stress impacts on canopy conductance along aridity gradients”.Here are the point-to-point responses (responses in upright Roman in black front) to the comments (original queries in Italic in blue front). The changed figures and tables are presented in the Appendix 1 and Appendix 2 (listed at the end of the “Response to community comment #2”).Specific comments:
1) There are expressions like “drought”, “dryness”, “low soil moisture” and “soil moisture stress” in this manuscript. I don’t think these have the same meaning. Please check and use it properly. Similarly, this manuscript focused on gs, but sometimes there are expressions like “canopy gs”.
Response: Thank you very much for your comment. We have replaced “dryness” with “drought”, and “soil moisture stress” with “low soil moisture” throughout the manuscript. Meanwhile, we used gs to present stomatal conductance at leaf level, and Gs to present canopy conductance.
2) I think hypothesis should be based on the information provided in the introduction. In terms of the hypothesis 2 “excess solar radiation and low temperatures will result in differences in gs among transects”, I don’t understand how low temperatures will affect gs according to the information in introduction.
Response: Thank you very much for your comment. We respond to this comment from three aspects.
(1) We clarified that “However, previous studies showed that the direction and intensity of solar radiation and temperature on gs strongly depend on their distribution range and the relationship with aridity. For example, the response of gs to solar radiation and temperature generally shows an increasing trend up to optimum values (Xu et al. 2021), while excess radiation (Costa et al. 2015; Doupis et al. 2020; Zeuthen et al. 1997) and high temperature associated high VPD or low SM (Seneviratne et al. 2010) would suppress gs.”
(2) We added the basic climatic context for the three grassland transect in the last paragraph of “1 Instruction” section: “The grassland transect span gradients of precipitation, SM, VPD, solar radiation, and temperature, provide an ideal platform for exploration of interactive effects of multiple stressors and biotic factors on Gs (Table S1). In addition, the three grassland transects experienced with different soilar radiation and temperature conditions at a given aridity, due to the difference in the geographical location of the three plateaus. The order of mean annual temperature and solar radiation is LP>MP>TP and LP<MP<TP, respectively.”
(3) We rephrased the second hypothesis as: “high solar radiation and low temperatures will jointly suppress Gs at a given aridity among transects. ”.
3) The last paragraph should be the last but one paragraph or in the methods.
Response: This paragraph has been revised and removed to section “2.2.3 Stable isotope analysis”: “Given that leaf δ18O at species level was affected by the leaf water evaporation process, variability in gs should show up in leaf δ18O (Barbour 2007; Barbour & Farquhar 2000; Farquhar et al. 1998). Negative relationship between △18O and gs has been observed at species (Barbour & Farquhar 2000; Cabrera-Bosquet et al. 2011; Grams et al. 2007; Moreno-Gutierrez et al. 2012) and canopy scales (Cabrera et al. 2021; Hirl et al. 2021), and among communities along soil (Ramirez et al. 2009) and climatic (Keitel et al. 2006) gradients. Consequently, we selected 1/△18O was used as a proxy for gs in this study.”
4) There may be interspecific difference in gs, so information on plant species and species composition of the three study sites should be provided.
The species, genera and families of species occurred in each community have been listed in “Supplementary 2” (Please see Appendix 2)”.
5) The headline of the first part in the discussion should be changed, because the patterns of gs among the tree transects are similar, but differ in magnitude. In addition, the authors attribute this difference to the temperature-induced changes in photosynthesis, which I don’t agree. Indeed, gs and photosynthesis are closely correlated, for example, to maximize carbon gain and minimize water loss according to the optimal stomatal behaviour. However, in my opinion, the correlation between gs and photosynthesis is regulated by stomatal behaviour.
Response: Thank you very much for your comment. We respond this comment from two aspects.
(1) The headline has been change as: “ 4.3 Differences in canopy conductance among transects” .
(2) The effects of VPD, solar radiation and temperature on the differences in canopy conductance among transects have been rephrased as: “
Significant differences in community 1/△18O were found among transects, and the order of Gs at a given aridity value was LP > MP > TP (Fig.2a). Among transects, only differences in VPD, solar radiation and temperature were significant (P>0.05) (Fig.1 and Fig.S1). In general, plants decrease their gs to respond to increasing VPD (Grossiord et al. 2020). While, intercept of linear regression between aridity and community 1/△18O decreased with decreasing VPD among transects (P>0.05) (Fig.3a). It indicated that the difference in VPD was not a contributor to the difference in Gs among transects.
We attribute the differences in Gs among transects to the direct effects of solar radiation and temperature on Gs and photosynthesis (Yu et al. 2002). This is inconsistent with the results within transect. High solar radiation exhibited negative effect on intercept of linear regression between aridity and community 1/△18O among transects (P<0.05) (Fig.3b). Excess ultraviolet-B radiation (Duan et al. 2008), insufficient thermal dissipation, and enhanced photorespiration under high solar radiation (Cui et al. 2003) can decrease photosynthesis, ultimately reducing gs. For example, Yu et al. (2012) observed that photosynthesis of wheat at leaf level on the TP was lower than that on North China Plain due to the high solar radiation.
Transect with low temperature exhibited low intercept of linear regression between aridity and community 1/△18O (Fig.3c), it indicated that Gs among transects also inhibited by low temperature. Generally, photosynthesis and Gs increased with temperature below optimum temperature (Xu et al. 2021). For example, photosynthesis of wheat was lower in a cold than in a warm environment (Yu et al. 2002). ”
6) line 25 delete “at leaf level”.
Response: Change has been done.
7) line 24 change “in one” and “in the other” into (1) and (2), respectively.
Response: Change has been made.
8) I suggest that “interaction effects” may be changed into “interactive effects”.
Response: Change has been made.
Appendix 1
Figure 1. Comparison of aridity (a), growing season precipitation (b), soil moisture (SM) (c), vapor pressure deficit (VPD) (d), solar radiation (SR) (e), temperature (f), maximum temperature (Tempmax) (g), and community leaf area (h) and specific leaf area (SLA) (i) among transects. LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05). Error bars indicate standard error of the mean.
Figure 2. Patterns of 1/△18O (a) along aridity gradient within transects, and among (b) transects. Different letters indicate significant differences (P < 0.001) among transects and grassland types. △18O, 18O enrichment of leaf organic matter above source water; LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau.
Figure 3. Patterns of the intercept obtained from standardized major axis analysis (SMA) among transects. VPD, vapor pressure deficit; SR, solar radiation; Tempmax, maximum temperature. LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Shaded area represents the 95% confidence interval of the SMA intercept.
Figure 4. Structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Figure 5. Structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Table 1 Pearson’s coefficients among community 1/△18O and environmental factors and plant properties.
Loess Plateau
Inner Mongolia Plateau
Tibet Plateau
Aridity
-0.848**
-0.843**
-0.773**
SM
0.719*
0.707*
0.659*
VPD
-0.554
-0.384
-0.912**
SR
-0.639*
-0.728*
-0.850**
Tempmean
0.641*
0.303
-0.670*
Tempmax
0.678*
0.038
-0.852**
LA
0.757*
0.913**
0.610
SLA
-0.519
-0.576
-0.648*
**, P<0.01; *, P<0.05. SM, soil moisture; VPD, vapor pressure deficit; SR, total solar radiation; Tempmean, mean temperature; Tempmax, maximum temperature; LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Table S1 Geographic and climatic information, δ18O of precipitation, and community △18O for sampling sites in Loess (LP), Inner Mongolia (MP), and Tibetan (TP), Plateau.
Site
Longitude
(°E)
Latitude
(°N)
Elevation
(m)
Aridity
Temperature
(℃)
Tempmax
(℃)
Precipitation
(mm)
Solar radiation
(kJ m-2 day-1)
VPD
(kPa)
SM
(m3 m-3)
δ18OP (‰)
△18O(‰)
Year
GSW
Year
GS
Year
GS
Year
GS
GS
Year
GS
LP01
113.36
36.29
804
0.57
11.85
18.19
29.6
599
546
12.95
15.60
4.78
7.53
0.16
-8.70
-6.92
26.82±0.84
LP02
112.29
35.99
894
0.60
9.96
17.60
29.2
549
501
13.31
16.04
3.57
7.41
0.17
-8.80
-6.86
28.78±1.73
LP03
111.64
35.99
833
0.64
10.66
18.61
30
520
475
12.69
15.65
4.04
8.59
0.13
-8.70
-6.79
30.30±1.77
LP04
110.18
36.07
966
0.63
10.72
18.03
29.9
519
478
14.25
17.02
4.52
8.45
0.15
-9.10
-7.09
29.68±1.00
LP05
109.24
36.74
1268
0.65
9.50
16.99
28.7
492
458
15.34
18.28
4.13
8.00
0.12
-9.20
-7.18
27.64±0.96
LP06
107.92
36.93
1383
0.68
7.46
15.71
27.8
424
394
15.32
18.31
2.53
6.44
0.12
-8.60
-6.74
28.75±1.39
LP07
107.19
37.58
1535
0.75
5.23
15.61
27.6
340
311
15.62
18.97
1.88
7.51
0.07
-7.70
-6.01
32.42±0.86
LP08
105.78
37.42
1293
0.85
5.87
16.94
28.8
222
211
15.53
18.95
2.01
8.71
0.10
-6.80
-5.08
30.77±1.95
LP09
104.92
37.44
1378
0.87
7.56
16.50
28.1
196
183
15.49
18.74
3.99
9.44
0.10
-6.30
-4.69
32.00±2.38
LP10
104.44
37.46
1714
0.87
7.71
15.31
26.8
189
179
15.56
18.77
4.75
9.06
0.10
-6.70
-4.83
34.60±1.39
Trend
0.009
0.035
0.024
<0.001
<0.001
0.012
0.005
0.445
0.058
0.007
<0.001
<0.001
NM01
123.51
44.59
144
0.68
5.10
16.60
29.6
425
410
13.67
17.28
1.11
6.98
0.17
-9.20
-7.14
32.54±0.90
NM02
121.04
44.52
269
0.73
5.80
16.66
30
393
378
14.73
18.44
2.56
8.59
0.11
-9.60
-7.52
32.49±0.71
NM03
120.33
45.11
660
0.71
3.72
13.60
27.4
387
372
14.94
18.81
2.30
6.74
0.15
-10.60
-8.36
32.28±0.65
NM04
118.36
44.77
1019
0.71
0.56
12.03
26.2
345
320
15.09
19.20
1.11
5.96
0.14
-11.40
-8.84
34.23±0.39
NM05
116.52
44.26
1129
0.77
1.17
12.27
26.2
283
267
15.21
19.35
1.53
6.50
0.11
-11.40
-8.67
34.22±1.52
NM06
116.67
43.55
1272
0.73
0.16
11.74
25.4
321
304
15.34
19.31
1.03
5.95
0.11
-11.60
-8.80
33.00±0.79
NM07
117.68
44.51
1024
0.73
1.96
12.10
26.3
319
298
14.88
18.99
1.70
5.94
0.14
-11.30
-8.56
34.31±0.37
NM08
114.89
44.01
1101
0.83
0.10
12.94
27.4
228
219
15.36
19.53
1.33
7.67
0.09
-10.40
-7.87
36.17±0.29
NM09
113.50
43.84
1022
0.86
2.47
14.20
28.3
199
190
15.59
19.76
2.49
9.00
0.06
-9.00
-7.16
35.59±0.63
NM10
112.15
43.63
955
0.88
3.69
14.87
30.1
183
169
15.35
19.57
2.96
9.46
0.06
-8.40
-6.48
35.56±0.21
Trend
0.626
0.995
0.450
<0.001
<0.001
0.026
0.018
0.104
0.015
<0.001
0.134
0.101
TP01
95.45
31.46
4104
0.40
0.41
5.70
17.2
606
572
17.76
19.94
1.71
2.61
0.19
-16.40
-14.22
31.53±1.35
TP02
93.53
31.85
4509
0.37
-1.50
3.14
15.4
593
560
17.57
20.02
1.72
2.17
0.21
-17.70
-15.86
32.25±1.65
TP03
92.01
31.64
4587
0.61
-4.37
4.40
17
430
414
18.62
20.91
1.06
3.39
0.26
-18.00
-16.50
34.00±0.17
TP04
90.74
31.38
4617
0.65
-6.76
5.89
17.8
426
414
18.99
21.41
0.34
4.27
0.17
-18.40
-16.57
39.17±1.41
TP05
89.72
31.54
4588
0.67
-3.06
6.93
19.2
426
412
18.80
21.27
1.51
4.94
0.15
-18.20
-16.39
37.77±0.51
TP06
87.82
31.87
4570
0.79
-2.57
6.77
19.2
286
261
19.27
22.01
2.18
5.50
0.15
-16.50
-14.99
39.07±1.32
TP07
85.84
31.92
4938
0.90
-3.77
3.74
17.6
125
95
19.28
22.22
2.49
4.70
0.13
-15.20
-13.71
35.54±0.74
TP08
83.34
32.41
4578
0.94
-3.90
5.71
20.1
75
62
18.99
22.08
2.32
5.77
0.11
-14.40
-12.85
38.56±1.43
TP09
81.23
32.30
4558
0.92
-3.49
5.29
19.3
102
89
19.41
22.50
2.37
5.45
0.07
-15.10
-12.78
36.99±0.51
TP10
80.15
32.48
4328
0.93
-1.27
6.73
21.5
89
78
19.86
23.12
3.10
6.33
0.09
-14.70
-12.41
42.34±0.60
Trend
0.356
0.360
0.006
<0.001
<0.001
<0.001
<0.001
0.069
<0.001
0.006
0.027
0.039
Tempmax, maximum temperature ; VPD, vapor deficit pressure; SM, soil moisture; δ18OP, the δ18O of precipitation; GSW, growing season. Trend indicates variation in variables along the aridity gradient.
Table S2 Differences in climatic variables among three transects.
Transect
Period
Mean
Standard deviation
Minimum
Maximum
P value
Aridity
LP
0.71
0.12
0.57
0.87
0.693
MP
0.76
0.07
0.68
0.88
TP
0.72
0.21
0.37
0.94
Precipitation
LP
Year
405
157
189
599
0.329
MP
308
84
183
425
TP
316
208
75
606
LP
Growing
season
374
141
179
546
0.408
MP
293
82
169
410
TP
296
204
62
572
Soil
moisture
LP
Growing
season
0.12
0.03
0.07
0.17
0.148
MP
0.11
0.04
0.06
0.17
TP
0.15
0.06
0.07
0.26
Vapor
Pressure
deficit
LP
Year
3.62a
1.10
1.88
4.78
<0.001
MP
1.81b
0.71
1.03
2.96
TP
1.88b
0.79
0.34
3.10
LP
Growing
season
8.11a
0.91
6.44
9.44
<0.001
MP
7.28a
1.33
5.94
9.46
TP
4.51b
1.39
2.17
6.33
Solar
radiation
LP
Year
14.61b
1.19
12.69
15.62
<0.001
MP
15.02b
0.54
13.67
15.59
TP
18.86a
0.72
17.57
19.86
LP
Growing
season
17.63c
1.41
15.60
18.97
<0.001
MP
19.02b
0.72
17.28
19.76
TP
21.55a
1.04
19.94
23.12
Temperature
LP
Year
8.65c
2.21
5.23
11.85
<0.001
MP
2.47b
2.04
0.10
5.80
TP
-3.03a
1.96
-6.76
0.41
LP
Growing
season
16.95c
1.16
15.31
18.61
<0.001
MP
13.70b
1.84
11.74
16.66
TP
5.43a
1.30
3.14
6.93
Maximum
temperature
LP
28.65a
1.06
26.80
30.00
<0.001
MP
27.69a
1.73
25.40
30.10
TP
18.43b
1.76
15.40
21.50
LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05).
Table S3 Characteristics of leaf δ18O and △18O at species level for sampling sites in Loess (LP), Inner Mongolia (MP), and Tibetan (TP) Plateau.
Sites
Number
Leaf δ18O
△18O
Mean
Max
Min
STD
CV
Mean
Max
Min
STD
CV
LP01
25
19.70
26.12
14.70
2.86
0.15
26.79
33.18
21.69
2.92
0.11
LP02
33
22.72
28.13
14.97
2.81
0.12
29.64
35.10
21.96
2.83
0.10
LP03
25
23.43
28.31
17.69
2.96
0.13
30.44
35.20
24.37
2.87
0.09
LP04
28
22.84
31.46
18.59
3.61
0.16
29.99
38.66
25.70
3.63
0.12
LP05
41
21.01
31.46
15.70
3.27
0.16
28.15
38.66
22.85
3.29
0.12
LP06
33
20.90
30.01
16.48
3.34
0.16
27.88
38.89
23.16
3.39
0.12
LP07
33
24.73
31.23
18.33
3.20
0.13
30.79
36.24
24.58
3.07
0.10
LP08
19
27.43
32.96
20.25
3.27
0.12
32.58
37.99
25.21
3.09
0.09
LP09
27
26.51
35.35
19.58
4.35
0.16
31.37
39.99
24.15
4.24
0.14
LP10
15
25.73
32.68
22.04
3.48
0.14
30.43
37.31
26.76
3.47
0.11
LP
279
22.69
35.35
12.07
4.42
0.19
32.29
43.89
21.69
4.4
0.14
MP01
18
23.04
29.24
17.42
3.57
0.15
30.61
36.58
24.68
3.87
0.13
MP02
37
23.48
28.73
18.69
2.26
0.10
31.18
36.44
25.87
2.21
0.07
MP03
30
23.54
30.97
19.31
2.71
0.12
31.95
39.55
27.80
2.82
0.09
MP04
17
22.85
28.10
17.46
3.25
0.14
31.83
37.13
26.41
3.26
0.10
MP05
13
26.54
31.73
22.60
2.59
0.10
35.27
40.62
31.12
2.66
0.08
MP06
22
25.85
32.65
21.14
3.25
0.13
34.62
41.68
28.42
3.47
0.10
MP07
15
24.03
27.40
21.24
2.27
0.09
32.76
36.14
29.92
2.29
0.07
MP08
22
27.59
31.71
21.71
3.05
0.11
35.57
39.73
29.65
3.08
0.09
MP09
17
28.23
31.56
23.18
2.36
0.08
35.41
39.57
30.37
2.22
0.06
MP10
12
29.16
32.33
21.36
2.90
0.10
36.13
41.23
30.04
2.65
0.07
MP
203
25.07
32.65
17.42
3.46
0.14
33.17
41.68
24.68
3.42
0.1
TP01
59
18.45
27.91
12.07
3.79
0.21
33.51
42.07
26.49
4.40
0.13
TP02
38
18.86
27.91
13.12
4.15
0.22
34.85
42.07
29.31
4.27
0.12
TP03
15
18.63
25.90
14.16
4.25
0.23
35.00
42.07
28.22
4.41
0.13
TP04
19
20.28
25.90
14.16
3.90
0.19
36.93
42.07
28.22
4.11
0.11
TP05
19
19.72
25.90
14.90
2.60
0.13
36.34
41.29
31.71
2.34
0.06
TP06
13
19.38
25.24
12.07
3.19
0.16
34.84
41.29
26.49
3.62
0.10
TP07
21
20.06
30.81
13.73
4.12
0.21
34.28
43.74
27.70
3.63
0.11
TP08
9
23.88
26.37
21.27
2.03
0.09
37.06
39.16
34.47
1.99
0.05
TP09
9
24.62
29.61
19.05
3.11
0.13
37.83
42.89
32.19
3.15
0.08
TP10
3
29.09
30.95
27.40
1.78
0.06
42.00
43.89
40.29
1.80
0.04
TP
205
19.72
30.95
12.07
4.13
0.21
35.08
43.89
26.49
4.15
0.12
Three Plateau
687
22.69
35.35
12.07
4.42
0.19
32.29
43.89
21.69
4.4
0.14
Table S4 Results of standardized major axis (SMA) line-fitting for the relationship between canopy stomatal conductance (using 1/△18O as proxy) and aridity.
Intercept
slope
r2
P
Loess Plateau
Estimate
0.047
-0.196
0.68
0.003
Lower
0.043
-0.027
Upper
0.052
-0.014
Inner Mongolia
Plateau
Estimate
0.044
-0.020
0.72
0.002
Lower
0.040
-0.027
Upper
0.049
-0.014
Tibet Plateau
Estimate
0.038
-0.015
0.60
0.008
Lower
0.034
-0.022
Upper
0.042
-0.011
Different letters indicate significant differences (P < 0.001) among transects in intercepts and slopes.
Table S5 Pearson coefficients for correlations among canopy stomatal conductance (Gs) and environmental factors and plant properties.
Transect
Variables
Gs
Aridity
Precipitation
SM
VPD
SR
MAT
MATMAX
LA
SLA
Loess Plateau
Gs
1
Aridity
-0.848**
1
Precipitation
0.856**
-.997**
1
SM
0.719*
-.781**
.795**
1
VPD
-0.554
0.616
-0.563
-0.251
1
SR
-0.639*
0.810**
-.827**
-.851**
0.217
1
Tempmean
0.641*
-0.665*
.710*
.766**
0.074
-.849**
1
Tempmax
0.678*
-0.698*
.737*
.751*
-0.026
-.795**
.980**
1
LA
.757*
-.881**
.863**
0.567
-.751*
-.637*
0.425
0.481
1
SLA
-0.519
0.460
-0.454
-0.499
0.356
0.422
-0.433
-0.483
-0.533
1
Inner Mongolia Plateau
Gs
1
Aridity
-.843**
1
Precipitation
.919**
-.945**
1
SM
.707*
-.941**
.877**
1
VPD
-0.384
.736*
-0.490
-.741*
1
SR
-.728*
.725*
-.846**
-.751*
0.196
1
Tempmean
0.303
-0.002
0.298
-0.009
.647*
-0.615
1
Tempmax
0.038
0.270
0.018
-0.235
.814**
-0.386
.943**
1
LA
.913**
-.721*
.875**
0.625
-0.218
-.731*
0.434
0.189
1
SLA
-0.576
.803**
-0.627
-.681*
.849**
0.310
0.397
0.628
-0.410
1
Tibetan Plateau
Gs
1
Aridity
-.773**
1
Precipitation
.675*
-.978**
1
SM
.659*
-.787**
.795**
1
VPD
-.912**
.931**
-.868**
-.820**
1
SR
-.850**
.963**
-.936**
-.801**
.943**
1
Tempmean
-.670*
0.325
-0.189
-0.454
0.622
0.393
1
Tempmax
-.852**
.795**
-.740*
-.795**
.935**
.832**
.760*
1
LA
0.610
-0.620
0.504
0.219
-0.624
-.658*
-0.401
-0.536
1
SLA
-.648*
0.558
-0.486
-.779**
.715*
0.516
.724*
.729*
-0.078
1
**, P<0.01; *, P<0.05. gs, stomatal conductance; SM, soil moisture; VPD, vapor pressure deficit; SR, total solar radiation; Tempmean, mean temperature; Tempmax, maximum temperature; LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Figure S1. Comparison of annual mean precipitation (mm) (a), vapor pressure deficit (VPD) (b), total solar radiation (TSR) (c), and air temperature (℃) (d) among three transects. LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05). Error bars indicate standard error of the mean.
Figure S2. Patterns of leaf δ18O and △18O at species level along aridity gradient in Loess (LP), Inner Mongolia (MP), and Tibetan (TP), Plateau. m, slope of the linear regression; b, intercept of the linear regression.
Figure S3. Hypothetical structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit.
Figure S4. Hypothetical structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Figure S5. Relationship between community 1/△18O and log-transformed leaf area (LA) (a) and specific leaf area (SLA) (b).
Appendix 2 Information of coexisting species in each community in Loess Plateau (LP), Inner Mongolia Plateau (MP), and Tibet Plateau (TP).
