Permafrost Landscape Research in the Northeast of Eurasia

Round 1

Reviewer 1 Report

This paper mainly summarizes the research on permafrost landscape in the northeastern Eurasian continent, and summarizes and analyzes the existing researches on the identification, classification, and mapping of permafrost landscape. The paper has certain reference significance for understanding the methods, conclusions and related applications of permafrost landscape research in northeastern Eurasia.

main comments：

• In the part of materials and methods, this paper introduces some materials and methods in the study of permafrost landscape. Therefore, it is suggested to increase the application scope and applicability of the methods and materials described in this paper in the study of permafrost landscape.
• In the part of permafrost landscape mapping, the description of GIS technologies currently used for permafrost landscape mapping is not enough, and the article only expands some applications. Therefore, we suggest to increase the overview and analysis of permafrost landscape mapping using GIS technologies.
• In this paper, the analysis of the future research prospect of permafrost landscape in the northeast of Eurasia is relatively weak. We suggest adding the prospect analysis or explanation of follow-up research.
• The article is a review article, but most of the current references are concentrated before 2018. It is suggested to add references in recent years to have a more comprehensive discussion and analysis of the latest research trends.

Author Response

Thanks for you comments.

1) In the part of materials and methods, this paper introduces some materials and methods in the study of permafrost landscape. Therefore, it is suggested to increase the application scope and applicability of the methods and materials described in this paper in the study of permafrost landscape. 

In the part of permafrost landscape mapping, the description of GIS technologies currently used for permafrost landscape mapping is not enough, and the article only expands some applications. Therefore, we suggest to increase the overview and analysis of permafrost landscape mapping using GIS technologies. 

I add two paragraphs, ll. 123-141, additional text in italic and blue in text:

The results of permafrost-landscape studies began to be used in GIS modeling [40-42]. The differentiation of the ground temperature and the active layer thickness in permafrost landscapes, the spatial distribution of these important permafrost characteristics was modeled using the permafrost-landscape map of the Yakut ASSR [52]. GIS and permafrost-landscape maps have given the impetus to the thematic mapping, and it became possible to compile special geocryological maps. The interpretation of old aerial photographs and a retrospective analysis of permafrost landscapes in a comparison with modern maps based on high-resolution satellite images makes it possible to determine the tendencies in the development of permafrost landscapes [53]. Remote sensing methods made it possible to map the dynamic state of permafrost landscapes by the age of recovery successions after wildfires [54]. The methodology for mapping permafrost landscapes is also being updated, using a new remote sensing methods [55].

The existing modeling experience shows that cartographic interpretations can be very useful for the operational assessment of the permafrost situation for researchers, primarily for specialists working in the permafrost zone. GIS modeling is primarily associated with assessing the vulnerability of permafrost landscapes to anthropogenic impacts and global warming. Identification of the main factors of vulnerability of permafrost landscapes - ice content and ground temperature, the active layer thickness makes it possible to determine the most sensitive permafrost landscapes [56].

2) In this paper, the analysis of the future research prospect of permafrost landscape in the northeast of Eurasia is relatively weak. We suggest adding the prospect analysis or explanation of follow-up research.

The last paragraph I added the my answer (ll. 468-480), in italic and blue in text:

Prospects for the study of permafrost landscapes in the Northeast of Eurasia in the future will primarily be associated with an assessment of the environment vulnerability and the adaptation of socio-economic conditions to modern climate warming. And it is the concept of the permafrost landscape, which connects all the components of a system [44], that can solve this problem. To do this, firstly, it is necessary to systematize the available data. The permafrost-landscape zoning served as the basis for compiling a cadastre of permafrost landscapes [52], and now it is the basis for compiling a database of geocryological data of different scales that ensure the success of studying permafrost ensuring environmental protection measures and the adaptation in conditions of changing the climate and permafrost. Secondly, to determine the trends in the development of permafrost landscapes and permafrost in general. What permafrost landscapes will be the most vulnerable to modern climate warming and anthropogenic impacts and are there any mechanisms for permafrost conservation. Thirdly, to determine ways of adapting socio-economic conditions to changes in permafrost. The development of permafrost-landscape research in these directions is seen in the future.

3) The article is a review article, but most of the current references are concentrated before 2018. It is suggested to add references in recent years to have a more comprehensive discussion and analysis of the latest research trends.

I added enough citations to articles after 2018.

Reviewer 2 Report

This is an interesting literature review focusing on Siberian permafrost landscape studies.  It is worth publishing, because Russian literature is not easily available world wide. However, the English language requires improvements, there are numerous sentances which are uselessly complicated and the massage is blurred. In my opition also punctuation should be corrected in places (the improved manuscript should be verified by a liguist).  I have put detailed comments on the manuscript file.  

Moreover, I would like to raise following points:

1) It would be good to also learn about the concept of "baydjarakhs" (thermokarst mounds)

2) Were there any Russian studies focusing on permafrost temperature change upon increasing biomass in tundra?

3) