the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Assessing CO2 and CH4 fluxes from mounds of African fungus-growing termites
Risto Vesala
Petri Rönnholm
Laura Arppe
Petra Manninen
Markus Jylhä
Jouko Rikkinen
Petri Pellikka
Janne Rinne
Abstract. Termites play an essential role in decomposing dead plant material in tropical ecosystems and are thus major sources of gaseous C emissions in many environments. In African savannas, fungus-growing termites are among the ecologically most influential termite species. We studied the gas exchange from mounds of two closely related fungus-growing species (Macrotermes subhyalinus and M. michaelseni, respectively) in shaded and open habitats together with soil fluxes around the mounds. The fluxes from active termite mounds varied from 116 to 2105 mg CO2-C m-2 h-1 for CO2 and from 0.06 to 3.66 mg CH4-C m-2 h-1 for CH4 fluxes. Mound CO2 fluxes varied seasonally with a 64 % decrease and 35 % increase in the fluxes from dry to wet season at the open grassland and shaded bushland sites, respectively. During the wet season, the CO2 fluxes were significantly correlated with termite mound volume. The diurnal measurements from two M. michaelseni mounds suggest that the gas fluxes peak during daytime and midnight supporting the previously presented model of thermally driven air circulation inside the mound and possibly enhanced ventilation during the night by the opening of foraging routes. The stability of the mound gas fluxes over diurnal and annual scales coincides with the constant nature of the nest internal gas and thermal environment that guarantees continuously favorable conditions for the fungal symbiont. Soil fluxes of both CO2 and CH4 were enhanced at up to 2 m distance from the mounds compared to the local soil respiration, indicating that, in addition to mound ventilation structures, a small proportion of the produced metabolic gases leave the nest also via surrounding soils.
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Matti Räsänen et al.
Status: closed
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RC1: 'Comment on bg-2023-24', Anonymous Referee #1, 04 Apr 2023
Regarding the closed/open mound category, I am not entirely clear on what the hypotheses are for each type. What is the reasoning for measuring both, and what are the implications for gas fluxes? I could see adding a discussion point focusing on this contrast.
Citation: https://doi.org/10.5194/bg-2023-24-RC1 -
AC1: 'Reply on RC1', Matti Räsänen, 03 Jun 2023
We thank the referee for their supportive comments.
To understand the influence of termite fluxes at the ecosystem scale it is necessary to measure both mound types. The two termite species (and mound types) studied here are the dominant mound-building termites and more or less equally present in the area. However, their distribution is not completely random or overlapping at a smaller scale. For example in the current study, open mound type was dominant in the bushland and the closed type in the grassland site. More detailed map of different mound types in the region is presented in the fig. 2 of the previous study (Vesala et. al., 2017). Because the two termite species are closely related and ecologically very similar we didn’t expect major differences in the fluxes. However, the highly different nest ventilation could potentially have some role (e.g. related to the proportion of gases that is emitted via the mound or surrounding soils, effect of methane oxidation, etc.) which we wanted to find out. The results however did not imply that the mound type would have any significant effects on the fluxes. We have now stated this point in the discussion.
Vesala, R., Niskanen, T., Liimatainen, K., Boga, H., Pellikka, P. and Rikkinen, J.: Diversity of fungus-growing termites (Macrotermes) and their fungal symbionts (Termitomyces) in the semiarid Tsavo Ecosystem, Kenya, Biotropica, 49(3), 402–412, doi:10.1111/btp.12422, 2017.
