Quantitative Assessment of Forest–Tundra Patch Dynamics in Polar Urals Due to Modern Climate Change

Round 1

Reviewer 1 Report

In the current study, an attempt is made to analyze modern climate-driven changes occurring within the ecotone of the upper tree line on the South-Eastern macroslope of Rai - Iz massif in Russia, from 1960 until recent times. The analysis was based on a quantitative assessment of changes in the area of different forest types. In general terms, I believe that the study is interesting but several issues must be solved.

General comments

The authors claim, "It was found that in half century the number of trees in study area almost doubled. Relative area of lots belonging to tundra with single trees phytocoenohora went down by 15.4% due to increase in the areas of light forest (8.1%), open forest (3.5%) and closed forest (3.8%)”. I believe that the results indeed support this conclusion. However, this conclusion is currently referred to the study area (red polygon in Figure 3), and it has not been evaluated for all areas in the same region. Therefore, I strongly recommend using robust statistical analysis to support the results at the population level, based on hypothesis testing.

Specific comments

-        Please improve the abstract section by restricting it to 200 words maximum, according to the journal's requirements.

-        Please use italics for species throughout the ms.

-         L187 Please add the Figure’s number.

-     Please improve some expressions, for example, L1 

Author Response

Dear Colleague,

Thank you for your valuable comments! Below are the answers to the your comments. We have made changes to the text of the article (highlighted in yellow).

With best regards,

Valery Fomin

Reviwer 1

I have some comments on the sentence: “At the same time even researchers supporting the concept of vegetation cover discretion, recognize the fact that selected boundaries are rarely sharp [ 13 ]” (lines 35-37), referencing Kark and van Rensburg (2006). Are you certain that you can position these authors as supporters of “the concept of vegetation cover discretion”? In reality, it is uncommon for researchers to claim that sharp boundaries often exist in nature. The issue, as explained in the subsequent text, lies in the necessity of reducing a non-discrete phenomenon to a "linear object" in order to compare data from different years or regions. The crux lies in having a clearly defined and comparable method of delineating this line.

Answer:

The article by Kark and van Rensburg (2006) is of an view paper. The authors are not supporters or opponents of the concept of discreteness of vegetation cover. I agree with the reviewer. This phrase needs to be changed.

I suggest the following text:

«Natural boundaries are relatively rarely sharp and, in general, human-related boundaries are sharper then natural ones». (Lines 30-32)

If you state, “It is possible to specify two families of methods used to solve the problem of boundary recognition” (lines 55-56), it would be beneficial to distinctly explain which of the two solutions you opt for and why, or propose a third alternative. It is better to explicitly state this rather than expect the reader to classify the method used in the work themselves.

Answer:

The method used in this work can be attributed to the first of the above group of methods (Lines 53-54).

Moreover, it would be advantageous if the Introduction more clearly delineated the article's objectives. While a significant portion of the Introduction discusses the methods used in this type of analysis, the study does not present a comparative analysis of results obtained from different methods; rather, it focuses on a single method selected by the authors. Simultaneously, a substantial part of the Results and Discussion section is devoted to phenomena resulting from climate change. I suggest balancing the content of the Introduction to clearly convey two objectives: demonstrating an effective method for analyzing these phenomena and highlighting the changes occurring in the study area.v

Answer:

In accordance with your recommendations, we have reformulated the purpose of the paper:

The purpose of this article is twofold: (1) demonstrating an effective method for mapping and analyzing of woody vegetation coover change close to upper limit of their growth and (2) and highlighting the climate driving changes occurring in upper treeline ecotone in the study area in the Polar Urals for the time interval more than fifty years.

Lines 64-67.

The description of the study area (chapter 2.1) includes elements of geology, geomorphology, and vegetation. However, the text from line 93 to 97 does not describe the study area itself but rather focuses on methods for locating and mapping trees. The last sentence lacks completion.

Answer:

Done. The paragraph has been moved to section 2.2. The last sentence is completed. (Lines 115-122).

A typo is present in the description of Fig. 3, where “treen” should be corrected to “trees.” Additionally, the distinction between the study area and an additional “region/area of interest” is not clearly explained in the caption. It might be beneficial to explicitly state in the figure caption that this represents the area for which the vegetation patches delineation method described in section 2.2 will be presented as an example. Furthermore, in the legend under Figure 3, there is a word "Tree" with two almost invisible dots underneath. The entire legend (apart from the scale) could be merged into the caption.

Answer:

Done. “treen” replaced by “trees”. Changes have been made to the figure 3 and its caption: the legend has been removed; the color of the border of the area has been changed to white; explanations have been made in the caption.

In chapter 2.2, it would be beneficial to specify the software in which the described analyses were conducted.

Answer:

Done.

All images 94 were georeferenced using QGIS geoinformation system (https://qgis.org/, accessed on 2 November 2022). Lines 117-118.

