Reproductive Phenology and Climatic Drivers of Plant Species Used as Food by the Hainan Gibbon, Nomascus hainanus (Primates: Hylobatidae)

Round 1

Reviewer 1 Report

The paper attempts to assess the course of reproductive phenology for the Hainan gibbon's nutritional needs. The introduction introduces the reader to the topic of research in a comprehensive way. Three research questions were posed. The "Materials and Methods" section is not fully described. The weakness of the work is the short period of phenological observations and the statistical methods used.   Tips and questions: -Chapter 2.1. should be supplemented with a climatogram and a map of research locations (among others, the location of the meteorological station and the location of research transects should be marked). -Does the observation once every two weeks allow to determine the beginning / fullness of flowering and fruiting with sufficient accuracy? -Do the meteorological elements: Tmean, Tmax, Precipitation, Sunshine show a trend? Knowing the trend can be used to draw the right conclusions. -In chapter 2.2. there is no description of the main plant species analyzed in the work. Not all potential readers will be familiar with the flora of Hainan National Park. Phenological spectra of some tree species should be included. What about the BBCH scale? -Why phenological observations were carried out only from July 2019 to December 2022. Please explain this in the paper (lines 116-117). Does such a short period allow us to draw real conclusions? -What does the word "Cyear" mean (Table 1). -From Fig. 3, the reader cannot find out whether the analyzed differences are significant/irrelevant. -The work lacks individual relationships between the monthly number of flowering and fruiting tree species and meteorological variables. How were the coincidence and collinearity of the variables of the regression equation tested? What was the distribution of the variables: Tmean, Tmax, Precipitation, Sunshine? How was it checked? How were the regression equations evaluated? Can meteorological conditions be defined as environmental variables? (e.g. table 2)? -The summary lacks specific guidelines. For example, what tree species should be planted to improve the Hainan gibbon's food resources?

Author Response

Reviewer #1:

 

The paper attempts to assess the course of reproductive phenology for the Hainan gibbon's nutritional needs. The introduction introduces the reader to the topic of research in a comprehensive way. Three research questions were posed. The "Materials and Methods" section is not fully described. The weakness of the work is the short period of phenological observations and the statistical methods used.

Response: Thanks very much for taking your time to review this manuscript. We really appreciate all your comments and suggestions! We have made revisions according to your suggestions and offer a point-by-point response below.

 

 

Tips and questions:

1. Chapter 2.1. should be supplemented with a climatogram and a map of research locations (among others, the location of the meteorological station and the location of research transects should be marked).

Response: We agree, and we have added both a climatogram as well as a map of research locations (line98, Figure. 1 ABC).

 

2. Does the observation once every two weeks allow to determine the beginning / fullness of flowering and fruiting with sufficient accuracy?

Response: This is a great question, and we appreciate your careful eye for detail! You are correct, this sampling pattern may be too coarse to accurately capture the full resolution of these flowering and fruiting dynamics. However, due to the remoteness of the study site, we were unable to monitor the full range of species every week. We were forced to choose between high-resolution temporal monitoring of a small number of species, or a coarser observation that would better capture the dynamics of all possible food-producing trees. Furthermore, monthly or bi-monthly observations have been used in several subtropical and tropical settings to determine the peak flowering and fruiting periods (Tissue and Wright,1995; Sakai, 1999; Du et al., 2019; Pan et al., 2020; Dagnachew et al., 2023). In addition, we studied phenological patterns, which require slightly less data precision than studies of plant phenological responses to climate change.

 

 

[1] Tissue, D.T. and Wright, S.J. Effect of seasonal water availability on phenology and the annual shoot carbohydrate cycle of tropical forest shrubs. Functional Ecology, 1995,9, 518-527.

[2] Sakai, S., Momose, K., Yumoto, T., Nagamitsu, T., Nagamasu, H., Hamid, A.A. and Nakashizuka, T. Plant reproductive phenology over four years including an episode of general flowering in a lowland dipterocarp forest, Sarawak, Malaysia. American Journal of Botany, 1999, 86, 1414-1436.

[3] Du Y, Yang B, Chen S‐C, Ma K. Diverging shifts in spring phenology in response to biodiversity loss in a subtropical forest. Journal of Vegetation Science, 2019; 00:1–9.