Citation: https://doi.org/10.5194/bg-2023-24-AC1
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AC1: 'Reply on RC1', Matti Räsänen, 03 Jun 2023
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RC2: 'Comment on bg-2023-24', Anonymous Referee #1, 06 Apr 2023
page 3, line 17: for information on feeding guild and termite methane see Zhou, Yong ,A. Carla Staver, and Andrew B. Davies. 2023. Species-Level Termite Methane Production Rates. Ecology 104(2): e3905. https://doi.org/10.1002/ecy.3905page 4, line 16: how are foraging strategies different here? Is it about what the termites are consuming, and why might different fluxes result?page 15: for mean CO2 and CH4 fluxes of mound and soils, are soils significant? It looks like methane in soils is negligible.page 15 figure 7: might be clearer to visualise this with mound and soil fluxes compared instead of just presenting soil fluxes, as this contextualizes both measurements.page 16, line 8: Fungus-farming termites are thought to have higher rates of methane production: see Rouland et al. 1993, Gomathi et al 2009, Zhou et al 2023.page 18, line 26: Sentence doesn't quite make sense - "In addition to the daily cycles of CO2 and CH4 fluxes, the relationship between CO2 and CH4 showed a clear diurnal pattern"page 18, line 30: methanotrophs will also influence CH4 concentrationsGeneral notes on formatting: there are some inconsistencies with subscripts on methane (CH4) and carbon dioxide (CO2) abbreviations.Citation: https://doi.org/
10.5194/bg-2023-24-RC2 -
AC2: 'Reply on RC2', Matti Räsänen, 03 Jun 2023
The comment was uploaded in the form of a supplement: https://bg.copernicus.org/preprints/bg-2023-24/bg-2023-24-AC2-supplement.pdf
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AC2: 'Reply on RC2', Matti Räsänen, 03 Jun 2023
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RC3: 'Comment on bg-2023-24', Anonymous Referee #2, 07 Apr 2023
Comments on the article ‘Assessing CO2 and CH4 fluxes from mounds of African fungus-growing termites’ from Matti Räsänen and co-authors
The article is well written, and contains interesting field data about a topic which is still relatively unknown, and of which relatively little data exists. The amount of mounds on which this story is based is small, but this is understandable considering the field conditions, and the difficulty to find suitable mounds. Also, the experiment is well designed in the sense that many environmental variables were measured. It is nice how some entomology studies are used to interpret the data.
There are a few general comments which should be addressed by the authors, followed by many detailed suggestions.
General comments
Dependency between species, nest type and location
The authors explain the difference between open and closed mounds in the beginning, and introduce the 2 termite species. They briefly indicate that 1 species makes closed mounds, and the other species open mounds. So, these variables (open/closed mound and species 1/species 2) are not independent. Nevertheless, this is not superclear through the paper. Looking at Table 1, termite species and mound type are listed as independent variables (separate columns), but they are not independent. Additionally to this, the authors try to compare the 2 different species in 2 different environments. But, looking at Table 1, the M. michaelseni only appears once in the bushland (out of 6 mounds), and the M. subhyalinus appears only 2 in the grassland (out of 6 mounds). While it is likely out of practical considerations that the authors decide to not look for equal sampling at each side, this should be discussed better.
So, I would advise the authors to better discuss and evaluate the fact that mound type and species are not independent and to better discuss whether observed differences between grassland and bushland are a consequence of the environment, or the fact that they were basically measuring different termite species (with different nest properties).
Discussion of diurnal variation
The part about the diurnal variation is interesting, but it is difficult to judge how valid/representative the measurements are. Please add on how many days the measurements were made, and how representative 4 or 5 time points are to determine a daily variation. Also, the authors mention that the largest CO2 flux coincides with the highest wind speed. But, to what extent can wind speed be a factor of influence on the CO2 flux if the mound is sheltered from wind speed during the measurement? Can the authors discuss this?
Discussion of differences between seasons
The differences between dry and wet season are interesting, but please discuss it further. For example, on page 17, line 15, the decrease in CH4/CO2 ratio is mentioned, seen from dry to wet season, and possibly linked to the activity of methanotrophic bacteria. So, the authors mention that during the wet season, mounds have higher water content, so these bacteria become more active. But, you also mention (page 19, line 5) that the mounds represent a stable humidity and temperature. Is there any data or literature which actually shows that the mound humidity changes with season? Or is this ‘just’ an hypothesis to fit your observation? Please elaborate.
