Quantitative Characteristics and Environmental Interpretation of Vegetation Restoration in Burned Areas of the Dry Valleys of Southwest China

Round 1

Reviewer 1 Report

The manuscript entitled “Quantitative characteristics and environmental interpretation of vegetation restoration in burned areas of the dry valleys of southwest China” investigates the post-fire vegetation state at the early stages after fire. In my view studies investigating post fire recovery based on field data are of particular interest given that climatic crisis changes not only the fire behavior and characteristics, with consequences on the post fire recovery, but also the post fire environment. However, I have some concerns about this study.

First of all the time since fire is very short to study community formation patterns. This study identifies seven different communities which most likely are not formed based on the community processes but to a great degree by chance. Nevertheless, some readers my find even these early results interesting. Therefore, this is not my main concern.

The methodology is very poorly described. The authors state the they have used ten plots for each of the 6 burned areas. That makes 60 plots. Then on each (10X10m) plot  five quadrants of 5X5m were sampled. How is this possible? You cannot fit 5 quadrants of 25m² in a 100m² plot. Further, this process would result in 300 quadrants. I think this has to be clarified. Also in the rest of the analysis, the term quadrat is used instead of the term plot, which I believe it is the correct one. The authors employ DCA and DCCA. It is not clear to me if the DCA was used on species or on environmental variables. It seems that is used on environmental variable but I find this process unnecessary since a direct ordination method is then employed (DCCA) which investigates the effect of factors on species and communities. I would like to see a DCA based on species in order to see if the classification made with TWINSPAN is the result of actual ecological processes or just a random effect. Further, I would recommend the authors to use eastness and northness as variables for aspect instead of the five classes that they have used. The number of environmental variables used is extremely small. Are there any additional information regarding past management or any current activities?

Finally, I believe the study lucks a “take home” message. It does not make as any smarter on the subject of post fire succession. I have made also some additional recommendations in the text and I also recommend the text to be edited by a native English speaker.

Extensive editing is needed

Author Response

Dear Reviewer

On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript, we appreciate editor and reviewers very much for positive and constructive comments and suggestions on our manuscript entitled"Quantitative characteristics and environmental interpretation of vegetation restoration in burned areas of the dry valleys of southwest China". Meanwhile, the manuscript checked by a native English-speaking colleague.

SUGGESTIONS FROM EDITOR:

Comments to the Author

The methodology is very poorly described. The authors state the they have used ten plots for each of the 6 burned areas. That makes 60 plots. Then on each (10X10m) plot five quadrants of 5X5m were sampled. How is this possible? You cannot fit 5 quadrants of 25m² in a 100m² plot. Further, this process would result in 300 quadrants. I think this has to be clarified.  Also in the rest of the analysis, the term quadrat is used instead of the term plot, which I believe it is the correct one. The authors employ DCA and DCCA. It is not clear to me if the DCA was used on species or on environmental variables. It seems that is used on environmental variable but I find this process unnecessary since a direct ordination method is then employed (DCCA) which investigates the effect of factors on species and communities. I would like to see a DCA based on species in order to see if the classification made with TWINSPAN is the result of actual ecological processes or just a random effect. Further, I would recommend the authors to use eastness and northness as variables for aspect instead of the five classes that they have used. The number of environmental variables used is extremely small. Are there any additional information regarding past management or any current activities?

1. A supplementary description of thestudy method is given.

Response：Thanks for you revise opinion. This section has been modified.

2.2.3. TWINSPAN quantitative classification

TWINSPAN, modified by Indicator species analysis, is capable of both quadrat and species classification, based on a Reciprocal averging axis(Cho et al. 2015). In the present study, WinTWINS 2.3 software was used to perform TWINSPAN quantitative classification based on the importance value matrix and environmental factor matrix of vegetation species in typical quadrats, and the results of the 4th classification (Zhao et al., 2019, Gholamhosein et al. 2018).

2. The description of the quadrat setup has been modified. (Fit 4 quadrants of 25m²in a 100m²)

Response：Thanks for you revise opinion. This section has been modified.