Transect
Site
Species
Genus
Family
LP
1
Allium tenuissimum
Allium
Amaryllidaceae
LP
1
Artemisia annua
Artemisia
Compositae
LP
1
Artemisia scoparia
Artemisia
Compositae
LP
1
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
1
Carex korshinskyi
Carex
Cyperaceae
LP
1
Cirsium arvense
Cirsium
Compositae
LP
1
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
1
Cynanchum thesioides
Cynanchum
Apocynaceae
LP
1
Erigeron canadensis
Erigeron
Compositae
LP
1
Heteropappus altaicus
Heteropappus
Compositae
LP
1
Lespedeza bicolor
Lespedeza
Fabaceae
LP
1
Leymus chinensis
Leymus
Poaceae
LP
1
Medicago ruthenica
Medicago
Fabaceae
LP
1
Polygala tenuifolia
Polygala
Polygalaceae
LP
1
Rubia cordifolia
Rubia
Rubiaceae
LP
1
Salix gordejevii
Salix
Salicaceae
LP
1
Ulmus pumila
Ulmus
Ulmaceae
LP
1
Vicia amoena
Vicia
Fabaceae
LP
1
Viola philippica
Viola
Violaceae
LP
1
Youngia japonica
Youngia
Compositae
LP
1
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
1
Scrophulariaceae
LP
2
Heteropappus altaicus
Heteropappus
Compositae
LP
2
Agropyron cristatum
Agropyron
Poaceae
LP
2
Anemone chinensis
Anemone
Ranunculaceae
LP
2
Artemisia lavandulifolia
Artemisia
Asteraceae
LP
2
Astragalus scaberrimus
Astragalus
Fabaceae
LP
2
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
2
Caragana sinica
Caragana
Fabaceae
LP
2
Carex korshinskyi
Carex
Cyperaceae
LP
2
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
2
Cleistogenes songorica
Cleistogenes
Poaceae
LP
2
Dianthus chinensis
Dianthus
Caryophyllaceae
LP
2
Echinops sphaerocephalus
Echinops
Compositae
LP
2
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
2
Incarvillea sinensis
Incarvillea
Bignoniaceae
LP
2
Lespedeza davurica
Lespedeza
Fabaceae
LP
2
Lespedeza juncea
Lespedeza
Fabaceae
LP
2
Patrinia scabiosifolia
Patrinia
Caprifoliaceae
LP
2
Periploca sepium
Periploca
Apocynaceae
LP
2
Plantago depressa
Plantago
Plantaginaceae
LP
2
Poa annua
Poa
Poaceae
LP
2
Polygala tenuifolia
Polygala
Polygalaceae
LP
2
Potentilla supina
Potentilla
Rosaceae
LP
2
Rosa xanthina
Rosa
Rosaceae
LP
2
Rubia cordifolia
Rubia
Rubiaceae
LP
2
Saussurea japonica
Saussurea
Compositae
LP
2
Scorzonera sinensis
Scorzonera
Compositae
LP
2
Setaria viridis
Setaria
Poaceae
LP
2
Themeda triandra
Themeda
Poaceae
LP
2
Thymus mongolicus
Thymus
Lamiaceae
LP
2
Tripolium pannonicum
Tripolium
Compositae
LP
2
Viola philippica
Viola
Violaceae
LP
2
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
3
Agropyron cristatum
Agropyron
Poaceae
LP
3
Artemisia leucophylla
Artemisia
Compositae
LP
3
Astragalus scaberrimus
Astragalus
Fabaceae
LP
3
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
3
Bupleurum chinense
Bupleurum
Apiaceae
LP
3
Carex korshinskyi
Carex
Cyperaceae
LP
3
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
3
Cleistogenes songorica
Cleistogenes
Poaceae
LP
3
Echinops sphaerocephalus
Echinops
Compositae
LP
3
Heteropappus altaicus
Heteropappus
Compositae
LP
3
Lespedeza davurica
Lespedeza
Fabaceae
LP
3
Poa annua
Poa
Poaceae
LP
3
Poa sphondylodes
Poa
Poaceae
LP
3
Polygala tenuifolia
Polygala
Polygalaceae
LP
3
Potentilla discolor
Potentilla
Rosaceae
LP
3
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
3
Selaginella tamariscina
Selaginella
Selaginellaceae
LP
3
Serratula centauroides
Serratula
Compositae
LP
3
Stipa sibirica
Stipa
Poaceae
LP
3
Themeda triandra
Themeda
Poaceae
LP
3
Tripolium pannonicum
Tripolium
Compositae
LP
3
Viola philippica
Viola
Violaceae
LP
3
Vitex negundo
Vitex
Lamiaceae
LP
3
Wikstroemia chamaedaphne
Wikstroemia
Thymelaeaceae
LP
3
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
4
Agropyron cristatum
Agropyron
Poaceae
LP
4
Agropyron desertorum
Agropyron
Poaceae
LP
4
Artemisia annua
Artemisia
Compositae
LP
4
Artemisia argyi
Artemisia
Compositae
LP
4
Artemisia argyi
Artemisia
Compositae
LP
4
Artemisia dalailamae
Artemisia
Compositae
LP
4
Astragalus melilotoides
Astragalus
Fabaceae
LP
4
Astragalus scaberrimus
Astragalus
Fabaceae
LP
4
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
4
Carex korshinskyi
Carex
Cyperaceae
LP
4
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
4
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
4
Heteropappus altaicus
Heteropappus
Compositae
LP
4
Ixeris polycephala
Ixeris
Compositae
LP
4
Lespedeza bicolor
Lespedeza
Fabaceae
LP
4
Poa annua
Poa
Poaceae
LP
4
Polygala sibirica
Polygala
Polygalaceae
LP
4
Polygala tenuifolia
Polygala
Polygalaceae
LP
4
Potentilla discolor
Potentilla
Rosaceae
LP
4
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
4
Rosa xanthina
Rosa
Rosaceae
LP
4
Scorzonera sinensis
Scorzonera
Compositae
LP
4
Vicia amoena
Vicia
Fabaceae
LP
4
Viola philippica
Viola
Violaceae
LP
4
Wikstroemia chamaedaphne
Wikstroemia
Thymelaeaceae
LP
4
Yulania denudata
Yulania
Magnoliaceae
LP
4
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
5
Artemisia annua
Artemisia
Compositae
LP
5
Artemisia argyi
Artemisia
Compositae
LP
5
Artemisia frigida
Artemisia
Compositae
LP
5
Artemisia japonica
Artemisia
Compositae
LP
5
Artemisia scoparia
Artemisia
Compositae
LP
5
Astragalus scaberrimus
Astragalus
Fabaceae
LP
5
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
5
Caragana microphylla
Caragana
Fabaceae
LP
5
Carduus nutans
Carduus
Compositae
LP
5
Cirsium arvense
Cirsium
Compositae
LP
5
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
5
Cleistogenes serotina
Cleistogenes
Poaceae
LP
5
Cynanchum thesioides
Cynanchum
Apocynaceae
LP
5
Dracocephalum moldavica
Dracocephalum
Lamiaceae
LP
5
Eragrostis pilosa
Eragrostis
Poaceae
LP
5
Erigeron annuus
Erigeron
Compositae
LP
5
Glycyrrhiza uralensis
Glycyrrhiza
Fabaceae
LP
5
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
5
Incarvillea sinensis
Incarvillea
Bignoniaceae
LP
5
Ixeris polycephala
Ixeris
Compositae
LP
5
Kalimeris hispida
Kalimeris
Compositae
LP
5
Koeleria pyramidata
Koeleria
Poaceae
LP
5
Lespedeza davurica
Lespedeza
Fabaceae
LP
5
Lespedeza juncea
Lespedeza
Fabaceae
LP
5
Leymus chinensis
Leymus
Poaceae
LP
5
Oxytropis myriophylla
Oxytropis
Fabaceae
LP
5
Poa annua
Poa
Poaceae
LP
5
Poa sphondylodes
Poa
Poaceae
LP
5
Polygala sibirica
Polygala
Polygalaceae
LP
5
Potentilla supina
Potentilla
Rosaceae
LP
5
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
5
Rubia cordifolia
Rubia
Rubiaceae
LP
5
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
5
Sonchus arvensis
Sonchus
Compositae
LP
5
Taraxacum mongolicum
Taraxacum
Compositae
LP
5
Tripolium pannonicum
Tripolium
Compositae
LP
5
Viola philippica
Viola
Violaceae
LP
5
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
6
Allium senescens
Allium
Liliaceae
LP
6
Anemone chinensis
Anemone
Ranunculaceae
LP
6
Artemisia argyi
Artemisia
Compositae
LP
6
Artemisia japonica
Artemisia
Compositae
LP
6
Astragalus scaberrimus
Astragalus
Fabaceae
LP
6
Carduus nutans
Carduus
Compositae
LP
6
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
6
Cleistogenes serotina
Cleistogenes
Poaceae
LP
6
Echinops sphaerocephalus
Echinops
Compositae
LP
6
Elymus dahuricus
Elymus
Poaceae
LP
6
Imperata cylindrica
Imperata
Poaceae
LP
6
Kalimeris hispida
Kalimeris
Compositae
LP
6
Lappula myosotis
Lappula
Boraginaceae
LP
6
Leontopodium leontopodinum
Leontopodium
Compositae
LP
6
Lespedeza bicolor
Lespedeza
Fabaceae
LP
6
Linum usitatissimum
Linum
Linaceae
LP
6
Medicago ruthenica
Medicago
Fabaceae
LP
6
Patrinia heterophylla
Patrinia
Caprifoliaceae
LP
6
Phlomoides umbrosa
Phlomoides
Lamiaceae
LP
6
Phragmites australis
Phragmites
Poaceae
LP
6
Poa sphondylodes
Poa
Poaceae
LP
6
Polygala tenuifolia
Polygala
Polygalaceae
LP
6
Potentilla chinensis
Potentilla
Rosaceae
LP
6
Potentilla sericea
Potentilla
Rosaceae
LP
6
Ranunculus japonicus
Ranunculus
Ranunculaceae
LP
6
Rubia cordifolia
Rubia
Rubiaceae
LP
6
Setaria viridis
Setaria
Poaceae
LP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
6
Sonchus arvensis
Sonchus
Compositae
LP
6
Stipa bungeana
Stipa
Poaceae
LP
6
Stipa capillata
Stipa
Poaceae
LP
6
Taraxacum mongolicum
Taraxacum
Compositae
LP
6
Tripolium pannonicum
Tripolium
Compositae
LP
7
Agropyron cristatum
Agropyron
Poaceae
LP
7
Artemisia argyi
Artemisia
Compositae
LP
7
Artemisia scoparia
Artemisia
Compositae
LP
7
Astragalus adsurgens
Astragalus
Fabaceae
LP
7
Astragalus galactites
Astragalus
Fabaceae
LP
7
Astragalus melilotoides
Astragalus
Fabaceae
LP
7
Astragalus propinquus
Astragalus
Fabaceae
LP
7
Bassia scoparia
Bassia
Amaranthaceae
LP
7
Carex korshinskyi
Carex
Cyperaceae
LP
7
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
7
Cleistogenes songorica
Cleistogenes
Poaceae
LP
7
Convolvulus arvensis
Convolvulus
Convolvulaceae
LP
7
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
7
Haplophyllum dauricum
Haplophyllum
Rutaceae
LP
7
Heteropappus altaicus
Heteropappus
Compositae
LP
7
Ixeris polycephala
Ixeris
Compositae
LP
7
Koeleria pyramidata
Koeleria
Poaceae
LP
7
Lespedeza bicolor
Lespedeza
Fabaceae
LP
7
Leymus chinensis
Leymus
Poaceae
LP
7
Medicago ruthenica
Medicago
Fabaceae
LP
7
Medicago sativa
Medicago
Fabaceae
LP
7
Melilotus albus
Melilotus
Leguminosae
LP
7
Polygonum sibiricum
Polygonum
Polygonaceae
LP
7
Scorzonera sinensis
Scorzonera
Compositae
LP
7
Setaria viridis
Setaria
Poaceae
LP
7
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
7
Sonchus arvensis
Sonchus
Compositae
LP
7
Stipa capillata
Stipa
Poaceae
LP
7
Stipa splendens
Stipa
Poaceae
LP
7
Suaeda glauca
Suaeda
Amaranthaceae
LP
7
Taraxacum mongolicum
Taraxacum
Compositae
LP
7
Thermopsis lanceolata
Thermopsis
Fabaceae
LP
8
Allium tenuissimum
Allium
Amaryllidaceae
LP
8
Alopecurus aequalis
Alopecurus
Poaceae
LP
8
Artemisia scoparia
Artemisia
Compositae
LP
8
Astragalus galactites
Astragalus
Fabaceae
LP
8
Astragalus propinquus
Astragalus
Fabaceae
LP
8
Bassia dasyphylla
Bassia
Amaranthaceae
LP
8
Carex korshinskyi
Carex
Cyperaceae
LP
8
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
8
Convolvulus ammannii
Convolvulus
Convolvulaceae
LP
8
Echinochloa crus-galli
Echinochloa
Poaceae
LP
8
Eragrostis pilosa
Eragrostis
Poaceae
LP
8
Peganum harmala
Peganum
Nitrariaceae
LP
8
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
8
Stipa capillata
Stipa
Poaceae
LP
8
Tragus racemosus
Tragus
Poaceae
LP
8
Tribulus terrestris
Tribulus
Zygophyllaceae
LP
8
Zygophyllum mucronatum
Zygophyllum
Zygophyllaceae
LP
9
Allium mongolicum
Allium
Amaryllidaceae
LP
9
Allium polyrhizum
Allium
Amaryllidaceae
LP
9
Artemisia annua
Artemisia
Compositae
LP
9
Artemisia argyi
Artemisia
Compositae
LP
9
Artemisia capillaris
Artemisia
Compositae
LP
9
Artemisia scoparia
Artemisia
Compositae
LP
9
Asparagus cochinchinensis
Asparagus
Asparagaceae
LP
9
Astragalus galactites
Astragalus
Fabaceae
LP
9
Caragana stenophylla
Caragana
Fabaceae
LP
9
Chloris virgata
Chloris
Poaceae
LP
9
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
9
Convolvulus ammannii
Convolvulus
Convolvulaceae
LP
9
Convolvulus arvensis
Convolvulus
Convolvulaceae
LP
9
Convolvulus tragacanthoides
Convolvulus
Convolvulaceae
LP
9
Echinochloa crus-galli
Echinochloa
Poaceae
LP
9
Euphorbia humifusa
Euphorbia
Euphorbiaceae
LP
9
Heteropappus altaicus
Heteropappus
Compositae
LP
9
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
9
Salsola collina
Salsola
Amaranthaceae
LP
9
Salsola passerina
Salsola
Amaranthaceae
LP
9
Stipa capillata
Stipa
Poaceae
LP
9
Suaeda glauca
Suaeda
Amaranthaceae
LP
9
Tribulus terrestris
Tribulus
Zygophyllaceae
LP
9
Zygophyllum mucronatum
Zygophyllum
Zygophyllaceae
LP
10
Heteropappus altaicus
Heteropappus
Compositae
LP
10
Lepidium apetalum
Lepidium
Brassicaceae
LP
10
Saussurea japonica
Saussurea
Compositae
LP
10
Alopecurus aequalis
Alopecurus
Poaceae
LP
10
Artemisia ordosica
Artemisia
Compositae
LP
10
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
10
Eragrostis pilosa
Eragrostis
Poaceae
LP
10
Allium polyrhizum
Allium
Amaryllidaceae
LP
10
Suaeda glauca
Suaeda
Amaranthaceae
LP
10
Alopecurus aequalis
Alopecurus
Poaceae
LP
10
Chenopodium album
Chenopodium
Amaranthaceae
LP
10
Carex korshinskyi
Carex
Cyperaceae
LP
10
Artemisia capillaris
Artemisia
Compositae
LP
10
Salsola passerina
Salsola
Amaranthaceae
LP
10
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
1
Heteropappus altaicus
Heteropappus
Compositae
MP
1
Echinochloa crus-galli
Echinochloa
Poaceae
MP
1
Setaria viridis
Setaria
Poaceae
MP
1
Incarvillea sinensis
Incarvillea
Bignoniaceae
MP
1
Artemisia ordosica
Artemisia
Compositae
MP
1
Chloris virgata
Chloris
Poaceae
MP
1
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
1
Bassia scoparia
Bassia
Amaranthaceae
MP
1
Lactuca sativa
Lactuca
Compositae
MP
1
Phragmites australis
Phragmites
Poaceae
MP
1
Medicago sativa
Medicago
Fabaceae
MP
1
Carex korshinskyi
Carex
Cyperaceae
MP
1
Calystegia pellita
Calystegia
Convolvulaceae
MP
1
Polygonum sibiricum
Polygonum
Polygonaceae
MP
1
Leymus chinensis
Leymus
Poaceae
MP
1
Artemisia sphaerocephala
Artemisia
Compositae
MP
1
Aeluropus littoralis
Aeluropus
Poaceae
MP
1
Medicago sativa
Medicago
Fabaceae
MP
2
Adenophora stricta
Adenophora
Campanulaceae
MP
2
Agropyron cristatum
Agropyron
Poaceae
MP
2
Allium anisopodium
Allium
Amaryllidaceae
MP
2
Allium ramosum
Allium
Amaryllidaceae
MP
2
Amethystea caerulea
Amethystea
Lamiaceae
MP
2
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
2
Artemisia desertorum
Artemisia
Compositae
MP
2
Artemisia lavandulifolia
Artemisia
Asteraceae
MP
2
Artemisia sieversiana
Artemisia
Compositae
MP
2
Artemisia sphaerocephala
Artemisia
Compositae
MP
2
Atraphaxis manshurica
Atraphaxis
Polygonaceae
MP
2
Carex pediformis
Carex
Cyperaceae
MP
2
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
2
Chloris virgata
Chloris
Poaceae
MP
2
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
2
Clematis hexapetala
Clematis
Ranunculaceae
MP
2
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
2
Cynanchum thesioides
Cynanchum
Apocynaceae
MP
2
Dysphania aristata
Dysphania
Amaranthaceae
MP
2
Enneapogon desvauxii
Enneapogon
Poaceae
MP
2
Ephedra sinica
Ephedra
Ephedraceae
MP
2
Eriochloa villosa
Eriochloa
Poaceae
MP
2
Erodium stephanianum
Erodium
Geraniaceae
MP
2
Euphorbia humifusa
Euphorbia
Euphorbiaceae
MP
2
Glycyrrhiza uralensis
Glycyrrhiza
Fabaceae
MP
2
Iris tenuifolia
Iris
Iridaceae
MP
2
Lespedeza davurica
Lespedeza
Fabaceae
MP
2
Medicago ruthenica
Medicago
Fabaceae
MP
2
Phragmites australis
Phragmites
Poaceae
MP
2
Salsola collina
Salsola
Amaranthaceae
MP
2
Serratula centauroides
Serratula
Compositae
MP
2
Setaria viridis
Setaria
Poaceae
MP
2
Stipa capillata
Stipa
Poaceae
MP
2
Stipa sibirica
Stipa
Poaceae
MP
2
Thalictrum squarrosum
Thalictrum
Ranunculaceae
MP
2
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
3
Allium tenuissimum
Allium
Amaryllidaceae
MP
3
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
3
Artemisia annua
Artemisia
Compositae
MP
3
Artemisia lavandulifolia
Artemisia
Asteraceae
MP
3
Astragalus adsurgens
Astragalus
Fabaceae
MP
3
Astragalus propinquus
Astragalus
Fabaceae
MP
3
Carex korshinskyi
Carex
Cyperaceae
MP
3
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
3
Convolvulus arvensis
Convolvulus
Convolvulaceae
MP
3
Eriochloa villosa
Eriochloa
Poaceae
MP
3
Erodium stephanianum
Erodium
Geraniaceae
MP
3
Euphorbia humifusa
Euphorbia
Euphorbiaceae
MP
3
Gerbera anandria
Gerbera
Compositae
MP
3
Heteropappus altaicus
Heteropappus
Compositae
MP
3
Leontopodium leontopodinum
Leontopodium
Compositae
MP
3
Lespedeza davurica
Lespedeza
Fabaceae
MP
3
Lespedeza juncea
Lespedeza
Fabaceae
MP
3
Leymus chinensis
Leymus
Poaceae
MP
3
Linum stelleroides
Linum
Linaceae
MP
3
Miscanthus sacchariflorus
Miscanthus
Poaceae
MP
3
Polygala tenuifolia
Polygala
Polygalaceae
MP
3
Polygonum divaricatum
Polygonum
Polygonaceae
MP
3
Potentilla betonicifolia
Potentilla
Rosaceae
MP
3
Potentilla verticillaris
Potentilla
Rosaceae
MP
3
Salsola collina
Salsola
Amaranthaceae
MP
3
Sanguisorba officinalis
Sanguisorba
Rosaceae
MP
3
Serratula centauroides
Serratula
Compositae
MP
3
Stipa sibirica
Stipa
Poaceae
MP
3
Thalictrum petaloideum
Thalictrum
Ranunculaceae
MP
4
Agropyron cristatum
Agropyron
Poaceae
MP
4
Allium bidentatum
Allium
Amaryllidaceae
MP
4
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
4
Bassia prostrata
Bassia
Amaranthaceae
MP
4
Carex korshinskyi
Carex
Cyperaceae
MP
4
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
4
Dysphania aristata
Dysphania
Amaranthaceae
MP
4
Iris tenuifolia
Iris
Iridaceae
MP
4
Koeleria pyramidata
Koeleria
Poaceae
MP
4
Lappula myosotis
Lappula
Boraginaceae
MP
4
Leymus chinensis
Leymus
Poaceae
MP
4
Medicago ruthenica
Medicago
Fabaceae
MP
4
Potentilla acaulis
Potentilla
Rosaceae
MP
4
Salsola collina
Salsola
Amaranthaceae
MP
4
Scorzonera sinensis
Scorzonera
Compositae
MP
4
Stipa capillata
Stipa
Poaceae
MP
4
Veratrum nigrum
Veratrum
Melanthiaceae
MP
5
Allium anisopodium
Allium
Amaryllidaceae
MP
5
Agropyron cristatum
Agropyron
Poaceae
MP
5
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
5
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
5
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
5
Artemisia frigida
Artemisia
Compositae
MP
5
Bassia prostrata
Bassia
Amaranthaceae
MP
5
Carex korshinskyi
Carex
Cyperaceae
MP
5
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
5
Allium tenuissimum
Allium
Amaryllidaceae
MP
5
Leymus chinensis
Leymus
Poaceae
MP
5
Stipa capillata
Stipa
Poaceae
MP
5
Salsola collina
Salsola
Amaranthaceae
MP
6
Agropyron cristatum
Agropyron
Poaceae
MP
6
Cleistogenes squarrosa
Cleistogenes
Poaceae
MP
6
Ephedra sinica
Ephedra
Ephedraceae
MP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
MP
6
Allium condensatum
Allium
Amaryllidaceae
MP
6
Artemisia annua
Artemisia
Compositae
MP
6
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
6
Artemisia frigida
Artemisia
Compositae
MP
6
Bassia prostrata
Bassia
Amaranthaceae
MP
6
Thermopsis lanceolata
Thermopsis
Fabaceae
MP
6
Koeleria pyramidata
Koeleria
Poaceae
MP
6
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
MP
6
Carex korshinskyi
Carex
Cyperaceae
MP
6
Allium tenuissimum
Allium
Amaryllidaceae
MP
6
Iris tenuifolia
Iris
Iridaceae
MP
6
Leymus chinensis
Leymus
Poaceae
MP
6
Allium ramosum
Allium
Amaryllidaceae
MP
6
Stipa sibirica
Stipa
Poaceae
MP
6
Poa annua
Poa
Poaceae
MP
6
Stipa capillata
Stipa
Poaceae
MP
6
Axyris amaranthoides
Axyris
Amaranthaceae
MP
6
Salsola collina
Salsola
Amaranthaceae
MP
7
Agropyron cristatum
Agropyron
Poaceae
MP
7
Scutellaria scordiifolia
Scutellaria
Lamiaceae
MP
7
Astragalus melilotoides
Astragalus
Fabaceae
MP
7
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
7
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
MP
7
Koeleria pyramidata
Koeleria
Poaceae
MP
7
Astragalus galactites
Astragalus
Fabaceae
MP
7
Allium bidentatum
Allium
Amaryllidaceae
MP
7
Carex korshinskyi
Carex
Cyperaceae
MP
7
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
7
Allium tenuissimum
Allium
Amaryllidaceae
MP
7
Iris tenuifolia
Iris
Iridaceae
MP
7
Leymus chinensis
Leymus
Poaceae
MP
7
Stipa capillata
Stipa
Poaceae
MP
7
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
8
Heteropappus altaicus
Heteropappus
Compositae
MP
8
Agropyron cristatum
Agropyron
Poaceae
MP
8
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
8
Artemisia annua
Artemisia
Compositae
MP
8
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
8
Allium polyrhizum
Allium
Amaryllidaceae
MP
8
Artemisia frigida
Artemisia
Compositae
MP
8
Asparagus schoberioides
Asparagus
Asparagaceae
MP
8
Bassia prostrata
Bassia
Amaranthaceae
MP
8
Astragalus galactites
Astragalus
Fabaceae
MP
8
Allium bidentatum
Allium
Amaryllidaceae
MP
8
Carex korshinskyi
Carex
Cyperaceae
MP
8
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
8
Allium tenuissimum
Allium
Amaryllidaceae
MP
8
Iris tenuifolia
Iris
Iridaceae
MP
8
Leymus chinensis
Leymus
Poaceae
MP
8
Allium ramosum
Allium
Amaryllidaceae
MP
8
Convolvulus ammannii
Convolvulus
Convolvulaceae
MP
8
Stipa capillata
Stipa
Poaceae
MP
8
Neopallasia pectinata
Neopallasia
Compositae
MP
8
Salsola collina
Salsola
Amaranthaceae
MP
9
Artemisia argyi
Artemisia
Compositae
MP
9
Scorzonera sinensis
Scorzonera
Compositae
MP
9
Eragrostis pilosa
Eragrostis
Poaceae
MP
9
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
9
Allium polyrhizum
Allium
Amaryllidaceae
MP
9
Asparagus schoberioides
Asparagus
Asparagaceae
MP
9
Peganum harmala
Peganum
Nitrariaceae
MP
9
Iris lactea
Iris
Iridaceae
MP
9
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
9
Allium bidentatum
Allium
Amaryllidaceae
MP
9
Carex korshinskyi
Carex
Cyperaceae
MP
9
Cleistogenes songorica
Cleistogenes
Poaceae
MP
9
Caragana stenophylla
Caragana
Fabaceae
MP
9
Convolvulus ammannii
Convolvulus
Convolvulaceae
MP
9
Stipa capillata
Stipa
Poaceae
MP
9
Salsola collina
Salsola
Amaranthaceae
MP
10
Setaria viridis
Setaria
Poaceae
MP
10
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
10
Asparagus schoberioides
Asparagus
Asparagaceae
MP
10
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
10
Allium bidentatum
Allium
Amaryllidaceae
MP
10
Carex korshinskyi
Carex
Cyperaceae
MP
10
Cleistogenes songorica
Cleistogenes
Poaceae
MP
10
Iris tenuifolia
Iris
Iridaceae
MP
10
Caragana stenophylla
Caragana
Fabaceae
MP
10
Stipa capillata
Stipa
Poaceae
MP
10
Salsola collina
Salsola
Amaranthaceae
TP
1
Allium przewalskianum
Allium
Amaryllidaceae
TP
1
Allium ramosum
Allium
Amaryllidaceae
TP
1
Anaphalis xylorhiza
Anaphalis
Compositae
TP
1
Androsace tapete
Androsace
Primulaceae
TP
1
Androsace umbellata
Androsace
Primulaceae
TP
1
Arenaria brevipetala
Arenaria
Caryophyllaceae
TP
1
Artemisia argyi
Artemisia
Compositae
TP
1
Aster tataricus
Aster
Compositae
TP
1
Astragalus propinquus
Astragalus
Fabaceae
TP
1
Calamagrostis lahulensis
Calamagrostis
Poaceae
TP
1
Caragana sinica
Caragana
Fabaceae
TP
1
Carex korshinskyi
Carex
Cyperaceae
TP
1
Chenopodium glaucum
Chenopodium
Amaranthaceae
TP
1
Elymus dahuricus
Elymus
Poaceae
TP
1
Eragrostis pilosa
Eragrostis
Poaceae
TP
1
Euphorbia stracheyi
Euphorbia
Euphorbiaceae
TP
1
Gentiana scabra
Gentiana
Gentianaceae
TP
1
Gentiana straminea
Gentiana
Gentianaceae
TP
1
Gentiana szechenyii
Gentiana
Gentianaceae
TP
1
Gentianopsis paludosa
Gentianopsis
Gentianaceae
TP
1
Geranium wilfordii
Geranium
Geraniaceae
TP
1
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
1
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
1
Heracleum hemsleyanum
Heracleum
Apiaceae
TP
1
Heteropappus altaicus
Heteropappus
Compositae
TP
1
Incarvillea sinensis
Incarvillea
Bignoniaceae
TP
1
Iris tectorum
Iris
Iridaceae
TP
1
Kobresia littledalei
Kobresia
Cyperaceae
TP
1
Leontopodium leontopodinum
Leontopodium
Compositae
TP
1
Phlomis younghusbandii
Phlomis
Lamiaceae
TP
1
Plantago depressa
Plantago
Plantaginaceae
TP
1
Poa annua
Poa
Poaceae
TP
1
Polygonum divaricatum
Polygonum
Polygonaceae
TP
1
Potentilla chinensis
Potentilla
Rosaceae
TP
1
Potentilla multifida
Potentilla
Rosaceae
TP
1
Potentilla saundersiana
Potentilla
Rosaceae
TP
1
Przewalskia tangutica
Przewalskia
Solanaceae
TP
1
Scorzonera sinensis