Also, it is observed by the authors that the soil CH4 flux is positive in the dry season, and uptake is seen in the wet season (‘The dry season mean soil CH4 flux was positive at the grassland and bushland site, whereas the mean wet season flux was nearly zero with most fluxes being negative (Fig. 7, S5 and S6’)).
This is unexpected, since usually higher soil moisture (wet season) leads to CH4 emission, while uptake occurs when the soil is drier. Maybe I have overlooked it, but did the authors measure soil moisture during both season, and how was it indeed drier/wetter in the wet/dry season? The graphs in the suppl material, are they for wet or dry season? There the authors seem to find a weak relation between soil moisture and CH4 flux. So, why do the authors observe more soil CH4 flux in the dry season? Discuss this.
Sample quantity/representativeness
This overlaps with the previous points, but just a general comment. The authors have only studied 12 mounds, only measured during 2 moments in the year, and only once diurnal variation was studied (during x days). Again, field conditions are hard, and it is understandable that the dataset is not larger. But I would encourage the authors to consider and evaluate this in their interpretation (can a comparison be made between dry and wet season based on just 2 moments? Can a conclusion on daily variation be made based on just a few measurements?).
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One curiosity, are there no local Kenyan researchers involved in (writing up) this research?
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Detailed suggestions
-Page 1, Line 19: is there a white space between ‘CO2’ and ‘and’?
-Page 4, line 12: to be result from→ to be a result of
-Page 4, line 17: and thus may cause different fluxes-→ which may result in different fluxes
-Page 7: line 10-11: diurnal variation measurements were made: on how many days?
-Fig 2: add on the x-axes which method this number belongs to (Calculated Cone volume/)
-Page 8, line 5: was→ were
-Page 9, sentence on line 8 and 9: sentence is incorrect, check if comma or verb is missing?
- Page 10: line 11-12: why are S1 and MR4 compared? They have a similar volume, but have a different species and environment, so is this comparison useful/valid?
- Figure 6: the legend of the triangles and circles is only given in the first figure (6a). Maybe add a sentence in the caption as well
- Fig 6f: you plot here the standard deviation of the CO2 flux. Please add to your material and methods how you obtain the standard deviation. Is this the standard error of the linear regression slope?
- Table 2: is there a white space missing between CH4 and flux?
- Page 16, line 12: mound outer dimensions correlate positively with the size….. This you take from literature, right? Although clear from the paper (you didn’t count the termites), maybe clarify this to the reader (sentence below just a suggestion, feel free to ignore or improve)
As found by previous studies, the mound outer dimensions of the Macrotermes species (of which both our species belong to) correlate positively…..
- Page 16, line 32: elaborate maybe 1 sentence what you mean with sterile, and why that leads to constant activity over the year
-Page 17, line 5 and 8. CO2 not written in subscript
Citation: https://doi.org/10.5194/bg-2023-24-RC3 -
AC3: 'Reply on RC3', Matti Räsänen, 03 Jun 2023
The comment was uploaded in the form of a supplement: https://bg.copernicus.org/preprints/bg-2023-24/bg-2023-24-AC3-supplement.pdf
-
AC3: 'Reply on RC3', Matti Räsänen, 03 Jun 2023
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RC4: 'Comment on bg-2023-24', Anonymous Referee #3, 02 May 2023
Räsänen and colleagues investigate CO2 and CH4 fluxes from mounds of fungus-growing termites and adjacent soil at selected sites in Kenya. They chose plots in open grassland and bushland and investigate diurnal courses of fluxes. Results highlight the scaling of mound volume to CO2 flux density and lower CH4 emissions compared to literature values from soil and grass-feeding termites. The authors also stress the importance of active or dead mounds in the landscape for upscaling fluxes.
Overall, the paper is well written, methods are well established, the topic is of relevance for greenhouse gas emission budgets as fluxes from termites are still understudied and flux estimates are associated with high uncertainties. A few plotting issues should be addressed. I particularly enjoyed reading the discussion section.