Data processing underwent using R software (The R Foundation, Austria, Vienna) (https://www.r-project.org/, accessed on 2 November 2023). Lines 120-122.

Additionally, there are various mistakes throughout the manuscript:
Line 114 – " Fig. (Figure 4) shows"

Answer:

Done. Line 103.
Line 122 – "to a be a forest"

Answer:

Done. "to a be a closed forest". Line 111.
Chapter 3.1 contains editing errors, including double words, unnecessary spaces, etc.

Line 187 – "Figure ??"

Answer:

Fixed. Figure 6c. Line 183.

Line 195 – “Humistratous" is not a recognized term within common language or standard scientific language. I found it in very few publications in Russian Journals. Is there a more commonly used term or a way to descriptively explain its meaning to the reader?

Answer:

Done. "Humistratous form" replaced by "creeping form". Line 191.

Line 213  and in the other places (also in Abstract) – I also have some doubts about the term "corrasion" in the context of trees. Wouldn't it be better to use the phrase "mechanical damage."

Answer:

Done. "Corrasion" replaced by "mechanical damage". Lines 209, 213, 227, 245.

Reviewer 2 Report

The Authors have presented an interesting and modern analysis. However, the text requires improvement, particularly in the Introduction.

I have some comments on the sentence: “At the same time even researchers supporting the concept of vegetation cover discretion, recognize the fact that selected boundaries are rarely sharp [ 13 ]” (lines 35-37), referencing Kark and van Rensburg (2006). Are you certain that you can position these authors as supporters of “the concept of vegetation cover discretion”? In reality, it is uncommon for researchers to claim that sharp boundaries often exist in nature. The issue, as explained in the subsequent text, lies in the necessity of reducing a non-discrete phenomenon to a "linear object" in order to compare data from different years or regions. The crux lies in having a clearly defined and comparable method of delineating this line.
If you state, “It is possible to specify two families of methods used to solve the problem of boundary recognition” (lines 55-56), it would be beneficial to distinctly explain which of the two solutions you opt for and why, or propose a third alternative. It is better to explicitly state this rather than expect the reader to classify the method used in the work themselves.
Moreover, it would be advantageous if the Introduction more clearly delineated the article's objectives. While a significant portion of the Introduction discusses the methods used in this type of analysis, the study does not present a comparative analysis of results obtained from different methods; rather, it focuses on a single method selected by the authors. Simultaneously, a substantial part of the Results and Discussion section is devoted to phenomena resulting from climate change. I suggest balancing the content of the Introduction to clearly convey two objectives: demonstrating an effective method for analyzing these phenomena and highlighting the changes occurring in the study area.
The description of the study area (chapter 2.1) includes elements of geology, geomorphology, and vegetation. However, the text from line 93 to 97 does not describe the study area itself but rather focuses on methods for locating and mapping trees. The last sentence lacks completion.

A typo is present in the description of Fig. 3, where “treen” should be corrected to “trees.” Additionally, the distinction between the study area and an additional “region/area of interest” is not clearly explained in the caption. It might be beneficial to explicitly state in the figure caption that this represents the area for which the vegetation patches delineation method described in section 2.2 will be presented as an example. Furthermore, in the legend under Figure 3, there is a word "Tree" with two almost invisible dots underneath. The entire legend (apart from the scale) could be merged into the caption.

In chapter 2.2, it would be beneficial to specify the software in which the described analyses were conducted.

Additionally, there are various mistakes throughout the manuscript:
Line 114 – " Fig. (Figure 4) shows"
Line 122 – "to a be a forest"
Chapter 3.1 contains editing errors, including double words, unnecessary spaces, etc.
Line 187 – "Figure ??"
Line 195 – “Humistratous" is not a recognized term within common language or standard scientific language. I found it in very few publications in Russian Journals. Is there a more commonly used term or a way to descriptively explain its meaning to the reader?
Line 213  and in the other places (also in Abstract) – I also have some doubts about the term "corrasion" in the context of trees. Wouldn't it be better to use the phrase "mechanical damage."

These corrections and clarifications will enhance the clarity and quality of the article.

Author Response

Dear Colleague,

Thank you for your valuable comments and suggestions! Below are the answers to your comments. We have made changes to the text of the article (highlighted in yellow).

With best regards,

Valery Fomin

Reviwer 2

General comments

The authors claim, "It was found that in half century the number of trees in study area almost doubled. Relative area of lots belonging to tundra with single trees phytocoenohora went down by 15.4% due to increase in the areas of light forest (8.1%), open forest (3.5%) and closed forest (3.8%)”. I believe that the results indeed support this conclusion. However, this conclusion is currently referred to the study area (red polygon in Figure 3), and it has not been evaluated for all areas in the same region. Therefore, I strongly recommend using robust statistical analysis to support the results at the population level, based on hypothesis testing.

Answer:

The rectangle indicated in Fig. 1 by the red line corresponds to the entire area shown in Fig. 3. We have corrected the color and type of the line for the area of interest to a white dotted line and made an explanation in the caption to avoid confusion with the research area.

