Chronosequence and Temporal Changes in Soil Conditions, Vegetation Structure and Leaf Traits in a Tropical Dry Forest in Brazil

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Review

As you know, currently the problem of reforestation as a result of various processes (deforestation, fires, natural disasters, etc.) is one of the most acute on the planet. This is due to the fact that the process of restoring forest ecosystems is slow in space and time, so it is possible to change the environmental conditions in which they develop. For example, against the background of global climate warming, the temperature of modern soils may be higher compared to soils in which pine or spruce stands developed 300 years ago. When studying ecosystem succession, an integrated approach is needed, using various assessment methods. The most sensitive techniques may be those that allow us to consider the lowest level of ecosystem organization - the biochemical one. Thanks to the improvement of the technical base, it is possible to obtain new data on the state of forest ecosystems, and therefore it is correct to make forecasts of their development. Despite the fact that there is a lot of data on successional processes in the literature, the issue of changing soil properties, vegetation structure and leaves in the tropical dry forest of Brazil has not been chronologically investigated. In this regard, the topic of the article is very modern.

The article makes a very good impression, there is a lot of new interesting material that is well structured. All the drawings are very informative and well described in the text. It should be emphasized that the authors were able to collect information from various authors, group their data and present it in a new edition. A large list of references does not allow us to doubt the correct interpretation of the new data obtained by the authors. I would like to emphasize the theoretical significance of the article, since the data obtained reveal the mechanisms of formation of soil resistance to anthropogenic impact, they reveal the individual stages of the formation of the forest ecosystem. There are some small comments in the work, which are discussed below.

3- replace the word in the title (traits), this is a colloquial style

16- specify the type of soil in the classification WRB

27- what is the hypothesis, it is not mentioned above. I suggest you remove it

30- Conservative-acquisition continuum...this has not been found anywhere

37 -the word replace traits

95- What is phenotypic plasticity? was it written about this in detail above? I didn't see it

120-133 write in more detail, more clearly.

150 - it is necessary to write about the soil cover, which soils dominate, classification according to WRB

197- in which laboratory did the analyses

186- content where , in the leaves?

198- where? In the leaves? or the soil?

282- the methods do not determine the chemical properties of soils, as the granulometric properties were determined, C, N

297- why the black figure?

297- on the abscissa axis, the successional stage of ecosystem development...write in more detail

320- Why is the drawing black? it would be necessary to combine them into groups, visualize

320- Why is the drawing black? should we combine them into groups, visualize

338- prediction? maybe you shouldn't enter this column, maybe you should make it a separate table?

370-381 it is very vaguely written, there is no clear statement. I recommend writing it more clearly. It is good to write a few words about the microbial transformation of organic matter, what is happening, is it possible to change the direction of anabolism/catabolism of organics

401 - have we received data that contradict the hypothesis? it would be necessary to write more precisely

429-442 it is well written, but, it seems to me, there are very few proposals on the pressing problem of our time, the challenge to society: carbon themes. Is it possible to change the course of succession with global climate change? Can the processes that you have studied become predictors of CO2 emissions into the atmosphere, etc

457 - very good

In conclusion, I want to say once again that the article is interesting. I wish the authors good luck and creative success!

 

 

Comments on the Quality of English Language

The article is written clearly, all terms are used correctly, there are no complaints about the manuscript. I think that the article will be understandable to everyone who knows English and is engaged in this field.

Author Response

As you know, currently the problem of reforestation as a result of various processes (deforestation, fires, natural disasters, etc.) is one of the most acute on the planet. This is due to the fact that the process of restoring forest ecosystems is slow in space and time, so it is possible to change the environmental conditions in which they develop. For example, against the background of global climate warming, the temperature of modern soils may be higher compared to soils in which pine or spruce stands developed 300 years ago. When studying ecosystem succession, an integrated approach is needed, using various assessment methods. The most sensitive techniques may be those that allow us to consider the lowest level of ecosystem organization - the biochemical one. Thanks to the improvement of the technical base, it is possible to obtain new data on the state of forest ecosystems, and therefore it is correct to make forecasts of their development. Despite the fact that there is a lot of data on successional processes in the literature, the issue of changing soil properties, vegetation structure and leaves in the tropical dry forest of Brazil has not been chronologically investigated. In this regard, the topic of the article is very modern.

