the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 06 Jun 2024
Decomposing the Tea Bag Index and finding slower organic matter loss rates at higher elevations and deeper soil horizons in a minerogenic salt marsh
Abstract. Environmental gradients can affect organic matter decay within and across wetlands and contribute to spatial heterogeneity in soil carbon stocks. We tested the sensitivity of decay rates to tidal flooding and soil depth in a minerogenic salt marsh using the tea bag index (TBI). Tea bags were buried at 10- and 50- cm along transects sited at lower, middle, and higher elevations that paralleled a headward eroding tidal creek. Plant and animal communities and soil properties were characterized once while replicate tea bags and porewaters were collected several times over one year. TBI decay rates were faster than prior litterbag studies in the same marsh, largely due to rapid green tea loss. Rooibos decay rates were comparable to natural marsh litter, potentially suggesting that is more useful as a standardized organic matter proxy than green tea. Decay was slowest at higher marsh elevations and not consistently related to other biotic (e.g., plants, crab burrows) and abiotic factors (e.g., porewater chemistry), indicating that local hydrology strongly affects organic matter loss rates. Tea BI rates were 32–118 % faster in the 10 cm horizon compared to 50 cm. Rates were fastest in the first three months and slowed 54–60 % at both depths between 3- and 6- months. Rates slowed further between 6- and 12- months but this was less dramatic at 10 cm (17 %) compared to 50 cm (50 %). Slower rates at depth and with time were unlikely due to the TBI stabilization factor, which was similar across depths and decreased from 6 to 12 months. Slower decay at 50 cm demonstrates that rates were constrained by the environmental conditions of this deeper horizon rather than the molecular composition of litter. Overall, these patterns suggest that hydrologic setting, which affects oxidant introduction and reactant removal and is often overlooked in marsh decomposition studies, may be a particularly important control on organic matter decay in the short term (3–12 months). transects sited at lower, middle, and higher elevations that paralleled a headward eroding tidal creek.
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RC1: 'Comment on egusphere-2024-1328', Anonymous Referee #1, 21 Jul 2024
Overall, this is an interesting article that investigates the decomposition rate changes of tea bags (TBI) and local plant litter at different soil depths and temperatures, while exploring the factors influencing litter decomposition rates. The writing is generally good, but some sections (such as Results and Discussion) need further refinement. Overall, I suggest major revisions to further enhance the quality of the article. I have several general questions and specific comments as follows:
General Comments:
(1) The title mentions "minerogenic salt marshes." How do these differ from organic marshes? Furthermore, the introduction and discussion sections do not extensively address or explore this distinction. Minerogenic marshes have specific characteristics that could potentially influence the decomposition rates at different soil depths. Could elaborate on this?(2) In Line 69, the authors discuss plant and animal effects. While the plant effects are covered, how do animals influence decomposition in this context? Specifically, Line 75 emphasizes animal burrows. How might animal burrows impact soil physicochemical properties and soil microorganisms?
(3) In Line 120, the authors mention using local plant detritus. Why is this important? How does comparing this with TBI enhance the study, and what specific questions or problems does it address? This should be clearly explained in the introduction.
(4) Lines 128-141 contain detailed information about study locations. Would it be possible to include a map or illustrative figure to better present the experimental setup?
(5) Lines 241-254 raise several questions. The data used are from 2003-2004; could there be discrepancies with the current situation? Also, why use root litter for local litter experiments? The root litter used weighs 10g, whereas TBI uses approximately 1.6g. Does this affect the comparability of the experiments? Moreover, local litter was placed at -10cm and -20cm depths, but not at -50cm. How many replicates were there for TBI, and are they consistent with local litter experiments?
(6) Lines 255-293, Data Analysis, is overly detailed and needs to be condensed for clarity.
(7) The results section presents extensive data and comparisons, thoroughly examining the data. However, this section should focus more on objectively describing data changes and significant differences, avoiding excessive interpretation and discussion. For instance, Lines 342-344, 370-375, 388-390, and 396-397 include speculative comments that are better suited for the discussion section.
(8) In the results section, the authors used a non-traditional TBI index calculation, separately calculating the decomposition rate and stabilization factor for green tea and rooibos tea. However, the terminology must be consistent throughout (e.g., kg, kr, Sg, Sr). Phrases like S=Sg and TBI decay appear in the text. The same issue exists in the discussion section. Please ensure consistent terminology.
(9) Lines 509-525 commendably summarize the discussion on TBI results and the relationship between k and S. However, the discussion would benefit from a clearer connection to the study's findings and implications.
Specific Comments:
(1) Line 32: Replace "Tea BI rate" with "TBI."(2) Line 59: The authors mention that effects on soil organic matter decay are "less well understood." What specific scientific questions or reasons contribute to this lack of understanding? Please clarify.
(3) Line 102: When discussing the advantages of TBI, "inexpensive" lacks professionalism. Consider using a more precise term.
(4) Line 137: Why were tea bags placed at -50 cm, and how was soil disturbance minimized during placement? How many experimental replicates were there?
(5) Line 208: Specify the initial weight of the tea bags.
(6) Line 228-229: Why does the methods section introduce potential results and discussion points instead of presenting them in the results section?
(7) Line 195: How were the crabs and snails measured or quantified?
(8) Line 288: Correct the citation format to "Clogg et al., (2009)."
(9) Previous comments may have already addressed this, but I remain curious. This study focuses on minerogenic marshes. Are the articles discussed in the discussion section based on minerogenic marshes, or do they include other types of wetlands as well?
Citation: https://doi.org/10.5194/egusphere-2024-1328-RC1 -
AC1: 'Reply on RC1', Satyatejas Reddy, 02 Oct 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1328/egusphere-2024-1328-AC1-supplement.pdf
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AC1: 'Reply on RC1', Satyatejas Reddy, 02 Oct 2024
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RC2: 'Comment on egusphere-2024-1328', Anonymous Referee #2, 09 Aug 2024
The manuscript focuses on decomposition processes in salt marsh environments, specifically within the Georgia Coast, USA. The authors employ the Tea Bag Index (TBI) standard protocol proposed by Keuskamp et al. (2013) to analyse organic matter decomposition. The study investigates various factors that influence decomposition by considering two burial depths and different relative marsh surface elevations within the tidal frame. Additionally, the authors measure key environmental and biotic variables, including soil temperature, soil stiffness, porewater characteristics (salinity, redox potential, pH), and biotic characteristics (plant density, belowground biomass, crab, and snail burrow density). Moreover, the study tests several assumptions of the TBI method by extending the prescribed incubation period from 3 to 12 months and comparing the decay dynamics of rooibos and green teas to prior studies that used local plant detritus. The manuscript also explores different approaches for calculating decay parameters.
The study is commendable for its attempt to delve into the potential weaknesses of the TBI method, such as exploring the effect of leaching and the assumption that the stabilization factor remains constant across different organic materials. Additionally, the study examines the influence of specific physical and biotic characteristics on decomposition, although distinguishing the causal relationships between the various drivers presents a challenge.
The writing is generally solid, but certain sections require additional polishing. Overall, I suggest major revisions to improve the quality of the article. In particular, I suggest improving the clarity of the method presentation and discussion in certain areas and better distinguishing between methods, results, and discussion. It's important to avoid anticipating results when explaining methods and to refrain from including discussion points when objectively presenting results.
General Comments:
- In the Methods section, the authors thoroughly describe their experimental design, including site locations, depths, and the various variables measured. To enhance clarity, would it be possible to add a figure featuring an image of the study site and a schematic of the experiment? Given the complexity and detail of the experiment, this would help the reader more clearly and directly understand the setup and more easily follow the results later on.
- The Methods section is extensive and detailed. However, in several instances, the authors anticipate and comment on results (lines 169, 186-187, 189-190, 195-196, 228-230, 281-283). Even though some of these results are from another study (Wu et al., 2022), it may be more appropriate to present and discuss them in the Results and Discussion sections, given that they are used as variables in correlation analyses.
