Estimation of Forest Ecosystem Climate Regulation Service Based on Actual Evapotranspiration of New Urban Areas in Guanshanhu District, Guiyang, Guizhou Province, China

Round 1

Reviewer 1 Report

I thank the authors for their tremendous efforts at improving the clarity of the logic and reasoning behind the paper. I think this is above all important, because not all of these issues have been settled in the science, and because there are still issues to be debated on these topics. Making the logic clear at least raises the level of the debate. 

I do think there are additional issues here that are still being neglected and thus encourage the authors to keep thinking about this issue. In many places in China (and elsewhere in the world), reforestation has brought with it significant problems in terms of watershed-level water availability. Where this article falls short, is in the discussion of the impacts of increased ET on local water availability. These may be positive. They may also be negative. But the authors have not really even tried to answer this question. There is a lot of literature on these topics, both in China and internationally... Thus, I would suggest the authors look at more of this research when further considering these issues. 

Such issues are, of course, important with regard to the valuation question. Thus, while the valuation numbers look good. The real question is whether we should genuinely think of this valuation in positive terms or not...?

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

I have thoroughly reviewed the resubmitted manuscript and also the authors’ responses to my previous report. The authors have extensively revised their manuscript. The introduction and the discussion sections were extended and several additions and corrections were incorporated in the revised manuscript. The work is interesting, however, in my opinion, the new approach proposed by the authors has still important issues that should be addressed.

Comments and suggestions

1. The introduction has been extended, but very little information is presented concerning the topic of the authors' works mainly in lines 66-78. Even these few works are poorly and in some cases falsely presented e.g. in lines 66-69 is mentioned that “In recent years, many studies have …….. to estimate the climate regulation value of ecosystems in China [19-21]”. These 19-21 works are not all implemented in China as stated: 19 in America and 20: in the Mediterranean. These studies should be thoroughly reviewed and the most important findings, if associated with the results of the present study, should be presented in detail.

2. The most important studies in the introduction are 22-23, which the authors mention as examples of estimating the climate regulation values according to evapotranspiration (though implemented for freshwater ecosystems). Both studies are in Chines and thus not easy to be reviewed by the readers. Considering their importance regarding the similarity of the methodological approach, the findings of these studies should also be presented in detail.

3. In lines 88-90 is stated that “The annual actual evapotranspiration of different types of forest ecosystems and the impervious surface was calculated with the help of ArcGIS”. Please remove the sentence.

4. In the “Materials and pre-processing”, it is better to change the title to “Materials and Methods”. It also appears that in the resubmitted study, several new stations were added, covering the whole study area. This is very important.

5. In subsection 2.3 K is defined (lines 136-137) as “evapotranspiration coefficient of ecosystem”. K refers to Kc, the “crop or plant coefficient” used worldwide. Please change it. Also, define K in more detail. K is a critical factor in your study driving all the differences in AET mentioned in this work. The K values used, should be presented (maybe in the form of a table) and especially the K for the “impervious surface”. This is extremely important, considering that the authors propose “a new approach”(line 90) to estimate climate regulation values and thus should give all the details to the readers to ensure the replicability of their approach.

6. The “impervious surface” should be described in detail. Mention their characteristics in conjunction with the other surfaces of your study.

7. Change the “artificial surface” in Figs 4 (a,b,c) and 5.

8. Based on the analysis presented in lines 230-234, the findings just suggest that coniferous forest evapotranspirates (on an annual basis) more than the other surfaces. Make a correction to your statement “The findings imply that coniferous forest plays an important role in climate regulation” or continue your analysis and justify the statement.

9. In lines 235-243, the authors repeat the numbers already presented in Table 2, without further analysis or explanation. It is suggested to remove the text or continue the discussion to make a point.

10. In lines 244-245 the authors state “Differences in evapotranspiration were calculated as the heat absorbed by evapotranspiration and then converted into an electricity quantity.”. I don’t understand the meaning of this sentence. I recommend deleting it.

11. Lines 285-306 are too general. The text can be considered as part of the introduction, but not, in any case, part of the Discussion of the results of this study. If incorporated in the introduction change “Significantly” in line 291.

12. Lines 307-316 are the only discussion presented in the paper. The references 62, 63, and 64, seem to be very important for the comparison with the findings of this study and they are the only references that the authors base their discussion, presenting climate regulation values. I suggest expanding the discussion by incorporating studies from other sites around the world, or/and at least presenting in more detail the findings and the methodology used in the above-mentioned studies since they are all in Chinese and thus not easily accessed by the readers.

Author Response

Please see the attachment 

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript address on the estimation of forest ecosystem climate regulation service based on actual evapotranspiration of new urban areas in Guanshanhu district, Guiyang, Guizhou province, China. Some interesting results could provide good information for ecological construction in new urban areas, and regional planning and decision making. The science and methodology of the manuscript appear sound, and adequately cited. The trend analysis of the climate regulation value of forest ecosystem was carried out on increasing but slow down. This study is a beneficial exploration of forest ecosystem climate regulation value estimation. One point that could perhaps be strengthened is more of an indication to the readers of the level of uniqueness of the study comparing with previous studies if there is any. I believe a moderate level of revisions should be made to the paper before it is ready to be considered for publication with Sustainability. See the detail comments below.

General Comment:

As I mentioned in summary, it will help readers to better understand the level of uniqueness of the study comparing with previous studies if there is any, add more sentences in the introduction section about what have been done.  

Specific Comments:

Figure 1. it would be good if authors can add a small location map where Guizhou Province is located at China, it will help international readers.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I have thoroughly reviewed the revised version of the manuscript, which has been extensively revised by the authors. Their response to my comments was also reviewed and all issues were properly addressed. I acknowledge the great efforts of the authors, made through the many review rounds, and I believe that the revised paper is of enhanced quality compared to all its previous versions.  The authors have extensively revised the introduction and discussion sections, as suggested, incorporating important findings from relevant studies around the world. They have also added very important information concerning details for the application of the proposed methodology, enhancing the replicability of their methodological approach and its application in other sites by other researchers.  It is very important, that in the revised paper, the limitations of the study and the limits for the application of the proposed methodology were also added as requested. In addition, many inappropriate, false or misleading statements were removed. Finally, the citation of new interesting works and the removal of not relevant ones were also implemented, further enhancing the quality of this paper.

In my opinion the resubmitted manuscript can be accepted for publication in its present form.

Reviewer 3 Report

The authors did a good job in revising the manuscript. They have addressed all my main concerns and also taken care of minor comments/editorial changes. I recommend that the manuscript be accepted for publication.