Variation in Niche and Interspecific Associations across Elevations in Subtropical Forest Communities of the Wuyi Mountains, Southeastern China

Comments 1: [Nevertheless, the analysis shows inconsistencies and gaps, which would make it possible to draw new/additional findings compared to the current ones. For example, it is not sufficiently taken into account that the associations of species can be realized in several directions, these cases are not treated coherently (tree-tree, shrub-shrub, and tree-shrub associations). It is also not sufficiently clear and consistent that a continuous elevation change (gradient) or relative height ranges (low, medium, high) are used as evaluation criteria - the two aspects are often confused, or the illustrations and the textual descriptions about them do not correspond to each other.]

Response 1: [We would like to express our gratitude for the comprehensive feedback. A review and improvement of the analysis framework will be undertaken to ensure that the associations of all species are comprehensively considered and consistently addressed. We have explicitly used altitude ranges (low, middle, high) as evaluation criteria in the manuscript at lines 166, 348, and 366-372, and ensured consistency in both illustrations and textual descriptions.]

Comments 2: [The description of the data collection method in Chapter 2.3.1 is rough and incomplete, we do not know exactly what the basic data covers, and the unit of measurement is not indicated either (e.g. IV, Rf, Ra, Rd).]

Response 2: [We are grateful for pointing out our mistake. The specific formula has been added in line 181 of Section 2.3.1 in the revised version, and the content covered by the underlying data has been clearly described in line 183-186.]

Comments 3: [In the result chapter, there are evaluation aspects that are not recorded/presented in the methodology section, e.g. low-medium-high elevation range (what is it related to?).]

Response 3: [We have written the definition of the low-medium-high elevation range in line 166 of chapter 2.2 to ensure consistency in what is assessed in the results section. This was done by categorizing the sample plots using a multiple regression tree, with elevation as the independent variable and the type and number of trees and shrubs within each sample plot as the dependent variable, to classify the sample plots into three categories, labeled H1, H2, and H3, respectively.]

Comments 4: [The 3rd and 4th sample plots mentioned in Chapter 2.2 cannot be identified in Table 1 (was the latter omitted or are the two combined?).]

Response 4: [Because the table was too long, the last two rows may not have been fully displayed. We have updated the content and format of the table to ensure that the basic information for all plots can be viewed. The updated table can be found on lines 174-175 of the manuscript.]

Comments 5: [The usability of the 4th plot (last four rows) in the analysis is completely irrelevant, because it is not a forest type (indicated as a subalpine meadow) and does not contain any dominant tree or shrub species (species list missing).]

Response 5: [Thank you for bringing this to our attention. We have reviewed the data for the fourth plot and will no longer list it separately as a forest type. The updated table can be found on lines 174-175 of the manuscript.]

Comments 6: [The scientific names of the plant species included in the study are not complete, the auctor is missing, use of the full name or genus abbreviation is not consistent either, these should be corrected based on the WFO Plant List.]

Response 6: [We have checked and corrected the scientific names of all plant species against the World Flora Online botanical name database, ensuring the use of complete names with author citations and adherence to standardized abbreviations. The updated botanical names are located on lines 163 and 164.]

Comments 7: [I feel that the situation of Table 1 and Table 2 is logically reversed. The latter (current Table 2) contains the complete information, in which all the properties of the examined species must be listed, such as the full name and author, and I recommend adding the plant families so that it can refer. When presenting the habitats and plots (current Table 1), this can be referred to later and the abbreviated, unauthored species names can be used.]

Response 7: [Thank you for your suggestion. In order to enhance the logical coherence of the document, we have adjusted the position of Table 1 and Table 2, as well as the order of the second and third paragraphs of Section 2.2. The complete names, authors, and family names of all surveyed species are listed in the current Table 1 (line 163). In subsequent sections of the manuscript, abbreviated species names without authors will be used.]

Comments 8: [The titles of the tables and figures are very incomplete, for example, I could not find a general description of them, in many cases, only a repeated listing of the table's columns can be read (double communication). Explanations of the symbols used are also missing in several places, e.g. The meaning of the lines in Figures 2 and 4, the interpretation of colors in Figure 3, etc.]

Response 8: [We have updated the titles of Figure 2 (lines 292-295), Figure 3 (lines 307-310), and Figure 4 (lines 332,333) to enhance the visual appeal and readability of the charts, facilitating a more expedient comprehension of the essential data by the readers.]