2.2.1. Quadrat setting

The investigation quadrats were set up in the burned areas during the early natural recovery period after forest fire disturbance in the Anning River Basin (Fig. 1 and Table 1). Surveys were conducted one year after the occurrence of fires in each burned area. According to the fire disturbance intensity, elevation and aspect, ten plots (10 m × 10 m) were set for each burned area, then quadrats (5 m × 5 m) were placed in the four corners of each plot. A total of six burned areas and 300 quadrats, 60 shrub plots, and 240 grass quadrats were set. The type, quantity, plant height, and coverage of understory vegetation in the quadrats were recorded. The inclinometer and compasswere used to measure the four environmental factors of elevation, slope, aspect, and slope position in each quadrat (Qiu et al. 2000).

3. the DCA ordination was used on classifying vegetation communities and exploring the relationships between communities.

Response：Thanks for you revise opinion. This section has been modified.

2.2.4. DCA ordination and DCCA ordination

DCA ordination and DCCA ordination are multivariate analysis techniques used to study the relationship between vegetation and the environment (Zhao et al. 2019, Jan et al. 2009). In the present study, DCA ordination and DCCA ordination of the quadrats and environment factors (elevation, slope, aspect, and slope position) were performed using CANOCO 4.5 software, and then the ordination diagram was drawn using CanoDraw for Windows 4.5 (Zhao et al. 2019).

The number of slope positions (1, 2, 3, 4, and 5) represented the bottom of the slope, downhill slope, middle slope, uphill slope, and top of the slope respectively. The larger the number, the higher the slope position. The original value of the aspect could not directly represent the degree of sunshine exposure. Therefore, each aspect was assigned a numerical value, where 1 refers to the north slope (317.15°–22.15°), 2 refers to the northeast slope (22.15°–67.15°) and northwest slope (292.15°–317.15°), 3 refers to the east slope (67.15°–112.15°) and west slope (247.15°–292.15°), 4 refers to the southeast slope (112.15°–157.15°) and southwest slope (202.15°–247.15°), and 5 refers to the south slope (157.15°–202.15°). The higher number of aspect, the more sunny it is (Qiu and Zhang 2000).

4. Due to data requirements of CANOCO 4.5 software，the five classes are used as variables for aspect.
5. The environmental variables were selected mainly as topographic factors to be suitable for the description of community distribution.

Author Response File: Author Response.docx

Reviewer 2 Report

The paper entitled “Quantitative characteristics and environmental interpretation of vegetation restoration in burned areas of the dry valleys of southwest China” is the result of applied research. There are some issues in methods, results and discussion that need to be improved. Therefore, major changes are recommended.

Comments

1) Keywords – there are two keywords that are in the title. Please consider replacing by other two keywords.

2) Line 31 – What do the authors want to mean by “preventing wind and sand”? Please clarify

3) Line 38 – only herbs and shrubs? Trees are not considered?

4) Line 47 – “closely separated” or short periodicity?

5) Line 49 – “far apart” or long periodicity?

6) Methods – Sampling design is missing. Please include it.

7) Methods – How were the variables surveyed and when. The text needs further details regarding the dates and methods used to measure/evaluated the variables listed in lines 113 and 114.

8) Methods – How were determined the variables in lines 115 and 116.

9) Equations 1 and 2 – have the same acronym. The authors could use IVTS and IVH.

10) Section 2.2.3 – Further details are needed for TWINSPAN quantitative classification

11) Section 2.2.4 – Further details are needed for DCA and DCCA.

12) Lines 136-144 – The text is not clear. Also, is it not clear the difference between aspect and slope direction. Please clarify.

13) Table 2 – Serial number or community type?

14) Discussion – The text is not clear. It is not always clear if the authors are refereeing to the results of this study or to the results of published references.

14) Discussion – Please check for coherence of the discussion. In this section the authors should discuss critically the results of this study and compared them with published references.

15) Line 278 – What do the authors want to mean by “relatively single”?

16) Line 292 – Reference for Hill and Gauch is missing

Moderate editing of English language required

Author Response

Dear Editors

On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript, we appreciate editor and reviewers very much for positive and constructive comments and suggestions on our manuscript entitled"Quantitative characteristics and environmental interpretation of vegetation restoration in burned areas of the dry valleys of southwest China". Meanwhile, the manuscript checked by a native English-speaking colleague.

SUGGESTIONS FROM EDITOR:

Comments to the Author

The paper entitled “Quantitative characteristics and environmental interpretation of vegetation restoration in burned areas of the dry valleys of southwest China” is the result of applied research. There are some issues in methods, results and discussion that need to be improved. Therefore, major changes are recommended.

