Relationships between Soil Nematode Communities and Soil Quality as Affected by Land-Use Type
and Jie Zhao 2,4,5,6,*
Round 1
Reviewer 1 Report
Dear Editor
The M/S titled "Relationships between soil nematode communities and soil multifunctionality as affected by land-use type" has a good idea.
On the other hand there are some problem.
i. In the M/S the hypotesis is finding difference in the different ecosystems. There are no any species identification. How many species, which species is dominant? There is no information.
ii. All the corelation and Regresion degrees are too low. We can not consider them as scientific results.
For this reason I regret to say that the paper can not accepted.
M. Bora Kaydan
Author Response
Responses to reviewers’ comments (forests-1872538)
Response: Changed as suggested (in highlight)
Reviewer #1:
The M/S titled "Relationships between soil nematode communities and soil multifunctionality as affected by land-use type" has a good idea.
On the other hand there are some problem.
Response: We appreciate the reviewer’s time and effort in providing us with a review of this manuscript. The comments have been responded point by point.
1. In the M/S the hypotesis is finding difference in the different ecosystems. There are no any species identification. How many species, which species is dominant? There is no information.
Response: Thanks for your valuable suggestions. Because the manuscript focuses on the analysis of trophic groups, and the information of the identified nematodes is displayed in the supplementary material. In addition, the specific distribution of nematodes is as follows. A total of 857 soil nematodes and 36 genera were identified in maize-soybean rotation field. Coomansus and Aporcedorus were the dominant genus. The average nematode density was 481 patches of 100 g-1 dry soil.1287 soil nematodes and 39 genus were identified in sugarcane field. Clarkus was the dominant genus. The average nematode density was 871 patches of 100 g-1 dry soil.1741 soil nematodes and 57 genus were identified in mulberry field. Acrobeloides, Filenchus were the dominant genus. The average nematode density was 317 patches of 100 g-1 dry soil. A total of 959 soil nematodes and 51 genera were identified. Filenchus、Clarkus and Mylonchulus were the dominant genus. The average nematode density was 456 patches of 100 g-1 dry soil.747 soil nematodes and 39 genus were identified in forage. Coomansus, filenchus were the most dominant genus. The average nematode density was 1535 patches of 100 g-1 dry soil. The same dominant genus of mulberry and forage were more in protective farmland, and the number of nematodes in sugarcane field was more.
2. All the corelation and Regresion degrees are too low. We can not consider them as scientific results.
For this reason I regret to say that the paper can not accepted.
M.Bora Kaydan
Response: Thank you for taking time to review the manuscript. We have replaced soil multifunctionality with soil quality index in the revised manuscript. The regression coefficient has a low fitting degree, and it can be seen that the overall trend of the two is positively correlated. Their relationship needs further research.
Please see the attachment for the revised manuscript.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Relationships between soil nematode communities and soil 2 multifunctionality as affected by land-use type
This study reports on relationships between soil properties and nematode communities in soil samples taken from replicated plots of reclaimed agricultural land in southern China. The authors find that forest soils support the largest nematode abundances and that this is positively correlated with several soil properties indicative of microbial respiration and carbon cycling, and possibly health/functionality. The paper is mostly well written and easy to follow, however I have a few comments about the introduction below. More significantly, the methods are not clearly enough justified to address the concern I have about the use of soil properties rather than ecosystem/soil processes (functions) to answer a question about multifunctionality. I have other concerns about the imperfect use of a randomized complete block design which appears to make the main result (effect of forest cover) a potentially spurious one.
Introduction
Can you state how you will define multifunctionality (i.e. which functions) in the introduction? Currently in the introduction it is only implied that you will consider more than just net primary production and nitrogen. This contrasts with the abstract where you appear to define multifunctionality as a set of ecosystem and soil properties (e.g., soil pH and soc content). Is this appropriate?
I appreciate your introductory paragraph about the karst landscape and land use types in the study area but I hoped to also learn what kinds of functional properties might be changing across the land use types? To draw only on your net primary production example, how does that vary across the 5 land uses?