Comments 9: [When mentioning the name of the species in the text, I do not recommend using the abbreviated name (e.g. B. acetosella), because it is only possible to find out what exactly it is after a long search.]

Response 9: [We have avoided using abbreviated names in the revised version to ensure that species names mentioned in the text are complete, making it easier for readers to identify and understand. The adjusted species names appear on lines 301-303,313-315,324,326,327 and 409-412.]

Comments 10: [I strongly miss a more precise discussion of elevation as a complex environmental combination, which element can be important in terms of interspecific associations and species niches (e.g. temperature, precipitation, humidity, radiation, soil properties). If there are related environmental data to a given elevation, I recommend using/including them for the analysis as well.]

Response 10: [We concur with your point and have added a discussion of elevation as a combination of complex environments to the revised edition, with the additions located on lines 366-373 and 387-397. Since our current survey did not obtain relevant environmental data, we have integrated previous research to explore the importance of environmental factors in interspecific relationships and species ecological niches.]

Comments 11: [The Conclusions chapter is currently meaningless and contains only general statements without specifics, which could be written even without knowing the results of the study. ]

Response 11: [The conclusion section has been revised (lines 474-486) to present a clear and concise summary of the study's findings, along with well-reasoned conclusions and recommendations.]

Comments 12: [The use of concepts is also not consistent throughout the manuscript, e.g. important value vs importance value, dominant species vs dominance species, etc., these also need to be checked and standardized.]

Response 12: [We apologize for any confusion that may have been caused. A review of the manuscript has been conducted with the objective of ensuring standardization and consistency of terminology.]

Comments 13: [In my opinion, the manuscript needs an overall (major) revision and correction. Based on the above, I recommend and request that the analysis framework, the set of analyzed data, the analysis aspects, and the highlighting/presentation of essential information be reconsidered. Please highlight the changed parts in the resubmitted material in color for visibility. I would like to make my detailed comments after the major revision, knowing the modifications that have been made.]

Response 13: [Thank you very much for all your suggestions. We have revised the manuscript based on your recommendations and highlighted the modified sections in color in the resubmitted materials. We sincerely look forward to your detailed comments in the following.]

Point 1: I also suggest checking the English grammar and spelling.

Response 1: [Thank you for your suggestions. With the assistance of LetPub, we have made grammar and spelling corrections to the manuscript.Please see the evidence of the language polishing process in the attachment.]

Comments 1: [The background provided is fine.]

Response 1: [We will continue to enrich the background information as well as the overall content of the manuscript.]

Comments 2: [The literature survey is not sufficient. In fact no related work is mentioned so I am unable to figure out what is the current status of the carried work.]

Response 2: [We are grateful for your valuable input. The logical order of the paragraphs in lines 69-96 of the introduction section of the manuscript and have added more related research on plant communities in Mount Wuyi, presented the current state of research in the field, and cited additional literature to support the context of our study.]

Comments 3: [The overall presentation of the manuscript is fair.]

Response 3: [We have implemented modifications to the manuscript's structure and content, and we anticipate receiving further suggestions.]

Comments 4: [However, authors have just analyzed niche elevations and overlaps.]

Response 4: [We have added a discussion of elevation as a combination of complex environments to the revised edition, with the additions located on lines 366-373 and 387-397. Since our current survey did not obtain relevant environmental data, we have integrated previous research to explore the importance of environmental factors in interspecific relationships and species ecological niches.]

Comments 5: [Results and discussion section are fine]

Response 5: [Thank you for your recognition. Thank you for your recognition.]

Comments 6: [Overall, the manuscript does not contain any novelty]

Response 6: [We are grateful for your observation of our deficiencies. In the forthcoming iteration of this paper, we will rethink the innovation points and continue to discuss the role of interspecific relationships and niche overlap in the community construction process of plant communities under different elevation gradients.]

Comments 7: [The inferences drawn from the study are generalized.]

Response 7: [We have rewritten the conclusions chapter on lines 474-486 to ensure that the specific findings of the study are accurately summarized and that meaningful conclusions and recommendations are provided.]

Comments 1: [References to literature are not designed according to the journal rules. In the text of the article, they are in the form of superscript characters.]

Response 1: [Thank you for pointing out the error. We have revised the format of the citation numbers in the article according to the journal's guidelines.]

Comments 2: [Line 103. What units of area are designated by this abbreviation ‘hm’? Hectares or square kilometers?]

