Climatic Influence on Growth Performance of Abies spectabilis in the Himalayas

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript has been written well. Information has been reviewed using all available resources following standard protocols. However, all sections must be supplemented using photographic illustrations, graphical illustrations etc. Moreover, information has been only limited to Nepal only. Please add information in line to the Himalayas. I also have some suggestions given below for improvement of the manuscript.

Comments for author File: Comments.pdf

Author Response

We sincerely appreciate the reviewers’ insightful comments and constructive feedback, which have significantly contributed to improving the quality and clarity of our manuscript. Below, we provide a point-by-point response to each comment and highlight the revisions made accordingly.

RESPONSE TO REVIEWER 1

General Comments for Authors 

The manuscript has been written well. Information has been reviewed using all available resources following standard protocols. However, all sections must be supplemented using photographic illustrations, graphical illustrations etc. Moreover, information has been only limited to Nepal only. Please add information in line to Himalayas. I have also some suggestions given below for improvement of the manuscript.

 

Comment 1. Line 39 please add few line related with the economic importance of this species (Abies spectabilis).

Response1: We have added a reference indicating  the economic importance of Abies spectabilis (Line 63).

Comment 2. Scientific name of species like Abies spectabilis must be etalic throughout the manuscript. Materials and methods

Response 2: The scientific name of Abies spectabilis has been italicized consistently throughout the manuscript.

Comment 3. Line 91-104 please add citation to the methodology followed.

Response 3: We have included appropriate citations for the methodology followed (Lines 129 and 140).

 

Climatic variability in the Central Himalaya

Comment 1. Please update the information of this section to all regions of The Himalayas which have five countries: India, Nepal, Bhutan, China (Tibet), and Pakistan. But your information is limited to only Nepal.

Response 1: This section has been expanded to include information covering climatic variability in the Himalaya (line 164-173).

Comment 2. Also include global context information too for this section.

Response 2: We have included relevant global context information to provide a more comprehensive perspective of the global climate change information  (lines 31-42).

 

Dendroecology to study ecological and environmental change

Comment 1. I suggest to add some pictorial illustrations of this part.

Response 1: We have added pictorial illustrations to support this section (line 375).

Comment 2. Also include global context information too for this section.

Response 2: Global context information has also been incorporated to strengthen this section (line 223 to 225)

 

Discussion

No changes were necessary, as the reviewer found this section well-written.This part has been written well. 

Reviewer 2 Report

Comments and Suggestions for Authors

 

The language of this paper is proficient, with clear and coherent expression that facilitates reader comprehension. In this study, the author conducted a review of literature published prior to July 2024, with data sourced from the Clarivate Web of Science database. The focus of the research is on the relationship between the radial growth of Abies spectabilis and climatic variables in the central and western Himalayas. The study finds a positive correlation between tree radial growth and the temperatures of the current and preceding growing seasons, or that tree growth may be constrained by winter temperatures or moisture availability during the pre-monsoon season. This paper highlights the significant impacts of climate change on the forest ecosystems in the region, offering insights into how these effects manifest under varying climatic conditions. However, upon a thorough review, I find that the study does not present any particularly novel findings. The primary conclusion is that radial tree growth is related to temperature and precipitation, which appears to reflect a general ecological mechanism, and as such, may not constitute a distinctive contribution to the field. Moreover, it is my understanding that review articles in ecology typically employ two types of data analysis methods: meta-analysis and data integration analysis. However, this study does not incorporate any data analysis or provide empirical support, but instead offers a descriptive and conclusive summary of the existing literature. This, in turn, reflects certain limitations in the depth of the research, despite its classification as a review article.

1. Lines 28-32: I find it difficult to fully understand the logical relationship between these sentences. The author first states that "climate change is fundamentally altering the growth and survival environment of conifer species," and then says "climate change and other human activities are driving forces behind the loss of biodiversity in terrestrial ecosystems." The author needs to clarify the distinctions and connections between the impacts of climate change and human activities on terrestrial ecosystems and conifer species.

2. How do changes in temperature and precipitation patterns due to climate change affect the growth of Abies spectabilis in the Himalayas? Has the rise in temperature pushed the growth limits of Abies spectabilis to higher altitudes, or do the negative impacts of temperature rise and changing precipitation patterns outweigh the benefits?

3. In terms of ecological adaptability of Abies spectabilis, how do anatomical characteristics of tree rings provide physiological feedback on climate change?

 

4. Over the past decades, has there been a significant trend in the tree ring growth of Abies spectabilis, particularly in the comparison between warm and dry years versus wet and cool years?

