The Effects of Different Vegetation Restoration Models on Soil Quality in Karst Areas of Southwest China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Several questions and remarks regarding the paper by Ou et al. “The effects of different vegetation restoration models on soil quality in Karst areas of Southwest China”.

 

Provide further details about the restoration models examined in this study. Were those stands planted artificially? If so, provide a planting scheme for these stands. At the start and end of the experiment, what was the density of these stands?

Provide information on the distances between the stand types (for all restoration models) under study.

What criteria did the authors apply to choose these tree species (listed in Table 1) from the many species of evergreen and deciduous broad-leaved trees?

The fifth model of restoration (disturbed forest) is positioned on the steepest slope. For this location, the lowest values of practically all the physical and chemical characteristics of the soil were determined. The speed and scale of erosion processes increased at this location because there was no vegetation (all shrubs and herbs were regularly cut down every year). Why is one of the leading causes of soil deterioration not discussed?

Table 1. Projection area… Is this the size of the test sites (40 by 40 metres to 50 by 50 metres)? Or is it the size of the entire forest covered in this type of vegetation (vegetation restoration model)?

Two depths of soil samples (0–20 cm and 20–40 cm) were collected. Why and how were soil physical and chemical characteristics measured for thicknesses ranging from 0 to 40 cm?

“…foreign tree species…” (Line 70 and 378). What do you mean by the term “foreign tree species”? The term "introduced species" is more suitable.

Table 4. Footnote: Bold numbers are considered highly weighted. Which values have high weighting? The table does not contain any values that are in bold.

Table 5. Correct the table size. Because the table size exceeds the page size, the last indicator (ALP) is missing.

The authors must correctly specify the Latin names of the plants. First, the first mention of the species' Latin name in the text should be given in full. Second, you must provide an accepted biological name, not synonyms: Cyclobalanopsis glauca - this name is a homotypic synonym of Quercus glauca Thunb. (accepted Latin name), Cyclosorus parasiticus - this name is a synonym of Christella parasitica (L.) H.Lév. (accepted Latin name), Microstegium vagans - this name is a synonym of Microstegium fasciculatum (L.) Henrard (accepted Latin name), Cipadessa cinerascens - this name is a synonym of Cipadessa baccifera (Roxb. ex Roth) Miq. (accepted Latin name), (accepted Latin name), Embelia rudis - this name is a synonym of Embelia vestita Roxb. (accepted Latin name), Argyreia seguinii - this name is a synonym of Argyreia pierreana Bois (accepted Latin name), Dalbergia balansae - this name is a synonym of Dalbergia assamica Benth. (accepted Latin name). Second, the first mention of the species' Latin name in the text should be given in full.

When writing Latin plant names, care must be taken to prevent errors. Please correct Jasminum nervosu to Jasminum nervosum (correct Latin name).

Add research limitations to the Discussion section.

Author Response

Dear reviewer,

I quite appreciate your favorite consideration and insightful comments. Now I have revised the manuscript in full accordance with your comments and found them very helpful. I hope this revision will make my paper more acceptable.. The point to point responds to your comments are listed as following:

Response to the reviewer’ comments:

Ref: forests-3037200
Title: The effects of different vegetation restoration models on soil quality in Karst areas of Southwest China

Journal: Forests

Reviewer: 

MAIN COMMENTS

1.Provide further details about the restoration models examined in this study. Were those stands planted artificially? If so, provide a planting scheme for these stands. At the start and end of the experiment, what was the density of these stands?.

Thanks to the advice of the experts, we have further described the recovery model, provided the experimental planting plan, and increased the stand density in the manuscript. Please refer to the revised manuscript for specific changes.

2.Provide information on the distances between the stand types (for all restoration models) under study.

Thanks for your suggestion, we have re-provided the distribution map of stand types and supplemented the distance between restoration models.

3. What criteria did the authors apply to choose these tree species (listed in Table 1) from the many species of evergreen and deciduous broad-leaved trees?

 According to your question, we have added the reasons for choosing the tree species to the manuscript. In karst areas of China, Zenia insignis Chun. is one of the main afforestation trees. In mixed evergreen and deciduous broad-leaved forests, Cyclobalanopsis glauca (Thunb.) Oerst. is one of the dominant species of glauca and Choerospondias axillaris (Roxb.) Burtt et Hill Therefore, we selected these three tree species for restoration models and determined the distribution ratio based on the survey's original vegetation results.

4. The fifth model of restoration (disturbed forest) is positioned on the steepest slope. For this location, the lowest values of practically all the physical and chemical characteristics of the soil were determined. The speed and scale of erosion processes increased at this location because there was no vegetation (all shrubs and herbs were regularly cut down every year). Why is one of the leading causes of soil deterioration not discussed?