Scorzonera
Compositae
TP
1
Scrophularia ningpoensis
Scrophularia
Scrophulariaceae
TP
1
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
1
Silene gallica
Silene
Caryophyllaceae
TP
1
Stipa capillata
Stipa
Poaceae
TP
1
Stipa purpurea
Stipa
Poaceae
TP
1
Taraxacum mongolicum
Taraxacum
Compositae
TP
1
Vicia amoena
Vicia
Fabaceae
TP
2
Anaphalis xylorhiza
Anaphalis
Compositae
TP
2
Artemisia argyi
Artemisia
Compositae
TP
2
Aster souliei
Aster
Compositae
TP
2
Aster tataricus
Aster
Compositae
TP
2
Astragalus strictus
Astragalus
Fabaceae
TP
2
Carex korshinskyi
Carex
Cyperaceae
TP
2
Elsholtzia densa
Elsholtzia
Lamiaceae
TP
2
Eragrostis alta
Eragrostis
Poaceae
TP
2
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
TP
2
Geranium wilfordii
Geranium
Geraniaceae
TP
2
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
2
Heracleum hemsleyanum
Heracleum
Apiaceae
TP
2
Kobresia pygmaea
Kobresia
Cyperaceae
TP
2
Lancea tibetica
Lancea
Phrymaceae
TP
2
Lasiocaryum densiflorum
Lasiocaryum
Boraginaceae
TP
2
Persicaria vivipara
Persicaria
Polygonaceae
TP
2
Phlomoides rotata
Phlomoides
Lamiaceae
TP
2
Poa annua
Poa
Poaceae
TP
2
Polygonum sibiricum
Polygonum
Polygonaceae
TP
2
Potentilla anserina
Potentilla
Rosaceae
TP
2
Potentilla parvifolia
Potentilla
Rosaceae
TP
2
Potentilla saundersiana
Potentilla
Rosaceae
TP
2
Przewalskia tangutica
Przewalskia
Solanaceae
TP
2
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
2
Stipa capillata
Stipa
Poaceae
TP
2
Taraxacum mongolicum
Taraxacum
Compositae
TP
2
Urtica hyperborea
Urtica
Urticaceae
TP
3
Astragalus propinquus
Astragalus
Fabaceae
TP
3
Carex korshinskyi
Carex
Cyperaceae
TP
3
Eragrostis alta
Eragrostis
Poaceae
TP
3
Kobresia pygmaea
Kobresia
Cyperaceae
TP
3
Lancea tibetica
Lancea
Phrymaceae
TP
3
Leontopodium leontopodinum
Leontopodium
Compositae
TP
3
Poa annua
Poa
Poaceae
TP
3
Potentilla anserina
Potentilla
Rosaceae
TP
3
Potentilla saundersiana
Potentilla
Rosaceae
TP
3
Saussurea japonica
Saussurea
Compositae
TP
3
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
3
Taraxacum mongolicum
Taraxacum
Compositae
TP
4
Astragalus arnoldii
Astragalus
Fabaceae
TP
4
Callianthemum pimpinelloides
Callianthemum
Ranunculaceae
TP
4
Carex korshinskyi
Carex
Cyperaceae
TP
4
Eragrostis alta
Eragrostis
Poaceae
TP
4
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
TP
4
Heteropappus boweri
Heteropappus
Compositae
TP
4
Kobresia pygmaea
Kobresia
Cyperaceae
TP
4
Leontopodium leontopodinum
Leontopodium
Compositae
TP
4
Oxytropis stracheyana
Oxytropis
Fabaceae
TP
4
Pedicularis alaschanica
Pedicularis
Scrophulariaceae
TP
4
Poa setulosa
Poa
Poaceae
TP
4
Przewalskia tangutica
Przewalskia
Solanaceae
TP
4
Rhodiola smithii
Rhodiola
Crassulaceae
TP
4
Saussurea japonica
Saussurea
Compositae
TP
4
Stipa capillata
Stipa
Poaceae
TP
4
Taraxacum mongolicum
Taraxacum
Compositae
TP
5
Arenaria edgeworthiana
Arenaria
Caryophyllaceae
TP
5
Astragalus adsurgens
Astragalus
Fabaceae
TP
5
Astragalus tribulifolius
Astragalus
Fabaceae
TP
5
Carex korshinskyi
Carex
Cyperaceae
TP
5
Carex littledalei
Carex
Cyperaceae
TP
5
Dolomiaea souliei
Dolomiaea
Compositae
TP
5
Dracocephalum heterophyllum
Dracocephalum
Lamiaceae
TP
5
Eragrostis pilosa
Eragrostis
Poaceae
TP
5
Heteropappus boweri
Heteropappus
Compositae
TP
5
Kobresia pygmaea
Kobresia
Cyperaceae
TP
5
Leontopodium leontopodinum
Leontopodium
Compositae
TP
5
Poa annua
Poa
Poaceae
TP
5
Potentilla chinensis
Potentilla
Rosaceae
TP
5
Potentilla supina
Potentilla
Rosaceae
TP
5
Rhodiola smithii
Rhodiola
Crassulaceae
TP
5
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
5
Stipa capillata
Stipa
Poaceae
TP
5
Stipa purpurea
Stipa
Poaceae
TP
5
Youngia japonica
Youngia
Compositae
TP
6
Astragalus adsurgens
Astragalus
Fabaceae
TP
6
Carex korshinskyi
Carex
Cyperaceae
TP
6
Dracocephalum heterophyllum
Dracocephalum
Lamiaceae
TP
6
Heteropappus boweri
Heteropappus
Compositae
TP
6
Incarvillea lutea
Incarvillea
Bignoniaceae
TP
6
Lagotis brachystachya
Lagotis
Plantaginaceae
TP
6
Oxytropis microphylla
Oxytropis
Fabaceae
TP
6
Przewalskia tangutica
Przewalskia
Solanaceae
TP
6
Rhodiola smithii
Rhodiola
Crassulaceae
TP
6
Sibbaldia parviflora
Sibbaldia
Rosaceae
TP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
6
Stipa capillata
Stipa
Poaceae
TP
6
Stipa purpurea
Stipa
Poaceae
TP
7
Androsace tapete
Androsace
Primulaceae
TP
7
Arenaria brevipetala
Arenaria
Caryophyllaceae
TP
7
Astragalus propinquus
Astragalus
Fabaceae
TP
7
Carex korshinskyi
Carex
Cyperaceae
TP
7
Eragrostis pilosa
Eragrostis
Poaceae
TP
7
Kalimeris hispida
Kalimeris
Compositae
TP
7
Kobresia pygmaea
Kobresia
Cyperaceae
TP
7
Lagotis brachystachya
Lagotis
Plantaginaceae
TP
7
Lasiocaryum densiflorum
Lasiocaryum
Boraginaceae
TP
7
Leontopodium leontopodinum
Leontopodium
Compositae
TP
7
Lepidium capitatum
Lepidium
Brassicaceae
TP
7
Poa annua
Poa
Poaceae
TP
7
Polygonum sibiricum
Polygonum
Polygonaceae
TP
7
Potentilla parvifolia
Potentilla
Rosaceae
TP
7
Potentilla plumosa
Potentilla
Rosaceae
TP
7
Pycnoplinthus uniflora
Pycnoplinthus
Brassicaceae
TP
7
Sibbaldia parviflora
Sibbaldia
Rosaceae
TP
7
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
7
Stipa purpurea
Stipa
Poaceae
TP
7
Taraxacum mongolicum
Taraxacum
Compositae
TP
8
Artemisia desertorum
Artemisia
Compositae
TP
8
Astragalus propinquus
Astragalus
Fabaceae
TP
8
Astragalus tribulifolius
Astragalus
Fabaceae
TP
8
Carex korshinskyi
Carex
Cyperaceae
TP
8
Heteropappus boweri
Heteropappus
Compositae
TP
8
Oxytropis microphylla
Oxytropis
Fabaceae
TP
8
Poa annua
Poa
Poaceae
TP
8
Ptilotrichum canescens
Ptilotrichum
Brassicaceae
TP
8
Stipa capillata
Stipa
Poaceae
TP
9
Artemisia desertorum
Artemisia
Compositae
TP
9
Astragalus hendersonii
Astragalus
Fabaceae
TP
9
Carex korshinskyi
Carex
Cyperaceae
TP
9
Oxytropis glacialis
Oxytropis
Fabaceae
TP
9
Oxytropis microphylla
Oxytropis
Fabaceae
TP
9
Ptilotrichum canescens
Ptilotrichum
Brassicaceae
TP
9
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
9
Stipa tianschanica
Stipa
Poaceae
TP
10
Stipa tianschanica
Stipa
Poaceae
TP
10
Ajania fruticulosa
Ajania
Compositae
TP
10
Oxytropis microphylla
Oxytropis
Fabaceae
-
AC3: 'Reply on CC2', Xue-Fa Wen, 14 Jul 2022
Response to reviews of manuscript “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” bg-2022-50
Response to community comment #2
Dear Zhaoguo Wang,
We would like to thank you for the thoughtful and valuable comments and suggestions on our manuscript entitled “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” (bg-2022-50). We have carefully revised our manuscript to take account of your comments and suggestions. Meanwhile, we have rephrased our manuscript title as “Excess radiation exacerbates drought stress impacts on canopy conductance along aridity gradients”.Here are the point-to-point responses (responses in upright Roman in black front) to the comments (original queries in Italic in blue front). The changed figures and tables are presented in the Appendix 1 and Appendix 2 (listed at the end of the “Response to community comment #2”).Specific comments:
1) There are expressions like “drought”, “dryness”, “low soil moisture” and “soil moisture stress” in this manuscript. I don’t think these have the same meaning. Please check and use it properly. Similarly, this manuscript focused on gs, but sometimes there are expressions like “canopy gs”.
Response: Thank you very much for your comment. We have replaced “dryness” with “drought”, and “soil moisture stress” with “low soil moisture” throughout the manuscript. Meanwhile, we used gs to present stomatal conductance at leaf level, and Gs to present canopy conductance.
2) I think hypothesis should be based on the information provided in the introduction. In terms of the hypothesis 2 “excess solar radiation and low temperatures will result in differences in gs among transects”, I don’t understand how low temperatures will affect gs according to the information in introduction.
Response: Thank you very much for your comment. We respond to this comment from three aspects.
(1) We clarified that “However, previous studies showed that the direction and intensity of solar radiation and temperature on gs strongly depend on their distribution range and the relationship with aridity. For example, the response of gs to solar radiation and temperature generally shows an increasing trend up to optimum values (Xu et al. 2021), while excess radiation (Costa et al. 2015; Doupis et al. 2020; Zeuthen et al. 1997) and high temperature associated high VPD or low SM (Seneviratne et al. 2010) would suppress gs.”
(2) We added the basic climatic context for the three grassland transect in the last paragraph of “1 Instruction” section: “The grassland transect span gradients of precipitation, SM, VPD, solar radiation, and temperature, provide an ideal platform for exploration of interactive effects of multiple stressors and biotic factors on Gs (Table S1). In addition, the three grassland transects experienced with different soilar radiation and temperature conditions at a given aridity, due to the difference in the geographical location of the three plateaus. The order of mean annual temperature and solar radiation is LP>MP>TP and LP<MP<TP, respectively.”
(3) We rephrased the second hypothesis as: “high solar radiation and low temperatures will jointly suppress Gs at a given aridity among transects. ”.
3) The last paragraph should be the last but one paragraph or in the methods.
Response: This paragraph has been revised and removed to section “2.2.3 Stable isotope analysis”: “Given that leaf δ18O at species level was affected by the leaf water evaporation process, variability in gs should show up in leaf δ18O (Barbour 2007; Barbour & Farquhar 2000; Farquhar et al. 1998). Negative relationship between △18O and gs has been observed at species (Barbour & Farquhar 2000; Cabrera-Bosquet et al. 2011; Grams et al. 2007; Moreno-Gutierrez et al. 2012) and canopy scales (Cabrera et al. 2021; Hirl et al. 2021), and among communities along soil (Ramirez et al. 2009) and climatic (Keitel et al. 2006) gradients. Consequently, we selected 1/△18O was used as a proxy for gs in this study.”
4) There may be interspecific difference in gs, so information on plant species and species composition of the three study sites should be provided.
The species, genera and families of species occurred in each community have been listed in “Supplementary 2” (Please see Appendix 2)”.
5) The headline of the first part in the discussion should be changed, because the patterns of gs among the tree transects are similar, but differ in magnitude. In addition, the authors attribute this difference to the temperature-induced changes in photosynthesis, which I don’t agree. Indeed, gs and photosynthesis are closely correlated, for example, to maximize carbon gain and minimize water loss according to the optimal stomatal behaviour. However, in my opinion, the correlation between gs and photosynthesis is regulated by stomatal behaviour.
Response: Thank you very much for your comment. We respond this comment from two aspects.
(1) The headline has been change as: “ 4.3 Differences in canopy conductance among transects” .
(2) The effects of VPD, solar radiation and temperature on the differences in canopy conductance among transects have been rephrased as: “
Significant differences in community 1/△18O were found among transects, and the order of Gs at a given aridity value was LP > MP > TP (Fig.2a). Among transects, only differences in VPD, solar radiation and temperature were significant (P>0.05) (Fig.1 and Fig.S1). In general, plants decrease their gs to respond to increasing VPD (Grossiord et al. 2020). While, intercept of linear regression between aridity and community 1/△18O decreased with decreasing VPD among transects (P>0.05) (Fig.3a). It indicated that the difference in VPD was not a contributor to the difference in Gs among transects.
We attribute the differences in Gs among transects to the direct effects of solar radiation and temperature on Gs and photosynthesis (Yu et al. 2002). This is inconsistent with the results within transect. High solar radiation exhibited negative effect on intercept of linear regression between aridity and community 1/△18O among transects (P<0.05) (Fig.3b). Excess ultraviolet-B radiation (Duan et al. 2008), insufficient thermal dissipation, and enhanced photorespiration under high solar radiation (Cui et al. 2003) can decrease photosynthesis, ultimately reducing gs. For example, Yu et al. (2012) observed that photosynthesis of wheat at leaf level on the TP was lower than that on North China Plain due to the high solar radiation.
Transect with low temperature exhibited low intercept of linear regression between aridity and community 1/△18O (Fig.3c), it indicated that Gs among transects also inhibited by low temperature. Generally, photosynthesis and Gs increased with temperature below optimum temperature (Xu et al. 2021). For example, photosynthesis of wheat was lower in a cold than in a warm environment (Yu et al. 2002). ”
6) line 25 delete “at leaf level”.
Response: Change has been done.
7) line 24 change “in one” and “in the other” into (1) and (2), respectively.
Response: Change has been made.
8) I suggest that “interaction effects” may be changed into “interactive effects”.
Response: Change has been made.
Appendix 1
Figure 1. Comparison of aridity (a), growing season precipitation (b), soil moisture (SM) (c), vapor pressure deficit (VPD) (d), solar radiation (SR) (e), temperature (f), maximum temperature (Tempmax) (g), and community leaf area (h) and specific leaf area (SLA) (i) among transects. LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05). Error bars indicate standard error of the mean.
Figure 2. Patterns of 1/△18O (a) along aridity gradient within transects, and among (b) transects. Different letters indicate significant differences (P < 0.001) among transects and grassland types. △18O, 18O enrichment of leaf organic matter above source water; LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau.
Figure 3. Patterns of the intercept obtained from standardized major axis analysis (SMA) among transects. VPD, vapor pressure deficit; SR, solar radiation; Tempmax, maximum temperature. LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Shaded area represents the 95% confidence interval of the SMA intercept.
Figure 4. Structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Figure 5. Structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Table 1 Pearson’s coefficients among community 1/△18O and environmental factors and plant properties.
Loess Plateau
Inner Mongolia Plateau
Tibet Plateau
Aridity
-0.848**
-0.843**
-0.773**
SM
0.719*
0.707*
0.659*
VPD
-0.554
-0.384
-0.912**
SR
-0.639*
-0.728*
-0.850**
Tempmean
0.641*
0.303
-0.670*
Tempmax
0.678*
0.038
-0.852**
LA
0.757*
0.913**
0.610
SLA
-0.519
-0.576
-0.648*
**, P<0.01; *, P<0.05. SM, soil moisture; VPD, vapor pressure deficit; SR, total solar radiation; Tempmean, mean temperature; Tempmax, maximum temperature; LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Table S1 Geographic and climatic information, δ18O of precipitation, and community △18O for sampling sites in Loess (LP), Inner Mongolia (MP), and Tibetan (TP), Plateau.
Site
Longitude
(°E)
Latitude
(°N)
Elevation
(m)
Aridity
Temperature
(℃)
Tempmax
(℃)
Precipitation
(mm)
Solar radiation
(kJ m-2 day-1)
VPD
(kPa)
SM
(m3 m-3)
δ18OP (‰)
△18O(‰)
Year
GSW
Year
GS
Year
GS
Year
GS
GS
Year
GS
LP01
113.36
36.29
804
0.57
11.85
18.19
29.6
599
546
12.95
15.60
4.78
7.53
0.16
-8.70
-6.92
26.82±0.84
LP02
112.29
35.99
894
0.60
9.96
17.60
29.2
549
501
13.31
16.04
3.57
7.41
0.17
-8.80
-6.86
28.78±1.73
LP03
111.64
35.99
833
0.64
10.66
18.61
30
520
475
12.69
15.65
4.04
8.59
0.13
-8.70
-6.79
30.30±1.77
LP04
110.18
36.07
966
0.63
10.72
18.03
29.9
519
478
14.25
17.02
4.52
8.45
0.15
-9.10
-7.09
29.68±1.00
LP05
109.24
36.74
1268
0.65
9.50
16.99
28.7
492
458
15.34
18.28
4.13
8.00
0.12
-9.20
-7.18
27.64±0.96
LP06
107.92
36.93
1383
0.68
7.46
15.71
27.8
424
394
15.32
18.31
2.53
6.44
0.12
-8.60
-6.74
28.75±1.39
LP07
107.19
37.58
1535
0.75
5.23
15.61
27.6
340
311
15.62
18.97
1.88
7.51
0.07
-7.70
-6.01
32.42±0.86
LP08
105.78
37.42
1293
0.85
5.87
16.94
28.8
222
211
15.53
18.95
2.01
8.71
0.10
-6.80
-5.08
30.77±1.95
LP09
104.92
37.44
1378
0.87
7.56
16.50
28.1
196
183
15.49
18.74
3.99
9.44
0.10
-6.30
-4.69
32.00±2.38
LP10
104.44
37.46
1714
0.87
7.71
15.31
26.8
189
179
15.56
18.77
4.75
9.06
0.10
-6.70
-4.83
34.60±1.39
Trend
0.009
0.035
0.024
<0.001
<0.001
0.012
0.005
0.445
0.058
0.007
<0.001
<0.001
NM01
123.51
44.59
144
0.68
5.10
16.60
29.6
425
410
13.67
17.28
1.11
6.98
0.17
-9.20
-7.14
32.54±0.90
NM02
121.04
44.52
269
0.73
5.80
16.66
30
393
378
14.73
18.44
2.56
8.59
0.11
-9.60
-7.52
32.49±0.71
NM03
120.33
45.11
660
0.71
3.72
13.60
27.4
387
372
14.94
18.81
2.30
6.74
0.15
-10.60
-8.36
32.28±0.65
NM04
118.36
44.77
1019
0.71
0.56
12.03
26.2
345
320
15.09
19.20
1.11
5.96
0.14
-11.40
-8.84
34.23±0.39
NM05
116.52
44.26
1129
0.77
1.17
12.27
26.2
283
267
15.21
19.35
1.53
6.50
0.11
-11.40
-8.67
34.22±1.52
NM06
116.67
43.55
1272
0.73
0.16
11.74
25.4
321
304
15.34
19.31
1.03
5.95
0.11
-11.60
-8.80
33.00±0.79
NM07
117.68
44.51
1024
0.73
1.96
12.10
26.3
319
298
14.88
18.99
1.70
5.94
0.14
-11.30
-8.56
34.31±0.37
NM08
114.89
44.01
1101
0.83
0.10
12.94
27.4
228
219
15.36
19.53
1.33
7.67
0.09
-10.40
-7.87
36.17±0.29
NM09
113.50
43.84
1022
0.86
2.47
14.20
28.3
199
190
15.59
19.76
2.49
9.00
0.06
-9.00
-7.16
35.59±0.63
NM10
112.15
43.63
955
0.88
3.69
14.87
30.1
183
169
15.35
19.57
2.96
9.46
0.06
-8.40
-6.48
35.56±0.21
Trend
0.626
0.995
0.450
<0.001
<0.001
0.026
0.018
0.104
0.015
<0.001
0.134
0.101
TP01
95.45
31.46
4104
0.40
0.41
5.70
17.2
606
572
17.76
19.94
1.71
2.61
0.19
-16.40
-14.22
31.53±1.35
TP02
93.53
31.85
4509
0.37
-1.50
3.14
15.4
593
560
17.57
20.02
1.72
2.17
0.21
-17.70
-15.86
32.25±1.65
TP03
92.01
31.64
4587
0.61
-4.37
4.40
17
430
414
18.62
20.91
1.06
3.39
0.26
-18.00
-16.50
34.00±0.17
TP04
90.74
31.38
4617
0.65
-6.76
5.89
17.8
426
414
18.99
21.41
0.34
4.27
0.17
-18.40
-16.57
39.17±1.41
TP05
89.72
31.54
4588
0.67
-3.06
6.93
19.2
426
412
18.80
21.27
1.51
4.94
0.15
-18.20
-16.39
37.77±0.51
TP06
87.82
31.87
4570
0.79
-2.57
6.77
19.2
286
261
19.27
22.01
2.18
5.50
0.15
-16.50
-14.99
39.07±1.32
TP07
85.84
31.92
4938
0.90
-3.77
3.74
17.6
125
95
19.28
22.22
2.49
4.70
0.13
-15.20
-13.71
35.54±0.74
TP08
83.34
32.41
4578
0.94
-3.90
5.71
20.1
75
62
18.99
22.08
2.32
5.77
0.11
-14.40
-12.85
38.56±1.43
TP09
81.23
32.30
4558
0.92
-3.49
5.29
19.3
102
89
19.41
22.50
2.37
5.45
0.07
-15.10
-12.78
36.99±0.51
TP10
80.15
32.48
4328
0.93
-1.27
6.73
21.5
89
78
19.86
23.12
3.10
6.33
0.09
-14.70
-12.41
42.34±0.60
Trend
0.356
0.360
0.006
<0.001
<0.001
<0.001
<0.001
0.069
<0.001
0.006
0.027
0.039
Tempmax, maximum temperature ; VPD, vapor deficit pressure; SM, soil moisture; δ18OP, the δ18O of precipitation; GSW, growing season. Trend indicates variation in variables along the aridity gradient.
Table S2 Differences in climatic variables among three transects.
Transect
Period
Mean
Standard deviation
Minimum
Maximum
P value
Aridity
LP
0.71
0.12
0.57
0.87
0.693
MP
0.76
0.07
0.68
0.88
TP
0.72
0.21
0.37
0.94
Precipitation
LP
Year
405
157
189
599
0.329
MP
308
84
183
425
TP
316
208
75
606
LP
Growing
season
374
141
179
546
0.408
MP
293
82
169
410
TP
296
204
62
572
Soil
moisture
LP
Growing
season
0.12
0.03
0.07
0.17
0.148
MP
0.11
0.04
0.06
0.17
TP
0.15
0.06
0.07
0.26
Vapor
Pressure
deficit
LP
Year
3.62a
1.10
1.88
4.78
<0.001
MP
1.81b
0.71
1.03
2.96
TP
1.88b
0.79
0.34
3.10
LP
Growing
season
8.11a
0.91
6.44
9.44
<0.001
MP
7.28a
1.33
5.94
9.46
TP
4.51b
1.39
2.17
6.33
Solar
radiation
LP
Year
14.61b
1.19
12.69
15.62
<0.001
MP
15.02b
0.54
13.67
15.59
TP
18.86a
0.72
17.57
19.86
LP
Growing
season
17.63c
1.41
15.60
18.97
<0.001
MP
19.02b
0.72
17.28
19.76
TP
21.55a
1.04
19.94
23.12
Temperature
LP
Year
8.65c
2.21
5.23
11.85
<0.001
MP
2.47b
2.04
0.10
5.80
TP
-3.03a
1.96
-6.76
0.41
LP
Growing
season
16.95c
1.16
15.31
18.61
<0.001
MP
13.70b
1.84
11.74
16.66
TP
5.43a
1.30
3.14
6.93
Maximum
temperature
LP
28.65a
1.06
26.80
30.00
<0.001
MP
27.69a
1.73
25.40
30.10
TP
18.43b
1.76
15.40
21.50
LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05).
Table S3 Characteristics of leaf δ18O and △18O at species level for sampling sites in Loess (LP), Inner Mongolia (MP), and Tibetan (TP) Plateau.
Sites
Number
Leaf δ18O
△18O
Mean
Max
Min
STD
CV
Mean
Max
Min
STD
CV
LP01
25
19.70
26.12
14.70
2.86
0.15
26.79
33.18
21.69
2.92
0.11
LP02
33
22.72
28.13
14.97
2.81
0.12
29.64
35.10
21.96
2.83
0.10
LP03
25
23.43
28.31
17.69
2.96
0.13
30.44
35.20
24.37
2.87
0.09
LP04
28
22.84
31.46
18.59
3.61
0.16
29.99
38.66
25.70
3.63
0.12
LP05
41
21.01
31.46
15.70
3.27
0.16
28.15
38.66
22.85
3.29
0.12
LP06
33
20.90
30.01
16.48
3.34
0.16
27.88
38.89
23.16
3.39
0.12
LP07
33
24.73
31.23
18.33
3.20
0.13
30.79
36.24
24.58
3.07
0.10
LP08
19
27.43
32.96
20.25
3.27
0.12
32.58
37.99
25.21
3.09
0.09
LP09
27
26.51
35.35
19.58
4.35
0.16
31.37
39.99
24.15
4.24
0.14
LP10
15
25.73
32.68
22.04
3.48
0.14
30.43
37.31
26.76
3.47
0.11
LP
279
22.69
35.35
12.07
4.42
0.19
32.29
43.89
21.69
4.4
0.14
MP01
18
23.04
29.24
17.42
3.57
0.15
30.61
36.58
24.68
3.87
0.13
MP02
37
23.48
28.73
18.69
2.26
0.10
31.18
36.44
25.87
2.21
0.07
MP03
30
23.54
30.97
19.31
2.71
0.12
31.95
39.55
27.80
2.82
0.09
MP04
17
22.85
28.10
17.46
3.25
0.14
31.83
37.13
26.41
3.26
0.10
MP05
13
26.54
31.73
22.60
2.59
0.10
35.27
40.62
31.12
2.66
0.08
MP06
22
25.85
32.65
21.14
3.25
0.13
34.62
41.68
28.42
3.47
0.10
MP07
15
24.03
27.40
21.24
2.27
0.09
32.76
36.14
29.92
2.29
0.07
MP08
22
27.59
31.71
21.71
3.05
0.11
35.57
39.73
29.65
3.08
0.09
MP09
17
28.23
31.56
23.18
2.36
0.08
35.41
39.57
30.37
2.22
0.06
MP10
12
29.16
32.33
21.36
2.90
0.10
36.13
41.23
30.04
2.65
0.07
MP
203
25.07
32.65
17.42
3.46
0.14
33.17
41.68
24.68
3.42
0.1
TP01
59
18.45
27.91
12.07
3.79
0.21
33.51
42.07
26.49
4.40
0.13
TP02
38
18.86
27.91
13.12
4.15
0.22
34.85
42.07
29.31
4.27
0.12
TP03
15
18.63
25.90
14.16
4.25
0.23
35.00
42.07
28.22
4.41
0.13
TP04
19
20.28
25.90
14.16
3.90
0.19
36.93
42.07
28.22
4.11
0.11
TP05
19
19.72
25.90
14.90
2.60
0.13
36.34
41.29
31.71
2.34
0.06
TP06
13
19.38
25.24
12.07
3.19
0.16
34.84
41.29
26.49
3.62
0.10
TP07
21
20.06
30.81
13.73
4.12
0.21
34.28
43.74
27.70
3.63
0.11
TP08
9
23.88
26.37
21.27
2.03
0.09
37.06
39.16
34.47
1.99
0.05
TP09
9
24.62
29.61
19.05
3.11
0.13
37.83
42.89
32.19
3.15
0.08
TP10
3
29.09
30.95
27.40
1.78
0.06
42.00
43.89
40.29
1.80
0.04
TP
205
19.72
30.95
12.07
4.13
0.21
35.08
43.89
26.49
4.15
0.12
Three Plateau
687
22.69
35.35
12.07
4.42
0.19
32.29
43.89
21.69
4.4
0.14
Table S4 Results of standardized major axis (SMA) line-fitting for the relationship between canopy stomatal conductance (using 1/△18O as proxy) and aridity.