Specific comments

-        Please improve the abstract section by restricting it to 200 words maximum, according to the journal's requirements.

Answer:

We have shortened the annotation as much as possible. Done

-        Please use italics for species throughout the ms.

Answer:

This is done in the LaTex editor, but unfortunately, when creating a pdf file, LaTex commands for writing italics do not work, for example, \emph{Larix sibirica} Ledeb. or \textit{Larix sibirica} Ledeb. or \it{Larix sibirica} Ledeb. This is one of the problems that users regularly encounter. We have tried all the described options that can fix this problem, but we cannot solve it yet.

I think that in the final version of the article, the technical specialists of the journal will make the correct version of the article with the correct spelling of the species names.

-         L187 Please add the Figure’s number.

Answer:

Fixed. Figure 6c. Line 183.

-     Please improve some expressions, for example, L1 

Answer:

Done. L1.

Round 2

Reviewer 1 Report

I believe that in the revised version of the ms the major issue has not been solved. The statistical analysis is essential for this research and it is totally missing from the ms. According to the authors, the aim of the study was to "highligh the climate driving changes occurring in upper treeline ecotone in the study area in the Polar Urals for the time interval more than fifty years". I don't understand why the research is limited only to the current study area. If so, the interest is limited to a local scale. I suggest generalizing the reseach outcomes by adding a relevant (basic) statistical analysis, which is critical in the frame of an international journal. 

Secondary issues:

-I suggest using italics for species names.

-Line 9: I think that it is "of" instead of "od"Please revise.

Author Response

Dear Reviewer,

Below we have provided answers to your comments

"I believe that in the revised version of the ms the major issue has not been solved. The statistical analysis is essential for this research and it is totally missing from the ms. According to the authors, the aim of the study was to "highligh the climate driving changes occurring in upper treeline ecotone in the study area in the Polar Urals for the time interval more than fifty years". I don't understand why the research is limited only to the current study area. If so, the interest is limited to a local scale. I suggest generalizing the reseach outcomes by adding a relevant (basic) statistical analysis, which is critical in the frame of an international journal". 

---

I don't understand why the research is limited only to the current study area. f so, the interest is limited to a local scale.

Answer:

Variability of soil and climatic conditions in the mountains complicates selection of sites uniform it terms of the set of conditions. While performing field research near the upper tree line an approach is usually taken that is based upon research and comparative analysis of the sites (test areas, transects, or height profiles) where direct parameters of the plants are directly measured or calculated. Usually, the area of these test sites varies from several hundred to several thousand square meters, or rarely includes several hectares.

In the paper authors moved from local sites to the study area in its whole, by defining position of each tree we recognized using aerial photos from early 1960-s and modern space photos. That was necessary in order to implement an illustrates capabilities of an approach based on selecting key phytocoenohora types, and localizing sites of transitioning from one type to another. The work was performed for the area of 7.3 mln square meters. At the same time we stress that research of Siberian Larch was performed using complete account of all trees visible on images under continuously changing gradients of environmental variables. The latter is very hard to achieve using only data sets for test sites or transects.

Gentle macroslope and well-expressed relief formed by moraine deposits, combined with strong impacts of snow and wind on vegetation, amid the regional climate warming allow assessment of Siberian Larch expansion into mountain tundra and illustrate specifics of a proposed quantitative method for assessment of tree dynamics near the upper tree line. Universality of the method for mapping and quantitative assessment of phytocoenohoras’ transformation, lowering mapping subjectivity level, and testing of the method for a selected study area in Polar Urals provides, in our opinion, the necessary level of universality and applicability of the said method for studies of climate-driven tree vegetation dynamics occurring at the upper tree line. Thus, in our opinion, it is not necessary to expand the study area.

I suggest generalizing the reseach outcomes by adding a relevant (basic) statistical analysis, which is critical in the frame of an international journal. 

Answer:

We accept the point, and added data from field studies on test sites with statistics and explanations. We added the following text and figures:

Added subsections: 2.2. Ground Measurements and 2.3. Trees recognition

Lines: 86 — 108.

Added new figures (3 and 4) caption to them.

Figure 4 has been changed (trial areas have been added) and an addition has been made to the caption to this figure.

Added a text fragment in the title of table 2

Secondary issues:

-I suggest using italics for species names.

Answer:

We use the recommended LaTex commands to write words in italics:

\textit{Larix sibirica} Ledeb.

\emph{Betula tortuosa} Ledeb.

\emph{Betula nana} L.

\emph{Juniperus sibirica} L.

Plant species names are not displayed in italics in current pdf-file (when converting LaTex code to a PDF ). Now we do not find a way to fix problem. We will ask specialist of publisher to help us to fix this problem.

-Line 9: I think that it is "of" instead of "od"Please revise.

Done. Line 9.

With best regards,

authors