[4] Pan Y Q, Du Y J, Chen W D, et al. Can plant phenology explain species coexistence: A case study in the subtropical evergreen broad-leaved forest of Gutianshan, Zhejiang, China (in Chinese). Scientia Sinica Vitae, 2020, 50: 362–372.

[5] Dagnachew, S., Teketay, D., Demissew, S., Awas, T. and Lemessa, D. The Effects of Monthly Rainfall and Temperature on Flowering and Fruiting Intensities Vary within and among Selected Woody Species in Northwestern Ethiopia. Forests, 2023, 14(3), p.541.

 

3. Do the meteorological elements: Tmean, Tmax, Precipitation, Sunshine show a trend? Knowing the trend can be used to draw the right conclusions.

Response: Yes. We have supplemented with a climatogram according to your suggestions and the meteorological elements at study site showed a trend in Fig. 1 (lines 98).

 

4. In chapter 2.2. there is no description of the main plant species analyzed in the work. Not all potential readers will be familiar with the flora of Hainan National Park. Phenological spectra of some tree species should be included. What about the BBCH scale?

Response: Thanks for your suggestion. We've added a description of the main plant species analyzed in our study (lines 106-108). We also have a description of the main plant species analyzed in chapter 3.1. We have provided a table with the scientific names of the 89 selected plant species in the supplementary file (Table. S1). The BBCH scale of ape-food species was 61 for the first flowering period and 65 for peak flowering, 81 for first fruiting, and 89 for peak fruiting (lines 111-115).

 

5. Why phenological observations were carried out only from July 2019 to December 2022. Please explain this in the paper (lines 116-117). Does such a short period allow us to draw real conclusions?

Response: For long term phenology study, we do not need to start from January, especially for the tropical phenology study. The phenology data in tropics is circular with no given starting season, and several papers have studied phenology without reviewing the entire year. Fox example, Tissue, D.T. and Joe Wright began their censuses from November 1989 and ending in October 1990 in tropical forest in Panama. Sakai et al. (1999) studied plant reproductive phenology over four years including an episode of general flowering in a lowland dipterocarp forest, Sarawak, Malaysia, and plant phenology was monitored twice a month from August 1992. Just as stated above, Saikai et al. (1999) studied an episode of general flowering using four years data, and we used 3.5 years data to explore general flowering/fruiting. We do admit that the relatively short monitoring period is a shortcoming of our study, and we have stated this shorting coming in the Discussion (Lines 343-347). In the future, long-term monitoring data are needed to gain a better understanding of the basic patterns of inter-annual variability in the dynamics of flowering and fruiting phenology of ape-feeding tree species.

 

[1] Tissue, D.T. and Wright, S.J. Effect of seasonal water availability on phenology and the annual shoot carbohydrate cycle of tropical forest shrubs. Functional Ecology, 1995,9, 518-527.

[2] Sakai, S., Momose, K., Yumoto, T., Nagamitsu, T., Nagamasu, H., Hamid, A.A. and Nakashizuka, T. Plant reproductive phenology over four years including an episode of general flowering in a lowland dipterocarp forest, Sarawak, Malaysia. American journal of botany, 1999, 86, 1414-1436.

 

6. What does the word "Cyear" mean (Table 1).

Response: Thank you for catching that mistake. CVyear is a term that describes the inter-annual variation of flowering and fruiting in gibbon food species from 2019 to 2022 (lines 200-203).

 

7. From Fig. 3, the reader cannot find out whether the analyzed differences are significant/irrelevant.

Response: I've added a more detailed legend to explain Fig.4(Fig. 3 before modification) in lines 210-213. Wind-pollinated species flowered significantly earlier than insect-pollinated species (Fig. 4B, P<0.05).

 

8. The work lacks individual relationships between the monthly number of flowering and fruiting tree species and meteorological variables. How were the coincidence and collinearity of the variables of the regression equation tested? What was the distribution of the variables: Tmean, Tmax, Precipitation, Sunshine? How was it checked? How were the regression equations evaluated?

