Effects of Soil Acidification on Bacterial and Fungal Communities in the Jiaodong Peninsula, Northern China

Round 1

Reviewer 1 Report

General impression

The article is well written, concise and pleasant to read. The effect of pH on soil microbial composition is already known and well documented in the literature. Still, this paper is still interesting especially for agricultural purposes, although it seems to me that some information and perhaps a fuller discussion on this aspect are missing.

 

Comments

-While the number of 45 samples is indicated in the legend of the first figure, it is not clear how many samples there are in the three groups or pH ranges (there are 5 points/group in the PCA). Also, the three agricultural lands are not well described: was there any cultivation during/before the sampling? If yes, were these cultivations organic? Are the agricultural lands with different pH scattered/mixed? Etc.

-The authors state that the changes in bacterial community composition is “rapid” compared to fungi. How the authors can know that? Since how long the pH is more acid in the acidified soils?

-The authors gave the composition of the microbial community at the phylum level: why not at the finer levels such as family or even genus level ? I was wondering if specific microorganisms, that are known to be important or an advantage for agricultural purposes, would be abundant or on the contrary missing in a pH range (and possible consequences). The title says "Effects of soil acidification on bacterial and fungal communities..." while the authors looked only the phyla.

OTU tables must be available as SI.

-Regarding the methodology, the authors did an ACP, which distance/dissimilarity matrix did they use? Euclidean distance based matrix?

-In the abstract, the authors specify “where variations in factors other than pH have been minimized”, which factors the authors are talking about and how can they know. Moreover, the authors analyzed a series of compounds that actually differ depending on the pH range. For example, the SOC concentrations. The author state “SOC content was decreased in response to the aggravation of soil acidification”. Why are there actually different SOC concentrations depending on pH? Is it only due to pH (directly/indirectly?)?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The paper can be accepted for publication in its form

Author Response

Thank you very much for the thorough review and for the very positive comments.