Beside some general thoughts, here are a few points that should be considered in the revision of the manuscript:
- I noticed that the title had already been modified at an earlier stage, but does “Assessing” really fit? What’s been assessed? I’d just leave the word out.
- No local collaborators as co-authors? In times where “helicopter science” is highly debated, it is hard to understand why not a single person from the region or with local expertise made it to the list of co-authors. I’m not saying that random people from the street should be chosen and I fully agree that a co-author must have made a considerable (scientific) contribution to the study, but weren’t there any African institutions involved where people could have been invited to contribute? Please, at least consider this in the planning phase of any upcoming field studies abroad.
- Abstract, Line 20-21: The fact that there is a 35% decrease of CO2 fluxes in the wet season compared to the dry season is unexpected. Maybe already indicate here the potential reasons.
- Carefully check the reference list. Not all papers cited in the text are listed.
- Figure 1 is overall very nice. What is the source of the above-ground biomass data?
- Sections on gas flux measurements: What is the sensitivity of the gas flux calculation to the mound volume? Have you done some calculations and could this be considered in the uncertainty estimation? Also, how stable, i.e. “how linear” was the concentration increase? Was Equation (2) really the best fit? Could you see any saturation of the concentration increase during chamber closure? And would have probably another method for flux calculation been better?
- Page 7, Line 8: How did you assure gas tightness? Was the collar smoothly inserting into the soil?
- Section 2.3: Very nice setup regarding air mixing!
- Section 2.4: How can nest temperatures from another year be used in this study? How comparable would they be? Isn’t nest temperature correlated with air temperature, soil temperature, wind speed? Or was just the relative diurnal course taken into account?
- Page 9, Line 3: “of” missing between “amount” and “woody”?
- Figure 3 (a): Rainfall should not be plotted as time series, but as a bar graph. Here it is the daily sum.
- Figure 3 (b) and (d): x-axes labels, ticks at 0, 6, 12, 18, 24
- Figure 4: The caption does not really tell what the lower panel shows, although it is quite obvious. Please add. A ratio should not be shown as a bar plot, but rather as points.
- Figure 5, x-axes labels, ticks at 6, 12, 18, 24
Citation: https://doi.org/10.5194/bg-2023-24-RC4 -
AC4: 'Reply on RC4', Matti Räsänen, 03 Jun 2023
The comment was uploaded in the form of a supplement: https://bg.copernicus.org/preprints/bg-2023-24/bg-2023-24-AC4-supplement.pdf
Status: closed
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RC1: 'Comment on bg-2023-24', Anonymous Referee #1, 04 Apr 2023
Regarding the closed/open mound category, I am not entirely clear on what the hypotheses are for each type. What is the reasoning for measuring both, and what are the implications for gas fluxes? I could see adding a discussion point focusing on this contrast.
Citation: https://doi.org/10.5194/bg-2023-24-RC1 -
AC1: 'Reply on RC1', Matti Räsänen, 03 Jun 2023
We thank the referee for their supportive comments.
To understand the influence of termite fluxes at the ecosystem scale it is necessary to measure both mound types. The two termite species (and mound types) studied here are the dominant mound-building termites and more or less equally present in the area. However, their distribution is not completely random or overlapping at a smaller scale. For example in the current study, open mound type was dominant in the bushland and the closed type in the grassland site. More detailed map of different mound types in the region is presented in the fig. 2 of the previous study (Vesala et. al., 2017). Because the two termite species are closely related and ecologically very similar we didn’t expect major differences in the fluxes. However, the highly different nest ventilation could potentially have some role (e.g. related to the proportion of gases that is emitted via the mound or surrounding soils, effect of methane oxidation, etc.) which we wanted to find out. The results however did not imply that the mound type would have any significant effects on the fluxes. We have now stated this point in the discussion.