Response: Thank you for your comment. We used the linear regressions of all five climatic variables with the number of flowering or fruiting species per month. to investigate the relationships between reproductive phenology and each of the environmental variables. We used a one-variable regression equation to explore the effect of climatic factors in the current month, the previous month, and the previous two months on flowering and fruiting. Therefore, there is no multicollinearity in our regression equation. We used the Shapiro-Wilks test for five climate factors (Tmean, Tmax, Tmin, precipitation, and sunshine), all of which were approximately normally distributed with W values close to one. We used the AIC information criterion to select the models which best explained the relationship between climate and reproductive phenology (lines 157-159). We used the same method in several previous published studies (Du et al.,2020; Song et al., 2021; Richardson & O’Keefe, 2009).

 

[1] Du, Y., Li, D., Yang, X., Peng, D., Tang, X., Liu, H., Li, D., Hong, X. and Song, X. Reproductive phenology and its drivers in a tropical rainforest national park in China: Implications for Hainan gibbon (Nomascus hainanus) conservation. Global Ecology and Conservation, 2020, 24, e01317.

[2] Song, Z., Du, Y., Primack, R.B., Miller‐Rushing, A.J., Ye, W. and Huang, Z. Surprising roles of climate in regulating flowering phenology in a subtropical ecosystem. Ecography, 2021, 44(9), pp.1379-1390.

[3] Richardson, A.D. and O’Keefe, J. Phenological differences between understory and overstory: a case study using the long-term Harvard Forest records. Phenology of ecosystem processes: applications in global change research, 2009, pp.87-117.

 

9. Can meteorological conditions be defined as environmental variables? (e.g. table 2)?

Response: Thank you for your suggestions. We have revised it (line 227, line 230, line 316. Line 326).

 

10. The summary lacks specific guidelines. For example, what tree species should be planted to improve the Hainan gibbon's food resources?

Response: Thank you for your comments. We rewrote the Conclusions according to your comments and included greater detail suggesting that the restoration of Hainan gibbon habitat is best achieved by planting tree species that produce fruit when it is otherwise scarce between January-April, such species include M. ligustrifolium, W. pubescens, S. laurinum, E. ciliata, and P. annamensis. (lines 20-23, lines 349-359).

 

Reviewer 2 Report

Reviewer report for manuscript entitled "Reproductive phenology and climatic drivers of gibbon food species of Hainan gibbon". This work is novel and of high quality and address very important topic of research. 

- Abstract part is well written. However, it needs some improvement to highlight the important finding of this work and need to provide some quantitative data. 

- The introduction part is very comprehensive and addressed the key literatures related to this topic and also cited the recent publications in the field. This part is well written. 

- In materials and methods part: this part is well written and provided all needed information

- In results part: need to provide some statistical measures for figure 1. All other figures and table are well presented and written with good explanation in text. 

- The discussion part is results were well discussed and this part provided a very good explanation and discussion for the obtained resulted and compared with the previous papers work. 

- Conclusion: this part is well written. However, it needs some improvement to highlight more the novelty of this work and further studies and potential uses of the obtained data. 

- 

acceptable 

Author Response

Reviewer #2:

 

Reviewer report for manuscript entitled "Reproductive phenology and climatic drivers of gibbon food species of Hainan gibbon". This work is novel and of high quality and address very important topic of research.

Response: Thank you for your positive comments. We have made revisions in accordance with your suggestions and offer a point-by-point response below.

 

- Abstract part is well written. However, it needs some improvement to highlight the important finding of this work and need to provide some quantitative data.

Response: Thanks for your suggestion. We have revised the abstract to draw attention to our findings. (lines 13-18, lines 20-23).

 

- The introduction part is very comprehensive and addressed the key literatures related to this topic and also cited the recent publications in the field. This part is well written.

- In materials and methods part: this part is well written and provided all needed information

Response: Thank you very much for your positive comments.

 

- In results part: need to provide some statistical measures for figure 1. All other figures and table are well presented and written with good explanation in text.

Response: Thanks for your advice. I've provided some legends that include more detailed information about the statistical analysis (lines184-186).

 

- The discussion part is results were well discussed and this part provided a very good explanation and discussion for the obtained resulted and compared with the previous papers work.

Response: Thank you very much.

 

- Conclusion: this part is well written. However, it needs some improvement to highlight more the novelty of this work and further studies and potential uses of the obtained data.

