Forest Resource Quality and Human Activity Intensity Change and Spatial Autocorrelation Analysis in Yulin City, China
Round 1
Reviewer 1 Report
Dear Authors,
I have read this paper multiple times to make sure I have the whole picture of your study. This is exactly my first remark: I indeed had to read it multiple times to understand it, because the paper does not follow the reader through your study, crucial information on data, methods, and even the purpose of the research are presented in the discussion etc. So please carefully restructure the content, so that relevant information can be found in the relevant chapters. My second general remark is that the research should be fundamentally reconsidered to make sure the aim of the research, the data and the methods are in harmony, and the results are valid. For this reason this paper cannot be fully reviewed in one instance, and my comments mostly refer to big issues, detailed review can only be done after the major issues are solved.
1 1 Introduction
Introduction describes forest as an ecosystem, and highlights its importance as such, especially from the ecosystem services point of view. However, it is unclear how the indicators applied in this research cover the wide range of forest services, or the ability of a forest to provide these services.
A clear aim of analysis should be provided at the beginning. What is the problem that needs to be solved, or what chain of causation we want to discover, or some other type of research question shall be formulated.
Further, what is the logic of the analysis, how we will get an answer to the research question by using the selected method? The reason why more clarity is needed on the research design is that it is unclear that:
- -if we need to know whether the forest quality is changing, then we do not need to deal with human influence, as the forest data are fully available, and they can be compared over time. 2017 and 2020 is a very short period, though.
- -if we want to know whether the changes in forest quality are caused by human influence, then we do not need two datasets for two years, a static analysis will tell. In this case natural conditions should also be considered as independent variables potentially influencing forest quality. Furthermore, the autocorrelation between natural conditions and human influence should also be tested and considered.
- -if we want to discover causal relationships between variables, a regression model would probably the best. Spatial autocorrelation provides us information on spatial structure, and would be more suitable for the forest quality analysis without the involvement of human influence.
The involvement of the changes of human influence over a short period of time (2017 and 2020) in the research in any form makes very little sense, as the change in this index can hardly be detected. The changes can be real (significant), however, minor.
2. Material and methods
- The title suggests that the study was conducted on sub-compartment level, but in the material and method section it is explained that it was in fact conducted on a 30x30m raster level. Either the title needs to be corrected (you can delete ‘sub-compartment level’), or more explanation is needed how the various data were transformed to sub-compartment level.
- The logic of the whole research should be more explained: how the natural conditions (climate, topography, geology etc.) influence the selected indicators and how their correlation can affect the analysis. It may be typical that as natural conditions change from the lowlands to the mountain tops, the natural conditions of forests also show gradual changes, while human impacts (e.g. population and road density) tend to be less intense along this gradient. Even if there were no forestry activity at all, the analysis would result in a strong correlation between human impact and forest condition, with no real causal relationship. On the other hand, if we analysed the change of indicators over time, careful consideration should be given to the frequency of the update of the indexes. For instance, are the soil types and soil thickness etc updated during the timeframe of the study, do they change, etc.?
- The introduction of the paper highlights the importance of the role of forests in the functioning of the biosphere, which implies that ‘forest quality’ in the title also refer to the natural state of the forests, however, it is not evident from what is written in the method section.
- The applied indices should be more explained:
- what is the purpose of the index, what it should represent
- how the indicators contribute to the purpose of the index, why they were selected
- there are indicators that refer to the tree stand directly, also indirect indicators that describe natural conditions, such as slope and aspect. Soil belong to both categories, as it can be seen as a part of the forest and it is directly influenced by human activity, and it is also influencing the tree stand. If the index is composed of these various indicators that are interrelated and their sensitivity to human influence is largely different, how they will work together, and how this effect the meaning of the index?
2.2.
Please provide explanation to acronyms.
2.3.1
- The selected indicators should be more explained: what they mean, why they were selected, how they are monitored, especially how frequently these data are updated in the inventory.
- The exact meaning of some of them is not obvious: ‘impervious surface area’, ‘quality grade of forest land’, ‘origin’. What do 'other' categories include?
- Soil type should be explained why and how it could interact with human influence.
- Soil thickness needs explanation, if it can significantly change over the study timeframe.
- Slope and aspect are not listed in the text as quality indicators, they should be listed and explained, how human influence can affect them, and what role they play in describing the forest resources.
2.3.5.
Just for clarity: In formula (6) ‘i' is supposed to mean the unit of analysis (raster points), isn’t it? If so, I think ‘I’ (which stands for the human influence or the forest resource quality index) should also have a ‘i' in the subscript, as the indices are calculated for each raster point if I got it right.
2.3.6.
It is difficult to understand: ‘The response correlation between the human activity intensity and the forest resource quality can indicate the regional forest resource quality.’
3.1.
Figure 2: which of the map represents 2017 and 2020?
References
32 The link provided leads to another article.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
The paper seems to be interesting and sound. However, I feel that it is rather local to prove an international trend. It also needs checking for typos and reference errors.
BR,
REV.
No comments.
Author Response
Point 1: The paper seems to be interesting and sound. However, I feel that it is rather local to prove an international trend. It also needs checking for typos and reference errors.
Response 1: We are deeply honored that you believe our paper has certain value and significance. However, you also pointed out that our paper has certain limitations in demonstrating international trends. We fully agree with your viewpoint and have supplemented it in the introduction section. We also attach great importance to the spelling and citation errors you mentioned and have made every effort to correct them.
Reviewer 3 Report
1. The paper needs to provide more information in the introduction section. It should add in more literature. And it also needs to show the importance and break-through parts of this study in this section.
2. Don't directly show the website link in the manuscript, such as "data (https://www.gscloud.cn) ". Add those into the notes.
3. It needs further explanation about the reason to use the 1km grid. What are the differences between it with the other scales?
4. The study only chose two years for analysis. Is the trend consistent from 2017 to 2020?
Minor editing of English language required
Author Response
Point 1: The paper needs to provide more information in the introduction section. It should add in more literature. And it also needs to show the importance and break-through parts of this study in this section.
Response 1: This suggestion was provided in more detail by other reviews, and we have made modifications (Reorganize the research background and purpose).
Point 2: Don't directly show the website link in the manuscript, such as "data (https://www.gscloud.cn) ". Add those into the notes.
Response 2: We have removed the website link and provided it uniformly at the end of the article in “Data Availability Statement”.
Point 3:. It needs further explanation about the reason to use the 1km grid. What are the differences between it with the other scales?
Response 3: In section 2.3.6, we have added an introduction to why we using a 1km grid.
Point 4: The study only chose two years for analysis. Is the trend consistent from 2017 to 2020?
Response 4: The changes in forest resource quality and human activity intensity in 2017 and 2020 were introduced in sections 3.1 and 3.2 of the paper, respectively. It can be seen that: from 2017 to 2020, the forest resource quality and the human activity intensity of Yulin City showed an overall upward trend.
