Impact of Temperature and Moisture on the Decomposition of Peat-Forming Plants: Results of a Two-Year Incubation Experiment

Round 1

Reviewer 1 Report

Given the significance of peatlands and the backdrop of climate change, a thorough investigation into the transformation processes of organic matter in peatlands becomes increasingly meaningful. This study examines the decomposition processes of representative peat-forming plants under varying temperature and moisture condition. Overall, the results did not yield many surprises, but the authors conducted a meticulous investigation, presenting the data comprehensively with great attention to writing. However, there are areas that could be improved:

1. It is necessary to supplement some information on the implementation of the experiment. How to adjust the moisture content of the material to 30%, 60%, and 90%? How many glass flasks were used in total(line 138)? What is the so-called air-permeable, moisture-impermeable films(line 152)? It is necessary to specify the product name or chemical composition. How to estimate the total carbon loss based on the accumulation curve( line 196)?

2. Please verify the WHC data in Table 1, as they seem too large. For example, is 2541 ± 241 actually 25.41% ± 2.41%?

3. The article is too lengthy, and the description of results lacks focus. It is appropriate to simplify the explanation of some noncritical results.

4. In order to make the entire article appear more concise, it is recommended to merge the results section and discussion section together, reduce the elaboration of noncritical results, and conduct in-depth analysis and discussion of important findings

Author Response

Dear Reviewer,

We are very thankful to you for the thoughtful reviewing of our manuscript, your valuable suggestions to improve our MS. Thanks a lot for your positive evaluation of our study.

We’ve considered all of your remarks and comments in the revised MS. Below you can find explanations for each one of your comments:

1. It is necessary to supplement some information on the implementation of the experiment. How to adjust the moisture content of the material to 30%, 60%, and 90%?

Thanks, for your valuable comment. To maintain a consistent moisture level in the plant samples, a certain quantity of bog water was added to each flask every 2–3 weeks based on their initial weight.  In the subsection 2.2. Experimental design and measurement of the peat-forming plant decay rates, we have added short explanation for a better understanding of this process (lines 160-161).

2. How many glass flasks were used in total (line 138)?

We’ve included the needed information to MS: “In total, 108 flasks were prepared for experimen” (lines 153-154).

3. What is the so-called air-permeable, moisture-impermeable films (line 152)? It is necessary to specify the product name or chemical composition.

Thank you very much, We’ve included the needed information to MS: name of the material to the article – polyethylene (line 170).

“…the flasks containing the plant samples were covered with polyethylene air-permeable, moisture-impermeable films…”

4. How to estimate the total carbon loss based on the accumulation curve ( line 196)?

Thanks for your comment, we have added the nedded information to MS (subsection 2.4. Data processing and statistical analyses) – line 217-222

5. Please verify the WHC data in Table 1, as they seem too large. For example, is 2541 ± 241 actually 25.41% ± 2.41%?

We have carefully reviewed the data, there are no errors in them. High water holding capacity of peats and peat-forming plants is also found in articles (Thomson A., Naumova G. Peat and products of its processing. - Litres, 2021; Naumova, G. V. Peat in biotechnology, Minsk, 1987). It’s well known that peat and othe organic materials cal hold high amount of water wich exceed the mass of organic material by 2-10 time and more.

7. The article is too lengthy, and the description of results lacks focus. It is appropriate to simplify the explanation of some noncritical results.

In order to make the entire article appear more concise, it is recommended to merge the results section and discussion section together, reduce the elaboration of noncritical results, and conduct in-depth analysis and discussion of important findings

Thanks a lot for your valuable comment. We have combined the results section and discussion, and we also tried to shorten some elements of the article and highlighted the most important points.

Again, we are very thankful anonymous reviewer for positive response on our study and very valuable comments which allow to improve our MS!

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is well-written and organized. My biggest concern is its significance/novelty is not clear. Other than that, I only have a few minor comments:

1. In the abstract and introduction, please start with the problem statement. In other words, what motivates you to carry out this study? What is its significance?

2. Please explain the productive and destructive processes in the introduction.

3. It seems that statements in lines 47-50 are from the literature. Why also state them in the abstract as if they are new findings from the present study?

