Changing Dynamic of Tree Species Composition and Diversity: A Case Study of Secondary Forests in Northern China in Response to Climate Change

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is a very interesting research topic, as it helps us understand the response of forest ecosystems to climate change. The manuscript is well written and provides a sufficient number of references. However, in order to improve the quality of the manuscript I have few comments and suggestions:

Apstrakt:

I think it is necessary to improve the abstract. Why do you only mention the Pielou index from 2021 as significant? What exactly is meant by: „the temperature of the study area will improve in spring and autumn, while precipitation will increase in spring, summer, and autumn from 2015 to 2021”?

Introduction:

You state: “The average global temperature has increased by approximately 0.85 ℃ in the past century”. Where did this conclusion come from - please provide a source?

You state: “Therefore, understanding the interaction between climate change and plant diversity is of great theoretical and practical significance for protecting biodiversity and maintaining ecosystem health”. Perhaps it is better to use the term ecosystem stability?

You state: “The amplification of the annual mean temperature in China, reaching 0.78 ± 0.27 ℃, is greater than the global one for the same period, and there is an obvious regional difference. Where did this conclusion come from - please provide a source?

You state: „When et al. (2017) studied the impact of climate change on plant diversity, they reported that species richness increased with increasing temperature; however, it did not correlate with changes in precipitation gradients“. Do you mean Wehn et al. (2017)?

You state:  „In our study, a series of field surveys were performed to investigate the growth, species composition, richness of trees, and changes in plant diversity in the Xiaoxing’an mountain forest region, Heilongjiang province, northern China, from 2015 to 2021. I don't think it can be said that you investigated  changes in plant diversity, but tree species diversity.

Study area:

The names of the tree species in the entire paper sometimes have the names of the authors, sometimes they don't. Additional confusion is created by abbreviations of species names. It happens that in one sentence you alternately list the full and abbreviated names of certain tree species, which is completely confusing. I suggest that in the work method where you list tree species for the first time, you can state the full names of the species and their authors. After that, it is not necessary to mention the authors of the species (none of them) in the text or in the tables.  Also, in table 2 it is necessary to indicate the full names of the tree species, after which you can use abbreviated names in the text, but of all species.

Figure 1.

The map is not quite clear, you need to correct it. It is enough to put the numbers of permanent quadrats in the appropriate color for a certain type of forest, or to remove the numbers of permanent quadrats, leaving only the existing legend. Certainly the title "study area" prevents visibility of locations.

Experimental design: 

You state that the quadrats were divided into three types: pure forest, broadleaf mixed forest, and conifer-broadleaf mixed forest. With pure forest, specify in the text that it is about both cases – broadleaf and coniferous pure forests.

Discussion:

It is not clear what the sentence means: ”However, the importance of many broad-leaved tree species, such as A. ukurunduense, A. tegmentosum, S. reticulata, S. taraikensis, U. macrocarpa, U. davidiana var. japonica, P. amurense, A.elata, etc”?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Abstract: The abstract does not clear. The flow is not good. English editing is required. Terms such as climate warming or global warming, need uniformity. 

Introduction: Words such as countless scientists need to be rephrased. Do we have rules of succession? I would like the author to rephrases such sentences. Introduction is now well articulated. 

Methods: How reliable is it to consider global climatic data to growth and development of plants of specific region? It would be better to related the site specific climatic data with the growth and development of plants of that region. 

Results: Mixed forests have high species diversity, it is an understood fact. How can this be your finding be unique? In many cases you have mentioned results are interesting? What does it mean? This should be made clear and specific. Secondary forest needs to be well defined. 

The overall conclusion is not convincing. 

Comments on the Quality of English Language

The language is very weak. Needs through editing. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The study conducted by the authors explores the growth, species composition, richness, and plant diversity in Northern China. The research questions focus on understanding how species composition changes with global warming and the response of tree diversity to this phenomenon. The authors have presented data and analysis, specifically examining precipitation, temperature and alpha diversity indicators. However, a clear connection between global warming and species composition is missing, as highlighted in research questions 1 and 2.

 

To enhance the research, the authors need to establish a more explicit link between global warming and seasonal variation to species composition. This connection could be achieved through the implementation of a model formulation, designed to test the significance of the relationship in addressing the stated research questions. Such a model would contribute to a more robust understanding of the impact of global warming on the studied parameters.

 

Additionally, considering the investigation of species compositions in different types of secondary forests, the authors may incorporate beta and gamma diversity indicators into their analysis. While alpha indicators provide insights into diversity within a community at a smaller scale (local or ecosystem), beta and gamma indicators offer a broader perspective, capturing diversity among different communities and across larger spatial scales. Inclusion of beta and gamma diversity indicators, would benefit the readers more and address the research questions posed.

Comments on the Quality of English Language

Good quality

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript needs substantial improvement. Since the line number is not provided, the comments are provided in the attached file.

Regards

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript has been improved. 

Comments on the Quality of English Language

It is ok.

Reviewer 4 Report

Comments and Suggestions for Authors

In the first round of the revision, the author have made considerable corrections in the manuscript and manuscript now can be accepted. However the quality of the figure 1 is not good at all. It is very tough top read the coordinates and legends of the figure. So kindly revise accordingly. In line 328-341, the author have provided the summary of the investigation, while also providing the separate conclusion section, so, i suggest author to kindly merged it with the conclusion section. because it is just repition of the information.

Comments on the Quality of English Language

Minor editing of English language required