Similarly, your hypotheses appear more as expected results, in particular your first hypothesis about a negative correlation between nematodes and soil disturbance. I think a hypothesis should include some prediction about the relationship between the land use types you are exploring and nematode communities, perhaps with reference to changes in an ecosystem property of function.
Methods/Results
I am concerned that all the forest plots came from a separate location which breaks the randomized complete block design. In particular I’m concerned that something is different about the forest locations compared to the other blocks and that may contribute to the significant differences observed between forests and other land uses. How are you/have you been able to address this potential confounding?
I am concerned about the use of soil properties in place of functions/processes. It seems other studies quantify things like litter decomposition, respiration, or productivity. I could imagine root growth might be another soil property, or nitrate turnover. However, soil properties like pH and SOC do not seem to be functions. I’m not sure how to interpret these data.
The Hooper, Vitousek 1998 reference seems incorrect as it does not appear to discuss z-scores for multifunctionality. I’m not sure why it’s being cited here, though a citation should be provided for this method.
I am concerned about a sentence from another paper being cited with regard to multifunctionality metrics: “Inclusion of strongly positively correlated (i.e., r > 0.5) individual processes is not recommended (46) in the calculation of multi-functionality indices, but our strongest correlation was 0.37 between the two litter-decomposition processes.” from Bradford et al. 2014 Discontinuity in the responses of ecosystem processes and multifunctionality to altered soil community composition. Was correlation among the metrics considered?
Author Response
Responses to reviewers’ comments (forests-1872538)
Response: Changed as suggested (in highlight)
Reviewer #2: This study reports on relationships between soil properties and nematode communities in soil samples taken from replicated plots of reclaimed agricultural land in southern China. The authors find that forest soils support the largest nematode abundances and that this is positively correlated with several soil properties indicative of microbial respiration and carbon cycling, and possibly health/functionality. The paper is mostly well written and easy to follow, however I have a few comments about the introduction below. More significantly, the methods are not clearly enough justified to address the concern I have about the use of soil properties rather than ecosystem/soil processes (functions) to answer a question about multifunctionality. I have other concerns about the imperfect use of a randomized complete block design which appears to make the main result (effect of forest cover) a potentially spurious one.
Response: We appreciate the reviewer’s time and effort in providing us with a review of this manuscript. The comments have been responded point by point.
Introduction
Can you state how you will define multifunctionality (i.e. which functions) in the introduction? Currently in the introduction it is only implied that you will consider more than just net primary production and nitrogen. This contrasts with the abstract where you appear to define multifunctionality as a set of ecosystem and soil properties (e.g., soil pH and soc content). Is this appropriate?
Response:
- Soil has multiple functions. In 2006, Commission of the European identified seven soil functions in Thematic strategy for Soil protection, including (1) biomass production in agriculture and forestry; (2) Storage, filtration and conversion of nutrients, other substances and water; (3) Biodiversity, including species and genetic diversity, and habitats; (4) The physical and cultural environment of human beings and their activities; (5) The source of raw materials; (6) Carbon pool; (7) Archives of geological and archaeological heritage. The method of soil ecosystem multifunctionality is subjective to the selection of soil function and index, and the calculation method is different from the threshold standard, so the calculated multifunctionality index is relative. For example, Delgado-Baquerizo et al. (2020) ecosystem services were included plant productivity, nutrient cycling, organic matter (OM) decomposition, pollutant degradation and pathogen control annually. And to obtain a quantitative multifunctionality index for each site, he normalized and standardized each of the six functions measured (ammonium, nitrate, potential net N mineralization, soil phosphorus, DNA content and plant productivity) using the Z-score transformation at first.