Intercept
slope
r2
P
Loess Plateau
Estimate
0.047
-0.196
0.68
0.003
Lower
0.043
-0.027
Upper
0.052
-0.014
Inner Mongolia
Plateau
Estimate
0.044
-0.020
0.72
0.002
Lower
0.040
-0.027
Upper
0.049
-0.014
Tibet Plateau
Estimate
0.038
-0.015
0.60
0.008
Lower
0.034
-0.022
Upper
0.042
-0.011
Different letters indicate significant differences (P < 0.001) among transects in intercepts and slopes.
Table S5 Pearson coefficients for correlations among canopy stomatal conductance (Gs) and environmental factors and plant properties.
Transect
Variables
Gs
Aridity
Precipitation
SM
VPD
SR
MAT
MATMAX
LA
SLA
Loess Plateau
Gs
1
Aridity
-0.848**
1
Precipitation
0.856**
-.997**
1
SM
0.719*
-.781**
.795**
1
VPD
-0.554
0.616
-0.563
-0.251
1
SR
-0.639*
0.810**
-.827**
-.851**
0.217
1
Tempmean
0.641*
-0.665*
.710*
.766**
0.074
-.849**
1
Tempmax
0.678*
-0.698*
.737*
.751*
-0.026
-.795**
.980**
1
LA
.757*
-.881**
.863**
0.567
-.751*
-.637*
0.425
0.481
1
SLA
-0.519
0.460
-0.454
-0.499
0.356
0.422
-0.433
-0.483
-0.533
1
Inner Mongolia Plateau
Gs
1
Aridity
-.843**
1
Precipitation
.919**
-.945**
1
SM
.707*
-.941**
.877**
1
VPD
-0.384
.736*
-0.490
-.741*
1
SR
-.728*
.725*
-.846**
-.751*
0.196
1
Tempmean
0.303
-0.002
0.298
-0.009
.647*
-0.615
1
Tempmax
0.038
0.270
0.018
-0.235
.814**
-0.386
.943**
1
LA
.913**
-.721*
.875**
0.625
-0.218
-.731*
0.434
0.189
1
SLA
-0.576
.803**
-0.627
-.681*
.849**
0.310
0.397
0.628
-0.410
1
Tibetan Plateau
Gs
1
Aridity
-.773**
1
Precipitation
.675*
-.978**
1
SM
.659*
-.787**
.795**
1
VPD
-.912**
.931**
-.868**
-.820**
1
SR
-.850**
.963**
-.936**
-.801**
.943**
1
Tempmean
-.670*
0.325
-0.189
-0.454
0.622
0.393
1
Tempmax
-.852**
.795**
-.740*
-.795**
.935**
.832**
.760*
1
LA
0.610
-0.620
0.504
0.219
-0.624
-.658*
-0.401
-0.536
1
SLA
-.648*
0.558
-0.486
-.779**
.715*
0.516
.724*
.729*
-0.078
1
**, P<0.01; *, P<0.05. gs, stomatal conductance; SM, soil moisture; VPD, vapor pressure deficit; SR, total solar radiation; Tempmean, mean temperature; Tempmax, maximum temperature; LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Figure S1. Comparison of annual mean precipitation (mm) (a), vapor pressure deficit (VPD) (b), total solar radiation (TSR) (c), and air temperature (℃) (d) among three transects. LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05). Error bars indicate standard error of the mean.
Figure S2. Patterns of leaf δ18O and △18O at species level along aridity gradient in Loess (LP), Inner Mongolia (MP), and Tibetan (TP), Plateau. m, slope of the linear regression; b, intercept of the linear regression.
Figure S3. Hypothetical structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit.
Figure S4. Hypothetical structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Figure S5. Relationship between community 1/△18O and log-transformed leaf area (LA) (a) and specific leaf area (SLA) (b).
Appendix 2 Information of coexisting species in each community in Loess Plateau (LP), Inner Mongolia Plateau (MP), and Tibet Plateau (TP).
Transect
Site
Species
Genus
Family
LP
1
Allium tenuissimum
Allium
Amaryllidaceae
LP
1
Artemisia annua
Artemisia
Compositae
LP
1
Artemisia scoparia
Artemisia
Compositae
LP
1
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
1
Carex korshinskyi
Carex
Cyperaceae
LP
1
Cirsium arvense
Cirsium
Compositae
LP
1
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
1
Cynanchum thesioides
Cynanchum
Apocynaceae
LP
1
Erigeron canadensis
Erigeron
Compositae
LP
1
Heteropappus altaicus
Heteropappus
Compositae
LP
1
Lespedeza bicolor
Lespedeza
Fabaceae
LP
1
Leymus chinensis
Leymus
Poaceae
LP
1
Medicago ruthenica
Medicago
Fabaceae
LP
1
Polygala tenuifolia
Polygala
Polygalaceae
LP
1
Rubia cordifolia
Rubia
Rubiaceae
LP
1
Salix gordejevii
Salix
Salicaceae
LP
1
Ulmus pumila
Ulmus
Ulmaceae
LP
1
Vicia amoena
Vicia
Fabaceae
LP
1
Viola philippica
Viola
Violaceae
LP
1
Youngia japonica
Youngia
Compositae
LP
1
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
1
Scrophulariaceae
LP
2
Heteropappus altaicus
Heteropappus
Compositae
LP
2
Agropyron cristatum
Agropyron
Poaceae
LP
2
Anemone chinensis
Anemone
Ranunculaceae
LP
2
Artemisia lavandulifolia
Artemisia
Asteraceae
LP
2
Astragalus scaberrimus
Astragalus
Fabaceae
LP
2
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
2
Caragana sinica
Caragana
Fabaceae
LP
2
Carex korshinskyi
Carex
Cyperaceae
LP
2
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
2
Cleistogenes songorica
Cleistogenes
Poaceae
LP
2
Dianthus chinensis
Dianthus
Caryophyllaceae
LP
2
Echinops sphaerocephalus
Echinops
Compositae
LP
2
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
2
Incarvillea sinensis
Incarvillea
Bignoniaceae
LP
2
Lespedeza davurica
Lespedeza
Fabaceae
LP
2
Lespedeza juncea
Lespedeza
Fabaceae
LP
2
Patrinia scabiosifolia
Patrinia
Caprifoliaceae
LP
2
Periploca sepium
Periploca
Apocynaceae
LP
2
Plantago depressa
Plantago
Plantaginaceae
LP
2
Poa annua
Poa
Poaceae
LP
2
Polygala tenuifolia
Polygala
Polygalaceae
LP
2
Potentilla supina
Potentilla
Rosaceae
LP
2
Rosa xanthina
Rosa
Rosaceae
LP
2
Rubia cordifolia
Rubia
Rubiaceae
LP
2
Saussurea japonica
Saussurea
Compositae
LP
2
Scorzonera sinensis
Scorzonera
Compositae
LP
2
Setaria viridis
Setaria
Poaceae
LP
2
Themeda triandra
Themeda
Poaceae
LP
2
Thymus mongolicus
Thymus
Lamiaceae
LP
2
Tripolium pannonicum
Tripolium
Compositae
LP
2
Viola philippica
Viola
Violaceae
LP
2
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
3
Agropyron cristatum
Agropyron
Poaceae
LP
3
Artemisia leucophylla
Artemisia
Compositae
LP
3
Astragalus scaberrimus
Astragalus
Fabaceae
LP
3
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
3
Bupleurum chinense
Bupleurum
Apiaceae
LP
3
Carex korshinskyi
Carex
Cyperaceae
LP
3
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
3
Cleistogenes songorica
Cleistogenes
Poaceae
LP
3
Echinops sphaerocephalus
Echinops
Compositae
LP
3
Heteropappus altaicus
Heteropappus
Compositae
LP
3
Lespedeza davurica
Lespedeza
Fabaceae
LP
3
Poa annua
Poa
Poaceae
LP
3
Poa sphondylodes
Poa
Poaceae
LP
3
Polygala tenuifolia
Polygala
Polygalaceae
LP
3
Potentilla discolor
Potentilla
Rosaceae
LP
3
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
3
Selaginella tamariscina
Selaginella
Selaginellaceae
LP
3
Serratula centauroides
Serratula
Compositae
LP
3
Stipa sibirica
Stipa
Poaceae
LP
3
Themeda triandra
Themeda
Poaceae
LP
3
Tripolium pannonicum
Tripolium
Compositae
LP
3
Viola philippica
Viola
Violaceae
LP
3
Vitex negundo
Vitex
Lamiaceae
LP
3
Wikstroemia chamaedaphne
Wikstroemia
Thymelaeaceae
LP
3
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
4
Agropyron cristatum
Agropyron
Poaceae
LP
4
Agropyron desertorum
Agropyron
Poaceae
LP
4
Artemisia annua
Artemisia
Compositae
LP
4
Artemisia argyi
Artemisia
Compositae
LP
4
Artemisia argyi
Artemisia
Compositae
LP
4
Artemisia dalailamae
Artemisia
Compositae
LP
4
Astragalus melilotoides
Astragalus
Fabaceae
LP
4
Astragalus scaberrimus
Astragalus
Fabaceae
LP
4
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
4
Carex korshinskyi
Carex
Cyperaceae
LP
4
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
4
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
4
Heteropappus altaicus
Heteropappus
Compositae
LP
4
Ixeris polycephala
Ixeris
Compositae
LP
4
Lespedeza bicolor
Lespedeza
Fabaceae
LP
4
Poa annua
Poa
Poaceae
LP
4
Polygala sibirica
Polygala
Polygalaceae
LP
4
Polygala tenuifolia
Polygala
Polygalaceae
LP
4
Potentilla discolor
Potentilla
Rosaceae
LP
4
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
4
Rosa xanthina
Rosa
Rosaceae
LP
4
Scorzonera sinensis
Scorzonera
Compositae
LP
4
Vicia amoena
Vicia
Fabaceae
LP
4
Viola philippica
Viola
Violaceae
LP
4
Wikstroemia chamaedaphne
Wikstroemia
Thymelaeaceae
LP
4
Yulania denudata
Yulania
Magnoliaceae
LP
4
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
5
Artemisia annua
Artemisia
Compositae
LP
5
Artemisia argyi
Artemisia
Compositae
LP
5
Artemisia frigida
Artemisia
Compositae
LP
5
Artemisia japonica
Artemisia
Compositae
LP
5
Artemisia scoparia
Artemisia
Compositae
LP
5
Astragalus scaberrimus
Astragalus
Fabaceae
LP
5
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
5
Caragana microphylla
Caragana
Fabaceae
LP
5
Carduus nutans
Carduus
Compositae
LP
5
Cirsium arvense
Cirsium
Compositae
LP
5
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
5
Cleistogenes serotina
Cleistogenes
Poaceae
LP
5
Cynanchum thesioides
Cynanchum
Apocynaceae
LP
5
Dracocephalum moldavica
Dracocephalum
Lamiaceae
LP
5
Eragrostis pilosa
Eragrostis
Poaceae
LP
5
Erigeron annuus
Erigeron
Compositae
LP
5
Glycyrrhiza uralensis
Glycyrrhiza
Fabaceae
LP
5
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
5
Incarvillea sinensis
Incarvillea
Bignoniaceae
LP
5
Ixeris polycephala
Ixeris
Compositae
LP
5
Kalimeris hispida
Kalimeris
Compositae
LP
5
Koeleria pyramidata
Koeleria
Poaceae
LP
5
Lespedeza davurica
Lespedeza
Fabaceae
LP
5
Lespedeza juncea
Lespedeza
Fabaceae
LP
5
Leymus chinensis
Leymus
Poaceae
LP
5
Oxytropis myriophylla
Oxytropis
Fabaceae
LP
5
Poa annua
Poa
Poaceae
LP
5
Poa sphondylodes
Poa
Poaceae
LP
5
Polygala sibirica
Polygala
Polygalaceae
LP
5
Potentilla supina
Potentilla
Rosaceae
LP
5
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
5
Rubia cordifolia
Rubia
Rubiaceae
LP
5
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
5
Sonchus arvensis
Sonchus
Compositae
LP
5
Taraxacum mongolicum
Taraxacum
Compositae
LP
5
Tripolium pannonicum
Tripolium
Compositae
LP
5
Viola philippica
Viola
Violaceae
LP
5
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
6
Allium senescens
Allium
Liliaceae
LP
6
Anemone chinensis
Anemone
Ranunculaceae
LP
6
Artemisia argyi
Artemisia
Compositae
LP
6
Artemisia japonica
Artemisia
Compositae
LP
6
Astragalus scaberrimus
Astragalus
Fabaceae
LP
6
Carduus nutans
Carduus
Compositae
LP
6
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
6
Cleistogenes serotina
Cleistogenes
Poaceae
LP
6
Echinops sphaerocephalus
Echinops
Compositae
LP
6
Elymus dahuricus
Elymus
Poaceae
LP
6
Imperata cylindrica
Imperata
Poaceae
LP
6
Kalimeris hispida
Kalimeris
Compositae
LP
6
Lappula myosotis
Lappula
Boraginaceae
LP
6
Leontopodium leontopodinum
Leontopodium
Compositae
LP
6
Lespedeza bicolor
Lespedeza
Fabaceae
LP
6
Linum usitatissimum
Linum
Linaceae
LP
6
Medicago ruthenica
Medicago
Fabaceae
LP
6
Patrinia heterophylla
Patrinia
Caprifoliaceae
LP
6
Phlomoides umbrosa
Phlomoides
Lamiaceae
LP
6
Phragmites australis
Phragmites
Poaceae
LP
6
Poa sphondylodes
Poa
Poaceae
LP
6
Polygala tenuifolia
Polygala
Polygalaceae
LP
6
Potentilla chinensis
Potentilla
Rosaceae
LP
6
Potentilla sericea
Potentilla
Rosaceae
LP
6
Ranunculus japonicus
Ranunculus
Ranunculaceae
LP
6
Rubia cordifolia
Rubia
Rubiaceae
LP
6
Setaria viridis
Setaria
Poaceae
LP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
6
Sonchus arvensis
Sonchus
Compositae
LP
6
Stipa bungeana
Stipa
Poaceae
LP
6
Stipa capillata
Stipa
Poaceae
LP
6
Taraxacum mongolicum
Taraxacum
Compositae
LP
6
Tripolium pannonicum
Tripolium
Compositae
LP
7
Agropyron cristatum
Agropyron
Poaceae
LP
7
Artemisia argyi
Artemisia
Compositae
LP
7
Artemisia scoparia
Artemisia
Compositae
LP
7
Astragalus adsurgens
Astragalus
Fabaceae
LP
7
Astragalus galactites
Astragalus
Fabaceae
LP
7
Astragalus melilotoides
Astragalus
Fabaceae
LP
7
Astragalus propinquus
Astragalus
Fabaceae
LP
7
Bassia scoparia
Bassia
Amaranthaceae
LP
7
Carex korshinskyi
Carex
Cyperaceae
LP
7
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
7
Cleistogenes songorica
Cleistogenes
Poaceae
LP
7
Convolvulus arvensis
Convolvulus
Convolvulaceae
LP
7
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
7
Haplophyllum dauricum
Haplophyllum
Rutaceae
LP
7
Heteropappus altaicus
Heteropappus
Compositae
LP
7
Ixeris polycephala
Ixeris
Compositae
LP
7
Koeleria pyramidata
Koeleria
Poaceae
LP
7
Lespedeza bicolor
Lespedeza
Fabaceae
LP
7
Leymus chinensis
Leymus
Poaceae
LP
7
Medicago ruthenica
Medicago
Fabaceae
LP
7
Medicago sativa
Medicago
Fabaceae
LP
7
Melilotus albus
Melilotus
Leguminosae
LP
7
Polygonum sibiricum
Polygonum
Polygonaceae
LP
7
Scorzonera sinensis
Scorzonera
Compositae
LP
7
Setaria viridis
Setaria
Poaceae
LP
7
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
7
Sonchus arvensis
Sonchus
Compositae
LP
7
Stipa capillata
Stipa
Poaceae
LP
7
Stipa splendens
Stipa
Poaceae
LP
7
Suaeda glauca
Suaeda
Amaranthaceae
LP
7
Taraxacum mongolicum
Taraxacum
Compositae
LP
7
Thermopsis lanceolata
Thermopsis
Fabaceae
LP
8
Allium tenuissimum
Allium
Amaryllidaceae
LP
8
Alopecurus aequalis
Alopecurus
Poaceae
LP
8
Artemisia scoparia
Artemisia
Compositae
LP
8
Astragalus galactites
Astragalus
Fabaceae
LP
8
Astragalus propinquus
Astragalus
Fabaceae
LP
8
Bassia dasyphylla
Bassia
Amaranthaceae
LP
8
Carex korshinskyi
Carex
Cyperaceae
LP
8
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
8
Convolvulus ammannii
Convolvulus
Convolvulaceae
LP
8
Echinochloa crus-galli
Echinochloa
Poaceae
LP
8
Eragrostis pilosa
Eragrostis
Poaceae
LP
8
Peganum harmala
Peganum
Nitrariaceae
LP
8
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
8
Stipa capillata
Stipa
Poaceae
LP
8
Tragus racemosus
Tragus
Poaceae
LP
8
Tribulus terrestris
Tribulus
Zygophyllaceae
LP
8
Zygophyllum mucronatum
Zygophyllum
Zygophyllaceae
LP
9
Allium mongolicum
Allium
Amaryllidaceae
LP
9
Allium polyrhizum
Allium
Amaryllidaceae
LP
9
Artemisia annua
Artemisia
Compositae
LP
9
Artemisia argyi
Artemisia
Compositae
LP
9
Artemisia capillaris
Artemisia
Compositae
LP
9
Artemisia scoparia
Artemisia
Compositae
LP
9
Asparagus cochinchinensis
Asparagus
Asparagaceae
LP
9
Astragalus galactites
Astragalus
Fabaceae
LP
9
Caragana stenophylla
Caragana
Fabaceae
LP
9
Chloris virgata
Chloris
Poaceae
LP
9
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
9
Convolvulus ammannii
Convolvulus
Convolvulaceae
LP
9
Convolvulus arvensis
Convolvulus
Convolvulaceae
LP
9
Convolvulus tragacanthoides
Convolvulus
Convolvulaceae
LP
9
Echinochloa crus-galli
Echinochloa
Poaceae
LP
9
Euphorbia humifusa
Euphorbia
Euphorbiaceae
LP
9
Heteropappus altaicus
Heteropappus
Compositae
LP
9
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
9
Salsola collina
Salsola
Amaranthaceae
LP
9
Salsola passerina
Salsola
Amaranthaceae
LP
9
Stipa capillata
Stipa
Poaceae
LP
9
Suaeda glauca
Suaeda
Amaranthaceae
LP
9
Tribulus terrestris
Tribulus
Zygophyllaceae
LP
9
Zygophyllum mucronatum
Zygophyllum
Zygophyllaceae
LP
10
Heteropappus altaicus
Heteropappus
Compositae
LP
10
Lepidium apetalum
Lepidium
Brassicaceae
LP
10
Saussurea japonica
Saussurea
Compositae
LP
10
Alopecurus aequalis
Alopecurus
Poaceae
LP
10
Artemisia ordosica
Artemisia
Compositae
LP
10
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
10
Eragrostis pilosa
Eragrostis
Poaceae
LP
10
Allium polyrhizum
Allium
Amaryllidaceae
LP
10
Suaeda glauca
Suaeda
Amaranthaceae
LP
10
Alopecurus aequalis
Alopecurus
Poaceae
LP
10
Chenopodium album
Chenopodium
Amaranthaceae
LP
10
Carex korshinskyi
Carex
Cyperaceae
LP
10
Artemisia capillaris
Artemisia
Compositae
LP
10
Salsola passerina
Salsola
Amaranthaceae
LP
10
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
1
Heteropappus altaicus
Heteropappus
Compositae
MP
1
Echinochloa crus-galli
Echinochloa
Poaceae
MP
1
Setaria viridis
Setaria
Poaceae
MP
1
Incarvillea sinensis
Incarvillea
Bignoniaceae
MP
1
Artemisia ordosica
Artemisia
Compositae
MP
1
Chloris virgata
Chloris
Poaceae
MP
1
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
1
Bassia scoparia
Bassia
Amaranthaceae
MP
1
Lactuca sativa
Lactuca
Compositae
MP
1
Phragmites australis
Phragmites
Poaceae
MP
1
Medicago sativa
Medicago
Fabaceae
MP
1
Carex korshinskyi
Carex
Cyperaceae
MP
1
Calystegia pellita
Calystegia
Convolvulaceae
MP
1
Polygonum sibiricum
Polygonum
Polygonaceae
MP
1
Leymus chinensis
Leymus
Poaceae
MP
1
Artemisia sphaerocephala
Artemisia
Compositae
MP
1
Aeluropus littoralis
Aeluropus
Poaceae
MP
1
Medicago sativa
Medicago
Fabaceae
MP
2
Adenophora stricta
Adenophora
Campanulaceae
MP
2
Agropyron cristatum
Agropyron
Poaceae
MP
2
Allium anisopodium
Allium
Amaryllidaceae
MP
2
Allium ramosum
Allium
Amaryllidaceae
MP
2
Amethystea caerulea
Amethystea
Lamiaceae
MP
2
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
2
Artemisia desertorum
Artemisia
Compositae
MP
2
Artemisia lavandulifolia
Artemisia
Asteraceae
MP
2
Artemisia sieversiana
Artemisia
Compositae
MP
2
Artemisia sphaerocephala
Artemisia
Compositae
MP
2
Atraphaxis manshurica
Atraphaxis
Polygonaceae
MP
2
Carex pediformis
Carex
Cyperaceae
MP
2
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
2
Chloris virgata
Chloris
Poaceae
MP
2
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
2
Clematis hexapetala
Clematis
Ranunculaceae
MP
2
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
2
Cynanchum thesioides
Cynanchum
Apocynaceae
MP
2
Dysphania aristata
Dysphania
Amaranthaceae
MP
2
Enneapogon desvauxii
Enneapogon
Poaceae
MP
2
Ephedra sinica
Ephedra
Ephedraceae
MP
2
Eriochloa villosa
Eriochloa
Poaceae
MP
2
Erodium stephanianum
Erodium
Geraniaceae
MP
2
Euphorbia humifusa
Euphorbia
Euphorbiaceae
MP
2
Glycyrrhiza uralensis
Glycyrrhiza
Fabaceae
MP
2
Iris tenuifolia
Iris
Iridaceae
MP
2
Lespedeza davurica
Lespedeza
Fabaceae
MP
2
Medicago ruthenica
Medicago
Fabaceae
MP
2
Phragmites australis
Phragmites
Poaceae
MP
2
Salsola collina
Salsola
Amaranthaceae
MP
2
Serratula centauroides
Serratula
Compositae
MP
2
Setaria viridis
Setaria
Poaceae
MP
2
Stipa capillata
Stipa
Poaceae
MP
2
Stipa sibirica
Stipa
Poaceae
MP
2
Thalictrum squarrosum
Thalictrum
Ranunculaceae
MP
2
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
3
Allium tenuissimum
Allium
Amaryllidaceae
MP
3
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
3
Artemisia annua
Artemisia
Compositae
MP
3
Artemisia lavandulifolia
Artemisia
Asteraceae
MP
3
Astragalus adsurgens
Astragalus
Fabaceae
MP
3
Astragalus propinquus
Astragalus
Fabaceae
MP
3
Carex korshinskyi
Carex
Cyperaceae
MP
3
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
3
Convolvulus arvensis
Convolvulus
Convolvulaceae
MP
3
Eriochloa villosa
Eriochloa
Poaceae
MP
3
Erodium stephanianum
Erodium
Geraniaceae
MP
3
Euphorbia humifusa
Euphorbia
Euphorbiaceae
MP
3
Gerbera anandria
Gerbera
Compositae
MP
3
Heteropappus altaicus
Heteropappus
Compositae
MP
3
Leontopodium leontopodinum
Leontopodium
Compositae
MP
3
Lespedeza davurica
Lespedeza
Fabaceae
MP
3
Lespedeza juncea
Lespedeza
Fabaceae
MP
3
Leymus chinensis
Leymus
Poaceae
MP
3
Linum stelleroides
Linum
Linaceae
MP
3
Miscanthus sacchariflorus
Miscanthus
Poaceae
MP
3
Polygala tenuifolia
Polygala
Polygalaceae
MP
3
Polygonum divaricatum
Polygonum
Polygonaceae
MP
3
Potentilla betonicifolia
Potentilla
Rosaceae
MP
3
Potentilla verticillaris
Potentilla
Rosaceae
MP
3
Salsola collina
Salsola
Amaranthaceae
MP
3
Sanguisorba officinalis
Sanguisorba
Rosaceae
MP
3
Serratula centauroides
Serratula
Compositae
MP
3
Stipa sibirica
Stipa
Poaceae
MP
3
Thalictrum petaloideum
Thalictrum
Ranunculaceae
MP
4
Agropyron cristatum
Agropyron
Poaceae
MP
4
Allium bidentatum
Allium
Amaryllidaceae
MP
4
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
4
Bassia prostrata
Bassia
Amaranthaceae
MP
4
Carex korshinskyi
Carex
Cyperaceae
MP
4
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
4
Dysphania aristata
Dysphania
Amaranthaceae
MP
4
Iris tenuifolia
Iris
Iridaceae
MP
4
Koeleria pyramidata
Koeleria
Poaceae
MP
4
Lappula myosotis
Lappula
Boraginaceae
MP
4
Leymus chinensis
Leymus
Poaceae
MP
4
Medicago ruthenica
Medicago
Fabaceae
MP
4
Potentilla acaulis
Potentilla
Rosaceae
MP
4
Salsola collina
Salsola
Amaranthaceae
MP
4
Scorzonera sinensis
Scorzonera
Compositae
MP
4
Stipa capillata
Stipa
Poaceae
MP
4
Veratrum nigrum
Veratrum
Melanthiaceae
MP
5
Allium anisopodium
Allium
Amaryllidaceae
MP
5
Agropyron cristatum
Agropyron
Poaceae
MP
5
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
5
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
5
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
5
Artemisia frigida
Artemisia
Compositae
MP
5
Bassia prostrata
Bassia
Amaranthaceae
MP
5
Carex korshinskyi
Carex
Cyperaceae
MP
5
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
5
Allium tenuissimum
Allium
Amaryllidaceae
MP
5
Leymus chinensis
Leymus
Poaceae
MP
5
Stipa capillata
Stipa
Poaceae
MP
5
Salsola collina
Salsola
Amaranthaceae
MP
6
Agropyron cristatum
Agropyron
Poaceae
MP
6
Cleistogenes squarrosa
Cleistogenes
Poaceae
MP
6
Ephedra sinica
Ephedra
Ephedraceae
MP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
MP
6
Allium condensatum
Allium
Amaryllidaceae
MP
6
Artemisia annua
Artemisia
Compositae
MP
6
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
6
Artemisia frigida
Artemisia
Compositae
MP
6
Bassia prostrata
Bassia
Amaranthaceae
MP
6
Thermopsis lanceolata
Thermopsis
Fabaceae
MP
6
Koeleria pyramidata
Koeleria
Poaceae
MP
6
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
MP
6
Carex korshinskyi
Carex
Cyperaceae
MP
6
Allium tenuissimum
Allium
Amaryllidaceae
MP
6
Iris tenuifolia
Iris
Iridaceae
MP
6
Leymus chinensis
Leymus
Poaceae
MP
6
Allium ramosum
Allium
Amaryllidaceae
MP
6
Stipa sibirica
Stipa
Poaceae
MP
6
Poa annua
Poa
Poaceae
MP
6
Stipa capillata
Stipa
Poaceae
MP
6
Axyris amaranthoides
Axyris
Amaranthaceae
MP
6
Salsola collina
Salsola
Amaranthaceae
MP
7
Agropyron cristatum
Agropyron
Poaceae
MP
7
Scutellaria scordiifolia
Scutellaria
Lamiaceae
MP
7
Astragalus melilotoides
Astragalus
Fabaceae
MP
7
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
7
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
MP
7
Koeleria pyramidata
Koeleria
Poaceae
MP
7
Astragalus galactites
Astragalus
Fabaceae
MP
7
Allium bidentatum
Allium
Amaryllidaceae
MP
7
Carex korshinskyi
Carex
Cyperaceae
MP
7
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
7
Allium tenuissimum
Allium
Amaryllidaceae
MP
7
Iris tenuifolia
Iris
Iridaceae
MP
7
Leymus chinensis
Leymus
Poaceae
MP
7
Stipa capillata
Stipa
Poaceae
MP
7
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
8
Heteropappus altaicus
Heteropappus
Compositae
MP
8
Agropyron cristatum
Agropyron
Poaceae
MP
8
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
8
Artemisia annua
Artemisia
Compositae
MP
8
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
8
Allium polyrhizum
Allium
Amaryllidaceae
MP
8
Artemisia frigida
Artemisia
Compositae
MP
8
Asparagus schoberioides
Asparagus
Asparagaceae
MP
8
Bassia prostrata
Bassia
Amaranthaceae
MP
8
Astragalus galactites
Astragalus
Fabaceae
MP
8
Allium bidentatum
Allium
Amaryllidaceae
MP
8
Carex korshinskyi
Carex
Cyperaceae
MP
8
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
8
Allium tenuissimum
Allium
Amaryllidaceae
MP
8
Iris tenuifolia
Iris
Iridaceae
MP
8
Leymus chinensis
Leymus
Poaceae
MP
