Estimation of Biomass Increase and CUE at a Young Temperate Scots Pine Stand Concerning Drought Occurrence by Combining Eddy Covariance and Biometric Methods

Round 1

Reviewer 1 Report

I have gone though the paper where authors used the 25 year data to estimate biomass increase and CUE at young temperate Scots pine stand using eddy covariance and biometric methods. Paper is very interesting to the reader and falling in the scope of the journal. Before accepting for publication, manuscript need minor revision, suggested below. 

Minor comments:

Abstract: abbreviation need to be define before using (e.g., dbh; depth at breast height)

Line no 32: kindly check the sub-script and super-script, many mistakes at many places (e.g., 2.0 – 2.1 t C ha-1 and 2.6 – 2.7 t C ha-1) and correct it thoroughly 

Line no 50 should be written like "above (AGB)-and below ground biomass (BGB)

Line no 71-73: sentences need to be supported with current research work (see; Journal of Sustainable Forestry 39 (6), 10.1080/10549811.2020.1794907; Land 10 (435), https://doi.org/10.3390/land10040435)

Overall state-of-the-art is missing in the introduction section, request author to revised it carefully, research gaps followed by objective.

Line no 113:  it should be 1080 m^2 (33 m x 33 m)

Results and discussion written in fruitful ways and interesting 

Conclusion need to be re-drawn in technical way (Two paragraph maximum), small paragraph is no meaning 

Author Response

Please see the attachment.

Your faithfully,

Paulina Dukat

Author Response File: Author Response.docx

Reviewer 2 Report

Authors estimate NPP by both the eddy covariance method and based on allometric equations and series of stem diameter increments recorded by dendrometers and by tree extractions. The paper, even scientifically being moderate is hard to read, as the sentences are too long with doubling information and not going directly to the point. Moreover, a plenty of of Tables are doubling information to the graphs. The paper should be carefully rewritten so that it is much shorter and sentences are crystal clear. As of now, it is more like a novel than a scientific literature. Apart from that here are some more detailed comments.

After taken this in account, paper could be published in Forests.

line 42, 46, 49: check subscript (CO2)

line 54: It would be worth to mention air pollution (tropospheric ozone) too. As it has large effect on carbon uptake (apart from mentioned meteorological conditions). You might include nice review 10.3390/atmos12010082

line 76: should ne Zianis et all.,

line 110: Pinus sylvestris, Betula pendula - use italics

line 124-126. Do not double the information. In line 120-121 you describe the EC setup so write directly in there the type of 3D anemometer and CO2/H2O analyser

line 127: use factors or values

line 128-134: check the abbreviations. Most of theme you define and never use in the text, then it does not make sense to use abbreviation.

line 133: soil water content was measured only in 2cm depth? That should be measured more deep

line 138: you should define ME

line 138-140: what is the percentage of the data used from IMGIW?

line 141: when you define abbreviation EC, then use it. Write shorter: for example 4300 trees ha-1

line 142: write exactly the average tree height, not approximately

line 144: you wrote that already. Do not double the information

line 159: define WPL abbreviation

line 161: should be AND Foken

line 163: which threshold was applied?

Site description needs rewriting so that the sentences are not vague and long and go directly to the point and do not double the information.

line 186: data are plural, therefore were sent

line 216. Does not make sense. Please rephrase.

Table 1: Please re-arrange the table so that it fits the requirements of the journal. There should not be bold lines around the table and in between the lines.

Figure 3: There is no reference to Fig. 3 in the text. Define DBH in the figure description again. The figures should be self-explanatory.

line 272: "However it was suggested" - who has suggested?

Figure 4: delete the dot between Figure and 4. The same for Fig. 3. Moreover, why to create a figure from Equations? It would be better to introduce equations as Eq. 1-6 instead of figure.

Table 2: Please re-arrange the table so that it fits the requirements of the journal. Moreover delete the table. Why to show it here when it is not your work? Just refer to this work in results, if you use the numbers from there, or refer to that in discussion.

line 297: first define CUE as in line 299 and then use it. Not the opposite.

line 300: GPP is already defined. Do not define it again.

line 301: the definition of vegetation period is not correct. During drought conditions it often happenes, that forest is a source of carbon. In here it wont be part of the vegetation period. Define it in another way.

line 316: should be "are shown"

line 317: I do not see it in Fig. 4. Did you mean Fig 6?

Figure 6: In the upper figure the min values from 2019-2020 are reaching only -1.5, whereas in the enlarged figure surrounded by the red line the min values is up to -2.5. How is that possible?

line 334: why do you again define P?

Table 3: Please re-arrange the table so that it fits the requirements of the journal. Moreover, delete the table. The data are already in Fig 7

line 380: the sentence should be without "of"

Table 4: Please re-arrange the table so that it fits the requirements of the journal. Do not use shaded background.

line 471, 474: Xu et all. - reference missing

line 485: Drake et all. (2011) - reference number missing

line 486: is it needed to write the division here?

line 492: inter alia should be in italics

line 502: why do you define again CUE?

line 500: the 4.2: NEP could be changed even due to air pollution, apart from drought conditions. See 10.3832/ifor2805-011 for example

line 529: what is 0.5 level?

line 552: missing reference number in Peichl et al. It is missing in more places. Check throughout the manuscript.

line 565: please put some indication of precipitation sum to see how dry was the 2018 year. The dry index starts in 2019.

Author Response

Please see the attachment.

Yours Faithfully,

Paulina Dukat

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Thank you for the updates you did. I think the paper is much clearer for the reader. I suggest to accept.