Effects of Lime Application and Understory Removal on Soil Microbial Communities in Subtropical Eucalyptus L’Hér. Plantations
Round 1
Reviewer 1 Report
There are serious grammatical errors throughout the manuscript. These need to be corrected before this work can be considered for publication.
The stated hypotheses that liming and removal of understory vegetation would affect microbial community composition do not represent significant research questions. Both liming and understory removal represent substantial ecological changes and it would be surprising if there were no effect on microbial communities. I think a more interesting question would be: how do the authors expect microbial community function to be affected by liming and understory removal? Why?
I don’t have expertise in PLFA, but the methods described seem reasonable based on what I know.
A major result that is not discussed at all is the change in PFLAs from December 2011 to December 2012. For example, in the control plot, total PLFAs decrease from ~2500 mg/g dry soil to ~1600 mg/g dry soil from December 2011 to December 2012. These temporal changes dwarf many of the treatment effects that they describe, yet are not explained or even mentioned in the manuscript.
The authors claim their results show that understory removal significantly reduced total PLFAs, but their Figure 2 does not that bear that out. The UR treatment shows a decrease in total PLFAs over time, but remains at the same level as (or slightly above) the control group by the end of the measurement period. Again, temporal changes are significant and should be explained or at least considered.
Unless I am misunderstanding their intent, the authors state that the decreased DOC resulted in decreased fungal activity, as ‘proven’ by their PLFA results. Rather, they observed a correlation between DOC and fungal PLFA markers, and did not prove that DOC caused a decrease in fungal activity.
While I agree with the authors that understory removal and liming seem like potentially detrimental interventions, I don’t understand how their results support this claim. Their results do show shifts in the fungal community especially, but they don’t show changes in the function of the microbial communities, or productivity of the plantations, which is presumably the primary purpose of liming and understory removal.
Author Response
Response to Reviewer 1 Comments
Point 1: There are serious grammatical errors throughout the manuscript. These need to be corrected before this work can be considered for publication.
Response 1: we invited Prof. Evan Siemann from Rice University to proofread the whole manuscript and improve the language accordingly as suggested. Hopefully, the current version of our manuscript is much better in readability than previous version now.
Point 2: The stated hypotheses that liming and removal of understory vegetation would affect microbial community composition do not represent significant research questions. Both liming and understory removal represent substantial ecological changes and it would be surprising if there were no effect on microbial communities. I think a more interesting question would be: how do the authors expect microbial community function to be affected by liming and understory removal? Why?
Response 2: As suggested, hypotheses were rewritten and Prof. Evan Siemann was involved to improve its readability accordingly (see page 2 line 91 to 95 in the revised version)
Point 3: I don’t have expertise in PLFA, but the methods described seem reasonable based on what I know.
A major result that is not discussed at all is the change in PFLAs from December 2011 to December 2012. For example, in the control plot, total PLFAs decrease from ~2500 mg/g dry soil to ~1600 mg/g dry soil from December 2011 to December 2012. These temporal changes dwarf many of the treatment effects that they describe, yet are not explained or even mentioned in the manuscript.
Response 3: As suggested, temporal changes of soil microbial biomass and composition were discussed in the revised version (See page 8 line 281 to 288). Specifically, Soil microorganisms are greatly affected by both quantity and quality of resources, as well as the soil habitat. Soil sampling time had significant effects on soil microbial biomass and composition in this study (Fig.2, Table 3), probably due to the seasonal variations in soil temperature and/or moisture. The present study region is within a typical subtropical monsoon climate, with distinct wet-hot and dry-cold seasons. Over 83% and 66% of annual precipitation and radiation inputs to this region occur during the wet-hot season (from April to September). The temporal changes in soil microbial biomass and composition could be ascribed to the changes in moisture, soil temperature, and the substrate availability, as indicated by other studies.
Point 4: The authors claim their results show that understory removal significantly reduced total PLFAs, but their Figure 2 does not that bear that out. The UR treatment shows a decrease in total PLFAs over time, but remains at the same level as (or slightly above) the control group by the end of the measurement period. Again, temporal changes are significant and should be explained or at least considered.
Response 4: we added and discussed the result that sampling time and UR had a significant interactive effects on soil total PLFAs to the revised version (see page 6 line 218-219; page 8 line 289-291, respectively).
Unless I am misunderstanding their intent, the authors state that the decreased DOC resulted in decreased fungal activity, as ‘proven’ by their PLFA results. Rather, they observed a correlation between DOC and fungal PLFA markers, and did not prove that DOC caused a decrease in fungal activity.
