Change in the Ecological Stoichiometry of Carex thunbergii in Response to Seasonal Dynamics and Environmental Factors in Shengjin Lake, China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is an interesting study and deserves to be published.  The experimental design is sound, and the data collected is adequate for the objectives of the research.  However, I am requesting some revision to improve the paper.  Specifically:

1) page 2, line 71; why do you say the growth rhythm is peculiar?  It seems normal, given the lake levels and climate of the region.

2) page 2 line 67; should say riparian zone, not "riparian."

3) page 2 line 93; can you give us a sense of space here?  How much does the water rise and fall in a given year in m or cm?  How much area is included in this riparian zone in m2 or ha?

4) page 3 line 103; again, how much total area is included in the sampling area for the 5 replications of the various vegetation types and bare ground?

5) page 3 line 123; ref#24 is not a methods ref, but might include the phos. method in it?  In this paper, you should at least tell us the difference in methodology used to extract total P and available P.  Also, later the available K is mentioned, but methods are not given.  Please add.

6) page 5 line 167; change "could not be told apart well" to "were not significantly different."

7) page 6 Figure 3; only the vegetated plots are shown, when there were also bare ground plots sampled and mentioned in the discussion section.  Please add the data for bare ground here.

8) page 7 line 234; there were actually 6 factors that were statistically significant, not 3.  There were the 5 listed in line 232, plus available K, according to your data (in Table 3).

9) page 8 figure 4; the data labels are CT, PC and RCE.  These are not explained, and don't match the data labels used in Figures 2 and 3, which were Ct, CP and CR.  Please clarify or change.

10)  page 9 Table 4; Since there were seasonal differences in some of the data, it might be interesting to show these correlations for the fall sampling and also for the spring, and see if they are the same or different.,

11) page 9 line 275; word should be "because," not "cause."

12) page 10 line 315; the pH mentioned here is high, but is not shown.  The pH and the rest of the soil data could be presented in a table as supplementary material, so we can see the values more clearly.  Only the total C, N and P are shown in the graphs, along with the ratios.

13) page 10 line 329; the bare soil plot data is mentioned, but was not shown in this paper.  Please add.  

14) page 11 line 358; can you tell us anything else about this site and the soils here?  Did you do a soil texture analysis?  What are the sources of N and P here?  Are they only from rising and falling lake water or are there additional sources that would affect the plants or soils here?  For example, human emissions are mentioned.  Please add more detail.  What kind of emissions?  Are they year-round or seasonal?  In what quantity or concentration?

15) page 11 line 369; again, why do you refer to the growth rhythm here as abnormal?  

16) page 11 lines 372-373; this conclusion about carbon and nitrogen sources in the wetland soils being stable and consistent was not mentioned in the abstract, and was not supported by the data.  I think the authors need to look carefully at their data, and then they can come up with a stronger conclusion paragraph, and add more meaning to their data.  The should go back to their objectives in lines 81 and 82, and then craft their conclusion statement to address their specific objectives.

Comments on the Quality of English Language

The English needs only minor editing.  For example, line 32 on page one, the phrase should be "ecosystem health," not "healthy."  Final editing of the finished manuscript by a native speaker or even a computer program should find all of these errors.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Exploring the C:N:P stoichiometry of dominant hygrophytes in riparian zones can deepen our understanding of specific plant adaptations and provide evidence to reveal the ecological process and quantify the ecological contributions of these plants on biogeochemical cycling. The manuscript is generally well-organized and written. Following are some suggestions in methods, data analysis, discussion, and writing.

 

Major comments

For the comparison among seasons, a paired T-test, rather than the independent T-test, should be used.

 

Both the relationships (and the correlations, e.g. Table 1 and 2) within soil attributes and within plant nutrients and the following discussions are quite unconvincing with such a low sample size and narrow geographical and species range. The authors can omit most of them.

 

L268 it is a pity that the authors did not perform photosynthetic measurements or determine the nutrient dynamics of other underground tissues of the plant. The increased C in leaves in spring can be also due to the transport of sugar from other organs…

 

Minor comments:

L87 “The The”

L107 how many quadrats did you set in each sampling zone?

L125 There are several errors in the use of superscripts and subscripts throughout the manuscript.

L140 check all the species names throughout.

L145 the abbreviations used here are different from those mentioned above (L120).

L173 use italic and lowercase “p” rather than P to avoid confusion from P content.

Fig2 The letters can be left out if the differences are not significant to draw a more concise plot.

L280 The increased N in the plant can be due to several reasons such as the improved root nutrient uptake capability, the increased chlorophyll and enzyme content induced by warmer and lighter environments, more available nitrogen in soil… The authors should summarize the possible reasons for a more rigorous discussion.

L285-292 nutrient stoichiometry is less related to allopathic inhibition. The authors should either provide more evidence or remove this part.

L349-352 There have been several papers arguing on whether the threshold of N:P can be used to affirm the nutrient limitation in the last 10-20 years and the classical knowledge cited in the paper has been proved inaccurate. Search and read these publications and remove this part.

L373 “biome” is wrong here.

 

The format of the references can be improved, including but not limited to the italic species name, the use of uppercase and lowercase letters

Comments on the Quality of English Language

it is fine

Author Response

Please see the attachment.

Author Response File: Author Response.pdf