Vesala, R., Niskanen, T., Liimatainen, K., Boga, H., Pellikka, P. and Rikkinen, J.: Diversity of fungus-growing termites (Macrotermes) and their fungal symbionts (Termitomyces) in the semiarid Tsavo Ecosystem, Kenya, Biotropica, 49(3), 402–412, doi:10.1111/btp.12422, 2017.
Citation: https://doi.org/10.5194/bg-2023-24-AC1
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AC1: 'Reply on RC1', Matti Räsänen, 03 Jun 2023
-
RC2: 'Comment on bg-2023-24', Anonymous Referee #1, 06 Apr 2023
page 3, line 17: for information on feeding guild and termite methane see Zhou, Yong ,A. Carla Staver, and Andrew B. Davies. 2023. Species-Level Termite Methane Production Rates. Ecology 104(2): e3905. https://doi.org/10.1002/ecy.3905page 4, line 16: how are foraging strategies different here? Is it about what the termites are consuming, and why might different fluxes result?page 15: for mean CO2 and CH4 fluxes of mound and soils, are soils significant? It looks like methane in soils is negligible.page 15 figure 7: might be clearer to visualise this with mound and soil fluxes compared instead of just presenting soil fluxes, as this contextualizes both measurements.page 16, line 8: Fungus-farming termites are thought to have higher rates of methane production: see Rouland et al. 1993, Gomathi et al 2009, Zhou et al 2023.page 18, line 26: Sentence doesn't quite make sense - "In addition to the daily cycles of CO2 and CH4 fluxes, the relationship between CO2 and CH4 showed a clear diurnal pattern"page 18, line 30: methanotrophs will also influence CH4 concentrationsGeneral notes on formatting: there are some inconsistencies with subscripts on methane (CH4) and carbon dioxide (CO2) abbreviations.Citation: https://doi.org/
10.5194/bg-2023-24-RC2 -
AC2: 'Reply on RC2', Matti Räsänen, 03 Jun 2023
The comment was uploaded in the form of a supplement: https://bg.copernicus.org/preprints/bg-2023-24/bg-2023-24-AC2-supplement.pdf
-
AC2: 'Reply on RC2', Matti Räsänen, 03 Jun 2023
-
RC3: 'Comment on bg-2023-24', Anonymous Referee #2, 07 Apr 2023
Comments on the article ‘Assessing CO2 and CH4 fluxes from mounds of African fungus-growing termites’ from Matti Räsänen and co-authors
The article is well written, and contains interesting field data about a topic which is still relatively unknown, and of which relatively little data exists. The amount of mounds on which this story is based is small, but this is understandable considering the field conditions, and the difficulty to find suitable mounds. Also, the experiment is well designed in the sense that many environmental variables were measured. It is nice how some entomology studies are used to interpret the data.
There are a few general comments which should be addressed by the authors, followed by many detailed suggestions.
General comments
Dependency between species, nest type and location
The authors explain the difference between open and closed mounds in the beginning, and introduce the 2 termite species. They briefly indicate that 1 species makes closed mounds, and the other species open mounds. So, these variables (open/closed mound and species 1/species 2) are not independent. Nevertheless, this is not superclear through the paper. Looking at Table 1, termite species and mound type are listed as independent variables (separate columns), but they are not independent. Additionally to this, the authors try to compare the 2 different species in 2 different environments. But, looking at Table 1, the M. michaelseni only appears once in the bushland (out of 6 mounds), and the M. subhyalinus appears only 2 in the grassland (out of 6 mounds). While it is likely out of practical considerations that the authors decide to not look for equal sampling at each side, this should be discussed better.
So, I would advise the authors to better discuss and evaluate the fact that mound type and species are not independent and to better discuss whether observed differences between grassland and bushland are a consequence of the environment, or the fact that they were basically measuring different termite species (with different nest properties).
