Multiple Ecological Drivers Determining Vegetation Attributes across Scales in a Mountainous Dry Valley, Southwest China

Round 1

Reviewer 1 Report

Review of Forest manuscript [forests-964370], "Multiple ecological drivers determining vegetation attributes across scales in a mountainous dry valley, Southwest China" submitted by Yang et al.  

Recommendation:  Accept after minor revision

Tough but enjoyable manuscript to read with only two comments. First, I have attached an annotated PDF with some grammar and editing changes.  It is always difficult to write in your second language.  Second, it would be great if the authors could explicitly state (if I read correctly) that they found mostly niche-partitioning was operant at one scale and neutral at another.

Minor stuff:

In a list of items – use a comma between the next to last item and the last item; i.e. red, white, and blue,  not red, white and blue.

Generally speaking, percent value should be whole numbers and not decimal fractions; i.e., 72% and not 71.8%.  Makes for easier reading and is probably true when you account for significant digits – not that anyone pays any attention to significant digits anymore (but they should).

Comments for author File: Comments.pdf

Author Response

We would like to thank the reviewer for the valuable comments and suggestions.

Tough but enjoyable manuscript to read with only two comments. First, I have attached an annotated PDF with some grammar and editing changes. It is always difficult to write in your second language. Second, it would be great if the authors could explicitly state (if I read correctly) that they found mostly niche-partitioning was operant at one scale and neutral at another.

Response: we have corrected the suggested edits throughout the MS (corrections are marked in red: line 16, 23-26, 54, 58, 64, 67-68, 75, 81, 90-92, 93, 101, 113-114, 118-119, 162-163, 173, 193, 204, 209, 219-220, 223, 242-243, 245, 251, 255-258, 262, 265-266, 284-285, 288, 290-291, 293, 295-296, 298-300, 317, 328, 330, 332, 337-345, 352, 354, 357, 373-374, 380, 385, 388-389, 392, 396-397, 405-406, 419, 428, 435, 439, 467-468, 471-472, and 477). As for the explicit statement of the scale-specific role of niche-partitioning and neutral process, based on the results of variation partitioning, we found significant and comparable effect of niche-partitioning and neutral processes at both regional and local scales.

Minor items:

1, In a list of items – use a comma between the next to last item and the last item; i.e. red, white, and blue, not red, white and blue.

Response: we have considered this editorial suggestion throughout the entire MS (corrections are marked in red: line 162-163, 173, 242-243, 245, 262, 265, 285, 291, 293, 328, 330, 402, 409, 411, and 428).

2, Generally speaking, percent value should be whole numbers and not decimal fractions; i.e., 72% and not 71.8%. Makes for easier reading and is probably true when you account for significant digits – not that anyone pays any attention to significant digits anymore (but they should).

Response: we have considered this editorial suggestion throughout the entire MS (corrections are marked in red: line 251, 255-258, 284, 288, 332, 337-343, 345, 354, 357, and 389).

3, Line 288: “Axis 1 was mostly correlated with asp (r=0.865), followed by KA (r=-0.686)”: were KA and asp correlated?

Response: Yes, KA and asp were significantly correlated, with KA was significantly higher at north aspect. This could also be detected in Figure 3.

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Corresponding Author,

The study describes an attempt to estimate how environmental and spatial processes jointly determine vegetation attributes across scales in a dry valley, one of the dry valleys in Hengduan Mountainous region suffering severe ecological degradation. Moreoover the  study also demonstrated how vegetation composition and structure varied along environmental gradients and y revealed the overriding role of topography in determining vegetation attributes in this mountainous dry valley.

Overall, the paper is well written and touches a topical subject in the context of forest ecology. However, there are few issues to be addressed before the manuscript can be suitable for publication.

Please following my suggestions in the attached file.

All the best

Rev

Comments for author File: Comments.pdf

Author Response

We would like to thank the reviewer for the valuable comments and suggestions.

The study describes an attempt to estimate how environmental and spatial processes jointly determine vegetation attributes across scales in a dry valley, one of the dry valleys in Hengduan Mountainous region suffering severe ecological degradation. Moreoover the study also demonstrated how vegetation composition and structure varied along environmental gradients and y revealed the overriding role of topography in determining vegetation attributes in this mountainous dry valley.

Overall, the paper is well written and touches a topical subject in the context of forest ecology. However, there are few issues to be addressed before the manuscript can be suitable for publication.

Please following my suggestions in the attached file.

1, Line 34: for this exhaustive introduction on the "community assembly" I would suggest to the author also the "Species Pool" theory.

Zobel, M. (1992). Plant species coexistence: the role of historical, evolutionary and ecological factors. Oikos, 314-320. 

Pärtel, M., Zobel, M., Zobel, K., & van der Maarel, E. (1996). The species pool and its relation to species richness: evidence from Estonian plant communities. Oikos, 111-117.

Response: The “species pool” theory is very comprehensive which explains species coexistence using a generalized framework encompassing all evolutionary, historical and ecological theories. However, our study only focused on niche-partitioning and neutral processes operating at regional and local scales to influence community assembly, which correspond to the ecological process mentioned in Zobel (1992); while the species pool derived from evolutionary and historical processes at biogeographical scale, and the interspecific interactions (i.e., competition) at neighborhood scale, are beyond the scope of our study. Also, the whole dry valley is treated to have the same regional species pool (Pärtel et al. 1996), and the spatial variation in community structure within the dry valley is due to the effect of ecological processes but not the species pool effect. Therefore, we elected to not include this suggestion in our introduction as our treatment to community assembly is not “exhaustive”, rather only focusing on ecological factors (at regional and local scales) but not evolutionary and historical processes, which is the main object and content of this study.

2, Line 122-123: please, verify the resolution of these images and improves it

Response: This figure was modified based on that of Lu et al. (2006). We have tried our best to improve it and the final resolution is 300 ppi.

Lu, T., Ma, K. M., Zhang, W. H. & Fu, B. J. Differential responses of shrubs and herbs present at the Upper Minjiang River basin (Tibetan Plateau) to several soil variables. Journal of Arid Environments 67, 373-390, doi:10.1016/j.jaridenv.2006.03.011 (2006).

3, Line 304: I think could be better envelope the species based on vegetation communities along environmental gradients (for example the forest belts along elevation)

Response: Figure 3 was based on scaling 2 (correlation triplot), in which the angles between species (response variables) and environmental variables (explanatory variables), and between species themselves, reflect their correlations; and the distances among species do not approximate their Euclidean distances. Thus, the envelope of species could be to some extent misleading. Moreover, various topographical and soil variables were included in the final model, and we would like to show the relationships between species and all the relevant environmental variables, not only with specific environmental variable.

4, Line 349: please add elevation non acronims also after in the text

Response: Done (line 350 and 363).

Author Response File: Author Response.docx