We have added a discussion of soil deterioration to the manuscript and revised it as follows:

The soil quality of DF model is significantly lower than that of artificial forest restoration and NF model, mainly due to the special geological and climatic conditions in karst area, which has the characteristics of small environmental capacity, weak anti-interference ability, low stability and weak self-regulation ability. The destruction of vegetation by human disturbance affected the material and energy balance of the karst soil-vegetation system, induced the reverse evolution of the soil-vegetation system, led to the intensification of soil and water loss and the easy loss of organic carbon in the surface soil. At the same time, human disturbance caused changes in karst vegetation community structure and litter return quality, increased the net mineralization rate of organic matter, and increased the risk of soil nutrient loss. This series of reasons led to serious degradation of soil quality in DF model.

5. Table 1. Projection area… Is this the size of the test sites (40 by 40 metres to 50 by 50 metres)? Or is it the size of the entire forest covered in this type of vegetation (vegetation restoration model)?

The Projection area refers to the size of the vegetation restoration model test site, and we have also added a description in the manuscript.

6. Two depths of soil samples (0–20 cm and 20–40 cm) were collected. Why and how were soil physical and chemical characteristics measured for thicknesses ranging from 0 to 40 cm?

As described in lines 95 to 97 of the manuscript, the soil layer in the experimental site is thin, and even in some places the soil layer is not 40cm.The original manuscript is as follows:

Exposed bedrock areas in the depression account for 15% of the land area with a soil depth of 20–160 cm, whereas exposed bedrock areas in sloping fields account for > 30% of the land area with a thin soil layer of 10–50 cm.

 

7. “…foreign tree species…” (Line 70 and 378). What do you mean by the term “foreign tree species”? The term "introduced species" is more suitable.

 Thank you very much for your careful and professional advice, we have already studied and revised the manuscript.

8. Table 4. Footnote: Bold numbers are considered highly weighted. Which values have high weighting? The table does not contain any values that are in bold.

 Thank you for your careful pointing out that it is indeed because of our negligence that we have studied and improved.

9. Table 5. Correct the table size. Because the table size exceeds the page size, the last indicator (ALP) is missing.

 What you pointed out is very timely, and we have already made adjustments.

10. 10. The authors must correctly specify the Latin names of the plants. First, the first mention of the species' Latin name in the text should be given in full. Second, you must provide an accepted biological name, not synonyms: Cyclobalanopsis glauca - this name is a homotypic synonym of Quercus glauca Thunb. (accepted Latin name), Cyclosorus parasiticus - this name is a synonym of Christella parasitica (L.) H.Lév. (accepted Latin name), Microstegium vagans - this name is a synonym of Microstegium fasciculatum (L.) Henrard (accepted Latin name), Cipadessa cinerascens - this name is a synonym of Cipadessa baccifera (Roxb. ex Roth) Miq. (accepted Latin name), (accepted Latin name), Embelia rudis - this name is a synonym of Embelia vestita Roxb. (accepted Latin name), Argyreia seguinii - this name is a synonym of Argyreia pierreana Bois (accepted Latin name), Dalbergia balansae - this name is a synonym of Dalbergia assamica Benth. (accepted Latin name). Second, the first mention of the species' Latin name in the text should be given in full.

 Thank you for your valuable suggestions, we have carefully revised the relevant issues, specifically refer to the revised manuscript.

11. When writing Latin plant names, care must be taken to prevent errors. Please correct Jasminum nervosu to Jasminum nervosum (correct Latin name).

 Thank you for your careful pointing out the problem. We have carefully revised the relevant problem, and refer to the revised manuscript for details.

12. Add research limitationsto the Discussion section.

Thanks to your suggestion, we have added research limitations to the conclusion of the manuscript as follows:

Thus, selection of the suitable vegetation types for restoration is vitally important for improvement in soil quality. Moreover, this study is beneficial for implementing ecological restoration practices and management in degraded karst areas. However, to assess soil quality more comprehensively and precisely, biological properties of soils should also be considered for SQI in future studies.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

 

The MS forests-3037200 with the title “the effects of different vegetation restoration models on soil quality in Karst areas of Southwest China” is well organized and written in well understandable English language. Some linguistic roughness is of minor importance.

The item of the study, to compare the effects of vegetation restoration strategies on soil quality and soil functionality is highly relevant for ecosystem management and –preservation in vulnerable areas like Karst regions.

The methodical design is well structured and leads the reader from initial descriptive evaluation steps to integrating conclusive evaluations like the constuction of an integrating Soil Quality Index that was used to differentiate the five compared vegetation restoration strategies in a wa that allows for generalization via PCA and determining a minimal data set (MDS).

The discussion and conclusion provides thorough interpretation of the results and their reasonable interpretation with relation to their probable process-background.

After minor revision, concerning mainly formal aspects that I claimed with my comments inserted directly in the PDF.