- In the original manuscript, we focused on calculating soil multifunctionality in terms of soil functions related to soil fertility, decomposition of organic and soil nitrogen cycle. However, considering your suggestion, we realized that it is not comprehensive enough to evaluate soil quality by only using existing indicators to construct soil multifunctionality indexes. Therefore, we reanalyzed the data and used the soil quality Index (SQI) to evaluate soil health rather than soil multifunctionality. In addition to the physical and chemical indexes involved in the overall quality evaluation, SQI also includes biological indexes (fungi, bacteria, arbuscular fungi, and actinomycetes) that are often ignored in the evaluation system. (L29-L32, L59-L75, L121-148, L170-186)
I appreciate your introductory paragraph about the karst landscape and land use types in the study area but I hoped to also learn what kinds of functional properties might be changing across the land use types? To draw only on your net primary production example, how does that vary across the 5 land uses?
Response:
- We show the variation table of soil functional properties of different land use types in the Supporting information. SOC,TN and C:N is highest in forest，lowest in cropland, followed by forage grass, sugarcane and mulberry.
- Thank you for providing us with good research ideas. Different ecosystems have different concerns, productivity on the one hand, net primary production on the other. In particular, natural and agricultural systems are different. agricultural systems have different crop differences that lead to different outcomes, and we'll think about that later. In the next research, we will conduct the net primary production research and explore soil function in depth.
Similarly, your hypotheses appear more as expected results, in particular your first hypothesis about a negative correlation between nematodes and soil disturbance. I think a hypothesis should include some prediction about the relationship between the land use types you are exploring and nematode communities, perhaps with reference to changes in an ecosystem property of function.
Response: In our discussion and conclusion, we showed that the abundance of nematodes was decreased in land use types with high disturbance degree. In the revised manuscript, nematodes and soil quality indices showed similar trends to previous trends in soil ecosystem multifunctionality. The prediction and analysis of nematodes and land use types need to be further studied
Methods/Results
I am concerned that all the forest plots came from a separate location which breaks the randomized complete block design. In particular I’m concerned that something is different about the forest locations compared to the other blocks and that may contribute to the significant differences observed between forests and other land uses. How are you/have you been able to address this potential confounding?
Response: The main object of Guangxi Mulun National Nature Reserve is to protect the subtropical karst forest ecosystem of global significance. Because mature forests were absent in all the blocks, five nearby mature forests (>50 years old) were selected for comparison in the Mulun National Natural Reserve. All the plots were distributed over the valley or bottom slopes. Three articles have been published on the application of this plot design (Li et al., 2018a; Li et al., 2018b; Li et al., 2018c)
I am concerned about the use of soil properties in place of functions/processes. It seems other studies quantify things like litter decomposition, respiration, or productivity. I could imagine root growth might be another soil property, or nitrate turnover. However, soil properties like pH and SOC do not seem to be functions. I’m not sure how to interpret these data.
Response: Soil ecosystem function refers to the functions closely related to ecosystem functions and services. Soil pH is important chemical properties of soil. The increase and decrease of soil pH will affect the distribution and transformation of soil nutrients, thus affecting community composition and ecosystem function. Soil organic carbon pool is an important indicator of soil fertility. Soil organic carbon content can well represent the decomposition and storage of carbon in soil. Both soil organic carbon and pH are important functions of soil (Allan et al., 2015; Jing et al., 2015; Chen et al., 2020; Garland et al., 2021).
The Hooper, Vitousek 1998 reference seems incorrect as it does not appear to discuss z-scores for multifunctionality. I’m not sure why it’s being cited here, though a citation should be provided for this method.
Response: Thank you for your carefully advice. I have read this article carefully, and there is no mention of Z-core in this literature. I realized that the literature was misquoted here. I am sorry for misleading your reading. We have corrected the problem and removed it now.
I am concerned about a sentence from another paper being cited with regard to multifunctionality metrics: “Inclusion of strongly positively correlated (i.e., r > 0.5) individual processes is not recommended (46) in the calculation of multi-functionality indices, but our strongest correlation was 0.37 between the two litter-decomposition processes.” from Bradford et al. 2014 Discontinuity in the responses of ecosystem processes and multifunctionality to altered soil community composition. Was correlation among the metrics considered?
