The Contribution of Roots, Mycorrhizal Hyphae, and Soil Free-Living Microbes to Soil Respiration and Its Temperature Sensitivity in a Larch Forest
Round 1
Reviewer 1 Report
Review comments for Forests
The Contribution of Roots, Mycorrhizal Hyphae, and Soil Free- Living Microbes to Soil Respiration and Its Temperature Sensitivity in a Larch Forest (forests-1416160)
Authors: Naoki Makita et al.
I have gone through the manuscript, which presents a very important topic within the scope of the Journal “Forests”. Authors' major focus is about the contribution of different component of soil respiration and their temperature sensitivity. The results about the separation of mycorrhizal respiration from autotrophic respiration and the higher temperature sensitivity for mycorrhizal respiration are novel and interesting. Overall, this manuscript is well written and the materials used were found clearly described in the study. However, the statistical analyses and Discussion section can be improved in my opinion. I recommend that this manuscript needs a minor revision for publication in Forests.
Line 38. Please delete “global change and”
Line 45-46 please delete “in litter”
Line 57-58 It is unclear. Please rewrite this sentence.
Line 109/118 please use one proper noun throughout the manuscript. Suggest using “SOM respiration”, not “SOM decomposition respiration” or “decomposition respiration”.
Line 138 the authors obtained a series of data about soil respiration and soil temperature in the field. Therefore, this equation (based on two sets of respiration and temperature) does not fit in my opinion.
Firgure1. please provide the scatterplot, not a broken-line graph, because the CO2 efflux was measured 1 or 2 times a month. Add the standard error.
Materials and Methods： I think that the calculation of Q10 should be based on plots so that you can compare the differences in Q10 among the different soil respiration components using ANOVE.
Discussion: Mycorrhizal respiration is more sensitive to temperature than root respiration and SOM respiration. Why? Please explain it.
Author Response
I have gone through the manuscript, which presents a very important topic within the scope of the Journal “Forests”. Authors' major focus is about the contribution of different component of soil respiration and their temperature sensitivity. The results about the separation of mycorrhizal respiration from autotrophic respiration and the higher temperature sensitivity for mycorrhizal respiration are novel and interesting. Overall, this manuscript is well written and the materials used were found clearly described in the study. However, the statistical analyses and Discussion section can be improved in my opinion. I recommend that this manuscript needs a minor revision for publication in Forests.
Response: We would like to give special thanks to the reviewer for checking our previous manuscript and for giving suggestions and constructive comments that greatly improved our manuscript.
Line 38. Please delete “global change and”
Response: We have deleted it.
Line 45-46 please delete “in litter”
Response: We have deleted it.
Line 57-58 It is unclear. Please rewrite this sentence.
Response: We have changed it to “Novel approaches to separate the autotrophic components have developed and enabled us to evaluate mycorrhizal hyphae growth in the soil” (Line 57-58).
Line 109/118 please use one proper noun throughout the manuscript. Suggest using “SOM respiration”, not “SOM decomposition respiration” or “decomposition respiration”.
Response: We have changed it to “SOM respiration” (Line 13, 109, 117).
Line 138 the authors obtained a series of data about soil respiration and soil temperature in the field. Therefore, this equation (based on two sets of respiration and temperature) does not fit in my opinion.
Response: Thank you so much for your suggestion. We have agreed with this suggestion and revised the equations (Line 135-139, Equation 1and 2). Note that this revision does not affect the results.
Firgure1. please provide the scatterplot, not a broken-line graph, because the CO2 efflux was measured 1 or 2 times a month. Add the standard error.
Response: Thank you for your advice. We have tried to make the scatterplot with S.E., but it became hard to see the 4 lines in Figure 1c. Thus, we wish to retain the original figure.
Materials and Methods： I think that the calculation of Q10 should be based on plots so that you can compare the differences in Q10 among the different soil respiration components using ANOVE.
Response: We appreciate the reviewer's interest in the calculation and statistical analysis on Q10. However, because of small replications and large spatial variations, we consider that it is difficult to characterize the different CO2 sources in the case of plot-base, and therefore we wish to retain the original calculation.
Discussion: Mycorrhizal respiration is more sensitive to temperature than root respiration and SOM respiration. Why? Please explain it.
Response: We have added the explanation for high Q10 of mycorrhizal respiration (Line 258-261).
Author Response File: 
Author Response.docx
Reviewer 2 Report
Authors present data describing “Contribution of roots, mycorrhizal hyphae and soil free-living microbes to soil respiration and its temperature sensitivity in a larch forest” in Japan. Overall I believe that the paper has scientific merit, and the questions about how soil respiration can be influenced by roots, mycorrhizal hyphae, and microbes, although the result was observed over a short period. Some comments are suggested to improve the study results.
- Please show the map of the study site.
- line 84. Please check the values of stand basal area. The value (5.5 m2 ha-1) is too low, You have 667 trees/ha with mean 30 cm DBH.
- line 174: Figure 2 (a): add the equation of the regression with determination of coefficient (R2).
- line 185: Figure 2 –> Figure 3. add the equations of the regression with determination of coefficient (R2).
Line 199. yr-1
Line 219; Italic letter in Pinus sylvestris
Check references by Journal’s rule.
Author Response
Authors present data describing “Contribution of roots, mycorrhizal hyphae and soil free-living microbes to soil respiration and its temperature sensitivity in a larch forest” in Japan. Overall I believe that the paper has scientific merit, and the questions about how soil respiration can be influenced by roots, mycorrhizal hyphae, and microbes, although the result was observed over a short period. Some comments are suggested to improve the study results.
