The article titled Microbial biobanking cyanobacteria-rich topsoil facilitates mine rehabilitation, by Wendy Williams and collaborators, is a resubmission of a previous manuscript that I reviewed some time ago. As I said in my previous review, this article explores a very important topic in ecological restoration: the rehabilitation of degraded soils provoked by mining activities. It has been a pleasure for me to read the new version, and to realize that authors have done a great job during these days to unequivocally improve the quality of the text. In its current version, the article is easy to follow and, perhaps much more important, the hypotheses and goals are clearly exposed. Methods are correctly applied. Results are robust and clear. And the discussion section presents a general view of the results within a framework of the current knowledge of the topic. Although I have some minor comments (please, see below), I think that the article is now ready to be published. The literature on this topic will beneficiate with the discoveries by Williams and collaborators. In any case, please, have a general look and rewrite some sentences and paragraphs. And highlight a little bit more in the discussion section the main discoveries of the work, for example, the discovery of some cyanobacteria genera that were previously not considered to be as pioneers of biological soil crust establishment.
SPECIFIC COMMENTS (by section)
In line 10, page 1, please, remove “removal” or “disturbance” to facilitate reading. Choose only one word.
In line 14, page 1, please, add a comma after “At J-A”.
I think that the first sentence should be “Soil disturbance results in a loss of resources and often has long lasting effects on soil stability, nutrient cycling and surface hydrology in drylands (…)”.
In line 5, page 2, instead of “that”, use “the”.
In lines 6-7, page 2, I think that the sentence “…whereby…events” is not necessary.
The sentence of lines 9-10, page 2, should be moved to the next paragraph.
The first time you introduce the term “biological soil crust”, use “biological soil crust”, not “biocrust”.
I line 14, page 2, please remove “…from rainfall…”.
Please, read carefully the third paragraph of this section. It looks like to me a little bit repetitive.
In fact, and although the introduction is well-written and easy to follow, I would recommend the authors to include five main points, with this order:
1. The problem of mine activities on soil degradation in drylands,
2. Potential solutions to this problem by using biological soil crust natural activities,
3. Properties and services provided by biological soil crusts in drylands,
4. Recommendations to use biocrusts for soil rehabilitation after mine activities, and
5. Goals and hypotheses of the present work.
In general, the introduction has this scheme, but I think that the paper will improve a lot if authors follow my recommendations.
In line 26, page 3, please include a comma after “study”.
In line 6, after Figure S1, I think that you should include “www.” before the URL information of the web site.
In general, you should clearly expose all along the methods section whether you measured your variables in the field or in the lab. For example, it is not clear for me if you used the penetrometer in the field or in the lab. This will facilitate comparison of results in the future.
In lines 9-10, page 7, I think that the sentence needs to be rewritten because it is difficult to understand in its current form.
Although statistical analyses are presented all along the methods section, I think that it is a better option to include a subsection in the section called “Data analyses” that includes all what authors have done with statistics. And authors should expose the statistical significance that they chose (0.1, 0.05, 0.01).
In line 14, page 9, “2YO” means 2 years old I suppose, but it is necessary to specify, mainly for non-native English speakers, like me.
In lines 1-10, page 10, authors present some very interesting discoveries that should highlight a little bit more. For example, in the discussion section, authors should mention them again and say that they are important because, until now, other cyanobacteria species were considered to be the pioneers in biocrust formation, but not the cyanobacteria that they saw in this work.
In line 3, page 10, add a comma, please, after “In this study”.
The second paragraph in page 10 is hard to follow. Please, rewrite.
Authors mention in page 10 that Symplocastrum and Symploca were codominant in the 2YO stockpile, but later in the discussion section they do not provide any potential explanation. And this is also a very interesting result to discuss in terms of ecological succession of cyanobacteria in biocrusts. Please, consider reviewing the literature and provide an explanation.
In lines 10-11, page 11, I suppose that you calculated richness, evenness and diversity with the Primer package, but it is not clear at all. This is why, in my opinion, it is important to have a subsection called “Data analyses” in the methods section.
In line 7, page 13, please add a comma after “In general”.
In the second paragraph in page 13, I see some contradictory ideas. Please, rewrite the whole paragraph.
The article by García-Pichel and Wojciechowski (2009) centers in the role of Microcoleus. And authors have not found a lot of Microcoleus in their work. So, please, use the cite with caution. In any case, as I said before, authors found other cyanobacteria that play a similar role to this of Microcoleus in North America. And they should highlight it, talking about biogeography, for example, or differences in biological crust formation and temporal succession. This is only an idea.
In line 30, page 14, please add a comma after “In China”.
I have no comments.
TABLES & FIGURES
Because authors have a lot of tables and figures, I deeply recommend including some of them as supplementary material. Please, include in the main text only figures and tables that support your main discoveries.