Discussion of diurnal variation
The part about the diurnal variation is interesting, but it is difficult to judge how valid/representative the measurements are. Please add on how many days the measurements were made, and how representative 4 or 5 time points are to determine a daily variation. Also, the authors mention that the largest CO2 flux coincides with the highest wind speed. But, to what extent can wind speed be a factor of influence on the CO2 flux if the mound is sheltered from wind speed during the measurement? Can the authors discuss this?
Discussion of differences between seasons
The differences between dry and wet season are interesting, but please discuss it further. For example, on page 17, line 15, the decrease in CH4/CO2 ratio is mentioned, seen from dry to wet season, and possibly linked to the activity of methanotrophic bacteria. So, the authors mention that during the wet season, mounds have higher water content, so these bacteria become more active. But, you also mention (page 19, line 5) that the mounds represent a stable humidity and temperature. Is there any data or literature which actually shows that the mound humidity changes with season? Or is this ‘just’ an hypothesis to fit your observation? Please elaborate.
Also, it is observed by the authors that the soil CH4 flux is positive in the dry season, and uptake is seen in the wet season (‘The dry season mean soil CH4 flux was positive at the grassland and bushland site, whereas the mean wet season flux was nearly zero with most fluxes being negative (Fig. 7, S5 and S6’)).
This is unexpected, since usually higher soil moisture (wet season) leads to CH4 emission, while uptake occurs when the soil is drier. Maybe I have overlooked it, but did the authors measure soil moisture during both season, and how was it indeed drier/wetter in the wet/dry season? The graphs in the suppl material, are they for wet or dry season? There the authors seem to find a weak relation between soil moisture and CH4 flux. So, why do the authors observe more soil CH4 flux in the dry season? Discuss this.
Sample quantity/representativeness
This overlaps with the previous points, but just a general comment. The authors have only studied 12 mounds, only measured during 2 moments in the year, and only once diurnal variation was studied (during x days). Again, field conditions are hard, and it is understandable that the dataset is not larger. But I would encourage the authors to consider and evaluate this in their interpretation (can a comparison be made between dry and wet season based on just 2 moments? Can a conclusion on daily variation be made based on just a few measurements?).
--------------------------------------------------------------------------------------------
One curiosity, are there no local Kenyan researchers involved in (writing up) this research?
--------------------------------------------------------------------------------------------
Detailed suggestions
-Page 1, Line 19: is there a white space between ‘CO2’ and ‘and’?
-Page 4, line 12: to be result from→ to be a result of
-Page 4, line 17: and thus may cause different fluxes-→ which may result in different fluxes
-Page 7: line 10-11: diurnal variation measurements were made: on how many days?
-Fig 2: add on the x-axes which method this number belongs to (Calculated Cone volume/)
-Page 8, line 5: was→ were
-Page 9, sentence on line 8 and 9: sentence is incorrect, check if comma or verb is missing?
- Page 10: line 11-12: why are S1 and MR4 compared? They have a similar volume, but have a different species and environment, so is this comparison useful/valid?
- Figure 6: the legend of the triangles and circles is only given in the first figure (6a). Maybe add a sentence in the caption as well
- Fig 6f: you plot here the standard deviation of the CO2 flux. Please add to your material and methods how you obtain the standard deviation. Is this the standard error of the linear regression slope?
- Table 2: is there a white space missing between CH4 and flux?
- Page 16, line 12: mound outer dimensions correlate positively with the size….. This you take from literature, right? Although clear from the paper (you didn’t count the termites), maybe clarify this to the reader (sentence below just a suggestion, feel free to ignore or improve)
As found by previous studies, the mound outer dimensions of the Macrotermes species (of which both our species belong to) correlate positively…..
