Greenhouse Gas Fluxes from the Epiphytic Lichens: Incubation Experiments

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript entitled "Greenhouse gas fluxes from the epiphytic lichens: incubation experiments" is an interesting study dealing with the measurement of GHGs from the lichen species under incubation experiments. Authors have measured the lichen diversity and related indices in the Siberian forest region and collected the sample for laboratory studies. In the laboratory, two incubation experiments were planned, one for measuring diel variation in GHGs for three species whereas another one for exploring role of different environmental conditions on GHGs emissions conducted in a 14 days incubation period. The concept of the study is interesting. However, there are a few suggestions and comments which can be incorporated in the manuscript. Though the findings of the study are interesting and present that a significant quantity of GHGs are released from these lichens, but what is the productivity or net primary productivity or photosynthesis uptake of GHGs by these species are not quantified and presented. This can be a major loophole for presenting an overall C balance for the lichens in an ecosystem. The findings are ecologically sound but seems to be biased or partially explored as only respiration without photosynthesis data will provide a half story of the species/organism.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The manuscript is written well, only a small language correction is required to make it clearer to the readers.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

 

Introduction

1.     Line 38. ELs have a high ecological value, and their specific biological characteristics play an important role in environmental improvement, biological diversity, and soil and water conservation.

This sentence needs further explanation because it is not self-evident. In particular, how can epiphytic lichens influence soil conservation if they are epiphytes? This applies to biological crusts, but I do not know how epiphytic lichens intervene.

2.     Line 40. They have valuable ecosystem functions, acting as a food source for mammals and invertebrates and as a habitat for many species. Please provide a reference for this sentence.

3.     It is important to clarify that those with a higher poleotolerance index also suffer more from air pollution. For example, include the reference: Fadel, D., Sid, A. S., Zga, N., Latrèche, F., & Ali, A. O. (2014). Cartography of Air Pollution in an Industrial City in North-Eastern Algeria by Using Two Indexes: Poleotolerance Index and Atmospheric Purity Index. Journal of Life Sciences, 8(1), 95-100.

Discussion

1.     The differences in lichen diversity observed in the plots cannot be explained based on pollution as pollution does not vary significantly between plots.

2.     The effect of wind accumulating pollutants is neither experimentally nor bibliographically evidenced. Please include at least some literature.

3.     It is difficult to assess whether methane emissions are important in the carbon cycle. You could compare it with emissions from other organisms, e.g., cows or animal compost...

4.     The brown stains they claim to observe on the stems seem to be an observational reference that has not been measured experimentally. This data would be needed.

Figures

Please delete figures 2 and 4, they are not needed. Renumber the figures in the current document as figure 3 is missing.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript has been revised partially as per the suggestions given earlier. However, there are a few generic question which need to be addressed clearly. First one is that authors are mentioning that negative flux represent photosynthesis whereas positive flux represent respiration (LN 244-245 and many more). Authors are advised to see the generic eco-physiological principle that respiration and photosynthesis both occur in presence of light. Authors should re-evaluate these observation and focus only on the flux/respiration component without giving more emphasis on photosynthesis as it was not measured appropriately. Secondly, the study design is still not appropriate. Authors have taken one site of 3 km stretch, considered three sub-sites and then at each sub-site selected four plants from where lichen species were selected (LN 148-150). So the site selection is quite low, in terms of ecological understanding and data robustness. Another point which I did not understand properly is the mention of cumulative temperature (LN 95-96)? What is the relevance of this cumulative temperature. Usually average temperature ranges are used for data representation. Elaborate the ecological significance of this value. Poleotolerance index seems to be less used term/approach and therefore can be elaborated by giving appropriate citation to the main workers (LN 180-181). These queries need appropriate response and citation support before proceeding further.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

I have no further comments or suggestions for the authors. It seems to me that the requested corrections have been made. Thank you for counting on me

Author Response

Благодарим Вас за оперативное рассмотрение нашей рукописи! Мы искренне ценим ваш ценный вклад.

Dear Reiviewer,  answers to questions in the attached file. relating to flux/respiration component, the study design, the relevance of cumulative temperature and the use of the poleotolerance index  you will find in the attached file These queries must be responded before the final acceptance of the manuscript.

Author Response File: Author Response.pdf