4. I don't understand the explanation in lines 77-81.

5. It would be helpful if some photos or microscopic images can be added to the results section to give direct visual impression.

Minor editing of English language is required

Author Response

Dear Reviewer,

We are very thankful to you for the thoughtful reviewing of our manuscript, your valuable suggestions to improve our MS. Thanks a lot for your positive evaluation of our study.

We’ve taken into account all of your remarks and comments in the revised MS. Below you can find explanations for each one of your comments:

The manuscript is well-written and organized. My biggest concern is its significance/novelty is not clear. Other than that, I only have a few minor comments:

1. In the abstract and introduction, please start with the problem statement. In other words, what motivates you to carry out this study? What is its significance?

Thank you very much for your valuable suggestion. We’ve included the additional explanation concerning the novelty (lines 92-96 in Introduction) and motivation of our study (lines 83-92 in Introduction)

There are very few studies on the decomposition of peat-forming plants under modeled conditions, so we appreciate your comments to help improve our research.

Under natural conditions, the aforementioned factors, such as temperature, moisture, and plant species, exert a combined influence on the decomposition rate of plant residues. Identifying the specific contribution of each factor to the processes of organic matter transformation is possible only through model experiments conducted under controlled conditions of moisture and temperature. Since the processes of decomposition of plant materials in the bogs of Western Siberia are slowed down, the long-term incubation experiments on their decomposition are necessary. In 600-days incubation experiment, we planned to separate the impact of main abiotic and biotic factors and their emergent properties on the plant residues decomposition process under carefully controlled humidity and temperature regime. Therefore, the novelty of our study are these two points – high duration and multifactorial of experiment on peat-forming plants decomposition and as well as the determination of their decay constant and temperature coefficients Q₁₀ during the various stage of decomposition at different combination of temperature-moisture conditions.

We have also added a sentence to the abstract reflecting the relevance of our study (lines 15-17):

Decomposition rate of plant residues is determined by both abiotic (temperature, moisture) and biotic factors (biochemical composition). Only controlled conditions of the incubation experiment can show the separate contribution of each factor to the decomposition.

2. Please explain the productive and destructive processes in the introduction.

Thank you for the recommendation, we’ve  included the needed information to introduction (lines 39-42):

Bog ecosystems play an important role in the global organic carbon (C_org) cycle due to the prevalence of productive processes (accumulation of organic matter in plant tissues and peat deposit formation) over destructive ones (decay of organic matter in plant residues).

3. It seems that statements in lines 47-50 are from the literature. Why also state them in the abstract as if they are new findings from the present study?

Thanks a lot for your comment. These studies were conducted in natural conditions rather than under controlled conditions. We have made this clarification:

According to several studies in natural conditions [3, 10, 11], the decomposition processes of peat-forming plant residues are most intense in the initial stages of degradation.

In the incubation experiment we also found these patterns so we think this is an important aspect.

4. I don't understand the explanation in lines 77-81.

The abovementioned text reflects the relevance of incubation. We believed,  that to study the influence of individual factors on the decomposition rate it is possible only in controlled laboratory conditions. We have made changes in the MS (lines 83-92).

Under natural conditions, the aforementioned factors, such as temperature, moisture, and plant species, exert a combined influence on the decomposition rate of plant residues. Identifying the specific contribution of each factor to the processes of organic matter transformation is possible only through model experiments conducted under controlled conditions of moisture and temperature. Since the processes of decomposition of plant materials in the bogs of Western Siberia are slowed down, the long-term incubation experiments on their decomposition are necessary. In 600-days incubation experiment, we planned to separate the impact of main abiotic and biotic factors and their emergent properties on the plant residues decomposition process under carefully controlled humidity and temperature regime.

5. It would be helpful if some photos or microscopic images can be added to the results section to give direct visual impression.

Unfortunately, we don’t have microscopic images, but we took this comment into consideration and added some pictures to “2.2. Experimental design and measurement of the peat-forming plant decay rates”.

We are very thankful anonymous reviewer for positive response on our study and very valuable comments which allow us to improve our MS!

Author Response File: Author Response.pdf