- Page 16, line 32: elaborate maybe 1 sentence what you mean with sterile, and why that leads to constant activity over the year
-Page 17, line 5 and 8. CO2 not written in subscript
Citation: https://doi.org/10.5194/bg-2023-24-RC3 -
AC3: 'Reply on RC3', Matti Räsänen, 03 Jun 2023
The comment was uploaded in the form of a supplement: https://bg.copernicus.org/preprints/bg-2023-24/bg-2023-24-AC3-supplement.pdf
-
AC3: 'Reply on RC3', Matti Räsänen, 03 Jun 2023
-
RC4: 'Comment on bg-2023-24', Anonymous Referee #3, 02 May 2023
Räsänen and colleagues investigate CO2 and CH4 fluxes from mounds of fungus-growing termites and adjacent soil at selected sites in Kenya. They chose plots in open grassland and bushland and investigate diurnal courses of fluxes. Results highlight the scaling of mound volume to CO2 flux density and lower CH4 emissions compared to literature values from soil and grass-feeding termites. The authors also stress the importance of active or dead mounds in the landscape for upscaling fluxes.
Overall, the paper is well written, methods are well established, the topic is of relevance for greenhouse gas emission budgets as fluxes from termites are still understudied and flux estimates are associated with high uncertainties. A few plotting issues should be addressed. I particularly enjoyed reading the discussion section.
Beside some general thoughts, here are a few points that should be considered in the revision of the manuscript:
- I noticed that the title had already been modified at an earlier stage, but does “Assessing” really fit? What’s been assessed? I’d just leave the word out.
- No local collaborators as co-authors? In times where “helicopter science” is highly debated, it is hard to understand why not a single person from the region or with local expertise made it to the list of co-authors. I’m not saying that random people from the street should be chosen and I fully agree that a co-author must have made a considerable (scientific) contribution to the study, but weren’t there any African institutions involved where people could have been invited to contribute? Please, at least consider this in the planning phase of any upcoming field studies abroad.
- Abstract, Line 20-21: The fact that there is a 35% decrease of CO2 fluxes in the wet season compared to the dry season is unexpected. Maybe already indicate here the potential reasons.
- Carefully check the reference list. Not all papers cited in the text are listed.
- Figure 1 is overall very nice. What is the source of the above-ground biomass data?
- Sections on gas flux measurements: What is the sensitivity of the gas flux calculation to the mound volume? Have you done some calculations and could this be considered in the uncertainty estimation? Also, how stable, i.e. “how linear” was the concentration increase? Was Equation (2) really the best fit? Could you see any saturation of the concentration increase during chamber closure? And would have probably another method for flux calculation been better?
- Page 7, Line 8: How did you assure gas tightness? Was the collar smoothly inserting into the soil?
- Section 2.3: Very nice setup regarding air mixing!
- Section 2.4: How can nest temperatures from another year be used in this study? How comparable would they be? Isn’t nest temperature correlated with air temperature, soil temperature, wind speed? Or was just the relative diurnal course taken into account?
- Page 9, Line 3: “of” missing between “amount” and “woody”?
- Figure 3 (a): Rainfall should not be plotted as time series, but as a bar graph. Here it is the daily sum.
- Figure 3 (b) and (d): x-axes labels, ticks at 0, 6, 12, 18, 24
- Figure 4: The caption does not really tell what the lower panel shows, although it is quite obvious. Please add. A ratio should not be shown as a bar plot, but rather as points.
- Figure 5, x-axes labels, ticks at 6, 12, 18, 24
Citation: https://doi.org/10.5194/bg-2023-24-RC4 -
AC4: 'Reply on RC4', Matti Räsänen, 03 Jun 2023
The comment was uploaded in the form of a supplement: https://bg.copernicus.org/preprints/bg-2023-24/bg-2023-24-AC4-supplement.pdf
Matti Räsänen et al.
Data sets
Dataset for "Influence of termite mound structure and habitat on the mound CO2 and CH4 fluxes for fungus-growing termites" Matti Räsänen, Risto Vesala, Petri Rönnholm, Laura Arppe, Petra Manninen, Markus Jylhä, Jouko Rikkinen, Petri Pellikka, and Janne Rinne https://doi.org/10.6084/m9.figshare.21739484.v1
Matti Räsänen et al.
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