1) Keywords – there are two keywords that are in the title. Please consider replacing by other two keywords.

2) Line 31 – What do the authors want to mean by “preventing wind and sand”? Please clarify

3) Line 38 – only herbs and shrubs? Trees are not considered?

4) Line 47 – “closely separated” or short periodicity?

5) Line 49 – “far apart” or long periodicity?

6) Methods – Sampling design is missing. Please include it.

7) Methods – How were the variables surveyed and when. The text needs further details regarding the dates and methods used to measure/evaluated the variables listed in lines 113 and 114.

8) Methods – How were determined the variables in lines 115 and 116.

9) Equations 1 and 2 – have the same acronym. The authors could use IVTS and IVH.

10) Section 2.2.3 – Further details are needed for TWINSPAN quantitative classification

11) Section 2.2.4 – Further details are needed for DCA and DCCA.

12) Lines 136-144 – The text is not clear. Also, is it not clear the difference between aspect and slope direction. Please clarify.

13) Table 2 – Serial number or community type?

14) Discussion – The text is not clear. It is not always clear if the authors are refereeing to the results of this study or to the results of published references. Discussion – Please check for coherence of the discussion. In this section the authors should discuss critically the results of this study and compared them with published references.

15) Line 278 – What do the authors want to mean by “relatively single”?

16) Line 292 – Reference for Hill and Gauch is missing

COMMENTS TO THE AUTHOR:

1) Keywords – there are two keywords that are in the title.  Please consider replacing by other two keywords.

Response：Thanks for you revise opinion. The two keywords have been replaced. (Quantitative characteristics; Environmental interpretation.)

2) Line 31 – What do the authors want to mean by “preventing wind and sand”?  Please clarify

Response：The word has been deleted.

3) Line 38 – only herbs and shrubs? Trees are not considered?

Response：Thanks for you revise opinion. The greatest contribution to community changes is made by the growth of herbs and shrubs. That’s mean the contribution to community changes is made by the growth of herbs and shrubs was higher than  other species. Shrub-grass vegetation can efficiently absorb soil nutrients and grow rapidly to cover the surface. Shrub-grass vegetation communities develop rapidly in burned areas, and then slowly succeed to woody plant communities.

4) Line 47 – “closely separated” or short periodicity?

Response：This description has been modified.

5) Line 49 – “far apart” or long periodicity?

Response：This description has been modified.

6) Methods – Sampling design is missing. Please include it.

Response：Thanks for you revise opinion.This section has been modified.

2.2. Methods

2.2.1. Quadrat setting

The investigation quadrats were set up in the burned areas during the early natural recovery period after forest fire disturbance in the Anning River Basin (Fig. 1 and Table 1). Surveys were conducted one year after the occurrence of fires in each burned area. According to the fire disturbance intensity, elevation and aspect, ten plots (10 m × 10 m) were set for each burned area, then quadrats (5 m × 5 m) were placed in the four corners of each plot. A total of six burned areas and 300 quadrats, 60 shrub plots, and 240 grass quadrats were set. The type, quantity, plant height, and coverage of understory vegetation in the quadrats were recorded. The inclinometer and compasswere used to measure the four environmental factors of elevation, slope, aspect, and slope position in each quadrat (Qiu et al. 2000).

7) Methods – How were the variables surveyed and when.  The text needs further details regarding the dates and methods used to measure/evaluated the variables listed in lines 113 and 114.

Response：This section has been modified. (Surveys were conducted one year after the occurrence of fires in each burned area.)

8) Methods – How were determined the variables in lines 115 and 116.

Response：This section has been modified.

9) Equations 1 and 2 – have the same acronym. The authors could use IVTS and IVH.

Response：This section has been modified.

10) Section 2.2.3 – Further details are needed for TWINSPAN quantitative classification

Response：Thanks for you revise opinion. This section has been supplemented.

2.2.3. TWINSPAN quantitative classification

TWINSPAN, modified by Indicator species analysis, is capable of both quadrat and species classification, based on a Reciprocal averging axis(Cho et al. 2015). In the present study, WinTWINS 2.3 software was used to perform TWINSPAN quantitative classification based on the importance value matrix and environmental factor matrix of vegetation species in typical quadrats, and the results of the 4th classification (Zhao et al., 2019, Gholamhosein et al. 2018).

11) Section 2.2.4 – Further details are needed for DCA and DCCA.