Response: Thanks for your suggestion. We have rewrote the conclusion section (lines 349-359).

 

Reviewer 3 Report

Reviewer comments for the manuscript titled ''Reproductive phenology and climatic drivers of gibbon food species of Hainan gibbon'' (ID: forests-2487446)

 Brief summary

The authors discuss the phenological patterns of many plant species used as food by Hainan gibbon in relation to several meteorological variables in China. The topic is interesting and the main contribution of the current work is the knowledge gained on the reproductive phenology of many gibbon food species, cumulatively, in connection with their aerial environment.

 Specific comments

1.        Line 58. Replace ‘and key drivers’ with ‘as possible proximate drivers’.

2.        Regarding ‘2.2. Phenology data’, provide a table with the scientific names of the 89 selected plant species used in the current stydy.  

3.        Regarding ‘2.3. Meteorological data’, what is the distance between the meteorological station/s, from which the data were obtained, and the study area?

4.        Line 140. What ‘published literature’?

5.        Line 169. Insert 'Champ. ex Benth.' after 'ligustrifolium'. The scientific names should be complete. Check for similar cases throughout the text.

6.       Figure 1. The four images of this figure have been marked with 'A', 'B', etc. These marks should be included in the figure legend. Check for similar cases.

7.     Table 1. Tables (and Figures) should be self-explanatory. For example, what is 'Cyear'? Another example is the bars in ‘Figure 3’. What do bars represent?

      8. Line 194. Replace ‘Fig. 3’ with ‘Fig 3 C, D’.

Overall, the grammar and style in the manuscript are generally good, with only a few minor editing of the English language required.

Author Response

Reviewer #3:

 

Reviewer comments for the manuscript titled ''Reproductive phenology and climatic drivers of gibbon food species of Hainan gibbon'' (ID: forests-2487446)

 

Brief summary

 

The authors discuss the phenological patterns of many plant species used as food by Hainan gibbon in relation to several meteorological variables in China. The topic is interesting and the main contribution of the current work is the knowledge gained on the reproductive phenology of many gibbon food species, cumulatively, in connection with their aerial environment.

Response: Thank you for your positive comments. We made revisions according to your suggestions.

 

Specific comments

 

1. Line 58. Replace ‘and key drivers’ with ‘as possible proximate drivers’.

Response: We've removed it.

 

2. Regarding ‘2.2. Phenology data’, provide a table with the scientific names of the 89 selected plant species used in the current stydy.  

Response: Thanks for your suggestion. We have provided a table with the scientific names of the 89 selected plant species in the supplementary file (Table. S1).

 

3. Regarding ‘2.3. Meteorological data’, what is the distance between the meteorological station/s, from which the data were obtained, and the study area?

Response: We have added more detail about the meteorological station (Lines 126-127). The meteorological station is about 10 kilometers from the study site.

 

4. Line 140. What ‘published literature’?

Response: On that line, we were referring to both Cortés-Flores et al., 2017, and Du et al., 2020.

 

[1] Cortés-Flores, J.; Hernández-Esquivel, K.; González-Rodríguez, A.; Ibarra-Manríquez, G. Flowering phenology, growth forms, and pollination syndromes in tropical dry forest species: Influence of phylogeny and abiotic factors. American Journal of Botany, 2017, 104, 39–49.

[2] Du, Y., Li, D., Yang, X., Peng, D., Tang, X., Liu, H., Li, D., Hong, X. and Song, X. Reproductive phenology and its drivers in a tropical rainforest national park in China: Implications for Hainan gibbon (Nomascus hainanus) conservation. Global Ecology and Conservation 2020, 24, e01317.

 

 

5. Line 169. Insert 'Champ. ex Benth.' after 'ligustrifolium'. The scientific names should be complete. Check for similar cases throughout the text.

Response: We thank the reviewer for pointing this out. We have fixed the error (line 175) and checked the names of plants throughout the rest of the text.

 

6. Figure 1. The four images of this figure have been marked with 'A', 'B', etc. These marks should be included in the figure legend. Check for similar cases.

Response: Thanks for your suggestion. We have added these marks in the figure legend (lines 184-186). The figures and tables throughout the text provided a more detailed description.

