Does Soil Acidification Matter? Nutrient Sustainability of Timber Harvesting in Forests on Selected Soils Developed in Sediments of the Early vs. Late Pleistocene

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Well designed study and quite solid manuscript.

I have only small technical remarks :

biomass compartments - I usually meet "components" with regard to biomass of different parts of the tree, I think it would be more consistent with other studies to change that term

description of results - please get rid of unnecessary fillers like "table 2 shows... " (L327)

tables and figures should be self explanatory (and they are) so no need to write what they show. Focus on the content of table/figure

in case of table 2 relevant information starts in L331 "No significant differences were found between..."

removal of those fillers will give you additional space for "important" text

Author Response

Reviewer#1 evaluation:

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Is the research design appropriate?	(x)	( )	( )	( )
Are the methods adequately described?	(x)	( )	( )	( )
Are the results clearly presented?	( )	(x)	( )	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

 

We are convinced that the changes and additions made in the corrected manuscript (see appendix, corrections in red) have significantly improved the quality in general and the presentation of the results. We hope reviewer#1 can agree with this.

 

For a point by point response please see the attachment!

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors of the article propose the development of a model for the loss and intake of nutrients in soils with different processes of soil formation in different types of logging. The article is of practical interest both in scientific terms for the development of effective models of nutrient balance, and for practical application in forestry. However, the authors overlooked many significant factors for building a model and describing sites, which, among other things, could affect the interpretation of the data obtained. Some comments on the text are given below:

1. Title: incorrect definition of plots. At the moment, it seems that you are exploring Pleistocene forests, and not forests that developed on soils formed during different periods of the Pleistocene.
2. Lines 62-63: the authors claim that the longer the process of soil formation on the site goes on, the more nutrient-poor the soils are. What is the reason for the decrease in nutrients? It would be more logical to assume that the more developed the soils are, the more resistant they are to leaching of nutrients.
3. Materials and methods: there is very little information on the morphology of sampling sites. There is no additional information about soils: the type, thickness of the forest floor, water regime, the presence of certain soil horizons and, finally, the depth to the parent rock and the initial type of soil formation. There are also some important geographical parameters missing, since the sites are located not only at a great distance from each other (5.3 km), but also have a significant height difference relative to sea level. Information about the radiation balance, humidification conditions, slope exposure, and thermal conditions are also missing.
4. Line 115: the depth of the root zone is indicated, but for a more complete description there is no information about the type of root system, a comparison of its development in different areas.
5. Line 119: the depth of calcite occurrence is noted. There is no explanation for what this information is needed for and what significance it carries for research (perhaps this justification could be placed in the discussion section, but looking ahead, it is not there either).
6. Line 232: it talks about the weathering of minerals. There is no information about the mineralogical composition of the parent rock and information about whether it is the same in different study sites.
7. Section 2.5.2. Weathering and leaching loss: is there no information on whether the model took into account the soil type and heterogeneity of the soil profile?
8. Section 2.5.3. Nutrient and organic carbon stocks in the root zone, amount of clay: usually the organic carbon content decreases with soil depth and has certain correlations with different nutrients. It is unclear what caused the choice of the described method for determining organic carbon?
9. Line 349: judging by table 2, the cation exchange capacity differs by more than 2 times and has an inverse dependence on the saturation of the bases for the sites. This contradicts the statement in the text about an insignificant difference.
10. Section 3.3. Dependence of nutrient balance on acidification: the dependence of the nutrient content on the pH of the medium is considered, although the pH values, as indicated earlier, do not significantly differ. At the same time, it is not shown how the leaching of soil elements depends on the capacity of soil colloids and saturation with bases, the values of which varied significantly between sites.
11. Line 477: it says that there is no significant difference in the balance of substances, although it was previously stated that the growth rate and, accordingly, the harvesting of trees in the Early Pleistocene site exceeded the second site. Accordingly, the degree of nutrient withdrawal should have been higher?
12. Line 486: a controversial statement about the loss of calcium, magnesium and potassium with filtrate from older soils. There are no references to support this claim. Perhaps phosphorus losses would be more likely, as demonstrated by the results of the study.
13. Lines 491-497: These descriptions would be more appropriate in the Materials and Methods section in a more detailed form.
14. Line 509-519: There is no more detailed description in the materials and methods.
15. Line 579: the description of the sites about Douglas fir and its impurities was not indicated. Is this a hypothetical scenario being described?
16. Lines 587-597: the beginning and the end of the paragraph contradict each other. At the beginning, it is again stated about relatively equal nutrient flows in the plots, at the end of the paragraph it is stated that nitrogen losses in one of the plots occur due to a larger alienation of biomass from it.

17. Lines 604-612: Perhaps this paragraph would be more appropriate in the introduction, along with a definition of what kind of nutrient losses you are considering?

It should be noted that the materials and methods section needs significant improvement, and the data omitted when considering this version of the text of the article could significantly affect the interpretation of the results and discussion of the data obtained. For example, such factors could include water, thermal conditions and the type of soils formed not only under different conditions, but also at different heights, which could affect their biological activity, and, accordingly, the degree of mobility and the level of accumulation of nutrients.

Author Response

Reviewer#2 evaluation:

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	( )	(x)	( )	( )
Is the research design appropriate?	( )	( )	( )	(x)
Are the methods adequately described?	( )	( )	( )	(x)
Are the results clearly presented?	( )	( )	( )	(x)
Are the conclusions supported by the results?	( )	( )	( )	(x)

 

We believe that unclear wording in the first version of the paper led to some misunderstandings. By addressing the criticisms of reviewer#2, we believe that the design of the study, the description of the methods and results, and the conclusions are now better described. This should address the justified criticism of reviewer#2. The experimental design seems justified to us, as comparable soil types with comparable properties were formed in both areas although the two study areas are 5 km apart and have a difference in height of 200 m. We were able to show this with the additional climate data and the morphological data of the soils. The results were improved at the suggestion of reviewer#2 by providing additional data on the morphology and mineralogy of the soils, which are very important for the understanding of the context. And with these clarifications, the conclusions are also placed in a clearer context with the results.

For a point by point response please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have done a lot of work to improve the text of the article and answered most of the comments satisfactorily. Some questions have been clarified and left with minor additions in their original form, which I can also agree with. The article has undergone significant changes and in this form may well be accepted for publication.