- Considering that the study provides an interesting analysis of the weaknesses of the TBI method, I suggest further clarifying and expanding the description of Keuskamp et al. (2013)’s method. At line 214, it is important to specify that the TBI k coefficient represents the decomposition rate constant of the labile fraction. According to Keuskamp et al. (2013), the decomposition rate constants for the labile and recalcitrant fractions are denoted by k1 and k2, respectively. During the initial phase, the labile fraction is rapidly decomposed, and the weight loss of the litter is primarily determined by k1. Additionally, in section 2.6, as discussed later, it should be specified that, according to Keuskamp et al. (2013), S is assumed to be equal for both tea types, meaning that the environmental stabilization of the labile material is considered independent of the relative size and composition of the hydrolysable fraction. The TBI method relies on several assumptions since its purpose is to measure k and S without requiring time series data by using two types of tea with differing characteristics. Clarifying this point would help the reader better follow the discussion later on.
- At the end of paragraph 2.6, the authors mention modifying the S equation for rooibos tea (Sr) by substituting ar and Hr, but they do not specify how this calculation was performed. Could the authors clarify how they calculated Sr? Specifically, how were the values of ar and Hr obtained? How did the authors determine when all the labile material in the rooibos tea had decomposed?
- At lines 246-247, the authors mention comparing TBI results with a prior litterbag experiment conducted from June 2003 to 2004. Did the authors evaluate the environmental conditions (e.g., temperature, rainfall) of the 2003-2004 period to determine if they are comparable to those of the TBI experiment?
- In several captions of tables (Table 1, Table 3, Table 5), the authors state, “Significant differences (<0.05) are denoted by superscripts”. I would suggest specifying which statistical test was used to determine the significance of the differences and clarifying that different letters indicate significant differences.
- The Results section is extensive and detailed. However, in several instances, the authors anticipate interpretation and discussion (lines 326-328, 342-344, 366-367, 388-390,396-397). The Results section would benefit from focusing more on objectively presenting the results, with speculative comments reserved for the Discussion section.
Specific Comments:
Lines 63-68: In the Introduction, the authors state that “water passage through the subsurface alters the thermodynamic favorability of different pathways for decomposition” without explaining how this occurs. Immediately after, they add that “the intensity of tidal flooding effects on plant and soil processes is strongest at creekbanks and lower elevations relative to interior and higher elevation areas,” but they do not clarify the reasoning behind this statement. To enhance comprehension for a multidisciplinary audience, I suggest briefly explaining these assertions.
Line 95: I suggest including a couple of examples of geochemical approaches for the sake of clarity.
Line 102: I would suggest using a different term instead of "inexpensive" to describe the method's advantage, as it is likely more accurate to say it is less expensive than other methods.
Line 121-125: The last lines of the introduction seem to anticipate some discussion of the results. However, I believe the authors may be aiming to explain the rationale behind their experimental design. If that’s the case, I suggest rephrasing the paragraph to make this intention clearer.
Line 135: As this is the first time this acronym NAVD appears in the text, I suggest spelling out its meaning, as done in the following lines (line 146: North American Vertical Datum of 1988 (m, NAVD 88)).
Lines 165-173: This paragraph starts with a description of the method used to measure porewater chemistry before listing the measured variables. For clarity, I suggest stating which variables were analysed at the beginning of the paragraph.
Line 203: Are the Lipton™ tea bags used in this study the same type as those used by Keuskamp et al. (2013)?
Line 218: I would specify that Hg and Hr were measured by Keuskamp et al. (2013) using a sequential extraction technique, with the hydrolysable fraction defined as the sum of nonpolar extractives (NPE), water solubles (WS), and acid solubles (AS), as opposed to the recalcitrant nonhydrolysable fraction, which includes AIS and ash.
Line 290: When stating that data were transformed as needed to meet assumptions of normality, it would be helpful to mention specific examples of transformations used (e.g., log10).