8
Allium ramosum
Allium
Amaryllidaceae
MP
8
Convolvulus ammannii
Convolvulus
Convolvulaceae
MP
8
Stipa capillata
Stipa
Poaceae
MP
8
Neopallasia pectinata
Neopallasia
Compositae
MP
8
Salsola collina
Salsola
Amaranthaceae
MP
9
Artemisia argyi
Artemisia
Compositae
MP
9
Scorzonera sinensis
Scorzonera
Compositae
MP
9
Eragrostis pilosa
Eragrostis
Poaceae
MP
9
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
9
Allium polyrhizum
Allium
Amaryllidaceae
MP
9
Asparagus schoberioides
Asparagus
Asparagaceae
MP
9
Peganum harmala
Peganum
Nitrariaceae
MP
9
Iris lactea
Iris
Iridaceae
MP
9
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
9
Allium bidentatum
Allium
Amaryllidaceae
MP
9
Carex korshinskyi
Carex
Cyperaceae
MP
9
Cleistogenes songorica
Cleistogenes
Poaceae
MP
9
Caragana stenophylla
Caragana
Fabaceae
MP
9
Convolvulus ammannii
Convolvulus
Convolvulaceae
MP
9
Stipa capillata
Stipa
Poaceae
MP
9
Salsola collina
Salsola
Amaranthaceae
MP
10
Setaria viridis
Setaria
Poaceae
MP
10
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
10
Asparagus schoberioides
Asparagus
Asparagaceae
MP
10
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
10
Allium bidentatum
Allium
Amaryllidaceae
MP
10
Carex korshinskyi
Carex
Cyperaceae
MP
10
Cleistogenes songorica
Cleistogenes
Poaceae
MP
10
Iris tenuifolia
Iris
Iridaceae
MP
10
Caragana stenophylla
Caragana
Fabaceae
MP
10
Stipa capillata
Stipa
Poaceae
MP
10
Salsola collina
Salsola
Amaranthaceae
TP
1
Allium przewalskianum
Allium
Amaryllidaceae
TP
1
Allium ramosum
Allium
Amaryllidaceae
TP
1
Anaphalis xylorhiza
Anaphalis
Compositae
TP
1
Androsace tapete
Androsace
Primulaceae
TP
1
Androsace umbellata
Androsace
Primulaceae
TP
1
Arenaria brevipetala
Arenaria
Caryophyllaceae
TP
1
Artemisia argyi
Artemisia
Compositae
TP
1
Aster tataricus
Aster
Compositae
TP
1
Astragalus propinquus
Astragalus
Fabaceae
TP
1
Calamagrostis lahulensis
Calamagrostis
Poaceae
TP
1
Caragana sinica
Caragana
Fabaceae
TP
1
Carex korshinskyi
Carex
Cyperaceae
TP
1
Chenopodium glaucum
Chenopodium
Amaranthaceae
TP
1
Elymus dahuricus
Elymus
Poaceae
TP
1
Eragrostis pilosa
Eragrostis
Poaceae
TP
1
Euphorbia stracheyi
Euphorbia
Euphorbiaceae
TP
1
Gentiana scabra
Gentiana
Gentianaceae
TP
1
Gentiana straminea
Gentiana
Gentianaceae
TP
1
Gentiana szechenyii
Gentiana
Gentianaceae
TP
1
Gentianopsis paludosa
Gentianopsis
Gentianaceae
TP
1
Geranium wilfordii
Geranium
Geraniaceae
TP
1
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
1
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
1
Heracleum hemsleyanum
Heracleum
Apiaceae
TP
1
Heteropappus altaicus
Heteropappus
Compositae
TP
1
Incarvillea sinensis
Incarvillea
Bignoniaceae
TP
1
Iris tectorum
Iris
Iridaceae
TP
1
Kobresia littledalei
Kobresia
Cyperaceae
TP
1
Leontopodium leontopodinum
Leontopodium
Compositae
TP
1
Phlomis younghusbandii
Phlomis
Lamiaceae
TP
1
Plantago depressa
Plantago
Plantaginaceae
TP
1
Poa annua
Poa
Poaceae
TP
1
Polygonum divaricatum
Polygonum
Polygonaceae
TP
1
Potentilla chinensis
Potentilla
Rosaceae
TP
1
Potentilla multifida
Potentilla
Rosaceae
TP
1
Potentilla saundersiana
Potentilla
Rosaceae
TP
1
Przewalskia tangutica
Przewalskia
Solanaceae
TP
1
Scorzonera sinensis
Scorzonera
Compositae
TP
1
Scrophularia ningpoensis
Scrophularia
Scrophulariaceae
TP
1
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
1
Silene gallica
Silene
Caryophyllaceae
TP
1
Stipa capillata
Stipa
Poaceae
TP
1
Stipa purpurea
Stipa
Poaceae
TP
1
Taraxacum mongolicum
Taraxacum
Compositae
TP
1
Vicia amoena
Vicia
Fabaceae
TP
2
Anaphalis xylorhiza
Anaphalis
Compositae
TP
2
Artemisia argyi
Artemisia
Compositae
TP
2
Aster souliei
Aster
Compositae
TP
2
Aster tataricus
Aster
Compositae
TP
2
Astragalus strictus
Astragalus
Fabaceae
TP
2
Carex korshinskyi
Carex
Cyperaceae
TP
2
Elsholtzia densa
Elsholtzia
Lamiaceae
TP
2
Eragrostis alta
Eragrostis
Poaceae
TP
2
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
TP
2
Geranium wilfordii
Geranium
Geraniaceae
TP
2
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
2
Heracleum hemsleyanum
Heracleum
Apiaceae
TP
2
Kobresia pygmaea
Kobresia
Cyperaceae
TP
2
Lancea tibetica
Lancea
Phrymaceae
TP
2
Lasiocaryum densiflorum
Lasiocaryum
Boraginaceae
TP
2
Persicaria vivipara
Persicaria
Polygonaceae
TP
2
Phlomoides rotata
Phlomoides
Lamiaceae
TP
2
Poa annua
Poa
Poaceae
TP
2
Polygonum sibiricum
Polygonum
Polygonaceae
TP
2
Potentilla anserina
Potentilla
Rosaceae
TP
2
Potentilla parvifolia
Potentilla
Rosaceae
TP
2
Potentilla saundersiana
Potentilla
Rosaceae
TP
2
Przewalskia tangutica
Przewalskia
Solanaceae
TP
2
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
2
Stipa capillata
Stipa
Poaceae
TP
2
Taraxacum mongolicum
Taraxacum
Compositae
TP
2
Urtica hyperborea
Urtica
Urticaceae
TP
3
Astragalus propinquus
Astragalus
Fabaceae
TP
3
Carex korshinskyi
Carex
Cyperaceae
TP
3
Eragrostis alta
Eragrostis
Poaceae
TP
3
Kobresia pygmaea
Kobresia
Cyperaceae
TP
3
Lancea tibetica
Lancea
Phrymaceae
TP
3
Leontopodium leontopodinum
Leontopodium
Compositae
TP
3
Poa annua
Poa
Poaceae
TP
3
Potentilla anserina
Potentilla
Rosaceae
TP
3
Potentilla saundersiana
Potentilla
Rosaceae
TP
3
Saussurea japonica
Saussurea
Compositae
TP
3
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
3
Taraxacum mongolicum
Taraxacum
Compositae
TP
4
Astragalus arnoldii
Astragalus
Fabaceae
TP
4
Callianthemum pimpinelloides
Callianthemum
Ranunculaceae
TP
4
Carex korshinskyi
Carex
Cyperaceae
TP
4
Eragrostis alta
Eragrostis
Poaceae
TP
4
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
TP
4
Heteropappus boweri
Heteropappus
Compositae
TP
4
Kobresia pygmaea
Kobresia
Cyperaceae
TP
4
Leontopodium leontopodinum
Leontopodium
Compositae
TP
4
Oxytropis stracheyana
Oxytropis
Fabaceae
TP
4
Pedicularis alaschanica
Pedicularis
Scrophulariaceae
TP
4
Poa setulosa
Poa
Poaceae
TP
4
Przewalskia tangutica
Przewalskia
Solanaceae
TP
4
Rhodiola smithii
Rhodiola
Crassulaceae
TP
4
Saussurea japonica
Saussurea
Compositae
TP
4
Stipa capillata
Stipa
Poaceae
TP
4
Taraxacum mongolicum
Taraxacum
Compositae
TP
5
Arenaria edgeworthiana
Arenaria
Caryophyllaceae
TP
5
Astragalus adsurgens
Astragalus
Fabaceae
TP
5
Astragalus tribulifolius
Astragalus
Fabaceae
TP
5
Carex korshinskyi
Carex
Cyperaceae
TP
5
Carex littledalei
Carex
Cyperaceae
TP
5
Dolomiaea souliei
Dolomiaea
Compositae
TP
5
Dracocephalum heterophyllum
Dracocephalum
Lamiaceae
TP
5
Eragrostis pilosa
Eragrostis
Poaceae
TP
5
Heteropappus boweri
Heteropappus
Compositae
TP
5
Kobresia pygmaea
Kobresia
Cyperaceae
TP
5
Leontopodium leontopodinum
Leontopodium
Compositae
TP
5
Poa annua
Poa
Poaceae
TP
5
Potentilla chinensis
Potentilla
Rosaceae
TP
5
Potentilla supina
Potentilla
Rosaceae
TP
5
Rhodiola smithii
Rhodiola
Crassulaceae
TP
5
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
5
Stipa capillata
Stipa
Poaceae
TP
5
Stipa purpurea
Stipa
Poaceae
TP
5
Youngia japonica
Youngia
Compositae
TP
6
Astragalus adsurgens
Astragalus
Fabaceae
TP
6
Carex korshinskyi
Carex
Cyperaceae
TP
6
Dracocephalum heterophyllum
Dracocephalum
Lamiaceae
TP
6
Heteropappus boweri
Heteropappus
Compositae
TP
6
Incarvillea lutea
Incarvillea
Bignoniaceae
TP
6
Lagotis brachystachya
Lagotis
Plantaginaceae
TP
6
Oxytropis microphylla
Oxytropis
Fabaceae
TP
6
Przewalskia tangutica
Przewalskia
Solanaceae
TP
6
Rhodiola smithii
Rhodiola
Crassulaceae
TP
6
Sibbaldia parviflora
Sibbaldia
Rosaceae
TP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
6
Stipa capillata
Stipa
Poaceae
TP
6
Stipa purpurea
Stipa
Poaceae
TP
7
Androsace tapete
Androsace
Primulaceae
TP
7
Arenaria brevipetala
Arenaria
Caryophyllaceae
TP
7
Astragalus propinquus
Astragalus
Fabaceae
TP
7
Carex korshinskyi
Carex
Cyperaceae
TP
7
Eragrostis pilosa
Eragrostis
Poaceae
TP
7
Kalimeris hispida
Kalimeris
Compositae
TP
7
Kobresia pygmaea
Kobresia
Cyperaceae
TP
7
Lagotis brachystachya
Lagotis
Plantaginaceae
TP
7
Lasiocaryum densiflorum
Lasiocaryum
Boraginaceae
TP
7
Leontopodium leontopodinum
Leontopodium
Compositae
TP
7
Lepidium capitatum
Lepidium
Brassicaceae
TP
7
Poa annua
Poa
Poaceae
TP
7
Polygonum sibiricum
Polygonum
Polygonaceae
TP
7
Potentilla parvifolia
Potentilla
Rosaceae
TP
7
Potentilla plumosa
Potentilla
Rosaceae
TP
7
Pycnoplinthus uniflora
Pycnoplinthus
Brassicaceae
TP
7
Sibbaldia parviflora
Sibbaldia
Rosaceae
TP
7
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
7
Stipa purpurea
Stipa
Poaceae
TP
7
Taraxacum mongolicum
Taraxacum
Compositae
TP
8
Artemisia desertorum
Artemisia
Compositae
TP
8
Astragalus propinquus
Astragalus
Fabaceae
TP
8
Astragalus tribulifolius
Astragalus
Fabaceae
TP
8
Carex korshinskyi
Carex
Cyperaceae
TP
8
Heteropappus boweri
Heteropappus
Compositae
TP
8
Oxytropis microphylla
Oxytropis
Fabaceae
TP
8
Poa annua
Poa
Poaceae
TP
8
Ptilotrichum canescens
Ptilotrichum
Brassicaceae
TP
8
Stipa capillata
Stipa
Poaceae
TP
9
Artemisia desertorum
Artemisia
Compositae
TP
9
Astragalus hendersonii
Astragalus
Fabaceae
TP
9
Carex korshinskyi
Carex
Cyperaceae
TP
9
Oxytropis glacialis
Oxytropis
Fabaceae
TP
9
Oxytropis microphylla
Oxytropis
Fabaceae
TP
9
Ptilotrichum canescens
Ptilotrichum
Brassicaceae
TP
9
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
9
Stipa tianschanica
Stipa
Poaceae
TP
10
Stipa tianschanica
Stipa
Poaceae
TP
10
Ajania fruticulosa
Ajania
Compositae
TP
10
Oxytropis microphylla
Oxytropis
Fabaceae
-
AC2: 'Reply on CC2', Xue-Fa Wen, 14 Jul 2022
-
RC1: 'Comment on bg-2022-50', Anonymous Referee #1, 01 May 2022
I enjoyed reading this succinct and interesting paper on the variations in the oxygen isotope composition of dry grasslands in China. In my opinion the key novel finding of this study is that leaf oxygen isotopic enrichment above source water (D18O) in multi-species grasslands consistently increases with aridity in three distant plateaus with contrasting dry climates. This is quite an impressive database on the oxygen isotopic composition of multiple grass species exposed to different climates, and the results are interesting, novel and compelling. However, I have several important suggestions for further improvement, which I hope the authors will find useful and reasonable.
- I think this paper would greatly benefit from the inclusion of a more open, thorough and detailed description of the raw bulk leaf d18O, LA and SLA data obtained in the different regions, including additional figures depicting this basic information. Readers interested in the oxygen isotope composition of plants in general will surely want to see the raw leaf d18O data, as well as more detailed data on the d18O composition of rainfall water in the different regions (amount-weighed annual averages, range of values, etc). These data were used to estimate D18Oenrichment in the different sampling sites, so it is important to report these basic raw data as well. I would also like to see the averages, ranges of values, standard deviations, etc of the leaf d18O, SLA and LA values of the different grass species sampled in each region, as well as a listing of grass species names in each plateau. The detailed species listing could be included as Supporting Information material, but it is still important to provide this basic information for each plateau/climate region separately. Ideally, all this important descriptive information could be synthesized in 1 or 2 additional figures (or tables) that should be provided at the beginning of the Results section. Also, please briefly comment in the Discussion how your leaf d18O and D18Oenrichment range of values compares to other datasets previously published in the literature, especially for arid and semiarid grasslands (in both China and elsewhere across world dryland ecosystems).
- The paper would also benefit from a more open acknowledgement that rainwater d18O is only a (reasonable) proxy of topsoil water d18O, which is the real source of water used by most grass species. Evaporative isotopic enrichment of soil water in upper soil layers during prolonged rainless periods in dryland ecosystems usually results in heavy enrichment in the 18O in the remaining soil water used by plants. Longer rainless periods and heavier evaporative enrichment of soil water in the drier sites along the aridity gradient could be also contributing to the reported patterns, but this questions is not addressed in the paper. I would appreciate the inclusion of a few sentences in the Discussion to address this caveat of the study. Despite this criticism, I admit that the approach used by the authors to estimate D18Oenrichment is legitimate, in the absence of data on culm water isotopic composition in each species (which I am assuming is not available). However, the readers should be aware that interspecific differences in rooting and water acquisition depth and phenology among coexisting grass species can lead to substantial differences in the isotopic composition of their water sources, which cannot be detected with the approach used in the present study (even though they will certainly affect the real d18O and D18Ovalues of the different species). This should also be mentioned and discussed in the paper.
- Important data are missing from the M&M section, including the elevation/altitude, mean annual rainfall d18O, mean annual VPD, and LMA, LA (average, range of values) of the 3 different plateaus. This important information could be provided by adding additional panels to Figure 1. Please also add an additional panel for mean annual temperature (the one shown is for mean summer temperature). In panel f, please enhance the scale and resolution of the Y axis, as some of the drier sites in the Tibetan Plateau appear to have extremely low precipitation values that are hard to interpret in the graph.
- I would recommend the authors to discuss the influence of temperature on leaf d18O and D18Oenrichment data much more in depth, according to earlier findings of Brent Helliker and collaborators, which I think are very relevant here (Helliker & Richter 2008 Nature, Song et al.,2011 New Phytologist).
- L83-90: Some of the references cited in this section may not be very adequate if they refer to the d18O of tree rings, which is a more complicated process influenced by other factors (post-photosinthetic and photosynthate transport processes, ligning synthesis, etc). I would recommend to cite here only papers dealing specifically with the d18O and/or D18Oenrichment of bulk leaves, which is the topic of the present paper (e.g. see Ramirez et al 2009 Plant Cell Environ or the work by Margaret Barbour, Regina Hirl or Cabrera-Bosquet and Araus). Also, some of the references cited in this section appear to be missing from the References section (Levesque, Keitel?).
- Lines 266-274: this section dealing with the relationships between SLA and leaf oxygen isotopes is very confusing and hard to interpret. Please try to better clarify the nature of this relationship in the different plateaus, preferably illustrating it with some additional graphs (1/D18Oenrichment vs SLA plots?). To the best of my knowledge, this relationship was first examined in depth by Prieto et al 2018 (Functional Ecology) in dry grassland species, so it would be interesting to compare and discuss the patterns encountered in both studies.
- L226: “and viceversa” is confusing and hard to interpret, please elaborate and explain what you mean here.
- L269-270: I don’t understand the term “high heat capacity” used in this sentence, please clarify.
- L16: this sentence is confusing and difficult to understand, please rephrase and clarify what you mean here.
- L51: I think this sentence is inaccurate, as it is indeed possible to measure the leaf gas exchange rates of whole canopies using the appropriate methods (e.g. see Liberati et al 2021 Global Change Biology).
- L78-79: Please rephrase and clarify your second hypothesis, it is difficult to understand.
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AC4: 'Response to reviewer1', Xue-Fa Wen, 14 Jul 2022
Response to reviews of manuscript “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” bg-2022-50
Response to reviewer#1
Dear Reviewer,
We would like to thank you for the thoughtful and valuable comments and suggestions on our manuscript entitled “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” (bg-2022-50). We have carefully revised our manuscript to take account of your comments and suggestions. Meanwhile, we have rephrased our manuscript title as “Excess radiation exacerbates drought stress impacts on canopy conductance along aridity gradients”.Here are the point-to-point responses (responses in upright Roman in black front) to the comments (original queries in Italic in blue front). The changed figures and tables are presented in the Appendix 1 and Appendix 2 (listed at the end of the “Response to reviewer#1”).General comments:
1) I think this paper would greatly benefit from the inclusion of a more open, thorough and detailed description of the raw bulk leaf d18O, LA and SLA data obtained in the different regions, including additional figures depicting this basic information. Readers interested in the oxygen isotope composition of plants in general will surely want to see the raw leaf d18O data, as well as more detailed data on the d18O composition of rainfall water in the different regions (amount-weighed annual averages, range of values, etc). These data were used to estimate D18Oenrichment in the different sampling sites, so it is important to report these basic raw data as well. I would also like to see the averages, ranges of values, standard deviations, etc of the leaf d18O, SLA and LA values of the different grass species sampled in each region, as well as a listing of grass species names in each plateau. The detailed species listing could be included as Supporting Information material, but it is still important to provide this basic information for each plateau/climate region separately. Ideally, all this important descriptive information could be synthesized in 1 or 2 additional figures (or tables) that should be provided at the beginning of the Results section. Also, please briefly comment in the Discussion how your leaf d18O and D18Oenrichment range of values compares to other datasets previously published in the literature, especially for arid and semiarid grasslands (in both China and elsewhere across world dryland ecosystems).
Response: Thank you very much for your valuable comments. Major revisions have been made as follows:(1) The patterns of raw leaf δ18O and △18O at species level along aridity gradient were added as an additional figure in “Supplementary 1” (Please see Appendix 1, Fig.S2). Meanwhile, characteristics (e.g. values of average, maximum, minimum, standard deviation and coefficient of variation of co-occurring species) of leaf δ18O and △18O at species level for sampling sites in Loess (LP), Inner Mongolia (MP), and Tibetan (TP) Plateau were added as an additional Table in “Supplementary 1” (Please see Appendix 1, Table S2). The values △18O of each community and amount weighted δ18O of precipitation have been listed in Table S1 (Please see Appendix 1, Table S1). Patterns of community LA and SLA among transects have been presented in Fig.1 (Please see Appendix 1, Fig.1).
(2) Information of coexisting species in each community have been listed in “Supplementary 2” (Please see Appendix 2)”.
(3) In “Discussion” section, we compared the community △18O with a study conducted in arid and semiarid grassland: “The community △18O ranges from 26.82‰ to 34.60‰ in Loess Plateau (LP), 32.28‰ to 36.17‰ in Inner Mongolia Plateau (MP), and 31.52‰ to 42.34‰ in Tibetan Plateau (TP) (Fig.2a, Table S1). Compared to a previous study conducted in a temperate grassland (mean annual precipitation was 753 mm) (28.2‰~30.53‰) (Hirl et al. 2021), the community △18O in this study was relative high. It indicated that the canopy conductance (Gs), presented by community 1/△18O, was relative low in this study. ”.
2) The paper would also benefit from a more open acknowledgement that rainwater d18O is only a (reasonable) proxy of topsoil water d18O, which is the real source of water used by most grass species. Evaporative isotopic enrichment of soil water in upper soil layers during prolonged rainless periods in dryland ecosystems usually results in heavy enrichment in the 18O in the remaining soil water used by plants. Longer rainless periods and heavier evaporative enrichment of soil water in the drier sites along the aridity gradient could be also contributing to the reported patterns, but this questions is not addressed in the paper. I would appreciate the inclusion of a few sentences in the Discussion to address this caveat of the study. Despite this criticism, I admit that the approach used by the authors to estimate D18Oenrichment is legitimate, in the absence of data on culm water isotopic composition in each species (which I am assuming is not available). However, the readers should be aware that interspecific differences in rooting and water acquisition depth and phenology among coexisting grass species can lead to substantial differences in the isotopic composition of their water sources, which cannot be detected with the approach used in the present study (even though they will certainly affect the real d18O and D18Ovalues of the different species). This should also be mentioned and discussed in the paper.
Response: Thanks very much for your comments and suggestions. We respond these comments from three aspects.(1) In section “4 Discussion”, we clarified that “Interspecific differences in rooting and water acquisition depth and phenology among coexisting species can lead to substantial differences in the δ18O of their water sources (Moreno-Gutierrez et al. 2012). Previous studies found that the water uptake depths of co-occurring species in grassland are commonly occurred in shallow soil layers throughout dry and wet periods (Bachmann et al. 2015; Hirl et al. 2019; Prieto et al. 2018). The differences in water acquisition depth could be ruled out as a major source of interspecific variation in leaf δ18O (Prieto et al. 2018).”
(2) In “2 Materials and methods” section, we clarified that: “Generally, data on long-term stem water isotopic composition in each species were not available. As precipitation was the only or mainly source water in dryland ecosystems, we assumed the amount-weighted δ18O of precipitation during growing season can reflect the δ18O of source water (Guerrieri et al. 2019; Maxwell et al. 2018). δ18O of monthly precipitation at each site was simulated using longitude, latitude, and elevation according to (Bowen et al. 2005).”
