Analysis Long-Term and Spatial Changes of Forest Cover in Typical Karst Areas of China

Round 1

Reviewer 1 Report

The article "Tracking long-term and spatial changes of forest land cover in typical karst areas of China" is an analysis of forest cover changes of a typical county in China. Xuanwei County in Yunnan Province, Western China was selected as the study area. The authors use the historical military map of 1944 as the starting point, then analyze the forest cover based on remote sensing images from 1977 to 2013. In their analysis, they mainly refer to the area covered by forests, but additionally consider elements such as: Elevations, Slope, Soil Tapes and Lithologies. The article is a relatively solid, though simple analysis using GIS tools. It is difficult to point out innovative elements of the article. Neither use of historical map as a base, nor use of remote sensing images, nor application of well known GIS tools are novelties emphasized by authors. The article may be a demonstration of a certain procedure in a specific area and from this point of view it has some scientific value.

The article is properly structured, it contains all the elements that a good scientific article should have. However, I have comments on the content:

1.       The Introduction chapter definitely needs expansion. The scientific background is very symbolically outlined. Please greatly expand the description of other research in this area. By the way, this will improve the too small number of references (currently only 31).

2.       Please indicate the source of all tables and figures.

3.       Figures 1 cd - what do they present? No designation in the legend.

4.       Please extend the description of research results. In the current version, the authors refer basically only to changes in forest area. This part is done correctly, it is especially interesting to include important events in China that may have influenced the results. What I miss is the analysis using results related to: Elevations, Slope, Soil Tapes and Lithologies. Please in these elements also try to somehow justify the results obtained. The description in 3.2.1 - 3.2.4 is just a simple description of the area changes shown in Table 2 (please add in the table the reference units - are these areas?). Even this description itself is very strangely subjective. E.g. 3.2.1 - The authors indicate the periods 1944-1977 and 1986-2000 as the time of greatest changes at 2000-2500m altitude. Meanwhile, much larger differences can be seen for e.g. 1977-1986 and 1986-2000 for altitudes of 1500-2000m? I understand that there is no point in describing all changes, but it would be good to pay attention at least to the biggest ones, and not some randomly selected ones.

5.       Similar remarks about the results are also related to the figure 7. Please review it calmly. e.g. lines 247-248 - I don't see in figure 7 cd the given values! Maybe this is a result of the fact that there are different scales in Figures 7a-h - this may mislead the reader, but I guess it also misled the Authors...

6.       When discussing the results please refer to other studies in this area where similar elements were studied or similar methodology was used. Please point out what is new in this study and what is better than in other studies.

7.       Please expand your conclusions, currently I would call them residual!

8.       I would consider changing the title. The current one suggests a proposal for some kind of monitoring. Instead of "Tracking" I would suggest "Analysis"

9.       There are too many auto-citations in the references - please limit!

The article needs improvement.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The topic of this study is valuable and fits the aims and scopes of Journal Land. The results are interesting to international readers, particularly figures 4 and 5. However, the writing of this manuscript must be improved substantially before publication. In its present form, the readers cannot tell why the authors conduct this study, what’s the new/innovation of this study, and what’s the policy implications of the results. More specific comments are as follows.

 

Title and keywords. I suggest to change “forest land cover” to “forest cover”

Abstract. Line 18. “reveal China’s forest change……and response to national policy”. The study area is only one county of China, not the whole country. So, the authors should rephrase their aims.

Introduction. Why conduct this study, what’s the question this manuscript wants to answer? The readers cannot get this information in its present form. The introduction must be improved substantially. For example, why forest cover change study is important in karst areas of China? The literature review is weak.

Materials and methods. Change “2.1 Description of the Study Area” to “study area”. Please check the whole manuscript redundant writing. In abstract, the authors said “Moreover, this paper aims to reveal China’s forest change process and its response to the national policy and economy”. But in methods, there is nothing mentioned about this aspect.

Figure 1. What is subfigure c and d? subtitles are necessary for all subfigures. DEM should be replaced by “Elevation”.

Figure 7 and Table 2. The left column of figure 7 repeated table 2. In my opinion, the left column of figure 7 should be removed, only the changes (right column) is enough.

Discussion. Very weak, must be enhanced substantially. Authors should discuss the results and how they can be interpreted in perspective of previous studies and of the working hypotheses. The findings and their implications should be discussed in the broadest context possible and limitations of the work highlighted. Future research directions may also be mentioned.

Line 187-189, 335-336, should be removed.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The changes made to the article have greatly improved its quality. I accept them, as well as the clarifications to my comments from the first review.

I still have comments on Table 2 and Figure 7, something is still wrong. Please check all of this calmly! I assume that there are % on the X-axis in Figures 7a-d? This is not entered. Errors include:

1. description from 3.2.2: "The period 1986 to 2000 presented a relatively large change, accounting for 48.26% at 6°-15° and 23.90% at 15°-25°, with a total of more than 72%." - Figure 7b shows negative values of change in this period and of other magnitudes?

2. period 2000-2007 slope 6-15% according to Table 2 shows an increase of about 12% and in the figure - 30%.

3. period 2000-2007 slope 2000-2500 according to table 2 - slight decrease, according to figure 7b - about 23% increase!

4. checking randomly other values are also errors.

Please bring Table 2 and Figure 7, along with the descriptions of the results in 3.2.1-3.2.4 to compatibility. I suspect that there is some calculation error, but this is unacceptable.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

After revision, the manuscript improved substantially. It is recommended to further polish writing and language, not just English grammar by a senior sholar of this field, before publication. For example, the title is confusing with grammar errors.

Author Response

Please see the attachment

Author Response File: Author Response.docx