Seasonal Variations in Plant Species Diversity and Phylogenetic Diversity in Abandoned Farmland of China’s Huang–Huai Plain

Round 1

Reviewer 1 Report

This paper deals with an interesting topic and it does so with a rich test data set and no less considerable statistics.

However, there are some small errors when presenting the parts of the work. The rigid order expected of a scientific article is broken. However, this does not detract from the robustness of the results obtained by the authors. Such details are:

The last paragraph of the Introduction (lines 98-100), in my opinion, is anticipating the results. We must understand scientific research as a process. In this process it goes from when the researchers consider a problem, apply a methodology, obtain some results and, after comparing results with existing literature, reach some conclusions. Using media terminology, this paragraph “spoils” what follows at paper. In my opinion, it does not add anything that is not going to be said later and should be deleted.

In line 127, equation (1) of the Importantace Values is stated. I do not question the appropriateness of that formula. But the authors must clarify if it is their own proposal or if it comes from the bibliography. In the second case, I suggest that you add the bibliographical reference of the author who proposed said index.

Continuing in the idea of giving credit to the methodology authors, it is good that they detail the expressions of the Shannon Diversity Index (lines 138-139);

Simpson Dominance Index (140-141);

Pielou Evenness Index (142-143) and

Margalef Richness Index (lines (144-145).

Please add the references:

Shannon, C.E., A mathematical theory of communication. Bell Syst. Tech. J. 1948, 27(3), 379–423.

Simpson, E.H. Measurement of diversity. Nature 1949, 163(4148), 668.

Pielou, E. The measurement of diversity in different types of biological collections. J. Theor. Biol. 1966, 13, 131–144.

Margalef, R. Diversidad de especies en las comunidades naturales. P. Inst. Biol. Apl. 1951, 9, 15–27.

Respectively

In line 241, the authors say that “We employed the Kruskal-Wallis test to compare the plant diversity indices”. This test is a statistical procedure; therefore, this phrase should be in "Material and Methods". For example, at the end of the description of the indices. And, of course, give credit to the author, adding the reference:

Kruskal W.H.; Wallis W.A. Use of ranks. J Am Stat Assoc 1952, 47, 583–621.

Another case like the previous one occurs in line 275 (“The results of Spearman correlation analysis”). The fact that this coefficient is going to be applied must be stated in “Material and Methods”. Please add it to "Material and Methods" and add to bibliographic references:

Spearman C. The proof and measurement of association between two things. Am J Psychol 1904, 15(1), 72–101.

In line 299 (“Monte Carlo permutation tests”), the same thing happens as in the two previous cases. Please, add it to “Material and Methods” and add to bibligraphic references:

Fishman, G. Monte Carlo: Concepts, Algorithms, and Applications, Springer Science & Business Media: Berlin, Germany, 2013; pp. 1-698.

In lines 407-408, Table 4 is shown (“The significance of the Spearman correlation analysis of each diversity index, Significance results are indicated by asterisks: "*" p < 0.05; "**" p < 0.01; "* **"p < 0.001.”). Obviously, this table shows a result obtained by the authors of the paper after applying a statistical procedure, therefore it should not appear in the "Discussion". Please relocate the table in the "Results" section.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This paper is a good descriptive/correlative study on the diversity of a single abandoned agricultural field.  There are a large number of citations in the paper but many of the citations are only tangentially applicable to the results.  

The methods section is not complete.  For example, is the quadrat size the same as the plot size? Did you sample one quadrat per plot per sample period?  How often was soil moisture taken?  What is the acreage of the experimental station?  Why are these not dependent patches instead of independent communities?  I don't see any real replication in this study. 

The analysis as described appears appropriate.  However, your discussion tries to explain the mechanisms you think are responsible for the patterns you see but with insufficient data.  I would scale back on your discussion to include only the explanation you can support. 

Just a few sentences need attention.  lines 54,57 and 87 either a word 

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

An interesting study deals with the variation of plant species and phylogenetic diversity across seasons. In general, the article is well written and the methods are appropriate. However, there are some points that need to be corrected/adjusted before the publication.

L54 and L57 I'm not sure I understand what you wanted to say in these sentences. Please rearrange them.

L98-100 That does not belong to the introductory section

L109-113 There is no information on how long these fields were abandoned and what the management was like before the abandonment.

L115 Please correct "quadrats" to "plots" throughout the text

L120-133 How did you determine the coverage and height of each species on the plots?

Table 2. These data are already much better presented in Figure 3. There is reason in giving them once again in the table

L241 This has already been said in the M&M section

Figure 3 There are only 4 significant p values in the figure. There is no need to show the others

L287 What is MAP?

Figure7. These ordination diagrams are unnecessary. In fact, they show nothing related to your presentation of results. They eventually could be used to interpret the differences in floristic composition among studied plots.

Figure 8. It is sufficient to display only graphs for significant r values. Maybe it's better to just put a table instead of graphs

L327-332 Unfortunately, you did not research functional diversity, so these sentences are not related to your results. They should be removed or more clearly linked to your results. The evaluation of functional diversity would enable you to better comment obtained results.

L333-341 I don't see a direct connection with your results. Please delete this paragraph or rewrite it.

Table 4. Should be moved to the Results section

L419-422 I'm not sure I understand what you're trying to say. The lack of human induced fertilization leads to natural conditions in the soil and to communities that correspond to such conditions.

L438-440 Do you mean higher plant diversity increase the input of organic carbon into the soil etc.?

L441-442 Delete or support with references. You did not compare different farmlands in your research.

L464-466 It is not clear to me what those measures would be. If we leave it to natural succession, we will achieve a diversity that corresponds to these ecological conditions. What could be better than that?

The English language is correct, but there is space for improvement to make the text more understandable.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Changes much improved the manuscript.  

Reviewer 3 Report

I appreciate the amendments and the paper can be published in its current form.