Response 5: we reanalyzed the factors that affecting fungi PLFA, and proved that decreased DOC led to fungal PLFA reduced (see page 9 line 312-318 in the revised version). Specifically, however, there was an apparently trend that understory removal decreased DOC (P=0.06) (Table 2), and thus resulted in the fungal PLFAs decreased in our 6-yr eucalyptus plantation, which was proven by the result of the fungal PLFA biomarker 18:2ω6, 9 correlating positively with DOC (Fig.3). Additionally, understory removal decreased SMC (P<0.01), and subsequently increased the fungal PLFAs, as indicated by the negative relationship between the fungal PLFA biomarker 18:2ω6, 9 and SMC (Fig.3). Consequently, the suppressing effect of understory removal on soil fungal PLFAs could be ascribed to the decreased in DOC.
While I agree with the authors that understory removal and liming seem like potentially detrimental interventions, I don’t understand how their results support this claim. Their results do show shifts in the fungal community especially, but they don’t show changes in the function of the microbial communities, or productivity of the plantations, which is presumably the primary purpose of liming and understory removal.
Response 6: In Results section, we added the results that both LA and UR treatments significantly decreased litter decomposition rates (3.4, Fig. 4, see page 7 line 244-251 in the revised version), proving that LA and UR have changed the function of soil microbial community.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript titled “Effects of lime application and understory removal on soil microbial communities in subtropical Eucalyptus plantations” is interesting, provide valuable information and the results are worth publishing. I found many grammars and typing error. Author should proofread it before submission. I have proofread the manuscript and corrected as much as possible.
Plagiarism of manuscript is 47% which should be less than 20%, especially for research manuscript.
29 should be “suitable” instead “suitably”
46 should be “distributes.” instead “distribute”
47 should be “Southeast Asia ” instead “southeast Asia ”
49 should be “ the lime” instead “lime”
58 should be “ actinomycetes” instead “actionmycetes ”
62 should be “on the soil” instead “on soil ”
66 should be “demand for ” instead “demand of “
66 should be “ and fibre” instead “and fiber”
72 should be “ make a substantial” instead “make substantial ”
82 should be “apparent ” instead “apparently ”
83 should be “ on the soil” instead “on soil ”
83 should be “ required” instead “requires ”
95 should be “ of the three” instead “of three ”
104 should be “with the lime ” instead “with lime”
130 should be “ after the soil” instead “after soil”
146 should be “ throughout” instead “through ”
149 should be “ was used” instead “were used ”
161 should be “was not ” instead “were not ”
173 should be “significant difference ” instead “ significant different”
190 should be “ significant” instead “significantly ”
232 should be “ induced analteration” instead “induced alteration ”
240 should be “ might have” instead “may have ”
433 should be “ primarily” instead “primary ”
436 should be “ change” instead “changes ”
443 should be “ significantly ” instead “siginificant ”
Author Response
Response to Reviewer 2 Comments
Point 1: the manuscript titled “Effects of lime application and understory removal on soil microbial communities in subtropical Eucalyptus plantations” is interesting, provide valuable information and the results are worth publishing. I found many grammars and typing error. Author should proofread it before submission. I have proofread the manuscript and corrected as much as possible.
Plagiarism of manuscript is 47% which should be less than 20%, especially for research manuscript.
Response 1: we invited Prof. Evan Siemann from Rice University to proofread the whole manuscript and improve the language accordingly as suggested. Hopefully, the current version of our manuscript is much better in readability than previous version now, and plagiarism of manuscript is lower.
