Authors' response to reviewers' comments

It's really a time-consuming thing to respond to each item of the reviever's comments.But it's a very important part to tell the editor that you have carefully considered the reviewers's comments and suggestions.  Sometimes the editors will send the authors' response to the reviewers for further checking when an articles are required to make major revision. Here I show one authors's detailed response.

___________________________________________- 

The Revision Explanation for all Reviewers
Reviewer(s)' Comments to Author:
Reviewer: 1
1. The significance of LAI for mountain areas should be clearly stated and extended.
Revision explanation:
Thank you very much for your good idea. Indeed, in the previous version of this manuscript, there are no specific statement about the significance of LAI for mountain areas. But it is really quite important and should be stated carefully in this paper. So according to your advice, we added the corresponding contents in the second paragraph of “Introduction”. During these contents, we illustrate the significance of LAI for mountain areas from 3 aspects. The detailed information can be seen from those of “For mountain areas, ……Firstly……Secondly……Lastly…..” in the latter part of the second paragraph of “Introduction”.

2. Every figure should have its independence and integration. Place name(s) should be included. Fig.1 and Fig. 11 are too poor.
Revision explanation:
Thanks a lot for your suggestion. According to it, we have added place name(s) in corresponding figures. Many figures indeed have poor quality. In order to improve it, we redesign and reproduce each of these figures according to the specific requirements of the editorial office of the journal.

3. English language of this manuscript is rather poor. It needs great improvement.
Revision explanation:
Thank you very much for your gentle reminder. After our revision on the technical problems, another member in our group whose English is quite well has checked the whole contents especially focusing on the grammar and vocabulary problems. After that, we have invited a native English-language colleague of professor Arthur Cracknell to help us improve the whole paper. Therefore there are great improvement in the language of this manuscript.

4. The study area has a very strange shape. How is it defined? It seems that it is cut.
Revision explanation:
Thank you very much for your question. You are quite right that it is cut out from a large area. It is defined according to the main type of vegetation. As stated in the part of “2.1 study area”, our study area locates in Dayekou forest center in Heihe watershed of Gansu province and has several kinds of vegetation. But our study focuses only on one kind of coniferous tree-Picea crassifolia. Our field measurements are performed aiming to this type of vegetation and thus the models we establish in this paper can only be used for it. So we cut out the concentrated distribution area of this type of vegetation and as a result, the shape of it seems a little strange. In order to make it more understandable, we add some explanation in the part of “Study area”.

5. A total of 11 figures is included. Too many! and most of them have poor quality.
Revision explanation:
Thank you very much for your gentle reminder. Your advice is quite justified. 11 figures seem too many. So according to it, we move 5 unnecessary figures and only reserve 6 of them. These 6 figures are all been reproduced according to the requirements of this journal, especially on the format and size of them. The corresponding information in the text have also been revised.

6. The leaf area index (LAI) is ecologically important, but what does it mean for mountain regions?
Revision explanation:
Thank you for your meticulous reminder. Yes, the LAI is ecologically important and also significant for mountain areas. According to your advice, we further review and read many papers and then conclude its significance from 3 aspects. The 1st is from the aspect for controlling water loss and soil erosion; the 2nd aspect focuses on the characterization of impact on local climate; the 3rd is from the aspect of reference for the study of carbon cycle (carbon source and sinks). These are illustrated based on the terrain and climate characteristics of mountain areas. The detailed contents can be seen from the second paragraph of “Introduction”.

7. The title of the manuscript (Retrieval and analysis of leaf area index in mountain area) is not very adequate. The text did not include analysis of leaf area index. It should be "Topographic correction-based retrieval of leaf area index in mountain areas".
Revision explanation:
Thank you very much for your excellent advice. We have corrected it according to your advice. Thanks again for all your comments which are very helpful for us!

Reviewer(s)' Comments to Author:
Reviewer: 2
1. The authors present LAI measurements its relation with reflectance and vegetation indices. The efforts made by authors is commendable but it is not very clear how the authors have removed topographic and shadow effect. It will be essential to compare reflectance measurements with the satellite observed reflectance.
Revision explanation:
Thank you very much for your praise as well as question. As out study focuses on the retrieval of LAI based on the comparison between field measurements and the satellite observed reflectance (together with vegetation indexes) before and after topographic correction, so it is essential to make this key point clear.
Due to the effect of topographical variation, there is a difference in the reflectance between shady slope and sunny slope, so we need to remove the topographic and shadow effect. This can be realized by using various topographic correction models which had begun from the beginning of the 1980s and become more and more popular nowadays. The specific model we use here is the SCS+C model which can remove the impact of terrain effectively based on the relationships among sun, senor and canopy simultaneously. Its main principle can be seen from equation (3) to (6). This model has been widely used and its effect has also been validated in many studies. In this study, the effectiveness of the correction can be validated from the different change on surface reflectance before and after topographic correction in shady slope and sunny slope.
In summary, through the topographic correction in combination with the slope and aspect of the study area from the DEM, the solar zenith angle and azimuth angle from the optical image, we finally remove the topographic and shadow effect efficiently. In order to make all above more clearly, we revise some contents in the part of “Topographic correction” in this manuscript. Based on these, our goal can be ultimately achieved.

2. Authors may consider to write conclusion separately and discussion combined with results.
Revision explanation:
Thanks a lot for your excellent suggestion. According to it, we have written the conclusion and discussion separately in the fifth part of this manuscript. And also the discussion is performed combined with the specific result. After all these, the conclusion and discussion become more targeted.
Thanks again for all your excellent comments which are quite valuable for us!

Editorial Office
Comments to the Author
Too many figures in this paper. please move the unnecessary ones. And send all figures back as Tiff format. The fonts in the figures and pictures are required to use Times New Roman, and word sizes should be in proportion to the figures (charts, pictures), and the resolution for color graph and grey scale image is required to be 150~225dpi, and the resolution for bitmap image is 600~900dpi.

You should ask a native English-language colleague to help you improving the language in the paper before resubmission.

Revision Explanation:
Thank you very much for your sincere advices. According to it, we have moved 5 unnecessary figures and only reserve 6 of them. These 6 figures are all been redesigned and reproduced according to your specific requirements, especially on the format and size of them. The corresponding information in the text have been revised. These figures are also been uploaded in Tiff format individually.

For the language problems, after our revision on the technical problems, another member in our group whose English is quite well has checked the whole contents especially focusing on the grammar and vocabulary problems. After that, we have invited a native English-language colleague of professor Arthur Cracknell to help us improve the whole paper. So there must have great improvement in the language of this manuscript.

Finally, thank you very much for all your excellent comments and advices again. These comments are very helpful for the improvement of this manuscript as well as our research in the future. We sincerely appreciate you for your fruitful work. Best wishes to you all!