Response：Thanks for you revise opinion. This section has been supplemented.

2.2.4. DCA ordination and DCCA ordination

DCA ordination and DCCA ordination are multivariate analysis techniques used to study the relationship between vegetation and the environment (Zhao et al. 2019, Jan et al. 2009). In the present study, DCA ordination and DCCA ordination of the quadrats and environment factors (elevation, slope, aspect, and slope position) were performed using CANOCO 4.5 software, and then the ordination diagram was drawn using CanoDraw for Windows 4.5 (Zhao et al. 2019).

12) Lines 136-144 – The text is not clear.  Also, is it not clear the difference between aspect and slope direction. Please clarify.

Response：This section has been modified. (Slope direction has been replaced with aspect.)

13) Table 2 – Serial number or community type?

Response：This section has been modified. (Serial number has been replaced with community type.)

• Discussion – The text is not clear. It is not always clear if the authors are refereeing to the results of this study or to the results of published references.Please check for coherence of the discussion. In this section the authors should discuss critically the results of this study and compared them with published references.

Response：This section has been modified and supplemented.

15) Line 278 – What do the authors want to mean by “relatively single”?

Response：The word has been modified. The community distribution range is large, but the species diversity and the community stability is low

16) Line 292 – Reference for Hill and Gauch is missing

Response：The literature has been supplemented. DCA ordination was proposed by Hill and Gauch after further research on the basis of correspondence analysis (Hill et al. 1980).

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The manuscript has improved in the second version and most of the questions were addressed by the authors. Yet, in the revised manuscript some minor issues should be addressed. Thus minor changes are recommended.

Comments

1) Methods – Sampling design is still not clear. Please clarify

2) Methods – How were determined the variables type, quantity, plant height, and coverage of understory vegetation

3) Equations 1 and 2 – have the same acronym. The authors could use IVTS and IVH.

Moderate editing of English language required

Author Response

Dear Editors and Reviewer

On behalf of my co-authors, we thank you very much for allowing us to revise our manuscript again, we appreciate the editor and reviewers very much for their positive and constructive comments and suggestions on our manuscript entitled "Quantitative characteristics and environmental interpretation of vegetation restoration in burned areas of the dry valleys of southwest China". Meanwhile, the manuscript was checked by a native English-speaking colleague again.

SUGGESTIONS FROM EDITOR:

Comments to the Author

The manuscript has improved in the second version and most of the questions were addressed by the authors. Yet, in the revised manuscript some minor issues should be addressed. Thus minor changes are recommended.

Comments

1) Methods – Sampling design is still not clear. Please clarify

2) Methods – How were determined the variables type, quantity, plant height, and coverage of understory vegetation

3) Equations 1 and 2 – have the same acronym. The authors could use IVTS and IVH.

RESPONSE TO THE REVIEWER：

• Methods – Sampling design is still not clear. Please clarify

Response：Thanks for you revise opinion.

The investigation quadrats were set up in the burned areas during the early natural recovery period after the forest fire in the Anning River Basin (Fig. 1 and Table 1). Surveys were conducted one year after the occurrence of fires in each burned area, and a shrub(10m×10m) quadrat was set at different slope positions (the bottom of the slope, downhill slope, middle slope, uphill slope, and top of the slope) of the shady slope and sunny slope of burned area respectively(Fig. 2). Both the shady slope and sunny slope had 5 quadrats, and 10 quadrats were set up for each burned area, and then grass quadrats (5m×5m) were placed in the four corners of each shrub quadrat(Fig. 2). A total of 6 burned areas had 300 quadrats, 60 shrub quadrats and 240 grass quadrats were established.

2) Methods – How were determined the variables type, quantity, plant height, and coverage of understory vegetation

Response：Thanks for you revise opinion.

Visually detect and record the amount and type of understory vegetation (compare with Flora of China). The coverage of understory vegetation were measured by vegetation cover measuring instrument (XST-PhotoNet-FVC). Use a tape to measure the height of understory vegetation.

• Equations 1 and 2 – have the same acronym. The authors could use IVTS and IVH.

Response：Thanks for you revise opinion, and this section has been modified.

In formulas (1) and (2), IVTS is the importance value of trees and shrubs; IVH is the importance value of herbs; RD is the relative density; RH is the relative height; and RC is the relative coverage.

Author Response File: Author Response.docx