(3) In section “4 Discussion”, we also clarified that: “However, soil evaporation always exhibited increasing trends with the increasing aridity, and usually resulted in heavy enrichment in δ18O in the remaining soil water used by plants (Lyu et al. 2021). Longer rainless periods and heavier evaporative enrichment of soil water along the aridity gradient could be also contributing to the decreasing trend of community 1/△18O. Our results may overestimate the decreasing trend of Gs along the aridity gradient.”
3) Important data are missing from the M&M section, including the elevation/altitude, mean annual rainfall d18O, mean annual VPD, and LMA, LA (average, range of values) of the 3 different plateaus. This important information could be provided by adding additional panels to Figure 1. Please also add an additional panel for mean annual temperature (the one shown is for mean summer temperature). In panel f, please enhance the scale and resolution of the Y axis, as some of the drier sites in the Tibetan Plateau appear to have extremely low precipitation values that are hard to interpret in the graph.
Response: Thank you very much for your comments and suggestions. We respond these comments from three aspects:(1) Values of longitude, latitude, altitude, mean annual and growing season values of abiotic variables (e.g. temperature, precipitation, VPD and soil moisture), δ18O of precipitation, and community △18O for sampling sites along the aridity gradient were added in Table S1 (Please see Appendix 1, Table S1).(2) Values of average, maximum, minimum, standard deviation and coefficient of variation of geographic and climatic information for transects were presented in Table S2 (Please see Appendix 1, Table S2).
(3) Changes in growing season climatic variables and community properties (leaf area and specific leaf area) among three transects were added as Figure 1 (Please see Appendix 1, Figure 1). Changes in mean annual precipitation, VPD, solar radiation, and temperature among three transects were added as Figure S2 (Please see Appendix 1, Figure S2).
(4) I would recommend the authors to discuss the influence of temperature on leaf d18O and D18Oenrichment data much more in depth, according to earlier findings of Brent Helliker and collaborators, which I think are very relevant here (Helliker & Richter 2008 Nature, Song et al.,2011 New Phytologist).
Response: Thank you very much for your comment. We discussed the effect of temperature on △18O in section “4.4 Using community-weighted 1/△18O as an indicator of canopy conductance” :
“The decreasing trend of community △18O along aridity may originated from temperature and VPD through their effects on evaporation and isotopic exchange between water and organic molecules (Barbour & Farquhar 2000; Helliker & Richter 2008; Song et al. 2011). For example, the equilibrium fractionation factor for water evaporation is depend on temperature (Bottinga & Craig 1968). Temperature and VPD gradients between leaf and ambient air influence the evaporative gradient from leaf to air (Helliker & Richter 2008; Song et al. 2011). In addition, biochemical 18O-fractionation during cellulose synthesis is sensitive to temperature, and the proportion of oxygen in cellulose derived from source water was humidity-sensitive (Hirl et al. 2021).
The potential effects of temperature and VPD on △18O via evaporation and isotopic exchange between water and organic molecules could be ruled out in this study. The growing season temperature variation was small along three transects (LP=3.3 °C, MP=4.9 °C, and TP=3.8 °C) (Table S1). However, the range of community △18O was 7.78‰ in LP, 3.89‰ in MP, and 6.17‰in TP (Table S1, Fig.2a). Previous studies demonstrated that the sensitivity of temperature to △18O was approximately 0.23‰/℃ (Helliker & Richter 2008; Song et al. 2011). It seems that the changes in temperature was not a main contributor to the large variability in community △18O. Meanwhile, positive relationship between community 1/△18O and temperature was observed in LP (P<0.05), and negative relationship between community 1/△18O and VPD was observed in TP (Table 1). However, partial correlation analyses showed that community 1/△18O was not related to temperature (P > 0.05) and VPD after controlling for Gs (Data were not shown). It indicated that the variability in community 1/△18O was mainly determined from Gs.”
Specific comments:
1) L83-90: Some of the references cited in this section may not be very adequate if they refer to the d18O of tree rings, which is a more complicated process influenced by other factors (post-photosinthetic and photosynthate transport processes, ligning synthesis, etc). I would recommend to cite here only papers dealing specifically with the d18O and/or D18Oenrichment of bulk leaves, which is the topic of the present paper (e.g. see Ramirez et al 2009 Plant Cell Environ or the work by Margaret Barbour, Regina Hirl or Cabrera-Bosquet and Araus). Also, some of the references cited in this section appear to be missing from the References section (Levesque, Keitel?).
Response: Thank you very much for your comments and suggestions. We rechecked the cited reference, corrected and rephrased this section as: “Given that leaf δ18O at species level was affected by the leaf water evaporation process, variability in gs should show up in leaf δ18O (Barbour 2007; Barbour & Farquhar 2000; Farquhar et al. 1998). Negative relationship between △18O and gs has been observed at species (Barbour & Farquhar 2000; Cabrera-Bosquet et al. 2011; Grams et al. 2007; Moreno-Gutierrez et al. 2012) and canopy scales (Cabrera et al. 2021; Hirl et al. 2021), and among communities along soil (Ramirez et al. 2009) and climate (Keitel et al. 2006) gradients. Consequently, we selected 1/△18O was used as a proxy for gs in this study. ”
2) Lines 266-274: this section dealing with the relationships between SLA and leaf oxygen isotopes is very confusing and hard to interpret. Please try to better clarify the nature of this relationship in the different plateaus, preferably illustrating it with some additional graphs (1/D18Oenrichment vs SLA plots?). To the best of my knowledge, this relationship was first examined in depth by Prieto et al 2018 (Functional Ecology) in dry grassland species, so it would be interesting to compare and discuss the patterns encountered in both studies.
Response: Thank you very much for your comment. We respond these comments from two aspects:(1) This paragraph has been corrected and rephrased as: “Our preliminary study demonstrated that gs was significantly affected by LA at species level in TP (Wang & Wen 2022). However, the effect of community LA on Gs was weak (P=0.061) (Fig.S5a), and variability in Gs along an aridity gradient was controlled by specific leaf area (SLA) (Table 1, Fig.S5b).This highlighted the difference in the biological drivers of gs at leaf and canopy scales. Contrary to the results of the dry grassland species in Mediterranean (Prieto et al. 2018) and karst communities in subtropical regions (Wang et al. 2021), community 1/△18O significantly decreased with SLA in this study (Table S1, Fig.S5). It indicated that the traditional leaf economic spectrum theory may not existed at community level in TP due to the multiple environmental stressors. SLA generally decreases with increasing solar radiation, and increases with temperature and water availability (Poorter et al. 2009). In this study, commumnity SLA was negatively related to soil moisture, and positively related to maxmium temperature (Table S5). It indicated that changes of commumnity SLA was mainly controlled by maxmium temperature. However, the direct effect of SLA on Gs in the structural equation was not significant (Fig.5c). This effect may be obscured by drought stress.”
(2) Meanwhile, relationship between community 1/△18O and LA and SLA have been added as Figure S5 (Please see Appendix 1, Figure S5).
3) L226: “and viceversa” is confusing and hard to interpret, please elaborate and explain what you mean here.
Response: Corrected and rephrased as: “In addition, a global meta-analysis demonstrated that ecosystem conductance was mainly limited by low SM in xeric sites, and by VPD in mesic sites (Novick et al. 2016).”
4) L269-270: I don’t understand the term “high heat capacity” used in this sentence, please clarify.
Response: This sentence has been deleted.
5) L16: this sentence is confusing and difficult to understand, please rephrase and clarify what you mean here.
Response: Corrected and rephrased as: “The Gs of TP was less than that of the other two plateaus due to the low temperature and high radiation.”
(6) L51: I think this sentence is inaccurate, as it is indeed possible to measure the leaf gas exchange rates of whole canopies using the appropriate methods (e.g. see Liberati et al 2021 Global Change Biology).
Response: This sentence has been deleted.
7) L78-79: Please rephrase and clarify your second hypothesis, it is difficult to understand.
Response: Thank you very much for your comment. We respond to this comment from three aspects.
(1) We clarified that “However, previous studies showed that the direction and intensity of solar radiation and temperature on gs strongly depend on their distribution range and the relationship with aridity. For example, the response of gs to solar radiation and temperature generally shows an increasing trend up to optimum values (Xu et al. 2021), while excess radiation (Costa et al. 2015; Doupis et al. 2020; Zeuthen et al. 1997) and high temperature associated high VPD or low SM (Seneviratne et al. 2010) would suppress gs.”
(2) We added the basic climatic context for the three grassland transect in the last paragraph of “1 Instruction” section: “The grassland transect span gradients of precipitation, SM, VPD, solar radiation, and temperature, provide an ideal platform for exploration of interactive effects of multiple stressors and biotic factors on Gs (Table S1). In addition, the three grassland transects experienced with different soilar radiation and temperature conditions at a given aridity, due to the difference in the geographical location of the three plateaus. The order of mean annual temperature and solar radiation is LP>MP>TP and LP<MP<TP, respectively.”
(3) We rephrased the second hypothesis as: “high solar radiation and low temperatures will jointly suppress Gs at a given aridity among transects. ”.
Appendix 1
Figure 1. Comparison of aridity (a), growing season precipitation (b), soil moisture (SM) (c), vapor pressure deficit (VPD) (d), solar radiation (SR) (e), temperature (f), maximum temperature (Tempmax) (g), and community leaf area (h) and specific leaf area (SLA) (i) among transects. LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05). Error bars indicate standard error of the mean.
Figure 2. Patterns of 1/△18O (a) along aridity gradient within transects, and among (b) transects. Different letters indicate significant differences (P < 0.001) among transects and grassland types. △18O, 18O enrichment of leaf organic matter above source water; LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau.
Figure 3. Patterns of the intercept obtained from standardized major axis analysis (SMA) among transects. VPD, vapor pressure deficit; SR, solar radiation; Tempmax, maximum temperature. LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Shaded area represents the 95% confidence interval of the SMA intercept.
Figure 4. Structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Figure 5. Structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Table 1 Pearson’s coefficients among community 1/△18O and environmental factors and plant properties.
Loess Plateau
Inner Mongolia Plateau
Tibet Plateau
Aridity
-0.848**
-0.843**
-0.773**
SM
0.719*
0.707*
0.659*
VPD
-0.554
-0.384
-0.912**
SR
-0.639*
-0.728*
-0.850**
Tempmean
0.641*
0.303
-0.670*
Tempmax
0.678*
0.038
-0.852**
LA
0.757*
0.913**
0.610
SLA
-0.519
-0.576
-0.648*
**, P<0.01; *, P<0.05. SM, soil moisture; VPD, vapor pressure deficit; SR, total solar radiation; Tempmean, mean temperature; Tempmax, maximum temperature; LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Table S1 Geographic and climatic information, δ18O of precipitation, and community △18O for sampling sites in Loess (LP), Inner Mongolia (MP), and Tibetan (TP), Plateau.
Site
Longitude
(°E)
Latitude
(°N)
Elevation
(m)
Aridity
Temperature
(℃)
Tempmax
(℃)
Precipitation
(mm)
Solar radiation
(kJ m-2 day-1)
VPD
(kPa)
SM
(m3 m-3)
δ18OP (‰)
△18O(‰)
Year
GSW
Year
GS
Year
GS
Year
GS
GS
Year
GS
LP01
113.36
36.29
804
0.57
11.85
18.19
29.6
599
546
12.95
15.60
4.78
7.53
0.16
-8.70
-6.92
26.82±0.84
LP02
112.29
35.99
894
0.60
9.96
17.60
29.2
549
501
13.31
16.04
3.57
7.41
0.17
-8.80
-6.86
28.78±1.73
LP03
111.64
35.99
833
0.64
10.66
18.61
30
520
475
12.69
15.65
4.04
8.59
0.13
-8.70
-6.79
30.30±1.77
LP04
110.18
36.07
966
0.63
10.72
18.03
29.9
519
478
14.25
17.02
4.52
8.45
0.15
-9.10
-7.09
29.68±1.00
LP05
109.24
36.74
1268
0.65
9.50
16.99
28.7
492
458
15.34
18.28
4.13
8.00
0.12
-9.20
-7.18
27.64±0.96
LP06
107.92
36.93
1383
0.68
7.46
15.71
27.8
424
394
15.32
18.31
2.53
6.44
0.12
-8.60
-6.74
28.75±1.39
LP07
107.19
37.58
1535
0.75
5.23
15.61
27.6
340
311
15.62
18.97
1.88
7.51
0.07
-7.70
-6.01
32.42±0.86
LP08
105.78
37.42
1293
0.85
5.87
16.94
28.8
222
211
15.53
18.95
2.01
8.71
0.10
-6.80
-5.08
30.77±1.95
LP09
104.92
37.44
1378
0.87
7.56
16.50
28.1
196
183
15.49
18.74
3.99
9.44
0.10
-6.30
-4.69
32.00±2.38
LP10
104.44
37.46
1714
0.87
7.71
15.31
26.8
189
179
15.56
18.77
4.75
9.06
0.10
-6.70
-4.83
34.60±1.39
Trend
0.009
0.035
0.024
<0.001
<0.001
0.012
0.005
0.445
0.058
0.007
<0.001
<0.001
NM01
123.51
44.59
144
0.68
5.10
16.60
29.6
425
410
13.67
17.28
1.11
6.98
0.17
-9.20
-7.14
32.54±0.90
NM02
121.04
44.52
269
0.73
5.80
16.66
30
393
378
14.73
18.44
2.56
8.59
0.11
-9.60
-7.52
32.49±0.71
NM03
120.33
45.11
660
0.71
3.72
13.60
27.4
387
372
14.94
18.81
2.30
6.74
0.15
-10.60
-8.36
32.28±0.65
NM04
118.36
44.77
1019
0.71
0.56
12.03
26.2
345
320
15.09
19.20
1.11
5.96
0.14
-11.40
-8.84
34.23±0.39
NM05
116.52
44.26
1129
0.77
1.17
12.27
26.2
283
267
15.21
19.35
1.53
6.50
0.11
-11.40
-8.67
34.22±1.52
NM06
116.67
43.55
1272
0.73
0.16
11.74
25.4
321
304
15.34
19.31
1.03
5.95
0.11
-11.60
-8.80
33.00±0.79
NM07
117.68
44.51
1024
0.73
1.96
12.10
26.3
319
298
14.88
18.99
1.70
5.94
0.14
-11.30
-8.56
34.31±0.37
NM08
114.89
44.01
1101
0.83
0.10
12.94
27.4
228
219
15.36
19.53
1.33
7.67
0.09
-10.40
-7.87
36.17±0.29
NM09
113.50
43.84
1022
0.86
2.47
14.20
28.3
199
190
15.59
19.76
2.49
9.00
0.06
-9.00
-7.16
35.59±0.63
NM10
112.15
43.63
955
0.88
3.69
14.87
30.1
183
169
15.35
19.57
2.96
9.46
0.06
-8.40
-6.48
35.56±0.21
Trend
0.626
0.995
0.450
<0.001
<0.001
0.026
0.018
0.104
0.015
<0.001
0.134
0.101
TP01
95.45
31.46
4104
0.40
0.41
5.70
17.2
606
572
17.76
19.94
1.71
2.61
0.19
-16.40
-14.22
31.53±1.35
TP02
93.53
31.85
4509
0.37
-1.50
3.14
15.4
593
560
17.57
20.02
1.72
2.17
0.21
-17.70
-15.86
32.25±1.65
TP03
92.01
31.64
4587
0.61
-4.37
4.40
17
430
414
18.62
20.91
1.06
3.39
0.26
-18.00
-16.50
34.00±0.17
TP04
90.74
31.38
4617
0.65
-6.76
5.89
17.8
426
414
18.99
21.41
0.34
4.27
0.17
-18.40
-16.57
39.17±1.41
TP05
89.72
31.54
4588
0.67
-3.06
6.93
19.2
426
412
18.80
21.27
1.51
4.94
0.15
-18.20
-16.39
37.77±0.51
TP06
87.82
31.87
4570
0.79
-2.57
6.77
19.2
286
261
19.27
22.01
2.18
5.50
0.15
-16.50
-14.99
39.07±1.32
TP07
85.84
31.92
4938
0.90
-3.77
3.74
17.6
125
95
19.28
22.22
2.49
4.70
0.13
-15.20
-13.71
35.54±0.74
TP08
83.34
32.41
4578
0.94
-3.90
5.71
20.1
75
62
18.99
22.08
2.32
5.77
0.11
-14.40
-12.85
38.56±1.43
TP09
81.23
32.30
4558
0.92
-3.49
5.29
19.3
102
89
19.41
22.50
2.37
5.45
0.07
-15.10
-12.78
36.99±0.51
TP10
80.15
32.48
4328
0.93
-1.27
6.73
21.5
89
78
19.86
23.12
3.10
6.33
0.09
-14.70
-12.41
42.34±0.60
Trend
0.356
0.360
0.006
<0.001
<0.001
<0.001
<0.001
0.069
<0.001
0.006
0.027
0.039
Tempmax, maximum temperature ; VPD, vapor deficit pressure; SM, soil moisture; δ18OP, the δ18O of precipitation; GSW, growing season. Trend indicates variation in variables along the aridity gradient.
Table S2 Differences in climatic variables among three transects.
Transect
Period
Mean
Standard deviation
Minimum
Maximum
P value
Aridity
LP
0.71
0.12
0.57
0.87
0.693
MP
0.76
0.07
0.68
0.88
TP
0.72
0.21
0.37
0.94
Precipitation
LP
Year
405
157
189
599
0.329
MP
308
84
183
425
TP
316
208
75
606
LP
Growing
season
374
141
179
546
0.408
MP
293
82
169
410
TP
296
204
62
572
Soil
moisture
LP
Growing
season
0.12
0.03
0.07
0.17
0.148
MP
0.11
0.04
0.06
0.17
TP
0.15
0.06
0.07
0.26
Vapor
Pressure
deficit
LP
Year
3.62a
1.10
1.88
4.78
<0.001
MP
1.81b
0.71
1.03
2.96
TP
1.88b
0.79
0.34
3.10
LP
Growing
season
8.11a
0.91
6.44
9.44
<0.001
MP
7.28a
1.33
5.94
9.46
TP
4.51b
1.39
2.17
6.33
Solar
radiation
LP
Year
14.61b
1.19
12.69
15.62
<0.001
MP
15.02b
0.54
13.67
15.59
TP
18.86a
0.72
17.57
19.86
LP
Growing
season
17.63c
1.41
15.60
18.97
<0.001
MP
19.02b
0.72
17.28
19.76
TP
21.55a
1.04
19.94
23.12
Temperature
LP
Year
8.65c
2.21
5.23
11.85
<0.001
MP
2.47b
2.04
0.10
5.80
TP
-3.03a
1.96
-6.76
0.41
LP
Growing
season
16.95c
1.16
15.31
18.61
<0.001
MP
13.70b
1.84
11.74
16.66
TP
5.43a
1.30
3.14
6.93
Maximum
temperature
LP
28.65a
1.06
26.80
30.00
<0.001
MP
27.69a
1.73
25.40
30.10
TP
18.43b
1.76
15.40
21.50
LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05).
Table S3 Characteristics of leaf δ18O and △18O at species level for sampling sites in Loess (LP), Inner Mongolia (MP), and Tibetan (TP) Plateau.
Sites
Number
Leaf δ18O
△18O
Mean
Max
Min
STD
CV
Mean
Max
Min
STD
CV
LP01
25
19.70
26.12
14.70
2.86
0.15
26.79
33.18
21.69
2.92
0.11
LP02
33
22.72
28.13
14.97
2.81
0.12
29.64
35.10
21.96
2.83
0.10
LP03
25
23.43
28.31
17.69
2.96
0.13
30.44
35.20
24.37
2.87
0.09
LP04
28
22.84
31.46
18.59
3.61
0.16
29.99
38.66
25.70
3.63
0.12
LP05
41
21.01
31.46
15.70
3.27
0.16
28.15
38.66
22.85
3.29
0.12
LP06
33
20.90
30.01
16.48
3.34
0.16
27.88
38.89
23.16
3.39
0.12
LP07
33
24.73
31.23
18.33
3.20
0.13
30.79
36.24
24.58
3.07
0.10
LP08
19
27.43
32.96
20.25
3.27
0.12
32.58
37.99
25.21
3.09
0.09
LP09
27
26.51
35.35
19.58
4.35
0.16
31.37
39.99
24.15
4.24
0.14
LP10
15
25.73
32.68
22.04
3.48
0.14
30.43
37.31
26.76
3.47
0.11
LP
279
22.69
35.35
12.07
4.42
0.19
32.29
43.89
21.69
4.4
0.14
MP01
18
23.04
29.24
17.42
3.57
0.15
30.61
36.58
24.68
3.87
0.13
MP02
37
23.48
28.73
18.69
2.26
0.10
31.18
36.44
25.87
2.21
0.07
MP03
30
23.54
30.97
19.31
2.71
0.12
31.95
39.55
27.80
2.82
0.09
MP04
17
22.85
28.10
17.46
3.25
0.14
31.83
37.13
26.41
3.26
0.10
MP05
13
26.54
31.73
22.60
2.59
0.10
35.27
40.62
31.12
2.66
0.08
MP06
22
25.85
32.65
21.14
3.25
0.13
34.62
41.68
28.42
3.47
0.10
MP07
15
24.03
27.40
21.24
2.27
0.09
32.76
36.14
29.92
2.29
0.07
MP08
22
27.59
31.71
21.71
3.05
0.11
35.57
39.73
29.65
3.08
0.09
MP09
17
28.23
31.56
23.18
2.36
0.08
35.41
39.57
30.37
2.22
0.06
MP10
12
29.16
32.33
21.36
2.90
0.10
36.13
41.23
30.04
2.65
0.07
MP
203
25.07
32.65
17.42
3.46
0.14
33.17
41.68
24.68
3.42
0.1
TP01
59
18.45
27.91
12.07
3.79
0.21
33.51
42.07
26.49
4.40
0.13
TP02
38
18.86
27.91
13.12
4.15
0.22
34.85
42.07
29.31
4.27
0.12
TP03
15
18.63
25.90
14.16
4.25
0.23
35.00
42.07
28.22
4.41
0.13
TP04
19
20.28
25.90
14.16
3.90
0.19
36.93
42.07
28.22
4.11
0.11
TP05
19
19.72
25.90
14.90
2.60
0.13
36.34
41.29
31.71
2.34
0.06
TP06
13
19.38
25.24
12.07
3.19
0.16
34.84
41.29
26.49
3.62
0.10
TP07
21
20.06
30.81
13.73
4.12
0.21
34.28
43.74
27.70
3.63
0.11
TP08
9
23.88
26.37
21.27
2.03
0.09
37.06
39.16
34.47
1.99
0.05
TP09
9
24.62
29.61
19.05
3.11
0.13
37.83
42.89
32.19
3.15
0.08
TP10
3
29.09
30.95
27.40
1.78
0.06
42.00
43.89
40.29
1.80
0.04
TP
205
19.72
30.95
12.07
4.13
0.21
35.08
43.89
26.49
4.15
0.12
Three Plateau
687
22.69
35.35
12.07
4.42
0.19
32.29
43.89
21.69
4.4
0.14
Table S4 Results of standardized major axis (SMA) line-fitting for the relationship between canopy stomatal conductance (using 1/△18O as proxy) and aridity.
Intercept
slope
r2
P
Loess Plateau
Estimate
0.047
-0.196
0.68
0.003
Lower
0.043
-0.027
Upper
0.052
-0.014
Inner Mongolia
Plateau
Estimate
0.044
-0.020
0.72
0.002
Lower
0.040
-0.027
Upper
0.049
-0.014
Tibet Plateau
Estimate
0.038
-0.015
0.60
0.008
Lower
0.034
-0.022
Upper
0.042
-0.011
Different letters indicate significant differences (P < 0.001) among transects in intercepts and slopes.
Table S5 Pearson coefficients for correlations among canopy stomatal conductance (Gs) and environmental factors and plant properties.
Transect
Variables
Gs
Aridity
Precipitation
SM
VPD
SR
MAT
MATMAX
LA
SLA
Loess Plateau
Gs
1
Aridity
-0.848**
1
Precipitation
0.856**
-.997**
1
SM
0.719*
-.781**
.795**
1
VPD
-0.554
0.616
-0.563
-0.251
1
SR
-0.639*
0.810**
-.827**
-.851**
0.217
1
Tempmean
0.641*
-0.665*
.710*
.766**
0.074
-.849**
1
Tempmax
0.678*
-0.698*
.737*
.751*
-0.026
-.795**
.980**
1
LA
.757*
-.881**
.863**
0.567
-.751*
-.637*
0.425
0.481
1
SLA
-0.519
0.460
-0.454
-0.499
0.356
0.422
-0.433
-0.483
-0.533
1
Inner Mongolia Plateau
Gs
1
Aridity
-.843**
1
Precipitation
.919**
-.945**
1
SM
.707*
-.941**
.877**
1
VPD
-0.384
.736*
-0.490
-.741*
1
SR
-.728*
.725*
-.846**
-.751*
0.196
1
Tempmean
0.303
-0.002
0.298
-0.009
.647*
-0.615
1
Tempmax
0.038
0.270
0.018
-0.235
.814**
-0.386
.943**
1
LA
.913**
-.721*
.875**
0.625
-0.218
-.731*
0.434
0.189
1
SLA
-0.576
.803**
-0.627
-.681*
.849**
0.310
0.397
0.628
-0.410
1
Tibetan Plateau
Gs
1
Aridity
-.773**
1
Precipitation
.675*
-.978**
1
SM
.659*
-.787**
.795**
1
VPD
-.912**
.931**
-.868**
-.820**
1
SR
-.850**
.963**
-.936**
-.801**
.943**
1
Tempmean
-.670*
0.325
-0.189
-0.454
0.622
0.393
1
Tempmax
-.852**
.795**
-.740*
-.795**
.935**
.832**
.760*
1
LA
0.610
-0.620
0.504
0.219
-0.624
-.658*
-0.401
-0.536
1
SLA
-.648*
0.558
-0.486
-.779**
.715*
0.516
.724*
.729*
-0.078
1
**, P<0.01; *, P<0.05. gs, stomatal conductance; SM, soil moisture; VPD, vapor pressure deficit; SR, total solar radiation; Tempmean, mean temperature; Tempmax, maximum temperature; LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Figure S1. Comparison of annual mean precipitation (mm) (a), vapor pressure deficit (VPD) (b), total solar radiation (TSR) (c), and air temperature (℃) (d) among three transects. LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05). Error bars indicate standard error of the mean.
Figure S2. Patterns of leaf δ18O and △18O at species level along aridity gradient in Loess (LP), Inner Mongolia (MP), and Tibetan (TP), Plateau. m, slope of the linear regression; b, intercept of the linear regression.
Figure S3. Hypothetical structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit.
Figure S4. Hypothetical structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
Figure S5. Relationship between community 1/△18O and log-transformed leaf area (LA) (a) and specific leaf area (SLA) (b).
Appendix 2 Information of coexisting species in each community in Loess Plateau (LP), Inner Mongolia Plateau (MP), and Tibet Plateau (TP).