Response: We have carefully read this literature and agree that this approach. It may avoid more date redundancy by excluding factors with higher correlation. We used Pearson correlation analysis to soil functions, and the correlation was very high between the data of soil functions. The data (r < 0.5) is not enough to support data analysis. Surprisingly, after using Pca to reduce the dimension, the results are consistent with the previous. It may be due to the relative importance of each indicator in our data. Therefore, we use the total data set (TDS) in the revised manuscript. The TDS can provide a comprehensive outcome in evaluating the SQI and apply all measurable and accessible soil data. (L170-186)
Please see the attachment for the revised manuscript.
references:
- Allan, E., Manning, P., Alt, F., Binkenstein, J., Blaser, S., Bluethgen, N., Boehm, S., Grassein, F., Hoelzel, N., Klaus, V.H., Kleinebecker, T., Morris, E.K., Oelmann, Y., Prati, D., Renner, S.C., Rillig, M.C., Schaefer, M., Schloter, M., Schmitt, B., Schoening, I., Schrumpf, M., Solly, E., Sorkau, E., Steckel, J., Steffen-Dewenter, I., Stempfhuber, B., Tschapka, M., Weiner, C.N., Weisser, W.W., Werner, M., Westphal, C., Wilcke, W., Fischer, M., 2015. Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition. Ecology Letters 18, 834-843.
- Chen, Q.-L., Ding, J., Zhu, D., Hu, H.-W., Delgado-Baquerizo, M., Ma, Y.-B., He, J.-Z., Zhu, Y.-G., 2020. Rare microbial taxa as the major drivers of ecosystem multifunctionality in long-term fertilized soils. Soil Biology and Biochemistry 141.
- Delgado-Baquerizo, M., Reich, P.B., Trivedi, C., Eldridge, D.J., Abades, S., Alfaro, F.D., Bastida, F., Berhe, A.A., Cutler, N.A., Gallardo, A., Garcia-Velazquez, L., Hart, S.C., Hayes, P.E., He, J.Z., Hseu, Z.Y., Hu, H.W., Kirchmair, M., Neuhauser, S., Perez, C.A., Reed, S.C., Santos, F., Sullivan, B.W., Trivedi, P., Wang, J.T., Weber-Grullon, L., Williams, M.A., Singh, B.K., 2020. Multiple elements of soil biodiversity drive ecosystem functions across biomes. Nat Ecol Evol 4, 210-220.
- Garland, G., Edlinger, A., Banerjee, S., Degrune, F., García-Palacios, P., Pescador, D.S., Herzog, C., Romdhane, S., Saghai, A., Spor, A., Wagg, C., Hallin, S., Maestre, F.T., Philippot, L., Rillig, M.C., van der Heijden, M.G.A., 2021. Crop cover is more important than rotational diversity for soil multifunctionality and cereal yields in European cropping systems. Nature Food 2, 28-37.
- Jing, X., Sanders, N.J., Shi, Y., Chu, H., Classen, A.T., Zhao, K., Chen, L., Shi, Y., Jiang, Y., He, J.S., 2015. The links between ecosystem multifunctionality and above- and belowground biodiversity are mediated by climate. Nat Commun 6, 8159.
- Li, D., Liu, J., Chen, H., Zheng, L., Wang, K., 2018a. Soil gross nitrogen transformations in responses to land use conversion in a subtropical karst region. J Environ Manage 212, 1-7.
- Li, D., Liu, J., Chen, H., Zheng, L., Wang, K., 2018b. Soil microbial community responses to forage grass cultivation in degraded karst soils, Southwest China. Land Degradation & Development 29, 4262-4270.
- Li, D., Liu, J., Chen, H., Zheng, L., Wen, L., Wang, K., 2018c. Forage grass cultivation increases soil organic carbon and nitrogen pools in a karst region, southwest China. Land Degradation & Development 29, 4397-4404.
Author Response File: Author Response.docx
Reviewer 3 Report
A very interesting topic for research work.
The abstract fully reflects the content of the article, it is written in clear and understandable language.