Response 2: [We offer our sincere apologies for the lack of precision in our description. The abbreviation on line 112 has been corrected to "hectares" to ensure consistency with the standard metric unit of measurement.]

Comments 3: [Line 279. In this paragraph, tree species with relatively larger niche widths are listed, and it turns out that these species completely coincide with the dominants listed in the Table 1. That is, the dominants turned out to be species with a wide ecological niche (within the studied area) and species with the highest IV (mportance value) values. Then why is additional niche analysis needed if the IV coefficient copes well with this task? The same applies to shrub species.]

Response 3: [The importance value and niche breadth of plants in a community can reveal different information. Importance value is a comprehensive indicator that measures the relative importance of a plant species in a community. Calculating importance values provides an overall assessment of a plant species' performance in the community, thereby evaluating its relative importance[1]. Niche breadth describes the breadth of environmental resources utilized by a species, reflecting the diversity and extent of resource utilization in the environment[2,3]. Therefore, the combined use of importance values and niche breadth can respectively reveal the construction processes and mechanisms of forest ecosystems from the perspectives of plant-plant and plant-environment relationships. Additionally, we initially identified dominant species based on their importance values, and subsequently conducted interspecific association and niche overlap analyses among dominant species at different elevations. Thus, after calculating importance values, we also computed the niche breadth of dominant species.]

Comments 4: [In Figure 4, what is shown by the circles of different colors and sizes? I guess these are the values of the niche overlap index, but it's not obvious. If the values are shown in color (judging by the scale), why is another circle size needed?]

Response 4: [Sorry for the lack of clarity in our description of the figures. The dimensions and chromaticity of the circles depicted in Figure 4 are both contingent upon the niche overlap index. Initially, an attempt was made to use color alone to represent the values. However, due to the large amount of data, the image appeared cluttered, and the differentiation between color blocks with similar data was low. Accordingly, we elected to integrate color and size to enhance the visual appeal and readability of the figures, facilitating more expedient comprehension of pivotal information by the reader.]

Comments 5: [By what criteria were plant species classified as trees or shrubs? In table 1, Vaccinium sprengelii is also found both in the tree and shrub layer. This should be specified in the methods section.]

Response 5: [Distinctions between trees and shrubs often involve subjective factors depending on the specific region under study[4-6]. Therefore, we referred to the Technical Guidelines for Biodiversity Monitoring-Terrestrial Vascular Plants (HJ 710.1-2014) as well as some previous studies when we established the sample plots. We defined the woody plants with diameter at breast height (DBH) less than or equal to 5 cm at 1.3 m in the shrub sample plots as shrub layer plants, and the woody plants with DBH greater than 5 cm as arborvitae layer plants[7,8]. This is the reason why some plants occur in both the tree and shrub layers at the same time. We have added explanations on lines 141-144.]

Comments 6: [In section 4.1. of Discussion, the authors talk about the causes of high species richness and diversity in sample plots located in the mid-elevation region, and discuss possible causes of this phenomenon. In my opinion, the authors unnecessarily separate the elevation of the sample plots (abiotic factor) from the plant communities (ecosystem) that grow there. In the Table 1, three types of communities correspond to three groups of elevation: evergreen, deciduous and coniferous forests, respectively. Deciduous trees may change habitat conditions through their leaf fall, which may favour the growth of other species. The site elevation factor does not exist by itself, it is related to other conditions.]

Response 6: [We concur with your point and have added a discussion of elevation as a combination of complex environments to the revised edition, with the additions located on lines 366-373 and 387-397. Since our current survey did not obtain relevant environmental data, we have integrated previous research to explore the importance of environmental factors in interspecific relationships and species ecological niches.]

Comments 7: [Secondly, the article does not show the distribution of species into these three groups, so the reader cannot see for himself the change in species diversity that the authors are talking about. There is the Figure 3, but it is very difficult to get this information from it. It would be possible to place a table with the species in supplementary materials.]

Response 7: [Thank you for your suggestion. An appendix in lines 500-504 has been included with the article to present the distribution and niche breadth of each dominant species across the three elevation groups.]

Comments 1: [Although the Wuyi Mountains is a suitable analysis system, some of the obtained results may go beyond the locality and can be generalized to the dynamic processes typical of subtropical forest vegetation. In my opinion, the different and occasionally opposite niche width and interspecific association responses revealed in the two vertical layers (tree and shrub) may be such. Please rethink about these aspects and expand the second paragraph of the conclusion chapter.]