Line 297: The authors state that porewater chemistry was surprisingly insensitive to relative marsh elevation. However, immediately after, they mention that salinity, which was previously listed among the porewater chemistry variables, positively correlates with relative elevation. Given this positive correlation, it would be more accurate to say that porewater chemistry is weakly sensitive to elevation.
Figure 1: To present the data more clearly, it might be helpful to indicate the number of samples that constitute each box in the box plots.
Table 1: The caption states that “Significant differences between tidal stages within a season are denoted by * (p<0.05).” However, it is unclear what the double asterisk (**) signifies in the table.
Line 319: As this subsection presents both decay rates and stabilization factors, it would be more appropriate to include "stabilization factors" in the title, rather than mentioning only decay rates.
Line 320: For completeness of the results, it would be helpful to mention the values of k and S calculated, as is done at line 346 for the litterbags experiment.
Figure 3: The caption states that “Contrasts between k and S at the 3- (blue), 6- (red), and 12- (green) time points are denoted by letters of the same color.” However, it is unclear what "contrasts" refers to. I suggest to clarify the meaning of "contrasts" and explain how the letters are used to denote differences.
Table 4: The table would be clearer if it indicated that the numbers presented are Spearman’s rank correlation coefficients (ρ).
Lines 403-404: Although it is useful and interesting to calculate both TBI k and tea-specific rates to compare them with previous findings and assess their behaviour with respect to environmental variables, I am unsure how accurate it is to directly compare these values, as they result from different calculations. If they are compared, I suggest providing commentary on the differences in their calculations.
Lines 447-448: Since green tea decomposition is used to determine ag, which is then used to calculate S, and from which ar is derived to subsequently determine k from W(t)r and ar, does the TBI k coefficient by Keuskamp et al. (2013) represent the decomposition rate of rooibos tea?
Lines 462-471: In these lines, the authors compare TBI decay rates with measurements from previous studies in the same area. However, they note that these earlier measurements were based on lignin, losses of structural polysaccharides, or plant tissue mass. I am unsure how accurate it is to directly compare these values, as they result from different calculations.
Figure 4: I suggest mentioning in the caption what the bars represent (e.g., standard deviation). Additionally, would it be possible to include standard deviation bars for the other studies presented in the figure?
Lines 619-620: The authors mention that their results suggest organic matter decay is less sensitive to molecular composition than to the soil environment. To strengthen the discussion, I suggest briefly elaborating on the reasons supporting this assertion.
Technical corrections:
Line 41: At the end of the abstract, there's a typographical error with a phrase that remains incomplete.
Line 265: The punctuation is missing.
Figure 4: Figure 4 is abbreviated as "Fig. 4," unlike the other figures. For consistency, I suggest standardizing the abbreviation format across all figures.
Citation: https://doi.org/10.5194/egusphere-2024-1328-RC2 -
AC2: 'Reply on RC2', Satyatejas Reddy, 02 Oct 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1328/egusphere-2024-1328-AC2-supplement.pdf
Interactive discussion
Status: closed
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RC1: 'Comment on egusphere-2024-1328', Anonymous Referee #1, 21 Jul 2024
Overall, this is an interesting article that investigates the decomposition rate changes of tea bags (TBI) and local plant litter at different soil depths and temperatures, while exploring the factors influencing litter decomposition rates. The writing is generally good, but some sections (such as Results and Discussion) need further refinement. Overall, I suggest major revisions to further enhance the quality of the article. I have several general questions and specific comments as follows:
General Comments:
(1) The title mentions "minerogenic salt marshes." How do these differ from organic marshes? Furthermore, the introduction and discussion sections do not extensively address or explore this distinction. Minerogenic marshes have specific characteristics that could potentially influence the decomposition rates at different soil depths. Could elaborate on this?(2) In Line 69, the authors discuss plant and animal effects. While the plant effects are covered, how do animals influence decomposition in this context? Specifically, Line 75 emphasizes animal burrows. How might animal burrows impact soil physicochemical properties and soil microorganisms?
(3) In Line 120, the authors mention using local plant detritus. Why is this important? How does comparing this with TBI enhance the study, and what specific questions or problems does it address? This should be clearly explained in the introduction.