 

7. Table 1. Tables (and Figures) should be self-explanatory. For example, what is 'Cyear'? Another example is the bars in ‘Figure 3’. What do bars represent?

Response: Thank you for catching our error. CVyear refers to the coefficient of inter-annual variation of flowering and fruiting in gibbon food species from 2019 to 2022 (lines 200-203). We have edited and added to our figures to include more detail. Similarly, I've added a more detailed legend to explain Fig.4 (lines 210-213) (Fig. 3 before modification). Wind-pollinated species flowered significantly earlier than insect-pollinated species (Fig. 4B, P<0.05).

 

8. Line 194. Replace ‘Fig. 3’ with ‘Fig 3 C, D’.

Response: Thanks for your advice. We have revised it (line 208).

 

Comments on the Quality of English Language

Overall, the grammar and style in the manuscript are generally good, with only a few minor editing of the English language required.

Response: Thank you for the suggestion. A native English speaker has reviewed our writing and offered several careful changes and revisions. It is our opinion that this has improved the readability of the manuscript, and we hope it meets your expectations for publication in Forests.

 

Reviewer 4 Report

To,

The Chief Editor,

Forests, MDPI,

Manuscript ID: forests-2487446

Subject: Submission of comments on the manuscript in “Forests "

 

Dear Chief Editor Forests, MDPI,

Thank you very much for the invitation to consider a potential reviewer for the manuscript (ID: forests-2487446). My comments responses are furnished below as per each reviewer’s comments. 

 Dear Chief Editor,

The reviewed manuscript authors conducted a regression analysis using field-monitored phenological and climatic data to understand the patterns of food availability across a three years period in the Hainan gibbon's habitat. Our findings indicate that there are significant seasonal and inter-annual variations in the reproductive phenology of these food species, with most species flowering from March to June and fruiting from August to December. Importantly, we show that during the January-April period, Hainan gibbons face severe food scarcity. We show that sunshine exerts a significant effect on flowering time while fruiting phenology is most sensitive to temperature. Our results imply that the restoration of Hainan gibbon habitat is best achieved by planting a greater proportion of tree species which produce fruit in the time of low food availability between January-April. Therefore, it might be conditionally accepted as subject to major revision. Instead, authors have to improve their manuscripts with many non-clear meanings, inaccuracies, and the authors need to address the following issues before it can be accepted for publication.

1. I have read the entire manuscript and my initial comment is that manuscript is poorly written. I have significant concerns about the grammar and vocabulary of the manuscript; therefore, I recommend the authors to used an English proofreading service.
2. The structure of the abstract should be improved, as well as the lack of several aspects that should be included in this section. Most of the abstracts contain confusing and uninformative sentences. Please give more precise objectives here (such as in the Abstract). The abstract should highlight the most important results of the parameters and characteristics assayed.
3. Introduction grammatical issues appear to be most prevalent in the introduction, making for very confusing reading. Further, the introduction is short but has no clear thread.
4. The figures are quite low resolution and difficult to make out. Higher-resolution versions will be needed for publication. Further, text in figure is not readble. for example, in Figures 1, 2, and 3.
5. The discussion should be interpreted with the results as well as discussed in relation to the present literature.
6. In Material and Methods:- indicate how many replicates assayed in each analysis/parameter. The number of samples or biological and technical replicates should be mentioned for each parameter in the methods.
7. The conclusion section is very poorly written. It should be extensively improved.
8. References: shall have to correct the whole References according to the ”Instructions for the Authors”, e.g. the Journal name must be abbreviated, journal name in italics, the year must be bold and you shall have to use the abbreviated number of the Journals cited. Further, some references the title to paper in title case some are in small letter case, hence please follow the journal instruction. Moreover, the scientific name must be italics. Please check the all refernce carefully.

Thank you and Best wishes

 

 

 

 

To,

The Chief Editor,

Forests, MDPI,

Manuscript ID: forests-2487446

Subject: Submission of comments on the manuscript in “Forests "

 

Dear Chief Editor Forests, MDPI,

Thank you very much for the invitation to consider a potential reviewer for the manuscript (ID: forests-2487446). My comments responses are furnished below as per each reviewer’s comments. 