The article makes a very good impression, there is a lot of new interesting material that is well structured. All the drawings are very informative and well described in the text. It should be emphasized that the authors were able to collect information from various authors, group their data and present it in a new edition. A large list of references does not allow us to doubt the correct interpretation of the new data obtained by the authors. I would like to emphasize the theoretical significance of the article, since the data obtained reveal the mechanisms of formation of soil resistance to anthropogenic impact, they reveal the individual stages of the formation of the forest ecosystem. There are some small comments in the work, which are discussed below.

Answer: we thank the reviewer for the positive comments.

 

3- replace the word in the title (traits), this is a colloquial style

Answer: we agree with the reviewer, and we replaced “soil traits” for “soil conditions” not only in the title but throughout the entire manuscript. We opted for keeping “leaf traits” because it is widely used in the literature, including widely cited papers on leaf economic spectrum (e.g., Wright, Ian J., et al. "The worldwide leaf economics spectrum." Nature 428: 821-827, 2004).

 

16- specify the type of soil in the classification WRB

Answer: we added the soil type (ferralsoils) in the WRB classification, as suggested.

 

27- what is the hypothesis, it is not mentioned above. I suggest you remove it

Answer: we added a prediction in line 19 and changed the word “hypothesis” for “prediction” in line 27.

 

30- Conservative-acquisition continuum...this has not been found anywhere

Answer: we replaced this keyword by “Leaf economics spectrum”.

 

37 -the word replace traits

Answer: we opted for keeping “leaf traits” because it is widely used in the literature, including widely cited papers on the leaf economics spectrum.

 

95- What is phenotypic plasticity? was it written about this in detail above? I didn't see it

Answer: we added a definition for phenotypic plasticity, see lines 87-89.

 

120-133 write in more detail, more clearly.

Answer: we rewrote some parts of this paragraph to improve the reading, see lines 112-135

 

150 - it is necessary to write about the soil cover, which soils dominate, classification according to WRB

Answer: we added this information in the description of the study area, see lines 103-104.

 

197- in which laboratory did the analyses

Answer: this information is given in the text, see lines 144-148: “Analyses of the soil samples from 2009 were carried out at EMBRAPA Solos (see Espírito-Santo et al. 2014) whereas the samples from 2018 were conducted at the soil analysis laboratory of the Institute of Agricultural Sciences (ICA) at the Federal University of Minas Gerais (UFMG), following the same EMBRAPA protocols used for the samples from 2009”.

 

186- content where , in the leaves?

Answer: in the leaves, we added this information to the sub-heading, see line 177.

 

198- where? In the leaves? or the soil?

Answer: in the leaves, we added this information to the sub-heading, see line 188.

 

282- the methods do not determine the chemical properties of soils, as the granulometric properties were determined, C, N

Answer: the protocols for determining soil physical and chemical properties were exactly the same in 2009 and 2018, thus we assume that the methods did not influence our results.

 

297- why the black figure?

Answer: we replace the black figure for a color figure.

 

297- on the abscissa axis, the successional stage of ecosystem development...write in more detail

Answer: the title of the abscissa axis is “successional stage”, and we wrote the stage (early, intermediate and late) below each pair of bars. We believe that this is sufficient to clearly understanding the figure. Additional details are given in the figure legend.

 

320- Why is the drawing black? it would be necessary to combine them into groups, visualize

Answer: we replace the black figure for a color figure.

 

338- prediction? maybe you shouldn't enter this column, maybe you should make it a separate table?