(4) Lines 128-141 contain detailed information about study locations. Would it be possible to include a map or illustrative figure to better present the experimental setup?
(5) Lines 241-254 raise several questions. The data used are from 2003-2004; could there be discrepancies with the current situation? Also, why use root litter for local litter experiments? The root litter used weighs 10g, whereas TBI uses approximately 1.6g. Does this affect the comparability of the experiments? Moreover, local litter was placed at -10cm and -20cm depths, but not at -50cm. How many replicates were there for TBI, and are they consistent with local litter experiments?
(6) Lines 255-293, Data Analysis, is overly detailed and needs to be condensed for clarity.
(7) The results section presents extensive data and comparisons, thoroughly examining the data. However, this section should focus more on objectively describing data changes and significant differences, avoiding excessive interpretation and discussion. For instance, Lines 342-344, 370-375, 388-390, and 396-397 include speculative comments that are better suited for the discussion section.
(8) In the results section, the authors used a non-traditional TBI index calculation, separately calculating the decomposition rate and stabilization factor for green tea and rooibos tea. However, the terminology must be consistent throughout (e.g., kg, kr, Sg, Sr). Phrases like S=Sg and TBI decay appear in the text. The same issue exists in the discussion section. Please ensure consistent terminology.
(9) Lines 509-525 commendably summarize the discussion on TBI results and the relationship between k and S. However, the discussion would benefit from a clearer connection to the study's findings and implications.
Specific Comments:
(1) Line 32: Replace "Tea BI rate" with "TBI."(2) Line 59: The authors mention that effects on soil organic matter decay are "less well understood." What specific scientific questions or reasons contribute to this lack of understanding? Please clarify.
(3) Line 102: When discussing the advantages of TBI, "inexpensive" lacks professionalism. Consider using a more precise term.
(4) Line 137: Why were tea bags placed at -50 cm, and how was soil disturbance minimized during placement? How many experimental replicates were there?
(5) Line 208: Specify the initial weight of the tea bags.
(6) Line 228-229: Why does the methods section introduce potential results and discussion points instead of presenting them in the results section?
(7) Line 195: How were the crabs and snails measured or quantified?
(8) Line 288: Correct the citation format to "Clogg et al., (2009)."
(9) Previous comments may have already addressed this, but I remain curious. This study focuses on minerogenic marshes. Are the articles discussed in the discussion section based on minerogenic marshes, or do they include other types of wetlands as well?
Citation: https://doi.org/10.5194/egusphere-2024-1328-RC1 -
AC1: 'Reply on RC1', Satyatejas Reddy, 02 Oct 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1328/egusphere-2024-1328-AC1-supplement.pdf
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AC1: 'Reply on RC1', Satyatejas Reddy, 02 Oct 2024
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RC2: 'Comment on egusphere-2024-1328', Anonymous Referee #2, 09 Aug 2024
The manuscript focuses on decomposition processes in salt marsh environments, specifically within the Georgia Coast, USA. The authors employ the Tea Bag Index (TBI) standard protocol proposed by Keuskamp et al. (2013) to analyse organic matter decomposition. The study investigates various factors that influence decomposition by considering two burial depths and different relative marsh surface elevations within the tidal frame. Additionally, the authors measure key environmental and biotic variables, including soil temperature, soil stiffness, porewater characteristics (salinity, redox potential, pH), and biotic characteristics (plant density, belowground biomass, crab, and snail burrow density). Moreover, the study tests several assumptions of the TBI method by extending the prescribed incubation period from 3 to 12 months and comparing the decay dynamics of rooibos and green teas to prior studies that used local plant detritus. The manuscript also explores different approaches for calculating decay parameters.
The study is commendable for its attempt to delve into the potential weaknesses of the TBI method, such as exploring the effect of leaching and the assumption that the stabilization factor remains constant across different organic materials. Additionally, the study examines the influence of specific physical and biotic characteristics on decomposition, although distinguishing the causal relationships between the various drivers presents a challenge.