 Dear Chief Editor,

The reviewed manuscript authors conducted a regression analysis using field-monitored phenological and climatic data to understand the patterns of food availability across a three years period in the Hainan gibbon's habitat. Our findings indicate that there are significant seasonal and inter-annual variations in the reproductive phenology of these food species, with most species flowering from March to June and fruiting from August to December. Importantly, we show that during the January-April period, Hainan gibbons face severe food scarcity. We show that sunshine exerts a significant effect on flowering time while fruiting phenology is most sensitive to temperature. Our results imply that the restoration of Hainan gibbon habitat is best achieved by planting a greater proportion of tree species which produce fruit in the time of low food availability between January-April. Therefore, it might be conditionally accepted as subject to major revision. Instead, authors have to improve their manuscripts with many non-clear meanings, inaccuracies, and the authors need to address the following issues before it can be accepted for publication.

1. I have read the entire manuscript and my initial comment is that manuscript is poorly written. I have significant concerns about the grammar and vocabulary of the manuscript; therefore, I recommend the authors to used an English proofreading service.
2. The structure of the abstract should be improved, as well as the lack of several aspects that should be included in this section. Most of the abstracts contain confusing and uninformative sentences. Please give more precise objectives here (such as in the Abstract). The abstract should highlight the most important results of the parameters and characteristics assayed.
3. Introduction grammatical issues appear to be most prevalent in the introduction, making for very confusing reading. Further, the introduction is short but has no clear thread.
4. The figures are quite low resolution and difficult to make out. Higher-resolution versions will be needed for publication. Further, text in figure is not readble. for example, in Figures 1, 2, and 3.
5. The discussion should be interpreted with the results as well as discussed in relation to the present literature.
6. In Material and Methods:- indicate how many replicates assayed in each analysis/parameter. The number of samples or biological and technical replicates should be mentioned for each parameter in the methods.
7. The conclusion section is very poorly written. It should be extensively improved.
8. References: shall have to correct the whole References according to the ”Instructions for the Authors”, e.g. the Journal name must be abbreviated, journal name in italics, the year must be bold and you shall have to use the abbreviated number of the Journals cited. Further, some references the title to paper in title case some are in small letter case, hence please follow the journal instruction. Moreover, the scientific name must be italics. Please check the all refernce carefully.

Thank you and Best wishes

 

 

 

 

Author Response

Reviewer #4:

 

To,

The Chief Editor,

Forests, MDPI,

Manuscript ID: forests-2487446

Subject: Submission of comments on the manuscript in “Forests "

 

 

Dear Chief Editor Forests, MDPI,

 

Thank you very much for the invitation to consider a potential reviewer for the manuscript (ID: forests-2487446). My comments responses are furnished below as per each reviewer’s comments.

 

Dear Chief Editor,

 

The reviewed manuscript authors conducted a regression analysis using field-monitored phenological and climatic data to understand the patterns of food availability across a three years period in the Hainan gibbon's habitat. Our findings indicate that there are significant seasonal and inter-annual variations in the reproductive phenology of these food species, with most species flowering from March to June and fruiting from August to December. Importantly, we show that during the January-April period, Hainan gibbons face severe food scarcity. We show that sunshine exerts a significant effect on flowering time while fruiting phenology is most sensitive to temperature. Our results imply that the restoration of Hainan gibbon habitat is best achieved by planting a greater proportion of tree species which produce fruit in the time of low food availability between January-April. Therefore, it might be conditionally accepted as subject to major revision. Instead, authors have to improve their manuscripts with many non-clear meanings, inaccuracies, and the authors need to address the following issues before it can be accepted for publication.

Response: Thank you for your positive comments. We have revised our manuscript carefully to improve the interpretation of the manuscript according to your suggestions.

 

1. I have read the entire manuscript and my initial comment is that manuscript is poorly written. I have significant concerns about the grammar and vocabulary of the manuscript; therefore, I recommend the authors to used an English proofreading service.

Response: A native English speaker has reviewed our writing and offered several careful changes and revisions. It is our opinion that this has improved the readability of the manuscript, and we hope it meets your expectations for publication in Forests.

 

2. The structure of the abstract should be improved, as well as the lack of several aspects that should be included in this section. Most of the abstracts contain confusing and uninformative sentences. Please give more precise objectives here (such as in the Abstract). The abstract should highlight the most important results of the parameters and characteristics assayed.