Comments for author File: Comments.pdf

Author Response

Dear reviewer,

I quite appreciate your favorite consideration and insightful comments. Now I have revised the manuscript in full accordance with your comments and found them very helpful. I hope this revision will make my paper more acceptable.. The point to point responds to your comments are listed as following:

Response to the reviewer’ comments:

Ref: forests-3037200
Title: The effects of different vegetation restoration models on soil quality in Karst areas of Southwest China

Journal: Forests

Reviewer:

MAIN COMMENTS

1. There are many expressions that need to be improved:

• Line 39-40. Replace “vital”with “central”, and what dose “heat elements” mean?

We have modified the incorrect statements in accordance with your opinion:

“Forest soils are central elements of forest ecosystems, providing essential living conditions for forest vegetation, comprising water, fertilizer, gas, and heat. Soils underpin forest vegetation and are a vital hub for the transformation of nutrient elements in ecosystems, thereby promoting forest health.” 

• Line 47-48. Replace “rich in rain and heat resources”with “with high precipitation and air temperature”, and what is unevenly distributed?(rainfall and heat or the area?).

The word "uneven distribution" in line 48 indicates rainfall and heat, and we have modified the incorrect statements in accordance with your opinion:

“The Karst area in Southwest China has a subtropical monsoon climate, with high precipitation and air temperature, but is unevenly distributed.”

• Line 55-56. Replace “...conserves water and soil ...”with “...conserves the amount of water and soil...”, replace “soil plant composite systems-” with “soil plant interaction, that are...”.

We have modified the incorrect statements in accordance with your opinion:

“Vegetation restoration not only conserves the amount of water and soil and reduces soil erosion, but also improves soil quality via soil plant interaction, that are key steps vital for rocky desertification management and ecological reconstruction.”

• Line 61. Replace “is”with “expected to be”.

We have modified the incorrect statements in accordance with your opinion:

“Therefore, the restoration of local ecosystems using native or local tree species-dependent vegetation restoration models expected to be highly beneficial .”

• Line 83. Add “..., as compared to conventional vegetation restoration strategies”after “...in Karst rocky desertification areas...”.

We have modified the incorrect statements in accordance with your opinion:

“ Our study objectives were; 1) to identify the restoration model(s) which improved soil quality in Karst rocky desertification areas, as compared to conventioanl vegetation reatoration strategies; 2) to identify key factors affecting soil quality in these areas.”

2. Materials and Methods

• Figure 1. The dashed line of figure 1 indicates the maximal territorial claim of the People´s Republic of China in the conflict zone in the South Chinese Ocean between China and the other neighboring states. Such a one-sided political statement has no place in a scientific paper. Therefore I urge the authors to delete tat part of the map that contributes no information to this study.

Your reminder is timely. We have replaced Figure 1.

• Lion 105. Replace “...in each plot...”with “...in stands of each of five vegetation restorations types...”.

Thanks for your valuable suggestions, we have made corresponding changes in the revised draft.

• Table 1. Replace “/”with “()”, and the unit of projection area should be “hm²”.

Thanks for your valuable suggestions, we have made corresponding changes in the revised draft.

3. Results

• Lion 185,206. F-value at p<0.01 different between the test members.

Thanks for your valuable suggestions, we have made corresponding changes in the revised draft.

• Table 4. The “bold numbers”mentioned in the footnote are not seen in the table.

Thanks for your careful reminder, we have revised Table 4 in the revised draft.

• Lion 315-316. The annotations should be written in the same order as in the legend to Fig 5 B.

We changed the order of the annotations as your suggested.

4. Discussion

• Lion 320-339. Refer please each statement to the respective table or figure. E.g. " ...MC level in EF and MF models ...(tab. 2)". To avoid that the readers would get lost here!

We noted the source of the chart for each statement as your suggested.

• Lion 353-354. Add a qualifier for soil microbial biomass biomass “...biomass under the given regional climate and soil conditions, ...”. And add an sentence at the end “and their availability were significant.”

We modified the sentence as your suggested.

• Lion 389. What´s about TP and pH that show with weights of about 0.17 and 0.175 comparable contribution to MDS (see Fig. 5). I think these both factors with high relevance for soil biota should be commented here as well.

Thanks for your suggestion, we have added relevant discussion in the revised draft, and the specific changes are as follows:

Studies have shown that the conversion of land use from agriculture to forest generally increases soil acidity, and atmospheric deposition makes a large contribution to soil acidification [56]. However, the rate of soil acidification also depends on the specific litter quality and litter decomposition rate of the tree species [24]. In this study, soil acidification was offset by a large amount of litter input in the DBF model. Therefore, pH value is also one of the main factors to characterize soil quality. The main direct source of phosphorus in soil is the decomposition of organic matter [57]. In this study, MF and DBF treatment had a large amount of litter input, which significantly increased the total phosphorus content and affected the soil quality.

5. Data Availability Statement. Why not? In an open scientific community it is a matter of course to make such important data publicly available.

Thank you for your suggestion and we are happy to share our experimental data.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have revised the manuscript in response to all comments and suggestions. Thanks to the authors for their work.