Material and methods described in an exhaustive way and allowing for an in-depth analysis of the experience.
Test methods selected correctly, typical for this type of research.
One can write a subsection of statistical analyzes.
The results are widely presented, so this section can be extended with more detailed descriptions of selected statistical methods / analyzes.
The presentation of the research results at a high level should be underlined.
The entries in the tables are explained in detail.
High-level discussion.
Please expand the conclusions as well.
After minor corrections, I recommend the work for printing.
Author Response
Responses to reviewers’ comments (forests-1872538)
Response: Changed as suggested (in highlight)
Reviewer #3:
A very interesting topic for research work.
The abstract fully reflects the content of the article, it is written in clear and understandable language.
Material and methods described in an exhaustive way and allowing for an in-depth analysis of the experience.
Test methods selected correctly, typical for this type of research.
One can write a subsection of statistical analyzes.
The results are widely presented, so this section can be extended with more detailed descriptions of selected statistical methods / analyzes.
Response: We appreciate the reviewer’s time and effort in providing us with a review of this manuscript. After much deliberation, we realized that it is not comprehensive enough to evaluate soil quality by only using existing indicators to construct soil multifunctionality indexes. We used the soil quality index instead of the soil multifunctionality index to evaluate soil quality in the revised manuscript. We have added the materials and methods described and allowed for an in-depth analysis of the experience (L121-148, L170-186)
The presentation of the research results at a high level should be underlined.
The entries in the tables are explained in detail.
High-level discussion.
Please expand the conclusions as well.
After minor corrections, I recommend the work for printing.
Response: Thank you for your carefully advice. We explained the contents in the table in detail and enriched the content of the research results (L170-186, L253-264), and we expanded the discussion and conclusoin (L334-L358), L361-362).
Please see the attachment for the revised manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear Editor,
I think the paper can be published in this form. But I would suggest the editor to consider the regression analysis again and decide.
With my very best regards.
M. Bora Kaydan
Author Response
Responses to reviewers’ comments (forests-1872538)
Reviewer #1:
I think the paper can be published in this form. But I would suggest the editor to consider the regression analysis again and decide.
Response: We appreciate the reviewer’s time and effort in providing us with a review of this manuscript. We constructed the Ordinary least squares (OLS) regression models. In linear correlation results, R2 values were between 0.2 and 0.3 (P<0.05). Many articles were published which indicated a significant positive relationship by using values in or below this range (Byrnes et al., 2014; Chen et al., 2020; Delgado-Baquerizo et al., 2020) .
Byrnes, J.E.K., Gamfeldt, L., Isbell, F., Lefcheck, J.S., Griffin, J.N., Hector, A., Cardinale, B.J., Hooper, D.U., Dee, L.E., Duffy, J.E., 2014. Investigating the relationship between biodiversity and ecosystem multifunctionality: challenges and solutions. Methods in Ecology and Evolution 5, 111-124.
Chen, Q.-L., Ding, J., Zhu, D., Hu, H.-W., Delgado-Baquerizo, M., Ma, Y.-B., He, J.-Z., Zhu, Y.-G., 2020. Rare microbial taxa as the major drivers of ecosystem multifunctionality in long-term fertilized soils. Soil Biology and Biochemistry 141.
Delgado-Baquerizo, M., Reich, P.B., Trivedi, C., Eldridge, D.J., Abades, S., Alfaro, F.D., Bastida, F., Berhe, A.A., Cutler, N.A., Gallardo, A., Garcia-Velazquez, L., Hart, S.C., Hayes, P.E., He, J.Z., Hseu, Z.Y., Hu, H.W., Kirchmair, M., Neuhauser, S., Perez, C.A., Reed, S.C., Santos, F., Sullivan, B.W., Trivedi, P., Wang, J.T., Weber-Grullon, L., Williams, M.A., Singh, B.K., 2020. Multiple elements of soil biodiversity drive ecosystem functions across biomes. Nat Ecol Evol 4, 210-220.
