December 16, 2016
Dear Dr. Zibulski,


Thanks for your responses to reviewers of your article bg-2016-141 submitted to Biogeosciences. Both reviewers are rather positive about your paper but raised many important points that must be addressed before I can consider recommending acceptance. In addition, there are other concerns, mentioned below (line numbers are for version that responded to Reviewer2):

My concerns are in line with those of reviewers regarding lack of clarity in presentation that difficult to evaluation of consistency of the relationship results - conclusions. Please find below the most important concerns that have not been properly address plus additional ones.

1. Regarding ratio C to N. The reviewer did not mean necessarily that you added the word “by weight”. I would rather change it to molar ratio to make it comparable con literature. For instance (Meyers and Ishiwatari 1993, used (as it was described originally) molar ratio.
2. Abstract. Sentence “…ratios (by weight), 13C and 15N data of 400 brown …
” is misleading since there is data for less than 20 samples not 400. Please change accordingly.
3. Abstract, line 120 and throughout the text. Regarding word “preferred”. Is it proven that there is preference? Or just they are there? Please change accordingly.
4. Lines 123-124. “Furthermore, because of the stability provided by 
water, they do not need to invest in a sturdy stem-structure and accordingly have lower C contents in 
 their biomass. 
” In an abstract, you convey the message of your results; you did not study sturdiness of mosses, Did you?
5. I understand the term “signature” for d13C, and d15N, but you really mean isotopic composition. I don´t see why not use proper terms.
6. Abstract, Line 119. Your statistic results in significant differences, but it appears that there are large standard deviations (Fig. 3) and not much differences are evidence in C/N. Are you sure that all requirements for a t-test are fulfilled? Normality, homoscedasticity, etc. C/N of Hylocomium splendens ( xero-mesophyloic) and of Hamatocaulis lapponicus (meso hygrophylic) in Fig. 3 are essentially the same but different according to the statistics. What is the value of this information to make it to the abstract (“main findings”)? Please change accordingly.
7. Abstract 124-129. With the exception of two cases (Fig. 3b), most determination coefficients (regression) are lower than ca. 10% or non-existent; and you suggest “… that a relationship between the individual habitat water-level and 
isotopic signature wascan be inferred as a function of microbial symbiosis ”. I do not see evidence for that. Please change accordingly.
8. Was sampling in 2011 and 1012 during the same season? Should this source of variability be considered? Why?
9. Lines 327-329. How can a general trend can be deduced if 17% of variance of first 2 axes?
10. Regarding Paq, ACL, and CPI. 
 What is the conclusion of this comparison? Can they be graphically compared? Do they support your conclusions? Reviewer 2 specifically ask for inclusion of those indices since “n-alkane data are inadequately presented and interpreted”

11. “The total content 
of carbon”. Total is redundant since we hope you are measuring total and not part of it.
12. Line 271. The argument “Considering the low n-alkane 
… “ is not necessary since we always have to use quantification standard independent of low or high contents
13. Line 279. Replace calculate with calculated
14. L. 298. R2 is regression, not correlation. What do you want to detect? 2 dependent variables or one dependent and one independent?
15. Line 257 -some samples. 
 Specify how many? Same with line 264. Does it change your conclusions?

16. Line 340. Xeric and mesic 
are adjectives and need a noun such as environments, or soils

17. L. 334-363. See comment # 6

18. 475. “ clear differences in ACL” are not so clear in the text. Please change accordingly.

19. Lines 530-532. See previous comments on C/N and d13C

20. Reviewer 1. # 35, about symbiosis. See my comment # 4


Sincerely yours

Silvio Pantoja
Associate Editor