Answer: we replaced “predicted” by “expected”, as described in the table legend. We prefer to keep this column in this table because it is easier to the reader to understand what pattern we expected according to the hypotheses that we proposed in the last paragraph of the Introduction section.

 

370-381 it is very vaguely written, there is no clear statement. I recommend writing it more clearly. It is good to write a few words about the microbial transformation of organic matter, what is happening, is it possible to change the direction of anabolism/catabolism of organics

Answer: we reformulated this entire paragraph according to the reviewer’s suggestions, see lines 353-372.

 

401 - have we received data that contradict the hypothesis? it would be necessary to write more precisely.

Answer: we rewrote this part of the text, see lines 384-395.

 

429-442 it is well written, but, it seems to me, there are very few proposals on the pressing problem of our time, the challenge to society: carbon themes. Is it possible to change the course of succession with global climate change? Can the processes that you have studied become predictors of CO2 emissions into the atmosphere, etc

Answer: we briefly addressed the climate change issue at the end of the Conclusion section, see line 449-450.

 

457 - very good

In conclusion, I want to say once again that the article is interesting. I wish the authors good luck and creative success!

Answer: we thank the reviewer for the positive comments.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

I made comments and suggestions on your manuscript. Fine below the suggested comments.

General comments:

·       Abbreviations are spelled out at their first appearance

·       All equipment used in the data collection must be followed by (manufacturing company, state, country).

Line 28: What does TDF stand for, please? Spell it out. Abbreviations are spelled out at their first appearance.

Line 112: “…The region's climate is Aw? What is Aw refer to?

Line 159: “…sensor (Smart Sensor S-LIA-M003)…” Please add the senor (manufacturing company, state, county).

Line 274 – 285: What do you mean by Early, Intermediate, and Late stages (Table 3)? Make a brief explanation of these stages as a headnote or footnote in Table 3.

Line 295 – 296:  The data displayed in Figure 1 (specific leaf area, polyphenols, chlorophyll a/b, and total chlorophyll), the mean separation is distorted. In Figure A, the mean separation ‘C’ is missing.  Figure 1B, late 2019, should take the least alphabetical designation. Figures 1C and D, assuming no variation among the stages in either 2009 or 2018, should be only a or b. Check your discussion accordingly.

With regards,

The reviewer

 

Comments for author File: Comments.pdf

Author Response

General comments:

 

• Abbreviations are spelled out at their first appearance

Answer: done

 

• All equipment used in the data collection must be followed by (manufacturing company, state, country).

 

Line 28: What does TDF stand for, please? Spell it out. Abbreviations are spelled out at their first appearance.

Answer: we added the abbreviation in the first appearance.

 

Line 112: “…The region's climate is Aw? What is Aw refer to?

Answer: we added this information, see lines 107-108.

 

Line 159: “…sensor (Smart Sensor S-LIA-M003)…” Please add the senor (manufacturing company, state, county).

Answer: we added this information, see line 151.

 

Line 274 – 285: What do you mean by Early, Intermediate, and Late stages (Table 3)? Make a brief explanation of these stages as a headnote or footnote in Table 3.

Answer: we fully described the age, land use history and structure of the three successional stages, see lines 112-135. We added the following sentence to the table legend: “See text for further details on the characterization of each successional stage”, see lines 164-165.

 

Line 295 – 296:  The data displayed in Figure 1 (specific leaf area, polyphenols, chlorophyll a/b, and total chlorophyll), the mean separation is distorted. In Figure A, the mean separation ‘C’ is missing.  Figure 1B, late 2019, should take the least alphabetical designation. Figures 1C and D, assuming no variation among the stages in either 2009 or 2018, should be only a or b. Check your discussion accordingly.

Answer: the mean separation (using groups of letters and asterisks) is explained in the legend of the figure: “Letters a, b, c on the bars = statistically significant differences among successional stages in 2009; letters d, e, f = differences among stages in 2018. * = statistically significant differences between years for each stage”.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

Thank you for addressing the previous comments.

Regards,

the reviewer