Point 2: 29 should be “suitable” instead “suitably”
Response 2: we use “suitable” instead “suitably” as suggest (see line 31 in our revised version)
Point 3: 46 should be “distributes.” instead “distribute”
Response 3: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 49 in our revised version)
Point 4: 47 should be “Southeast Asia ” instead “southeast Asia ”
Response 4: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 50 in our revised version)
Point 5: 49 should be “ the lime” instead “lime”
Response 5: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 51 in our revised version)
Point 6: 58 should be “ actinomycetes” instead “actinomycetes ”
Response 6: we use “actinomycetes” instead “actinomycetes” as suggest (see line 61 in our revised version)
Point 7: 62 should be “on the soil” instead “on soil ”
Response 7: we use “on the soil” instead “on soil” as suggest (see line 65 in our revised version)
Point 8: 66 should be “demand for ” instead “demand of “
Response 8: we use “demand for” instead “demand of” as suggest (see line 70 in our revised version)
Point 9: 66 should be “ and fibre” instead “and fiber”
Response 9: we use “and fibre” instead “and fiber” as suggest (see line 70 in our revised version)
Point 10: 72 should be “ make a substantial” instead “make substantial ”
Response 10: we use “make a substantial” make substantial” as suggest (see line 76 in our revised version)
Point 11: 82 should be “apparent ” instead “apparently ”
Response 11: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 85-87 in our revised version)
Point 12:83 should be “ on the soil” instead “on soil ”
Response 12: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 85-87 in our revised version)
Point 13: 83 should be “ required” instead “requires ”
Response 13: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 85-87 in our revised version)
Point 14: 95 should be “ of the three” instead “of three ”
Response 14 we use “of the three” instead “instead “of three” as suggest (see line 100 in our revised version)
Point 15: 104 should be “with the lime ” instead “with lime”
Response 15: we use “with the lime” instead “instead “with lime” as suggest (see line 110 in our revised version)
Point 16:130 should be “ after the soil” instead “after soil”
Response 16: we use “after the soil” instead “after soil” as suggest (see line 138 in our revised version)
Point 17:146 should be “ throughout” instead “through ”
Response 17: we use “throughout” instead “through” as suggest (see line164 in our revised version)
Point 18:149 should be “ was used” instead “were used ”
Response 18: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 163-167 in our revised version)
Point 19:161 should be “was not ” instead “were not ”
Response 19: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 177-180 in our revised version)
Point 20:173 should be “significant difference ” instead “ significant different”
Response 20: we use “significant difference” instead “significant different” as suggest (see line 195 in our revised version)
Point 21:190 should be “ significant” instead “significantly ”
Response 21: we use “significant” instead “significantly” as suggest (see line 212 in our revised version)
Point 22:232 should be “induced analteration” instead “induced alteration ”
Response 22: we rewritten the sentence and Prof. Evan Siemann was involved to improve its readability accordingly (see line 267-268 in our revised version)
Point 23:240 should be “might have” instead “may have”
Response 23: we use “might have” instead “may have” as suggest (see line 275 in our revised version)
Point 24:433 should be “ primarily” instead “primary ”
436 should be “ change” instead “changes ”
443 should be “ significantly ” instead “siginificant ”
Response 24: we failure to find out the reviewer mentioned mistakes above, but we invited Prof. Evan Siemann from Rice University to proofread the whole manuscript and improve the language accordingly. We think the current version of our manuscript is much better in readability than previous version.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors have made significant improvements. There are still some grammatical errors that should be corrected. I also question their ability to conclude that changes in the microbial community caused the changes in function that they observed since they did not do any controlled manipulation of the microbial community. Association or links between the two observations would be a more appropriate description (although I agree that causation is likely).
Author Response
Point 1: The authors have made significant improvements. There are still some grammatical errors that should be corrected. I also question their ability to conclude that changes in the microbial community caused the changes in function that they observed since they did not do any controlled manipulation of the microbial community. Association or links between the two observations would be a more appropriate description (although I agree that causation is likely).
Response 1: We appreciate the reviewer’s time and effort for review of our manuscript again and we are glad the reviewer’s satisfied with our work.
According to the comments, we read through the manuscript and carefully checked the grammars. We made a lot of changes to the grammars errors in the revised version (e.g. line 18, line 21-22, line 49-51, line 85-89, line 182, and so on).
Regarding the comment on the conclusion, we toned down the statement about the casual effects on microbial community on ecological function. In this study, we examined the linkage between soil microbial community compositions and litter decomposition rate which are closely related with soil functioning. We found that lime application and understory removal negatively affected the microbial biomass and litter decomposition rate. Since litter decomposition is mainly controlled by soil microbes, we concluded that lime application and understory removal treatments would potentially change soil functions (e.g. soil nutrient cycling and litter decomposition) via the soil microbial community changes. To make it clearer, we re-organized and rephrased the abstract and conclusion sections, and state that “Furthermore, both lime application and understory removal significantly reduced the litter decomposition rates, which indicate the lime application and understory removal may impact the microbial-mediated soil ecological process. Our results suggest that lime application may not be suitable for the management of subtropical Eucalyptus plantations. Likewise, understory vegetation helps to maintain soil microbial communities and litter decomposition rate, it should not be removed from Eucalyptus plantations” in Abstract section (see line 31-36 in the revised version) and “In addition, both lime application and understory removal significantly reduced the litter decomposition rates (Fig.4), which indicates the lime application and understory removal may impact the microbial-mediated soil ecological process (i.e. soil nutrient cycling). We propose that lime application may not be suitable for the management of subtropical Eucalyptus plantation, while understory fern D. dichotoma functions as a facilitator in Eucalyptus plantation and should not be removed. In general, our findings in this study would be helpful for the development of management practices that optimize the yield and sustainability of subtropical plantations” in Conclusion section (see line332-338 in the revised version).
Author Response File: Author Response.docx