Response 1: [Thank you for your suggestions. We have rethought the second paragraph of the conclusion chapter, adding the complexity of the effects of different elevations on the two vertical layers, and expanded the conclusions to the dynamic processes of subtropical forest vegetation. You can find the revised content in lines 493-502.]

Comments 2: [If you are comparing the data by elevation ranges in the analyses, then do so consistently throughout the entire manuscript (instead of a simple gradient), including the abstract. Although the occurrence of forest stands is along an altitudinal gradient across the mountain, the consecutive ranges of this gradient determine the relative position and order of the forest communities, meaning H1 in a low-elevated altitudinal range, H2 in a medium-elevated altitudinal range, and H3 in a high-elevated altitudinal range.The terms ’interspecific relationship’ and ’elevational range’ or ’altitudinal range’ must be used consistently throughout the entire manuscript.]

Response 2: [Thank you very much for pointing out the issues we overlooked. We have reviewed the entire manuscript, using elevation ranges as the basis for analysis and discussion, and ensured the consistency of terms. The revised content is located at lines 15, 18-20, 22, 60, 61, 64, 66, 74, 79, 95, 96, 99, 104, 125, 220, 221, 247, 275, 277, 286, 287, 291, 312, 313, 317-319, 330, 331, 340, 346, 357, 368, 374, 375, 378, 387, 397, 432, 459, 468, 488, 490, and 515.]

Comments 3: [In the title, it is worth displaying the results more specifically (niche, inter-specific association) and naming the type of vegetation (i.e. forest comm-unities instead of plant communities)]

Response 3: [Based on your suggestions, we have changed the title to “Variation in niche and interspecific associations across elevations in subtropical forest communities of the Wuyi Mountains, southeastern China” to highlight the research results and vegetation type. The revised title is located at lines 2-4.]

Comments 4: [Figure 1. a detailed explanation is missing, e.g. meaning of numbers, elevation unit, interpretation of contour line - please fill it in.]

Response 4: [Thank you for letting us know about the missing content. We have explained the meaning of the numbers, the elevation units, and the contour lines in Figure 1. You can find the revised content is located at lines 154-156.]

Comments 5: [Table 2. A general table heading is missing (repeated listing of the table's columns is not desirable) - please fill it in.]

Response 5: [We apologize for previously misunderstanding your comment. We have revised the title for Table 2. The updated title is located at lines 178-179.]

Comments 6: [H1, H2, H3 need a more detailed explanation, would these be the elevation ranges or elevation-related forest types, etc.? If so, please state this (it is important for the entire study!)]

Response 6: [Thank you for your suggestion. H1, H2, and H3 represent elevation ranges. We have added this explanation at line 169 of the manuscript.]

Comments 7: [Figure 2. the designations of the categories seem a bit random, what is more important: the level of significance or the positive-negative relationship (for example, a non-significant positive relationship is also indicated by a full symbol, and an extremely significant negative relationship could be considered insignificant) - I recommend rethinking the case-related symbols in order to highlight important cases more effectively.]

Response 7: [We wanted to highlight the positive and negative associations, so we have changed the symbols of the categories and enhanced the consistency of the symbols to make them easier to identify. Significant and highly significant positive associations are now indicated with solid symbols, non-significant positive associations with semi-solid symbols, and all negative associations with hollow symbols. The modified figures and explanations are located at lines 291-298.]

Comments 8: [Figure 4. here, not the analysis, but its result is depicted; according to my understanding, the numbers are relative values, if so, please clarify. The colors of the relative scale is inconsistent, I would recommend a much clearer transition between 0-1 (e.g. the increasing strength/tone of a basic color). Since the scale is the same in all sub-figures, it is worthwhile to indicate it only once (in the simpliest way mention it only in the figure legend).]

Response 8: [You are correct, Figure 4 presents the results. The numbers are relative values. They represent the relative similarity in resource use between two species rather than absolute quantities or frequencies. The niche overlap index is calculated by comparing the proportional use of different resources by the two species, indicating the degree of overlap in their niches. The higher the value, the greater the similarity in resource use between the species, making it a relative measure. We have changed the color scheme of the figure to make it clearer and removed the redundant figure legends. The revised figure is located at line 332.]

Point 1: As English language correstion, the consistent form and use of technical terms should be provided across the entire manuscript.

Response 1: [Thank you for  your suggestions. We have reviewed the manuscript again and ensured consistency in format and terminology.]