Contrasting biosphere responses to hydrometeorological extremes: revisiting the 2010 western Russian heatwave

Flach, Milan; Sippel, Sebastian; Gans, Fabian; Bastos, Ana; Brenning, Alexander; Reichstein, Markus; Mahecha, Miguel D.

doi:https://doi.org/10.5194/bg-15-6067-2018

Articles | Volume 15, issue 20

https://doi.org/10.5194/bg-15-6067-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-15-6067-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 15, issue 20

Research article

| Highlight paper

|

16 Oct 2018

Research article | Highlight paper |

| 16 Oct 2018

Contrasting biosphere responses to hydrometeorological extremes: revisiting the 2010 western Russian heatwave

Milan Flach, Sebastian Sippel, Fabian Gans, Ana Bastos, Alexander Brenning, Markus Reichstein, and Miguel D. Mahecha

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Final revised paper (published on 16 Oct 2018)
Preprint (discussion started on 04 Apr 2018)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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RC1: 'Reviewer Comments', Anonymous Referee #1, 24 Apr 2018
- AC1: 'Response to Anonymous Referee #1', Milan Flach, 07 Jun 2018
RC2: 'Reviewer 2 comments', Anonymous Referee #2, 02 May 2018
- AC2: 'Response to Anonymous Referee #2', Milan Flach, 07 Jun 2018

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (13 Jun 2018) by Paul Stoy

AR by Milan Flach on behalf of the Authors (17 Jul 2018) Author's response Manuscript

ED: Referee Nomination & Report Request started (19 Jul 2018) by Paul Stoy

RR by Anonymous Referee #1 (08 Aug 2018)

Suggestions for revision or reasons for rejection

Review of the Revised Manuscript: “Contrasting biosphere responses to hydrometerological extremes: revisiting the 2010 western Russian Heatwave” by Flach and coauthors

Main Comments

As was raised in my first review of this manuscript, what I find hardest to reconcile is the concept of GPP compensation between two ecosystems that are spatially distinct and that occur at different times. When aggregating over the spring and summer corresponding to the RHW the text makes it seem like overall the impact of the RHW was ‘good’ in terms of the net change in GPP integrated over the whole region. However it was the agricultural ecosystems that were severely impact over the summer. Although there is one remark that post-RHW GPP anomalies were negligible indicating a recovery of the agricultural ecosystems this could be emphasised more by the discussion of Figure 9.

Despite the authors reassuring in the response to reviewers that they would carefully check the manuscript text I was very disappointed at how poorly this was done. I have now noted in the minor comments most of the instances that I have found in the hope that they can be rectified in the next revision.

Minor Comments

• The authors need to get someone to check the text more carefully. There are several instances where the tense changes from past to present which is quite irritating. e.g. “positive GPP anomalies occurred during the spring event, whereas negative GPP anomalies are occurring during the summer heatwave” It is not sufficient to note appreciation to the journal for language editing services if they have yet to be used.
• Furthermore, when citing other research terms/phrases such as “probably breaking temperature records of several centuries” and “The RHW is often associated with an atmospheric blocking situation” are ambiguous. Did the RHW break records or not? Was the RHW associated with atmospheric blocking? (yes) Be specific.
• Replace: “a negative soil moisture contributed” with “a negative soil moisture anomaly contributed”. Again, please check the text; one cannot assume that every reader will necessarily be able to know which words are missing.
• I would suggest replacing 3.5 “may facilitate our knowledge about the RHW” with “may further our understanding of the RHW”
• 3.10: “The positive GPP response in spring might be a reaction to warmer, more optimal spring temperatures (Wang et al., 2017) possibly accompanied by enough water availability” Why not check this so that your statement can be more definitive?
• 3.14: “Increased GPP in spring may negatively influence soil moisture and thus GPP during summer (Buermann et al., 2013).” Perhaps elaborate on this a bit more
• 3.20 remove ‘equitably’
• 5.1: “We consider turbulent fluxes to be biospheric response variables because they are strongly determined by processes in the terrestrial biosphere.” I don’t quite agree. Latent heat is also a hydrological variable. Is this sentence necessary?
• 5.3: “The selected variables cover the spatial extent of Europe (latitude 34.5-71.5˚N; longitude: -18-60.5˚E ) and are regridded on a spatial resolution of 0.25˚ from 2001 to 2011 in an eight-daily temporal resolution.” Perhaps specify that the period is selected as the common period that all datasets cover, a necessary condition for the analysis
• 5.5 I would say ‘dominant land cover class’
• There are three references to Figure 4 prior to the first reference to Figure 2 (and Figure 3). Usually the figures are ordered according to when they are first referenced in the manuscript text. Please fix as this oversight is irritating.
• 5.31 replace ‘strategy’ with ‘methodology’
• 8.13: “They are to compute the spatial and temporal distance between res+ and res- .” Awkward sentence, perhaps something is missing. Please rephrase.
• Figure 5. Could the authors make the colorbars larger? They are currently illegible.
• 10.2: “We find that the GPP response is entirely positive during the shortlasting hydrometeorological spring event (+17:8 Tg C, Tab. 1), while it is mainly negative during the summer (+8:8 Tg C,-49 Tg C, Tab. 5 1). Nonetheless, 18% of the GPP summer losses associated with the RHW in the southern region are instantaneously compensated by over-productive vegetation in the northern latitudes.” I’m still not comfortable with how this has been phrased. Please correct me if I have misunderstood but authors argue that the positive GPP anomaly in the high latitudes compensate for the negative GPP anomaly in the mid-latitudes. They are different locations and vegetation types. Yes over the whole EU domain, there is a net positive GPP anomaly but this still doesn’t equate to a good outcome over the mid-latitude croplands. Perhaps looking in the season after the RHW would provide a sense of the recovery. Perhaps including a map of the net GPP change across both spring and summer would convey that while over the domain as a whole there is a ‘GPP compensation’ but that there are still regions that could be considered worse off locally.
• 10.10: “integrated annual (spring and summer)” what about winter and autumn?
• I was a bit lost on how to interpret Figure 8 as it shows some soil moisture information that is never discussed. Perhaps the authors could include a statement on how the temperatures correspond to the anomalous soil moisture conditions
• 13.1: I’m not sure the simple linear regression model is adding value here? It doesn’t tell us anything new.
• 14.10: “The absence of events after the summer heatwave which implies a fast recovery of the ecosystems.” This would be useful if stated much sooner.
• 15.25: “Regarding the RHW in particular, compensation effects remain unconsidered in previous studies to the best of our knowledge.” Perhaps because the authors consider ‘compensation’ occurring over two different regions and times as opposed to the same region or at the same time. This is what I find hard to reconcile and I was not satisfied with the revisions made when I commented on this in the first review.
• I’m a bit perplexed that there is both an appendix and supplementary material. Could these perhaps been combined?

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ED: Publish subject to minor revisions (review by editor) (11 Aug 2018) by Paul Stoy

AR by Milan Flach on behalf of the Authors (27 Sep 2018) Author's response Manuscript

ED: Publish as is (02 Oct 2018) by Paul Stoy

AR by Milan Flach on behalf of the Authors (04 Oct 2018) Author's response Manuscript

Short summary

Northern forests enhanced their productivity during and before the 2010 Russian mega heatwave. We scrutinize this issue with a novel type of multivariate extreme event detection approach. Forests compensate for 54 % of the carbon losses in agricultural ecosystems due to vulnerable conditions in spring and better water management in summer. The findings highlight the importance of forests in mitigating climate change, while not alleviating the consequences of extreme events for food security.