Response: We wish to express our strong appreciation to the reviewers for their insightful comments on our paper. We feel the comments have helped us significantly improve the paper.
Please show the map of the study site.
Response: We appreciate the reviewer's suggestion. However, because of single small study-site, we consider that this map may not be necessary, and therefore wish to add the information on study site (Line 79).
line 84. Please check the values of stand basal area. The value (5.5 m2 ha-1) is too low, You have 667 trees/ha with mean 30 cm DBH.
Response: Thank you so much for the suggestions. We have mistaken the calculation and modified them to 45 m2 ha-1 (Line 84).
line 174: Figure 2 (a): add the equation of the regression with determination of coefficient (R2).
Response: We have made a new Table 1 and added the equation of the regression with determination of coefficient (R2) (Table 1).
line 185: Figure 2 –> Figure 3. add the equations of the regression with determination of coefficient (R2).
Response: This error has been corrected in accordance with the reviewer's comment. Accordingly, we have added the equation of the regression with determination of coefficient (R2) (Table 1).
Line 199. yr-1
Response: We have revised it (Line 207).
Line 219; Italic letter in Pinus sylvestris
Response: We have changed it (Line 227).
Check references by Journal’s rule.
Response: We have checked the references again (Line 318-397).
Author Response File: Author Response.docx
Reviewer 3 Report
I like the idea of partitioning total respiration into root respiration, mycorrhizal respiration, and SOM decomposition respiration. This is something not well-explored. The manuscript is well-written, direct to the point, and easy to understand. The flow of the story is straightforward. I have a few comments for the authors to consider.
|
Line/s |
Comments |
|
152-153 |
In lines 142-143, it was mentioned that …’The respiration was not measured during January-April due to snowpack in the winter season. However, in lines 152-153, it was stated that …’ Rsoil showed strong seasonality; it was lowest in February and highest in mid-August’… Please clarify which respiration was not measured during January – April? |
|
152-156 |
‘The mean percentage of Rsoil was 42%, 6%, and 52% in Rroot, Rmyc, and Rsom, respectively (Figure 1d)’… At what period coverage these were measured? |
|
Figure 2 |
Care to put the regression equation in Figure 2a? |
|
Figure 3 |
‘Figure 2’ in the Figure caption should have been Figure 3? Also put the regression equation. |
|
219 |
‘Pinus sylvestris’, italics please. |
|
227-232 |
‘For the heterotrophic component, Rsom accounted for most (52%–67%) of Rsoil in early spring and late autumn’… The explanation of an increase in Rsom during fall was discussed. How about in early spring where it is only the start of leaf emergence? Why Rsom was high? |
|
205 -214 |
You can get some insights on these suggested papers:
https://0-academic-oup-com.brum.beds.ac.uk/femsec/article/59/2/418/552685 https://0-www-tandfonline-com.brum.beds.ac.uk/doi/full/10.3402/tellusb.v65i0.20792 https://0-iopscience-iop-org.brum.beds.ac.uk/article/10.1088/1748-9326/4/2/024005
|
Author Response
I like the idea of partitioning total respiration into root respiration, mycorrhizal respiration, and SOM decomposition respiration. This is something not well-explored. The manuscript is well-written, direct to the point, and easy to understand. The flow of the story is straightforward. I have a few comments for the authors to consider.
Response: We have acknowledged the highly evaluation of our study. The comments have helped us significantly improve the paper.
152-153
In lines 142-143, it was mentioned that …’The respiration was not measured during January-April due to snowpack in the winter season. However, in lines 152-153, it was stated that …’ Rsoil showed strong seasonality; it was lowest in February and highest in mid-August’… Please clarify which respiration was not measured during January – April?
Response: This was our mistake. Because the respirations were measured during the months from May to December with non-snowpack period in 2019, we have collected them to “it was lowest in December and highest in mid-August.” (Line 152-153).
152-156
‘The mean percentage of Rsoil was 42%, 6%, and 52% in Rroot, Rmyc, and Rsom, respectively (Figure 1d)’… At what period coverage these were measured?
Response: We have added the information as follows “During the months from May to December in 2019” (Line 155).
Figure 2
Care to put the regression equation in Figure 2a?
Response: We have added the equation of the regression (Table 1).
Figure 3
‘Figure 2’ in the Figure caption should have been Figure 3? Also put the regression equation.
Response: We have revised it to “Figure 3” (Line 187). We have added the equation of the regression (Table 1).
219
‘Pinus sylvestris’, italics please.
Response: We have revised it (Line 227).
227-232
‘For the heterotrophic component, Rsom accounted for most (52%–67%) of Rsoil in early spring and late autumn’… The explanation of an increase in Rsom during fall was discussed. How about in early spring where it is only the start of leaf emergence? Why Rsom was high?
Response: We appreciate this suggestion. Due to increases in decomposition activity for spring thaw, we think that Rsom was high. We have revised the sentences with explanation on spring thaw in the text (Line 236-242).
205 -214
You can get some insights on these suggested papers:
https://0-academic-oup-com.brum.beds.ac.uk/femsec/article/59/2/418/552685
https://0-www-tandfonline-com.brum.beds.ac.uk/doi/full/10.3402/tellusb.v65i0.20792
https://0-iopscience-iop-org.brum.beds.ac.uk/article/10.1088/1748-9326/4/2/024005
Response: We appreciate this suggestion. We read three papers: Lipson DA. (2007), Aguilos M.et al. (2013), and Reth S. et al. (2009), which sufficiently helped us to construct our idea.
Author Response File: Author Response.docx