Transect
Site
Species
Genus
Family
LP
1
Allium tenuissimum
Allium
Amaryllidaceae
LP
1
Artemisia annua
Artemisia
Compositae
LP
1
Artemisia scoparia
Artemisia
Compositae
LP
1
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
1
Carex korshinskyi
Carex
Cyperaceae
LP
1
Cirsium arvense
Cirsium
Compositae
LP
1
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
1
Cynanchum thesioides
Cynanchum
Apocynaceae
LP
1
Erigeron canadensis
Erigeron
Compositae
LP
1
Heteropappus altaicus
Heteropappus
Compositae
LP
1
Lespedeza bicolor
Lespedeza
Fabaceae
LP
1
Leymus chinensis
Leymus
Poaceae
LP
1
Medicago ruthenica
Medicago
Fabaceae
LP
1
Polygala tenuifolia
Polygala
Polygalaceae
LP
1
Rubia cordifolia
Rubia
Rubiaceae
LP
1
Salix gordejevii
Salix
Salicaceae
LP
1
Ulmus pumila
Ulmus
Ulmaceae
LP
1
Vicia amoena
Vicia
Fabaceae
LP
1
Viola philippica
Viola
Violaceae
LP
1
Youngia japonica
Youngia
Compositae
LP
1
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
1
Scrophulariaceae
LP
2
Heteropappus altaicus
Heteropappus
Compositae
LP
2
Agropyron cristatum
Agropyron
Poaceae
LP
2
Anemone chinensis
Anemone
Ranunculaceae
LP
2
Artemisia lavandulifolia
Artemisia
Asteraceae
LP
2
Astragalus scaberrimus
Astragalus
Fabaceae
LP
2
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
2
Caragana sinica
Caragana
Fabaceae
LP
2
Carex korshinskyi
Carex
Cyperaceae
LP
2
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
2
Cleistogenes songorica
Cleistogenes
Poaceae
LP
2
Dianthus chinensis
Dianthus
Caryophyllaceae
LP
2
Echinops sphaerocephalus
Echinops
Compositae
LP
2
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
2
Incarvillea sinensis
Incarvillea
Bignoniaceae
LP
2
Lespedeza davurica
Lespedeza
Fabaceae
LP
2
Lespedeza juncea
Lespedeza
Fabaceae
LP
2
Patrinia scabiosifolia
Patrinia
Caprifoliaceae
LP
2
Periploca sepium
Periploca
Apocynaceae
LP
2
Plantago depressa
Plantago
Plantaginaceae
LP
2
Poa annua
Poa
Poaceae
LP
2
Polygala tenuifolia
Polygala
Polygalaceae
LP
2
Potentilla supina
Potentilla
Rosaceae
LP
2
Rosa xanthina
Rosa
Rosaceae
LP
2
Rubia cordifolia
Rubia
Rubiaceae
LP
2
Saussurea japonica
Saussurea
Compositae
LP
2
Scorzonera sinensis
Scorzonera
Compositae
LP
2
Setaria viridis
Setaria
Poaceae
LP
2
Themeda triandra
Themeda
Poaceae
LP
2
Thymus mongolicus
Thymus
Lamiaceae
LP
2
Tripolium pannonicum
Tripolium
Compositae
LP
2
Viola philippica
Viola
Violaceae
LP
2
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
3
Agropyron cristatum
Agropyron
Poaceae
LP
3
Artemisia leucophylla
Artemisia
Compositae
LP
3
Astragalus scaberrimus
Astragalus
Fabaceae
LP
3
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
3
Bupleurum chinense
Bupleurum
Apiaceae
LP
3
Carex korshinskyi
Carex
Cyperaceae
LP
3
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
3
Cleistogenes songorica
Cleistogenes
Poaceae
LP
3
Echinops sphaerocephalus
Echinops
Compositae
LP
3
Heteropappus altaicus
Heteropappus
Compositae
LP
3
Lespedeza davurica
Lespedeza
Fabaceae
LP
3
Poa annua
Poa
Poaceae
LP
3
Poa sphondylodes
Poa
Poaceae
LP
3
Polygala tenuifolia
Polygala
Polygalaceae
LP
3
Potentilla discolor
Potentilla
Rosaceae
LP
3
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
3
Selaginella tamariscina
Selaginella
Selaginellaceae
LP
3
Serratula centauroides
Serratula
Compositae
LP
3
Stipa sibirica
Stipa
Poaceae
LP
3
Themeda triandra
Themeda
Poaceae
LP
3
Tripolium pannonicum
Tripolium
Compositae
LP
3
Viola philippica
Viola
Violaceae
LP
3
Vitex negundo
Vitex
Lamiaceae
LP
3
Wikstroemia chamaedaphne
Wikstroemia
Thymelaeaceae
LP
3
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
4
Agropyron cristatum
Agropyron
Poaceae
LP
4
Agropyron desertorum
Agropyron
Poaceae
LP
4
Artemisia annua
Artemisia
Compositae
LP
4
Artemisia argyi
Artemisia
Compositae
LP
4
Artemisia argyi
Artemisia
Compositae
LP
4
Artemisia dalailamae
Artemisia
Compositae
LP
4
Astragalus melilotoides
Astragalus
Fabaceae
LP
4
Astragalus scaberrimus
Astragalus
Fabaceae
LP
4
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
4
Carex korshinskyi
Carex
Cyperaceae
LP
4
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
4
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
4
Heteropappus altaicus
Heteropappus
Compositae
LP
4
Ixeris polycephala
Ixeris
Compositae
LP
4
Lespedeza bicolor
Lespedeza
Fabaceae
LP
4
Poa annua
Poa
Poaceae
LP
4
Polygala sibirica
Polygala
Polygalaceae
LP
4
Polygala tenuifolia
Polygala
Polygalaceae
LP
4
Potentilla discolor
Potentilla
Rosaceae
LP
4
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
4
Rosa xanthina
Rosa
Rosaceae
LP
4
Scorzonera sinensis
Scorzonera
Compositae
LP
4
Vicia amoena
Vicia
Fabaceae
LP
4
Viola philippica
Viola
Violaceae
LP
4
Wikstroemia chamaedaphne
Wikstroemia
Thymelaeaceae
LP
4
Yulania denudata
Yulania
Magnoliaceae
LP
4
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
5
Artemisia annua
Artemisia
Compositae
LP
5
Artemisia argyi
Artemisia
Compositae
LP
5
Artemisia frigida
Artemisia
Compositae
LP
5
Artemisia japonica
Artemisia
Compositae
LP
5
Artemisia scoparia
Artemisia
Compositae
LP
5
Astragalus scaberrimus
Astragalus
Fabaceae
LP
5
Bothriochloa ischaemum
Bothriochloa
Poaceae
LP
5
Caragana microphylla
Caragana
Fabaceae
LP
5
Carduus nutans
Carduus
Compositae
LP
5
Cirsium arvense
Cirsium
Compositae
LP
5
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
5
Cleistogenes serotina
Cleistogenes
Poaceae
LP
5
Cynanchum thesioides
Cynanchum
Apocynaceae
LP
5
Dracocephalum moldavica
Dracocephalum
Lamiaceae
LP
5
Eragrostis pilosa
Eragrostis
Poaceae
LP
5
Erigeron annuus
Erigeron
Compositae
LP
5
Glycyrrhiza uralensis
Glycyrrhiza
Fabaceae
LP
5
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
5
Incarvillea sinensis
Incarvillea
Bignoniaceae
LP
5
Ixeris polycephala
Ixeris
Compositae
LP
5
Kalimeris hispida
Kalimeris
Compositae
LP
5
Koeleria pyramidata
Koeleria
Poaceae
LP
5
Lespedeza davurica
Lespedeza
Fabaceae
LP
5
Lespedeza juncea
Lespedeza
Fabaceae
LP
5
Leymus chinensis
Leymus
Poaceae
LP
5
Oxytropis myriophylla
Oxytropis
Fabaceae
LP
5
Poa annua
Poa
Poaceae
LP
5
Poa sphondylodes
Poa
Poaceae
LP
5
Polygala sibirica
Polygala
Polygalaceae
LP
5
Potentilla supina
Potentilla
Rosaceae
LP
5
Potentilla tanacetifolia
Potentilla
Rosaceae
LP
5
Rubia cordifolia
Rubia
Rubiaceae
LP
5
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
5
Sonchus arvensis
Sonchus
Compositae
LP
5
Taraxacum mongolicum
Taraxacum
Compositae
LP
5
Tripolium pannonicum
Tripolium
Compositae
LP
5
Viola philippica
Viola
Violaceae
LP
5
Ziziphus jujuba
Ziziphus
Rhamnaceae
LP
6
Allium senescens
Allium
Liliaceae
LP
6
Anemone chinensis
Anemone
Ranunculaceae
LP
6
Artemisia argyi
Artemisia
Compositae
LP
6
Artemisia japonica
Artemisia
Compositae
LP
6
Astragalus scaberrimus
Astragalus
Fabaceae
LP
6
Carduus nutans
Carduus
Compositae
LP
6
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
6
Cleistogenes serotina
Cleistogenes
Poaceae
LP
6
Echinops sphaerocephalus
Echinops
Compositae
LP
6
Elymus dahuricus
Elymus
Poaceae
LP
6
Imperata cylindrica
Imperata
Poaceae
LP
6
Kalimeris hispida
Kalimeris
Compositae
LP
6
Lappula myosotis
Lappula
Boraginaceae
LP
6
Leontopodium leontopodinum
Leontopodium
Compositae
LP
6
Lespedeza bicolor
Lespedeza
Fabaceae
LP
6
Linum usitatissimum
Linum
Linaceae
LP
6
Medicago ruthenica
Medicago
Fabaceae
LP
6
Patrinia heterophylla
Patrinia
Caprifoliaceae
LP
6
Phlomoides umbrosa
Phlomoides
Lamiaceae
LP
6
Phragmites australis
Phragmites
Poaceae
LP
6
Poa sphondylodes
Poa
Poaceae
LP
6
Polygala tenuifolia
Polygala
Polygalaceae
LP
6
Potentilla chinensis
Potentilla
Rosaceae
LP
6
Potentilla sericea
Potentilla
Rosaceae
LP
6
Ranunculus japonicus
Ranunculus
Ranunculaceae
LP
6
Rubia cordifolia
Rubia
Rubiaceae
LP
6
Setaria viridis
Setaria
Poaceae
LP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
6
Sonchus arvensis
Sonchus
Compositae
LP
6
Stipa bungeana
Stipa
Poaceae
LP
6
Stipa capillata
Stipa
Poaceae
LP
6
Taraxacum mongolicum
Taraxacum
Compositae
LP
6
Tripolium pannonicum
Tripolium
Compositae
LP
7
Agropyron cristatum
Agropyron
Poaceae
LP
7
Artemisia argyi
Artemisia
Compositae
LP
7
Artemisia scoparia
Artemisia
Compositae
LP
7
Astragalus adsurgens
Astragalus
Fabaceae
LP
7
Astragalus galactites
Astragalus
Fabaceae
LP
7
Astragalus melilotoides
Astragalus
Fabaceae
LP
7
Astragalus propinquus
Astragalus
Fabaceae
LP
7
Bassia scoparia
Bassia
Amaranthaceae
LP
7
Carex korshinskyi
Carex
Cyperaceae
LP
7
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
7
Cleistogenes songorica
Cleistogenes
Poaceae
LP
7
Convolvulus arvensis
Convolvulus
Convolvulaceae
LP
7
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
LP
7
Haplophyllum dauricum
Haplophyllum
Rutaceae
LP
7
Heteropappus altaicus
Heteropappus
Compositae
LP
7
Ixeris polycephala
Ixeris
Compositae
LP
7
Koeleria pyramidata
Koeleria
Poaceae
LP
7
Lespedeza bicolor
Lespedeza
Fabaceae
LP
7
Leymus chinensis
Leymus
Poaceae
LP
7
Medicago ruthenica
Medicago
Fabaceae
LP
7
Medicago sativa
Medicago
Fabaceae
LP
7
Melilotus albus
Melilotus
Leguminosae
LP
7
Polygonum sibiricum
Polygonum
Polygonaceae
LP
7
Scorzonera sinensis
Scorzonera
Compositae
LP
7
Setaria viridis
Setaria
Poaceae
LP
7
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
LP
7
Sonchus arvensis
Sonchus
Compositae
LP
7
Stipa capillata
Stipa
Poaceae
LP
7
Stipa splendens
Stipa
Poaceae
LP
7
Suaeda glauca
Suaeda
Amaranthaceae
LP
7
Taraxacum mongolicum
Taraxacum
Compositae
LP
7
Thermopsis lanceolata
Thermopsis
Fabaceae
LP
8
Allium tenuissimum
Allium
Amaryllidaceae
LP
8
Alopecurus aequalis
Alopecurus
Poaceae
LP
8
Artemisia scoparia
Artemisia
Compositae
LP
8
Astragalus galactites
Astragalus
Fabaceae
LP
8
Astragalus propinquus
Astragalus
Fabaceae
LP
8
Bassia dasyphylla
Bassia
Amaranthaceae
LP
8
Carex korshinskyi
Carex
Cyperaceae
LP
8
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
8
Convolvulus ammannii
Convolvulus
Convolvulaceae
LP
8
Echinochloa crus-galli
Echinochloa
Poaceae
LP
8
Eragrostis pilosa
Eragrostis
Poaceae
LP
8
Peganum harmala
Peganum
Nitrariaceae
LP
8
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
8
Stipa capillata
Stipa
Poaceae
LP
8
Tragus racemosus
Tragus
Poaceae
LP
8
Tribulus terrestris
Tribulus
Zygophyllaceae
LP
8
Zygophyllum mucronatum
Zygophyllum
Zygophyllaceae
LP
9
Allium mongolicum
Allium
Amaryllidaceae
LP
9
Allium polyrhizum
Allium
Amaryllidaceae
LP
9
Artemisia annua
Artemisia
Compositae
LP
9
Artemisia argyi
Artemisia
Compositae
LP
9
Artemisia capillaris
Artemisia
Compositae
LP
9
Artemisia scoparia
Artemisia
Compositae
LP
9
Asparagus cochinchinensis
Asparagus
Asparagaceae
LP
9
Astragalus galactites
Astragalus
Fabaceae
LP
9
Caragana stenophylla
Caragana
Fabaceae
LP
9
Chloris virgata
Chloris
Poaceae
LP
9
Cleistogenes hackelii
Cleistogenes
Poaceae
LP
9
Convolvulus ammannii
Convolvulus
Convolvulaceae
LP
9
Convolvulus arvensis
Convolvulus
Convolvulaceae
LP
9
Convolvulus tragacanthoides
Convolvulus
Convolvulaceae
LP
9
Echinochloa crus-galli
Echinochloa
Poaceae
LP
9
Euphorbia humifusa
Euphorbia
Euphorbiaceae
LP
9
Heteropappus altaicus
Heteropappus
Compositae
LP
9
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
9
Salsola collina
Salsola
Amaranthaceae
LP
9
Salsola passerina
Salsola
Amaranthaceae
LP
9
Stipa capillata
Stipa
Poaceae
LP
9
Suaeda glauca
Suaeda
Amaranthaceae
LP
9
Tribulus terrestris
Tribulus
Zygophyllaceae
LP
9
Zygophyllum mucronatum
Zygophyllum
Zygophyllaceae
LP
10
Heteropappus altaicus
Heteropappus
Compositae
LP
10
Lepidium apetalum
Lepidium
Brassicaceae
LP
10
Saussurea japonica
Saussurea
Compositae
LP
10
Alopecurus aequalis
Alopecurus
Poaceae
LP
10
Artemisia ordosica
Artemisia
Compositae
LP
10
Reaumuria soongarica
Reaumuria
Tamaricaceae
LP
10
Eragrostis pilosa
Eragrostis
Poaceae
LP
10
Allium polyrhizum
Allium
Amaryllidaceae
LP
10
Suaeda glauca
Suaeda
Amaranthaceae
LP
10
Alopecurus aequalis
Alopecurus
Poaceae
LP
10
Chenopodium album
Chenopodium
Amaranthaceae
LP
10
Carex korshinskyi
Carex
Cyperaceae
LP
10
Artemisia capillaris
Artemisia
Compositae
LP
10
Salsola passerina
Salsola
Amaranthaceae
LP
10
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
1
Heteropappus altaicus
Heteropappus
Compositae
MP
1
Echinochloa crus-galli
Echinochloa
Poaceae
MP
1
Setaria viridis
Setaria
Poaceae
MP
1
Incarvillea sinensis
Incarvillea
Bignoniaceae
MP
1
Artemisia ordosica
Artemisia
Compositae
MP
1
Chloris virgata
Chloris
Poaceae
MP
1
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
1
Bassia scoparia
Bassia
Amaranthaceae
MP
1
Lactuca sativa
Lactuca
Compositae
MP
1
Phragmites australis
Phragmites
Poaceae
MP
1
Medicago sativa
Medicago
Fabaceae
MP
1
Carex korshinskyi
Carex
Cyperaceae
MP
1
Calystegia pellita
Calystegia
Convolvulaceae
MP
1
Polygonum sibiricum
Polygonum
Polygonaceae
MP
1
Leymus chinensis
Leymus
Poaceae
MP
1
Artemisia sphaerocephala
Artemisia
Compositae
MP
1
Aeluropus littoralis
Aeluropus
Poaceae
MP
1
Medicago sativa
Medicago
Fabaceae
MP
2
Adenophora stricta
Adenophora
Campanulaceae
MP
2
Agropyron cristatum
Agropyron
Poaceae
MP
2
Allium anisopodium
Allium
Amaryllidaceae
MP
2
Allium ramosum
Allium
Amaryllidaceae
MP
2
Amethystea caerulea
Amethystea
Lamiaceae
MP
2
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
2
Artemisia desertorum
Artemisia
Compositae
MP
2
Artemisia lavandulifolia
Artemisia
Asteraceae
MP
2
Artemisia sieversiana
Artemisia
Compositae
MP
2
Artemisia sphaerocephala
Artemisia
Compositae
MP
2
Atraphaxis manshurica
Atraphaxis
Polygonaceae
MP
2
Carex pediformis
Carex
Cyperaceae
MP
2
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
2
Chloris virgata
Chloris
Poaceae
MP
2
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
2
Clematis hexapetala
Clematis
Ranunculaceae
MP
2
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
2
Cynanchum thesioides
Cynanchum
Apocynaceae
MP
2
Dysphania aristata
Dysphania
Amaranthaceae
MP
2
Enneapogon desvauxii
Enneapogon
Poaceae
MP
2
Ephedra sinica
Ephedra
Ephedraceae
MP
2
Eriochloa villosa
Eriochloa
Poaceae
MP
2
Erodium stephanianum
Erodium
Geraniaceae
MP
2
Euphorbia humifusa
Euphorbia
Euphorbiaceae
MP
2
Glycyrrhiza uralensis
Glycyrrhiza
Fabaceae
MP
2
Iris tenuifolia
Iris
Iridaceae
MP
2
Lespedeza davurica
Lespedeza
Fabaceae
MP
2
Medicago ruthenica
Medicago
Fabaceae
MP
2
Phragmites australis
Phragmites
Poaceae
MP
2
Salsola collina
Salsola
Amaranthaceae
MP
2
Serratula centauroides
Serratula
Compositae
MP
2
Setaria viridis
Setaria
Poaceae
MP
2
Stipa capillata
Stipa
Poaceae
MP
2
Stipa sibirica
Stipa
Poaceae
MP
2
Thalictrum squarrosum
Thalictrum
Ranunculaceae
MP
2
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
3
Allium tenuissimum
Allium
Amaryllidaceae
MP
3
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
3
Artemisia annua
Artemisia
Compositae
MP
3
Artemisia lavandulifolia
Artemisia
Asteraceae
MP
3
Astragalus adsurgens
Astragalus
Fabaceae
MP
3
Astragalus propinquus
Astragalus
Fabaceae
MP
3
Carex korshinskyi
Carex
Cyperaceae
MP
3
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
3
Convolvulus arvensis
Convolvulus
Convolvulaceae
MP
3
Eriochloa villosa
Eriochloa
Poaceae
MP
3
Erodium stephanianum
Erodium
Geraniaceae
MP
3
Euphorbia humifusa
Euphorbia
Euphorbiaceae
MP
3
Gerbera anandria
Gerbera
Compositae
MP
3
Heteropappus altaicus
Heteropappus
Compositae
MP
3
Leontopodium leontopodinum
Leontopodium
Compositae
MP
3
Lespedeza davurica
Lespedeza
Fabaceae
MP
3
Lespedeza juncea
Lespedeza
Fabaceae
MP
3
Leymus chinensis
Leymus
Poaceae
MP
3
Linum stelleroides
Linum
Linaceae
MP
3
Miscanthus sacchariflorus
Miscanthus
Poaceae
MP
3
Polygala tenuifolia
Polygala
Polygalaceae
MP
3
Polygonum divaricatum
Polygonum
Polygonaceae
MP
3
Potentilla betonicifolia
Potentilla
Rosaceae
MP
3
Potentilla verticillaris
Potentilla
Rosaceae
MP
3
Salsola collina
Salsola
Amaranthaceae
MP
3
Sanguisorba officinalis
Sanguisorba
Rosaceae
MP
3
Serratula centauroides
Serratula
Compositae
MP
3
Stipa sibirica
Stipa
Poaceae
MP
3
Thalictrum petaloideum
Thalictrum
Ranunculaceae
MP
4
Agropyron cristatum
Agropyron
Poaceae
MP
4
Allium bidentatum
Allium
Amaryllidaceae
MP
4
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
4
Bassia prostrata
Bassia
Amaranthaceae
MP
4
Carex korshinskyi
Carex
Cyperaceae
MP
4
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
4
Dysphania aristata
Dysphania
Amaranthaceae
MP
4
Iris tenuifolia
Iris
Iridaceae
MP
4
Koeleria pyramidata
Koeleria
Poaceae
MP
4
Lappula myosotis
Lappula
Boraginaceae
MP
4
Leymus chinensis
Leymus
Poaceae
MP
4
Medicago ruthenica
Medicago
Fabaceae
MP
4
Potentilla acaulis
Potentilla
Rosaceae
MP
4
Salsola collina
Salsola
Amaranthaceae
MP
4
Scorzonera sinensis
Scorzonera
Compositae
MP
4
Stipa capillata
Stipa
Poaceae
MP
4
Veratrum nigrum
Veratrum
Melanthiaceae
MP
5
Allium anisopodium
Allium
Amaryllidaceae
MP
5
Agropyron cristatum
Agropyron
Poaceae
MP
5
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
5
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
5
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
5
Artemisia frigida
Artemisia
Compositae
MP
5
Bassia prostrata
Bassia
Amaranthaceae
MP
5
Carex korshinskyi
Carex
Cyperaceae
MP
5
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
5
Allium tenuissimum
Allium
Amaryllidaceae
MP
5
Leymus chinensis
Leymus
Poaceae
MP
5
Stipa capillata
Stipa
Poaceae
MP
5
Salsola collina
Salsola
Amaranthaceae
MP
6
Agropyron cristatum
Agropyron
Poaceae
MP
6
Cleistogenes squarrosa
Cleistogenes
Poaceae
MP
6
Ephedra sinica
Ephedra
Ephedraceae
MP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
MP
6
Allium condensatum
Allium
Amaryllidaceae
MP
6
Artemisia annua
Artemisia
Compositae
MP
6
Chenopodium glaucum
Chenopodium
Amaranthaceae
MP
6
Artemisia frigida
Artemisia
Compositae
MP
6
Bassia prostrata
Bassia
Amaranthaceae
MP
6
Thermopsis lanceolata
Thermopsis
Fabaceae
MP
6
Koeleria pyramidata
Koeleria
Poaceae
MP
6
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
MP
6
Carex korshinskyi
Carex
Cyperaceae
MP
6
Allium tenuissimum
Allium
Amaryllidaceae
MP
6
Iris tenuifolia
Iris
Iridaceae
MP
6
Leymus chinensis
Leymus
Poaceae
MP
6
Allium ramosum
Allium
Amaryllidaceae
MP
6
Stipa sibirica
Stipa
Poaceae
MP
6
Poa annua
Poa
Poaceae
MP
6
Stipa capillata
Stipa
Poaceae
MP
6
Axyris amaranthoides
Axyris
Amaranthaceae
MP
6
Salsola collina
Salsola
Amaranthaceae
MP
7
Agropyron cristatum
Agropyron
Poaceae
MP
7
Scutellaria scordiifolia
Scutellaria
Lamiaceae
MP
7
Astragalus melilotoides
Astragalus
Fabaceae
MP
7
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
7
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
MP
7
Koeleria pyramidata
Koeleria
Poaceae
MP
7
Astragalus galactites
Astragalus
Fabaceae
MP
7
Allium bidentatum
Allium
Amaryllidaceae
MP
7
Carex korshinskyi
Carex
Cyperaceae
MP
7
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
7
Allium tenuissimum
Allium
Amaryllidaceae
MP
7
Iris tenuifolia
Iris
Iridaceae
MP
7
Leymus chinensis
Leymus
Poaceae
MP
7
Stipa capillata
Stipa
Poaceae
MP
7
Anemarrhena asphodeloides
Anemarrhena
Asparagaceae
MP
8
Heteropappus altaicus
Heteropappus
Compositae
MP
8
Agropyron cristatum
Agropyron
Poaceae
MP
8
Cymbaria daurica
Cymbaria
Orobanchaceae
MP
8
Artemisia annua
Artemisia
Compositae
MP
8
Chenopodium acuminatum
Chenopodium
Amaranthaceae
MP
8
Allium polyrhizum
Allium
Amaryllidaceae
MP
8
Artemisia frigida
Artemisia
Compositae
MP
8
Asparagus schoberioides
Asparagus
Asparagaceae
MP
8
Bassia prostrata
Bassia
Amaranthaceae
MP
8
Astragalus galactites
Astragalus
Fabaceae
MP
8
Allium bidentatum
Allium
Amaryllidaceae
MP
8
Carex korshinskyi
Carex
Cyperaceae
MP
8
Cleistogenes hackelii
Cleistogenes
Poaceae
MP
8
Allium tenuissimum
Allium
Amaryllidaceae
MP
8
Iris tenuifolia
Iris
Iridaceae
MP
8
Leymus chinensis
Leymus
Poaceae
MP
8
Allium ramosum
Allium
Amaryllidaceae
MP
8
Convolvulus ammannii
Convolvulus
Convolvulaceae
MP
8
Stipa capillata
Stipa
Poaceae
MP
8
Neopallasia pectinata
Neopallasia
Compositae
MP
8
Salsola collina
Salsola
Amaranthaceae
MP
9
Artemisia argyi
Artemisia
Compositae
MP
9
Scorzonera sinensis
Scorzonera
Compositae
MP
9
Eragrostis pilosa
Eragrostis
Poaceae
MP
9
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
9
Allium polyrhizum
Allium
Amaryllidaceae
MP
9
Asparagus schoberioides
Asparagus
Asparagaceae
MP
9
Peganum harmala
Peganum
Nitrariaceae
MP
9
Iris lactea
Iris
Iridaceae
MP
9
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
9
Allium bidentatum
Allium
Amaryllidaceae
MP
9
Carex korshinskyi
Carex
Cyperaceae
MP
9
Cleistogenes songorica
Cleistogenes
Poaceae
MP
9
Caragana stenophylla
Caragana
Fabaceae
MP
9
Convolvulus ammannii
Convolvulus
Convolvulaceae
MP
9
Stipa capillata
Stipa
Poaceae
MP
9
Salsola collina
Salsola
Amaranthaceae
MP
10
Setaria viridis
Setaria
Poaceae
MP
10
Tribulus terrestris
Tribulus
Zygophyllaceae
MP
10
Asparagus schoberioides
Asparagus
Asparagaceae
MP
10
Corispermum mongolicum
Corispermum
Amaranthaceae
MP
10
Allium bidentatum
Allium
Amaryllidaceae
MP
10
Carex korshinskyi
Carex
Cyperaceae
MP
10
Cleistogenes songorica
Cleistogenes
Poaceae
MP
10
Iris tenuifolia
Iris
Iridaceae
MP
10
Caragana stenophylla
Caragana
Fabaceae
MP
10
Stipa capillata
Stipa
Poaceae
MP
10
Salsola collina
Salsola
Amaranthaceae
TP
1
Allium przewalskianum
Allium
Amaryllidaceae
TP
1
Allium ramosum
Allium
Amaryllidaceae
TP
1
Anaphalis xylorhiza
Anaphalis
Compositae
TP
1
Androsace tapete
Androsace
Primulaceae
TP
1
Androsace umbellata
Androsace
Primulaceae
TP
1
Arenaria brevipetala
Arenaria
Caryophyllaceae
TP
1
Artemisia argyi
Artemisia
Compositae
TP
1
Aster tataricus
Aster
Compositae
TP
1
Astragalus propinquus
Astragalus
Fabaceae
TP
1
Calamagrostis lahulensis
Calamagrostis
Poaceae
TP
1
Caragana sinica
Caragana
Fabaceae
TP
1
Carex korshinskyi
Carex
Cyperaceae
TP
1
Chenopodium glaucum
Chenopodium
Amaranthaceae
TP
1
Elymus dahuricus
Elymus
Poaceae
TP
1
Eragrostis pilosa
Eragrostis
Poaceae
TP
1
Euphorbia stracheyi
Euphorbia
Euphorbiaceae
TP
1
Gentiana scabra
Gentiana
Gentianaceae
TP
1
Gentiana straminea
Gentiana
Gentianaceae
TP
1
Gentiana szechenyii
Gentiana
Gentianaceae
TP
1
Gentianopsis paludosa
Gentianopsis
Gentianaceae
TP
1
Geranium wilfordii
Geranium
Geraniaceae
TP
1
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
1
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
1
Heracleum hemsleyanum
Heracleum
Apiaceae
TP
1
Heteropappus altaicus
Heteropappus
Compositae
TP
1
Incarvillea sinensis
Incarvillea
Bignoniaceae
TP
1
Iris tectorum
Iris
Iridaceae
TP
1
Kobresia littledalei
Kobresia
Cyperaceae
TP
1
Leontopodium leontopodinum
Leontopodium
Compositae
TP
1
Phlomis younghusbandii
Phlomis
Lamiaceae
TP
1
Plantago depressa
Plantago
Plantaginaceae
TP
1
Poa annua
Poa
Poaceae
TP
1
Polygonum divaricatum
Polygonum
Polygonaceae
TP
1
Potentilla chinensis
Potentilla
Rosaceae
TP
1
Potentilla multifida
Potentilla
Rosaceae
TP
1
Potentilla saundersiana
Potentilla
Rosaceae
TP
1
Przewalskia tangutica
Przewalskia
Solanaceae
TP
1
Scorzonera sinensis
Scorzonera
Compositae
TP
1
Scrophularia ningpoensis
Scrophularia
Scrophulariaceae
TP
1
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
1
Silene gallica
Silene
Caryophyllaceae
TP
1
