Effects of Dodonaea viscosa Afforestation on Soil Nutrients and Aggregate Stability in Karst Graben Basin
Round 1
Reviewer 1 Report
The MS submitted by Lijun Liuwith co-authors is focused on impact of the Dodonaea viscosa on soils properties (nutrients and water-stability of aggregates) during afforestation. Authors raises interesting questions in the article, but have not yet responded to them. The introduction, objects and methods are well written, but unfortunately the results and discussion part is poorly written. The MS still needs to be improved in my opinion.
General comments
Since you do not 1) provide data on the texture of soils and 2) do not correct by the sand fraction the aggregate fractions content in the analysis of the water-stability of aggregates, the conclusions obtained about the composition and redistribution of aggregate fractions cannot be understood unambiguously now.
Like many other researchers, I think you make the mistake of calling the fraction 0.053–0.25 mm «microaggregates». Microaggregates are complex structures with specific properties (Totsche et al., 2018, review), not only the size fraction less than 0.25 mm you get from wet or dry sieving of soil. Please, think about this in the future. Hovewer, it would be easier to understand if you would just write about fractions of X-X mm in the text, without the additional epithet: ”coarse”, “micro”, “silt + clay-sized”.
It should be clear from your text what was done by you, in this article, and what was shown earlier. for example, as here: (L297-298) The turnover of soil aggregates in the cropland soil was rapid [24]. If your objects, part of the experiment was previously published, write about it explicitly.
In the discussion part, you should describe, how your results fits the research objects. Now you have a lot of everything cited, but there is no logic or any sense to the narrative. Try also describe the difference between soil under shrub and soils under Dodonaea viscosa.
Some specific remarks
L125 better to write “particles” instead of aggregates here and further in the text “and < 0.053 mm aggregates are silt + clay-sized fractions”
L179 It’s better to place the reference to table 1 after the first sentence, than in the end (L185)
L186 strictly speaking, water is not a nutrient
L192 word “particle” is redundunt here
L202 I do not see decline (b and b in 20 and 40 years of afforestation, correspondingly)
L204 be more careful when you describe the differences. it's not exactly like that, if you look at the symbols on Figure 1 (b – bc – cd) à 10 and 40 y differ
L210-220 very hard to read the text. write what you see, not the bare numbers. what does it mean to change parameters. E.g., "aggregate stability increases in the series 10-20-40 y (indicator X, table 2)"
L226-231, 235-242, 246-254 the same thing. Readers will see all correlations on their own in the table 3 and 4, figure 2. at least like here (L252-254) or even in discussion part:
The water-stable aggregates in the cropland soil were dominated by the size of < 2 mm, and the content of coarse aggregates (>2 mm) was less than 6% (Figure 2) (L295-296).
This is also results, not a discussion (L302-306): Compared with the cropland, the content of coarse aggregates in the soils of D. viscosa and shrub was significantly higher; however, only the content of micro-aggregates in the soils of D. viscosa was significantly lower than that in the cropland, whereas the contents of silt + clay-sized fractions and micro-aggregates in the soils of the shrub were considerably inferior to those of cropland.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The section 3.5 and relation to this discussion do not make sense since it considers the correlations of the variables and the indicators dependent on them. I recommend delete this data in whole text.
Probably soil of the study area contain a lot of calcium. Calcium significantly affects on aggregates. In this regard, the article loses some relationships without Ca-content and pH data.
Other comments and notes in the text
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Titel: Effects of Dodonaea viscosa Afforestation on Soil Nutrients and Aggregate Stability in Karst Graben Basin
The topic itself a very good topic, reforestation is very important issue everywhere on the Globe.
The manuscript is logically well built, the different chapters are connected to each other.
Some critical remarks:
Titel:
The title can be changed a little bit, as soil physical parameters are more expressed in the whole article.
Materials and methods part:
Line 95 h-1 instead of ha-1.
Line 99: please specify what ‘lime soil’ is according to USDA ST, I couldn’t find this among the soil classes.
That would be great if the Authors can provide a better, deeper description, map of the investigated area soil, topography, geology, land use (change) etc. Furthermore, a schematic figure, map can help a lot to understand the sampling procedure, the locations of the sampling plots, sites.
2.2 soil aggregate separation in line 110. Probably Investigation of soil aggregate stability is a better subtitle and after that, the methods of aggregate stability can be inserted from line 137-166.
2.3. soil analyzes, it may be soil chemical analyzes as this subchapter is focusing on different soil chemical parameters.
2.4 As the aggregate stability moved to the 2.2 subchapter, this chapter would be statistical analyzes.
The results are well demonstrated with nice tables and figures.
Discussion:
Logically following the presented results, not only repeating the results in this chapter but the Authors tried to explore the significance of their results.
4.1. Probably it would be more fruitful instead of using soil properties, writing soil chemical properties.
Soil water, or moisture content (line 283) and OC (line 353) cannot cement the soil particles.
The manuscript can be published after minor revision, it is a nice case study, confirming the positive effects of afforestation on soil properties.
Author Response
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Author Response File: Author Response.pdf