5. The three results presented in this study do not seem to have a strong logical connection. The first result is a detailed description of the climate variability in the central Himalayas, the second result discusses the application of tree ecology in the study of ecological and environmental changes, and the third result describes quantitative wood anatomy exploring the functional traits of the xylem. I fail to see a tight logical connection between these results. The title of the article is "Climatic influences on growth performances of Abies spectabilis in the Himalayas," and I believe the primary focus of the results should be on the growth performances of Abies spectabilis.

6. Do trees of different ages respond differently to climate change? Is there a significant difference in the growth performance of young versus old trees under climate variability?

7. The figure 1 would be more informative if it showed the larger spatial context on one side and then as a zoom-in the displayed map. Not all readers may be familiar in detail with the Central Himalaya and Nepaly in that area.

 

 

 

Author Response

 

Comment 1. Lines 28-32: I find it difficult to fully understand the logical relationship between these sentences. The author first states that "climate change is fundamentally altering the growth and survival environment of conifer species," and then says "climate change and other human activities are driving forces behind the loss of biodiversity in terrestrial ecosystems." The author needs to clarify the distinctions and connections between the impacts of climate change and human activities on terrestrial ecosystems and conifer species.

Response 1: Logical connection has been established with explanation with additional references in the text. We have revised these sentences to clarify the distinctions and connections between the impacts of climate change and human activities on conifer species and terrestrial ecosystems. The revised section now explicitly differentiates the direct effects of climate change from anthropogenic influences. (line 31 to 42 and 55 to 57)

 

Comment 2. How do changes in temperature and precipitation patterns due to climate change affect the growth of Abies spectabilis in the Himalayas? Has the rise in temperature pushed the growth limits of Abies spectabilis to higher altitudes, or do the negative impacts of temperature rise and changing precipitation patterns outweigh the benefits?

Response 2: We have expanded our discussion on how temperature and precipitation changes influence tree growth, including whether warming trends have pushed growth limits to higher altitudes or whether the negative impacts of temperature rise and altered precipitation patterns outweigh the benefits.

Various studies show the change in the winter temperature signal in tree growth since the 1980s (Zheng, Gaire and Shi, 2021). Tangible impacts of climate change in Abies spectabilis in Himalayas are the variations recorded in the growth of trees due to their sensitivity to the extreme climatic conditions to which they are exposed. At lower elevations, rising temperatures have led to negative growth trends, primarily due to increased moisture stress and vapour pressure deficits (Panthi et al., 2020). Drought conditions during pre-monsoon seasons have emerged as significant limiting factors for tree growth (Schwab et al. 2018) and the low spring moisture availability reduced Himalayan fir growth at low- to middle-elevations (Gaire et al. 2023). The prevailing negative impacts of increased temperatures and altered precipitation patterns may outweigh the benefits, particularly in lower elevation habitats. One study based on transects studies at upper species and tree limit highlight the potential for A. spectabilis to adapt to warmer conditions by moving to higher altitudes (Suwal et al. 2016). 

 

Comment 3. In terms of ecological adaptability of Abies spectabilis, how do anatomical characteristics of tree rings provide physiological feedback on climate change?

Response 3: We have elaborated on how the anatomical characteristics of tree rings provide physiological feedback on climate change, highlighting how species modulate key functional traits in relation to anatomical structure.

 The anatomical traits of tree rings potentially provide valuable insights into ecological adaptability of this species by providing critical physiological feedback on climate change by reflecting the tree's adaptive responses to varying environmental condition.

The species exhibits adjustments in tracheid number, lumen area, cell wall thickness and hydraulic conductivity in its range limits in Central Himalaya (Pandey 2024). It also exhibits significant water potential  in the treeline ecotone of western Himalaya showing its pivotal role in phenology and seed germination (Singh et al. 2024).

 

Comment 4. Over the past decades, has there been a significant trend in the tree ring growth of Abies spectabilis, particularly in the comparison between warm and dry years versus wet and cool years?

Response 4: We are unable to add an analysis of tree-ring growth trends in Abies spectabilis over the past decades, particularly comparing responses during warm, dry years versus cool, wet years due to lack of relevant literature. However, Species' response to climate is complex and varies with elevation and specific climatic conditions. The tree-ring studies indicated that the growth of this species is influenced by both temperature and precipitation  highlighting the complex interplay between climate factors and tree growth. Although there is no specific study based on comparison between warm and dry years compared to wet and cool years, one study reported a weakened sensitivity to climate, particularly in response to spring conditions (Bista et al. 2021) especially after 1970s. The long-term growth trends of  A. spectabilis have decreased at low- to mid-elevation sites but increased at the treeline during the period 1981–2011 (Gaire et al. 2023, Panthi et al. 2020, Pandey et al. 2020). 