Stipa capillata
Stipa
Poaceae
TP
1
Stipa purpurea
Stipa
Poaceae
TP
1
Taraxacum mongolicum
Taraxacum
Compositae
TP
1
Vicia amoena
Vicia
Fabaceae
TP
2
Anaphalis xylorhiza
Anaphalis
Compositae
TP
2
Artemisia argyi
Artemisia
Compositae
TP
2
Aster souliei
Aster
Compositae
TP
2
Aster tataricus
Aster
Compositae
TP
2
Astragalus strictus
Astragalus
Fabaceae
TP
2
Carex korshinskyi
Carex
Cyperaceae
TP
2
Elsholtzia densa
Elsholtzia
Lamiaceae
TP
2
Eragrostis alta
Eragrostis
Poaceae
TP
2
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
TP
2
Geranium wilfordii
Geranium
Geraniaceae
TP
2
Gueldenstaedtia verna
Gueldenstaedtia
Fabaceae
TP
2
Heracleum hemsleyanum
Heracleum
Apiaceae
TP
2
Kobresia pygmaea
Kobresia
Cyperaceae
TP
2
Lancea tibetica
Lancea
Phrymaceae
TP
2
Lasiocaryum densiflorum
Lasiocaryum
Boraginaceae
TP
2
Persicaria vivipara
Persicaria
Polygonaceae
TP
2
Phlomoides rotata
Phlomoides
Lamiaceae
TP
2
Poa annua
Poa
Poaceae
TP
2
Polygonum sibiricum
Polygonum
Polygonaceae
TP
2
Potentilla anserina
Potentilla
Rosaceae
TP
2
Potentilla parvifolia
Potentilla
Rosaceae
TP
2
Potentilla saundersiana
Potentilla
Rosaceae
TP
2
Przewalskia tangutica
Przewalskia
Solanaceae
TP
2
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
2
Stipa capillata
Stipa
Poaceae
TP
2
Taraxacum mongolicum
Taraxacum
Compositae
TP
2
Urtica hyperborea
Urtica
Urticaceae
TP
3
Astragalus propinquus
Astragalus
Fabaceae
TP
3
Carex korshinskyi
Carex
Cyperaceae
TP
3
Eragrostis alta
Eragrostis
Poaceae
TP
3
Kobresia pygmaea
Kobresia
Cyperaceae
TP
3
Lancea tibetica
Lancea
Phrymaceae
TP
3
Leontopodium leontopodinum
Leontopodium
Compositae
TP
3
Poa annua
Poa
Poaceae
TP
3
Potentilla anserina
Potentilla
Rosaceae
TP
3
Potentilla saundersiana
Potentilla
Rosaceae
TP
3
Saussurea japonica
Saussurea
Compositae
TP
3
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
3
Taraxacum mongolicum
Taraxacum
Compositae
TP
4
Astragalus arnoldii
Astragalus
Fabaceae
TP
4
Callianthemum pimpinelloides
Callianthemum
Ranunculaceae
TP
4
Carex korshinskyi
Carex
Cyperaceae
TP
4
Eragrostis alta
Eragrostis
Poaceae
TP
4
Euphorbia fischeriana
Euphorbia
Euphorbiaceae
TP
4
Heteropappus boweri
Heteropappus
Compositae
TP
4
Kobresia pygmaea
Kobresia
Cyperaceae
TP
4
Leontopodium leontopodinum
Leontopodium
Compositae
TP
4
Oxytropis stracheyana
Oxytropis
Fabaceae
TP
4
Pedicularis alaschanica
Pedicularis
Scrophulariaceae
TP
4
Poa setulosa
Poa
Poaceae
TP
4
Przewalskia tangutica
Przewalskia
Solanaceae
TP
4
Rhodiola smithii
Rhodiola
Crassulaceae
TP
4
Saussurea japonica
Saussurea
Compositae
TP
4
Stipa capillata
Stipa
Poaceae
TP
4
Taraxacum mongolicum
Taraxacum
Compositae
TP
5
Arenaria edgeworthiana
Arenaria
Caryophyllaceae
TP
5
Astragalus adsurgens
Astragalus
Fabaceae
TP
5
Astragalus tribulifolius
Astragalus
Fabaceae
TP
5
Carex korshinskyi
Carex
Cyperaceae
TP
5
Carex littledalei
Carex
Cyperaceae
TP
5
Dolomiaea souliei
Dolomiaea
Compositae
TP
5
Dracocephalum heterophyllum
Dracocephalum
Lamiaceae
TP
5
Eragrostis pilosa
Eragrostis
Poaceae
TP
5
Heteropappus boweri
Heteropappus
Compositae
TP
5
Kobresia pygmaea
Kobresia
Cyperaceae
TP
5
Leontopodium leontopodinum
Leontopodium
Compositae
TP
5
Poa annua
Poa
Poaceae
TP
5
Potentilla chinensis
Potentilla
Rosaceae
TP
5
Potentilla supina
Potentilla
Rosaceae
TP
5
Rhodiola smithii
Rhodiola
Crassulaceae
TP
5
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
5
Stipa capillata
Stipa
Poaceae
TP
5
Stipa purpurea
Stipa
Poaceae
TP
5
Youngia japonica
Youngia
Compositae
TP
6
Astragalus adsurgens
Astragalus
Fabaceae
TP
6
Carex korshinskyi
Carex
Cyperaceae
TP
6
Dracocephalum heterophyllum
Dracocephalum
Lamiaceae
TP
6
Heteropappus boweri
Heteropappus
Compositae
TP
6
Incarvillea lutea
Incarvillea
Bignoniaceae
TP
6
Lagotis brachystachya
Lagotis
Plantaginaceae
TP
6
Oxytropis microphylla
Oxytropis
Fabaceae
TP
6
Przewalskia tangutica
Przewalskia
Solanaceae
TP
6
Rhodiola smithii
Rhodiola
Crassulaceae
TP
6
Sibbaldia parviflora
Sibbaldia
Rosaceae
TP
6
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
6
Stipa capillata
Stipa
Poaceae
TP
6
Stipa purpurea
Stipa
Poaceae
TP
7
Androsace tapete
Androsace
Primulaceae
TP
7
Arenaria brevipetala
Arenaria
Caryophyllaceae
TP
7
Astragalus propinquus
Astragalus
Fabaceae
TP
7
Carex korshinskyi
Carex
Cyperaceae
TP
7
Eragrostis pilosa
Eragrostis
Poaceae
TP
7
Kalimeris hispida
Kalimeris
Compositae
TP
7
Kobresia pygmaea
Kobresia
Cyperaceae
TP
7
Lagotis brachystachya
Lagotis
Plantaginaceae
TP
7
Lasiocaryum densiflorum
Lasiocaryum
Boraginaceae
TP
7
Leontopodium leontopodinum
Leontopodium
Compositae
TP
7
Lepidium capitatum
Lepidium
Brassicaceae
TP
7
Poa annua
Poa
Poaceae
TP
7
Polygonum sibiricum
Polygonum
Polygonaceae
TP
7
Potentilla parvifolia
Potentilla
Rosaceae
TP
7
Potentilla plumosa
Potentilla
Rosaceae
TP
7
Pycnoplinthus uniflora
Pycnoplinthus
Brassicaceae
TP
7
Sibbaldia parviflora
Sibbaldia
Rosaceae
TP
7
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
7
Stipa purpurea
Stipa
Poaceae
TP
7
Taraxacum mongolicum
Taraxacum
Compositae
TP
8
Artemisia desertorum
Artemisia
Compositae
TP
8
Astragalus propinquus
Astragalus
Fabaceae
TP
8
Astragalus tribulifolius
Astragalus
Fabaceae
TP
8
Carex korshinskyi
Carex
Cyperaceae
TP
8
Heteropappus boweri
Heteropappus
Compositae
TP
8
Oxytropis microphylla
Oxytropis
Fabaceae
TP
8
Poa annua
Poa
Poaceae
TP
8
Ptilotrichum canescens
Ptilotrichum
Brassicaceae
TP
8
Stipa capillata
Stipa
Poaceae
TP
9
Artemisia desertorum
Artemisia
Compositae
TP
9
Astragalus hendersonii
Astragalus
Fabaceae
TP
9
Carex korshinskyi
Carex
Cyperaceae
TP
9
Oxytropis glacialis
Oxytropis
Fabaceae
TP
9
Oxytropis microphylla
Oxytropis
Fabaceae
TP
9
Ptilotrichum canescens
Ptilotrichum
Brassicaceae
TP
9
Sibbaldianthe bifurca
Sibbaldianthe
Rosaceae
TP
9
Stipa tianschanica
Stipa
Poaceae
TP
10
Stipa tianschanica
Stipa
Poaceae
TP
10
Ajania fruticulosa
Ajania
Compositae
TP
10
Oxytropis microphylla
Oxytropis
Fabaceae
-
RC2: 'Comment on bg-2022-50', Anonymous Referee #2, 15 Jun 2022
The manuscript by Wang et al. used the community 1/â³18O as the proxy for the time-intergrated canopy conductance, and the investigated the interactive effects of multiple environment stressors and community traits on the spatial variability of canopy conductance along aridity gradients in three Plateaus with different radiation and temperature conditions. Without doubt, the topic is of urgent current interest. The study was generally well designed and executed with reasonable data analyses, and it was well written. However, there are a few problems in the present version; thus, I would recommend a minor revision of the paper before publication.
General comments:
(1) The second hypothesis does not make sense to me. It is an abrupt hypothesis, as authors described in earlier paragraphs that solar radiation and temperature can have both positive and negative impacts on gs. It would be useful to added the basic climatic context for the three grassland transect.
(2) It is essential that the authors to discuss the influence of temperature and VPD on â³18O spanning large altitudinal and/or latitudinal gradients, because temperature and VPD may lead to large inter-site offsets in leaf δ18O values.
Specific comments:
(1) Line 109: replace "plats" with " plots".
(2) Lines 175-177, partial correlation analyses can be used to examine the actual links between 1/â³18O and soil moisture and vapor pressure deficit in Tibetan Plateau.
(3) Figure 4, please add the meaning of the asterisks and arrows.
(4) Line 270, SLA integrates leaf tissue density and thickness.
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AC5: 'Response to reviewer#2', Xue-Fa Wen, 14 Jul 2022
Response to reviews of manuscript “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” bg-2022-50
Response to reviewer#2
Dear Reviewer,
We would like to thank you for the thoughtful and valuable comments and suggestions on our manuscript entitled “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” (bg-2022-50). We have carefully revised our manuscript to take account of your comments and suggestions. Meanwhile, we have rephrased our manuscript title as “Excess radiation exacerbates drought stress impacts on canopy conductance along aridity gradients”.Here are the point-to-point responses (responses in upright Roman in black front) to the comments (original queries in Italic in blue front).
General comments:
1) The second hypothesis does not make sense to me. It is an abrupt hypothesis, as authors described in earlier paragraphs that solar radiation and temperature can have both positive and negative impacts on gs. It would be useful to added the basic climatic context for the three grassland transect.
Response: Thank you very much for your comment. We respond to this comment from three aspects.
(1) We clarified that “However, previous studies showed that the direction and intensity of solar radiation and temperature on gs strongly depend on their distribution range and the relationship with aridity. For example, the response of gs to solar radiation and temperature generally shows an increasing trend up to optimum values (Xu et al. 2021), while excess radiation (Costa et al. 2015; Doupis et al. 2020; Zeuthen et al. 1997) and high temperature associated high VPD or low SM (Seneviratne et al. 2010) would suppress gs.”
(2) We added the basic climatic context for the three grassland transect in the last paragraph of “1 Instruction” section: “The grassland transect span gradients of precipitation, SM, VPD, solar radiation, and temperature, provide an ideal platform for exploration of interactive effects of multiple stressors and biotic factors on Gs (Table S1). In addition, the three grassland transects experienced with different soilar radiation and temperature conditions at a given aridity, due to the difference in the geographical location of the three plateaus. The order of mean annual temperature and solar radiation is LP>MP>TP and LP<MP<TP, respectively.”
(3) We rephrased the second hypothesis as: “high solar radiation and low temperatures will jointly suppress Gs at a given aridity among transects. ”.
2) It is essential that the authors to discuss the influence of temperature and VPD on △18O spanning large altitudinal and/or latitudinal gradients, because temperature and VPD may lead to large inter-site offsets in leaf δ18O values.
Response: Thank you very much for your comment. We respond these comments from two aspects in section “Discussion”.
(1) We clarified that the decreasing trend of community △18O along aridity may originated from temperature and VPD through their effects on evaporation and isotopic exchange between water and organic molecules: “The decreasing trend of community △18O along aridity may originated from temperature and VPD through their effects on evaporation and isotopic exchange between water and organic molecules (Barbour & Farquhar 2000; Helliker & Richter 2008; Song et al. 2011). For example, the equilibrium fractionation factor for water evaporation is depend on temperature (Bottinga & Craig 1968). Temperature and VPD gradients between leaf and ambient air influence the evaporative gradient from leaf to air (Helliker & Richter 2008; Song et al. 2011). In addition, biochemical 18O-fractionation during cellulose synthesis is sensitive to temperature, and the proportion of oxygen in cellulose derived from source water was humidity-sensitive (Hirl et al. 2021).”
(2) We demonstrated that the potential effects of temperature and VPD on △18O via evaporation and isotopic exchange between water and organic molecules could be ruled out in this study: “The potential effects of temperature and VPD on △18O via evaporation and isotopic exchange between water and organic molecules could be ruled out in this study. The growing season temperature variation was small along three transects (LP=3.3 °C, MP=4.9 °C, and TP=3.8 °C) (Table S1). However, the range of community △18O was 7.78‰ in LP, 3.89‰ in MP, and 6.17‰in TP (Table S1, Fig.2a). Previous studies demonstrated that the sensitivity of temperature to △18O was approximately 0.23‰/℃ (Helliker & Richter 2008; Song et al. 2011). It seems that the changes in temperature was not a main contributor to the large variability in community △18O. Meanwhile, positive relationship between community 1/△18O and temperature was observed in LP (P<0.05), and negative relationship between community 1/△18O and VPD was observed in TP (Table 1). However, partial correlation analyses showed that community 1/△18O was not related to temperature (P > 0.05) and VPD after controlling for Gs (Data were not shown). It indicated that the variability in community 1/△18O was mainly determined from Gs.”
Specific comments:
1) Line 109: replace "plats" with " plots".
Response: Corrected, thank you.
2) Lines 175-177, partial correlation analyses can be used to examine the actual links between 1/△18O and soil moisture and vapor pressure deficit in Tibetan Plateau.
Response: Corrected and rephrased as: “Partial correlation analyses showed that 1/△18O was not related to SM (P > 0.05) after controlling for VPD, indicating that variability in 1/△18O in TP was mainly determined by VPD.”
3) Figure 4, please add the meaning of the asterisks and arrows.
Response: To avoid confusion, we split Figure 4 into two graphs (Figure 4 and Figure 5). Meanwhile, the meaning of the asterisks and arrows have been added.
Figure 4. Structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Figure 5. Structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
4) Line 270, SLA integrates leaf tissue density and thickness.
Response: Thank you very much for your comment. This sentence has been removed, and this paragraph has been corrected and rephrased as: “Our preliminary study demonstrated that gs was significantly affected by LA at species level in TP (Wang & Wen 2022). However, the effect of community LA on Gs was weak (P=0.061) (Fig.S5a), and variability in Gs along an aridity gradient was controlled by specific leaf area (SLA) (Table 1, Fig.S5b).This highlighted the difference in the biological drivers of gs at leaf and canopy scales. Contrary to the results of the dry grassland species in Mediterranean (Prieto et al. 2018) and karst communities in subtropical regions (Wang et al. 2021), community 1/△18O significantly decreased with SLA in this study (Table S1, Fig.S5). It indicated that the traditional leaf economic spectrum theory may not existed at community level in TP due to the multiple environmental stressors. SLA generally decreases with increasing solar radiation, and increases with temperature and water availability (Poorter et al. 2009). In this study, commumnity SLA was negatively related to soil moisture, and positively related to maxmium temperature (Table S5). It indicated that changes of commumnity SLA was mainly controlled by maxmium temperature. However, the direct effect of SLA on Gs in the structural equation was not significant (Fig.5c). This effect may be obscured by drought stress.”
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AC5: 'Response to reviewer#2', Xue-Fa Wen, 14 Jul 2022
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RC3: 'Comment on bg-2022-50', Anonymous Referee #3, 21 Jun 2022
This manuscript used 18O enrichment of leaf organic matter above source water (Δ18O) as proxy for gs per leaf area to explore the effect of drought stress on gs the interaction effects of abiotic and biotic constraints on canopy along aridity gradients in Loess Plateau (LP), Inner Mongolian Plateau (MP), and Tibetan Plateau (TP). The topic and methods are interesting. However, some corrections are needed before it is ready for publication in an international scientific journal. My comments and suggestions are the following.
- Introduction: Please put the last paragraph (Line 81-91) before the penultimate paragraph (Line 72-80).
- Fig.1: Is the Y variable in (b) consistent with (f)? If yes, please unify them. Similarly, please modify the Y variable in (c) (d) (g) (h).
- Fig.2: Please delete the “***” in Fig. 2(b).
- Fig.3: The X variable name in Fig.3(c) (TSR) is inconsistent with the name in the legend (SR). Please modify it.
- Table 1: The asterisk in the seventh row is inconsistent with other rows. Please revised them.
- Fig.4: Please label the P value in each figure to ensure the reliability of the model. In addition, please add a priori model of effects of variables on the gs to Supplementary Information.
- Fig.4: Why are there many types of SEMs for gs? Even in the same area, there are two SEMs for gs. How to determine which is the most accurate?
- There are many problems in the manuscript. For example, (1) “s” of gs should be a subscript; (2) leaf area (Line 114); (3) as follows (Line 118); (4) “max” of Tempmax should be a subscript (Line 194); (5) All the abbreviations in the figures should be explained; etc. Please check the full text carefully.
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AC6: 'Response to reviewer#3', Xue-Fa Wen, 14 Jul 2022
Response to reviews of manuscript “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” bg-2022-50
Response to reviewer#3
Dear Reviewer,
We would like to thank you for the thoughtful and valuable comments and suggestions on our manuscript entitled “Excess radiation exacerbates drought stress impacts on stomatal conductance along aridity gradients” (bg-2022-50). We have carefully revised our manuscript to take account of your comments and suggestions. Meanwhile, we have rephrased our manuscript title as “Excess radiation exacerbates drought stress impacts on canopy conductance along aridity gradients”.Here are the point-to-point responses (responses in upright Roman in black front) to the comments (original queries in Italic in blue front).
Specific comments:
1) Introduction: Please put the last paragraph (Line 81-91) before the penultimate paragraph (Line 72-80).
Response: Thank you very much for your comment. This paragraph has been revised and removed to section “2.2.3 Stable isotope analysis”: “Given that leaf δ18O at species level was affected by the leaf water evaporation process, variability in gs should show up in leaf δ18O (Barbour 2007; Barbour & Farquhar 2000; Farquhar et al. 1998). Negative relationship between △18O and gs has been observed at species (Barbour & Farquhar 2000; Cabrera-Bosquet et al. 2011; Grams et al. 2007; Moreno-Gutierrez et al. 2012) and canopy scales (Cabrera et al. 2021; Hirl et al. 2021), and among communities along soil (Ramirez et al. 2009) and climate (Keitel et al. 2006) gradients. Consequently, we selected 1/△18O was used as a proxy for gs in this study. ”.
2) Fig.1: Is the Y variable in (b) consistent with (f)? If yes, please unify them. Similarly, please modify the Y variable in (c) (d) (g) (h).
Response: Thank you very much for your comment. Figure 1 has been changed as follows according to the comment of reviewer 1.
Figure 1. Comparison of aridity (a), growing season precipitation (b), soil moisture (SM) (c), vapor pressure deficit (VPD) (d), solar radiation (SR) (e), temperature (f), maximum temperature (g), and community leaf area (h) and leaf specific leaf area (SLA) (i) among transects. LP: Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Lowercase letters indicate significant differences among transects (P<0.05). Error bars indicate standard error of the mean.
3) Fig.2: Please delete the “***” in Fig. 2(b).
Response: Thank you very much for your comment. Change has been done.
Figure 2. Patterns of 1/△18O (a) along aridity gradient within transects, and among (b) transects. Different letters indicate significant differences (P < 0.001) among transects and grassland types. LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau.
4) Fig.3: The X variable name in Fig.3(c) (TSR) is inconsistent with the name in the legend (SR). Please modify it.
Response: Thank you very much for your comment. Change has been done.
Figure 3. Patterns of the intercept obtained from standardized major axis analysis (SMA) among transects. VPD, vapor pressure deficit; SR, solar radiation; Tempmax, maximum temperature. LP, Loess Plateau; MP, Inner Mongolia Plateau; TP, Tibet Plateau. Shaded area represents the 95% confidence interval of the SMA intercept.
5) Table 1: The asterisk in the seventh row is inconsistent with other rows. Please revised them.
Response: Thank you very much for your comment. Change has been done.
Table 1 Pearson’s coefficients among community 1/△18O and environmental factors and plant properties.
Loess Plateau
Inner Mongolia Plateau
Tibet Plateau
Aridity
-0.848**
-0.843**
-0.773**
SM
0.719*
0.707*
0.659*
VPD
-0.554
-0.384
-0.912**
SR
-0.639*
-0.728*
-0.850**
Tempmean
0.641*
0.303
-0.670*
Tempmax
0.678*
0.038
-0.852**
LA
0.757*
0.913**
0.610
SLA
-0.519
-0.576
-0.648*
**, P<0.01; *, P<0.05. SM, soil moisture; VPD, vapor pressure deficit; SR, total solar radiation; Tempmean, mean temperature; Tempmax, maximum temperature; LA, log-transformed leaf area; SLA, log-transformed specific leaf area.
6) Fig.4: Please label the P value in each figure to ensure the reliability of the model. In addition, please add a priori model of effects of variables on the gs to Supplementary Information.
Response: Thank you very much for your comment. To ensure the reliability of the model, P value of SEM model has been added in each sub-figure.
Figure 4. Structural equation models of abiotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
Figure 5. Structural equation models of abiotic and biotic factors explaining 1/△18O in Loess Plateau (LP) (a), Inner Mongolia Plateau (MP) (b) and Tibet Plateau (TP) (c). △18O, 18O enrichment of leaf organic matter above source water; Tempmax: maximum temperature; SR, solar radiation; SM, soil moisture; VPD, vapor pressure deficit. LA, log-transformed leaf area; SLA, log-transformed specific leaf area. Solid and dashed arrows represent significant and non-significant relationships in a fitted SEM, respectively. ***, P<0.001; **, P<0.01; *, P<0.05.
7) Fig.4: Why are there many types of SEMs for gs? Even in the same area, there are two SEMs for gs. How to determine which is the most accurate?
Response: Thank you very much for your comment. To avoid confusion, we split Figure 4 into two graphs (Figure 4 and Figure 5). Figure 4 are the best-fitting models illustrating the effects of abiotic variables on 1/△18O, and Figure 5 are the best-fitting models illustrating the effects of abiotic and biotic variables on 1/△18O.
8) There are many problems in the manuscript. For example, (1) “s” of gs should be a subscript; (2) leaf area (Line 114); (3) as follows (Line 118); (4) “max” of Tempmax should be a subscript (Line 194); (5) All the abbreviations in the figures should be explained; etc. Please check the full text carefully
Response: Change has been done according to your suggestions.
Peer review completion