The writing is generally solid, but certain sections require additional polishing. Overall, I suggest major revisions to improve the quality of the article. In particular, I suggest improving the clarity of the method presentation and discussion in certain areas and better distinguishing between methods, results, and discussion. It's important to avoid anticipating results when explaining methods and to refrain from including discussion points when objectively presenting results.
General Comments:
- In the Methods section, the authors thoroughly describe their experimental design, including site locations, depths, and the various variables measured. To enhance clarity, would it be possible to add a figure featuring an image of the study site and a schematic of the experiment? Given the complexity and detail of the experiment, this would help the reader more clearly and directly understand the setup and more easily follow the results later on.
- The Methods section is extensive and detailed. However, in several instances, the authors anticipate and comment on results (lines 169, 186-187, 189-190, 195-196, 228-230, 281-283). Even though some of these results are from another study (Wu et al., 2022), it may be more appropriate to present and discuss them in the Results and Discussion sections, given that they are used as variables in correlation analyses.
- Considering that the study provides an interesting analysis of the weaknesses of the TBI method, I suggest further clarifying and expanding the description of Keuskamp et al. (2013)’s method. At line 214, it is important to specify that the TBI k coefficient represents the decomposition rate constant of the labile fraction. According to Keuskamp et al. (2013), the decomposition rate constants for the labile and recalcitrant fractions are denoted by k1 and k2, respectively. During the initial phase, the labile fraction is rapidly decomposed, and the weight loss of the litter is primarily determined by k1. Additionally, in section 2.6, as discussed later, it should be specified that, according to Keuskamp et al. (2013), S is assumed to be equal for both tea types, meaning that the environmental stabilization of the labile material is considered independent of the relative size and composition of the hydrolysable fraction. The TBI method relies on several assumptions since its purpose is to measure k and S without requiring time series data by using two types of tea with differing characteristics. Clarifying this point would help the reader better follow the discussion later on.
- At the end of paragraph 2.6, the authors mention modifying the S equation for rooibos tea (Sr) by substituting ar and Hr, but they do not specify how this calculation was performed. Could the authors clarify how they calculated Sr? Specifically, how were the values of ar and Hr obtained? How did the authors determine when all the labile material in the rooibos tea had decomposed?
- At lines 246-247, the authors mention comparing TBI results with a prior litterbag experiment conducted from June 2003 to 2004. Did the authors evaluate the environmental conditions (e.g., temperature, rainfall) of the 2003-2004 period to determine if they are comparable to those of the TBI experiment?
- In several captions of tables (Table 1, Table 3, Table 5), the authors state, “Significant differences (<0.05) are denoted by superscripts”. I would suggest specifying which statistical test was used to determine the significance of the differences and clarifying that different letters indicate significant differences.
- The Results section is extensive and detailed. However, in several instances, the authors anticipate interpretation and discussion (lines 326-328, 342-344, 366-367, 388-390,396-397). The Results section would benefit from focusing more on objectively presenting the results, with speculative comments reserved for the Discussion section.
Specific Comments:
Lines 63-68: In the Introduction, the authors state that “water passage through the subsurface alters the thermodynamic favorability of different pathways for decomposition” without explaining how this occurs. Immediately after, they add that “the intensity of tidal flooding effects on plant and soil processes is strongest at creekbanks and lower elevations relative to interior and higher elevation areas,” but they do not clarify the reasoning behind this statement. To enhance comprehension for a multidisciplinary audience, I suggest briefly explaining these assertions.
Line 95: I suggest including a couple of examples of geochemical approaches for the sake of clarity.
Line 102: I would suggest using a different term instead of "inexpensive" to describe the method's advantage, as it is likely more accurate to say it is less expensive than other methods.
Line 121-125: The last lines of the introduction seem to anticipate some discussion of the results. However, I believe the authors may be aiming to explain the rationale behind their experimental design. If that’s the case, I suggest rephrasing the paragraph to make this intention clearer.