Response: Thank you for your suggestions. We have extensively rewritten the abstract to better highlight our findings and their importance.  (line 9, lines 13-18 and lines 20-23).

 

3. Introduction grammaticalissues appear to be most prevalent in the introduction, making for very confusing reading. Further, the introduction is short but has no clear thread.

Response: Thank you for your suggestions. We have rewritten the introduction with the intent to improve its logical flow and readability. It now guides the reader through an understanding of how inter-annual variability (particularly pronounced in Asian forests known to be susceptible to masting events) may influence food resource availability for the critically endangered Hainan gibbon. The introduction makes it clear that the population is heavily reliant on fruit-bearing trees in what remains of their local ecosystem, and that the inter-annual production of fruit on these trees can be quite variable. We closed the introduction by identifying three principal questions.

 

4. The figures are quite low resolution and difficult to make out. Higher-resolution versions will be needed for publication. Further, text in figure is not readble. for example, in Figures 1, 2, and 3.

Response: We apologize. Our figures have been adjusted to improve readability.

 

5. The discussion should be interpreted with the results as well as discussed in relation to the present literature.

Response: Thank you for your suggestions. We have revised the discussion section in the context of the present literature (lines 235-241, lines245-256, lines 258-259, lines 277-280 and lines 304-307, lines 343-347).

 

6. In Material and Methods:- indicate how many replicates assayed in each analysis/parameter. The number of samples or biological and technical replicates should be mentioned for each parameter in the methods.

Response: Our study did not involve samples or biological and technical replicates, and we have added more detailed parameters in the methods section (lines 150-152).

7. The conclusion section is very poorly written. It should be extensively improved.

Response: Thank you for your feedback. We appreciate your comments and have considered them. We have improved the conclusion section and find it to be considerably more readable. We hope that it meets your standard for publication in Forests (lines 349-359).

 

8. References: shall have to correct the whole References according to the ”Instructions for the Authors”, e.g. the Journal name must be abbreviated, journal name in italics, the year must be bold and you shall have to use the abbreviated number of the Journals cited. Further, some references the title to paper in title case some are in small letter case, hence please follow the journal instruction. Moreover, the scientific name must be italics. Please check the all refernce carefully.

Response: We thank the reviewer for pointing this out. We have carefully revised the references in accordance with the instructions to the authors and have checked the full text. Thank you again for your time and effort in reviewing our work.

 

Reviewer 5 Report

The present paper provided useful information on the tree species restoration for the conservation of the Hainan gibbon in the Hainan Tropical Rainforest National Park, China. It is an interesting and good writing paper. In my opinion, it can be published at the present state. However, I still curious about that: Have you plotted or check the nonlinear relationships between the climatic factors and the phenology of flowering and fruiting? 

Author Response

Reviewer #5:

 

The present paper provided useful information on the tree species restoration for the conservation of the Hainan gibbon in the Hainan Tropical Rainforest National Park, China. It is an interesting and good writing paper. In my opinion, it can be published at the present state. However, I still curious about that: Have you plotted or check the nonlinear relationships between the climatic factors and the phenology of flowering and fruiting?

Response: Thank you very much for your endorsement of the article! We tested models with quadratic terms and linear terms to account for potential nonlinear relationships between the dependent variables (climatic factors in the current month, the previous month, and the previous two months) and flowering and fruiting. By testing whether the regression was significantly improved by including quadratic terms, we compared linear model and quadratic equation by ANOVA, and selected the best model based on the P value and minimization of AIC values. We found that the linear model's AIC values were lower than those of a model using a quadratic equation, and as such we only included the data for the linear model.

Round 2

Reviewer 1 Report

The manuscript may be published in issues of the journal Forests.

Reviewer 3 Report

The authors have done a good job and I recommend this manuscript for publication.

No serious issues were found.

Reviewer 4 Report

Dear Chief Editor,

Thank you for providing the opportunity to review the revised manuscript. The authors have addressed all comments and incorporated changes suggested by reviewers during the first round of revisions. The revised version of the manuscript is improved as expected. Based on these revisions, now this study is a suitable contribution to the Forests. I recommend the manuscript for publication.

Thank you

With best regards

Minor editing of English language required