Comment 5. The three results presented in this study do not seem to have a strong logical connection. The first result is a detailed description of the climate variability in the central Himalayas, the second result discusses the application of tree ecology in the study of ecological and environmental changes, and the third result describes quantitative wood anatomy exploring the functional traits of the xylem. I fail to see a tight logical connection between these results. The title of the article is "Climatic influences on growth performances of Abies spectabilis in the Himalayas," and I believe the primary focus of the results should be on the growth performances of Abies spectabilis.

Response 5: We acknowledge the reviewer’s concern regarding the logical coherence of the results section. We have restructured this section to better align with the manuscript’s title, ensuring a stronger focus on the growth performance and how anatomical response confer the capability of Abies spectabilis to altered climatic conditions.

We presented the description of the climate variability in the central Himalayas to contextualize the growth patterns of Abies spectabilis under changing environmental conditions. The discussion about tree ecological trait quantitative wood anatomy provide mechanistic insights into how conifers species adapt and dynamically respond to climatic variability, directly influencing its growth performance.

Comment 6. Do trees of different ages respond differently to climate change? Is there a significant difference in the growth performance of young versus old trees under climate variability?

Response 6: We have included a discussion on whether young and old trees exhibit different growth responses to climate variability and whether significant differences exist in their performance. (Lines 533-540)

Comment 7. The figure 1 would be more informative if it showed the larger spatial context on one side and then as a zoom-in the displayed map. Not all readers may be familiar in detail with the Central Himalaya and Nepaly in that area.

Response 7: We have modified Figure 1 to include a larger spatial context alongside a zoomed-in section of the Central Himalayas, ensuring better geographical clarity for readers unfamiliar with the region.

Reviewer 3 Report

Comments and Suggestions for Authors

 

The review examines the climate impact on the growth rates of fir in the Himalayas. Some comments.

It is necessary to provide a photo of the anatomical structure of annual rings with early and late wood.

Describe what kind of root system does the fir have in the Himalayas?

It is necessary to describe in more detail what explains the longer recovery of fir after drought compared to juniper?

 It is necessary to describe the reaction of the fir cell wall to changing climatic conditions.

It is necessary to describe due to what the efficiency of water use in conifers is higher than in broad-leaved species

The list of references must be brought into line with the requirements of the journal.

Author Response

Comment 1: It is necessary to provide a photo of the anatomical structure of annual rings with early and late wood.

Response 1: We have added a photograph depicting the anatomical structure of annual rings, including earlywood and latewood with a brief description presented in the caption.

Comment 2: Describe what kind of root system does the fir have in the Himalayas?

Response 2: We could not find a literature specifically dealing with the detailed description of the root system of Abies spectabilis in the Himalayas. Almost nothing is known about the vertical root distribution for Himalayan fir trees. We are aware of only one scientific paper published  especially focusing for 10 tree species. However, it does not include Abies spectabilis. (Lines 478-483)

Comment 3: It is necessary to describe in more detail what explains the longer recovery of fir after drought compared to juniper?

Response 3: We have expanded our discussion to explain why Abies spectabilis exhibits a longer recovery period after drought compared to juniper. (lines 445-465)

Comment 4: It is necessary to describe the reaction of the fir cell wall to changing climatic conditions.

Response 4: There is no published data providing an explanation of how the fir cell wall responds to changing climatic conditions. A separate manuscript is under final preparation including cell walls based on tree ring sectors.  (378-388, 399-420)

Comment 5: It is necessary to describe due to what the efficiency of water use in conifers is higher than in broad-leaved species

Response 5: The possible cause of why the efficiency of water use in conifers is higher than in broad-leaved species described  (lines 313-326).

Comment 6: The list of references must be brought into line with the requirements of the journal.

Response 6: The reference list has been revised to comply with the journal’s formatting requirements.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I really appreciate how thoroughly the authors addressed most of the points, especially adding those references and reworking the logic in the results section. The map tweak in Figure 1 looks solid too. For Comment 4 (tree-ring trends), no worries about the data gaps! I totally get it when studies are limited. You did a great job highlighting what’s out there (like the elevation-dependent growth stuff). Maybe just slap a quick note in the limitations section like Future work could dig deeper into warm/dry or cool/wet year comparisons?

Comments on the Quality of English Language

The English language is used effectively, showcasing a strong grasp of syntax and style. It's a pleasure to read!