Line 135: As this is the first time this acronym NAVD appears in the text, I suggest spelling out its meaning, as done in the following lines (line 146: North American Vertical Datum of 1988 (m, NAVD 88)).
Lines 165-173: This paragraph starts with a description of the method used to measure porewater chemistry before listing the measured variables. For clarity, I suggest stating which variables were analysed at the beginning of the paragraph.
Line 203: Are the Lipton™ tea bags used in this study the same type as those used by Keuskamp et al. (2013)?
Line 218: I would specify that Hg and Hr were measured by Keuskamp et al. (2013) using a sequential extraction technique, with the hydrolysable fraction defined as the sum of nonpolar extractives (NPE), water solubles (WS), and acid solubles (AS), as opposed to the recalcitrant nonhydrolysable fraction, which includes AIS and ash.
Line 290: When stating that data were transformed as needed to meet assumptions of normality, it would be helpful to mention specific examples of transformations used (e.g., log10).
Line 297: The authors state that porewater chemistry was surprisingly insensitive to relative marsh elevation. However, immediately after, they mention that salinity, which was previously listed among the porewater chemistry variables, positively correlates with relative elevation. Given this positive correlation, it would be more accurate to say that porewater chemistry is weakly sensitive to elevation.
Figure 1: To present the data more clearly, it might be helpful to indicate the number of samples that constitute each box in the box plots.
Table 1: The caption states that “Significant differences between tidal stages within a season are denoted by * (p<0.05).” However, it is unclear what the double asterisk (**) signifies in the table.
Line 319: As this subsection presents both decay rates and stabilization factors, it would be more appropriate to include "stabilization factors" in the title, rather than mentioning only decay rates.
Line 320: For completeness of the results, it would be helpful to mention the values of k and S calculated, as is done at line 346 for the litterbags experiment.
Figure 3: The caption states that “Contrasts between k and S at the 3- (blue), 6- (red), and 12- (green) time points are denoted by letters of the same color.” However, it is unclear what "contrasts" refers to. I suggest to clarify the meaning of "contrasts" and explain how the letters are used to denote differences.
Table 4: The table would be clearer if it indicated that the numbers presented are Spearman’s rank correlation coefficients (ρ).
Lines 403-404: Although it is useful and interesting to calculate both TBI k and tea-specific rates to compare them with previous findings and assess their behaviour with respect to environmental variables, I am unsure how accurate it is to directly compare these values, as they result from different calculations. If they are compared, I suggest providing commentary on the differences in their calculations.
Lines 447-448: Since green tea decomposition is used to determine ag, which is then used to calculate S, and from which ar is derived to subsequently determine k from W(t)r and ar, does the TBI k coefficient by Keuskamp et al. (2013) represent the decomposition rate of rooibos tea?
Lines 462-471: In these lines, the authors compare TBI decay rates with measurements from previous studies in the same area. However, they note that these earlier measurements were based on lignin, losses of structural polysaccharides, or plant tissue mass. I am unsure how accurate it is to directly compare these values, as they result from different calculations.
Figure 4: I suggest mentioning in the caption what the bars represent (e.g., standard deviation). Additionally, would it be possible to include standard deviation bars for the other studies presented in the figure?
Lines 619-620: The authors mention that their results suggest organic matter decay is less sensitive to molecular composition than to the soil environment. To strengthen the discussion, I suggest briefly elaborating on the reasons supporting this assertion.
Technical corrections:
Line 41: At the end of the abstract, there's a typographical error with a phrase that remains incomplete.
Line 265: The punctuation is missing.
Figure 4: Figure 4 is abbreviated as "Fig. 4," unlike the other figures. For consistency, I suggest standardizing the abbreviation format across all figures.
Citation: https://doi.org/10.5194/egusphere-2024-1328-RC2 -
AC2: 'Reply on RC2', Satyatejas Reddy, 02 Oct 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1328/egusphere-2024-1328-AC2-supplement.pdf
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Satyatejas G. Reddy
W. Reilly Farrell
Fengrun Wu
Steven C. Pennings
Jonathan Sanderman
Meagan Eagle
Christopher Craft
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