Three reviews on Finlay et al. are largely positive, but also describe—with remarkable agreement—some shortcomings of the manuscript. All agree that the text does a good job of reviewing the literature, but that it fails to synthesize the material in a coherent way. The reviewers were all dismayed by the brevity of the “Key questions and knowledge gaps” section at the end of the manuscript. There were other points of agreement amongst the reviewers: 1) that the long discussion of laboratory experiments concludes with a statement that laboratory scale processes may not play a significant role in soil-scale mineral dissolution reactions. 2) Section 5 is too long (dense, “hard to digest”). In my view, the motivations were needed (up front) in this section for briefly summarizing the geologic history of weathering and evolution in the context of understanding weathering in forest soils. I found the review interesting, I just wasn’t sure why it was offered.

I agree with the reviewers that while much of the manuscript is well written, it lacks synthesis. The organization around scale (at least in the first sections) works well, but each section could use a summary. Reviewer 3 suggests breaking out subsections as well, which may be helpful in the longer sections. The later sections (6-8) break from the organization around scale, which make take some more explanation. In my read, the discussion of PROFILE and ForSAFE in section 7 should have been done in the same section and style as discussion of other models (CRUNCH, B-WITCH, etc).

I recommend that the authors revise the manuscript, with an eye to synthesis. The key questions/knowledge gap section needs to be expanded, perhaps in concert with condensing some other sections. As a review, it is also worth considering how to educate non-biologically trained readers in the key points. The jargon was thick at times (mor layers, Ericoid mycorrhyzas, sporophytes, etc). The jargon is okay in some respects (it speaks to specialists), but needs to be balanced by plain language summaries of each section. One reviewer suggests that a number of the figures can be dropped, as they do not bring anything new. Perhaps the authors could come up with a new figure that summarizes (synthesizes) key aspects of weathering associated with microorganisms, with an eye toward educating the non-biological community.

Thank you for your revisions, and explanations of the work you have done. The additions of summary statements at the ends of each section, and the reduction in number of figures do improve the manuscript. However, the manuscript text has grown by several pages in the process, because almost no text was deleted.
In particular, the reviewers of the original version of the manuscript had commented on the length of section 5, and that this section was dense and "hard to digest". The section is now a page longer, not counting the new summary paragraph!
Please trim the text by ~10%. In particular, since the subject is biological weathering in boreal forest soils (per the introduction, although not the title), perhaps material from outside this context can be reduced.

Thank you for making some cuts in section 5.

Dear Authors,

First, we apologize for taking the time to inform our decision for this time. I am Nobuhito Ohte and inherited the role of a handling editor from Suzanne Anderson.

The reviewers recognized the importance and contributions of your to the research filed, but they have suggested some substantial points to be improved before further evaluation. Please revise carefully point by point that the reviewers suggested.

Sincerely,

Nobuhito Ohte, Handling editor

Dear Authors,

Thank you so much again for the resubmission of your revised manuscript. The reviewer who was willing to review your revised manuscript has reviewed again and rated high potential for publication. I also agree with the reviewer's evaluation. But, the reviewer suggested several points for revision. I think these suggestions will be effective in attracting readers of related scientific fields. I would like to ask you again a special favor for making your manuscript better.

Sincerely,

Nobuhito Ohte, Handling Editor

Dear Authors,

I feel that the manuscript is now ready for publication.
I would like to thank you again for your quick response and revisions.
Please follow the editorial processes after acceptance.

Best regards,

Nobuhito Ohte, Handling editor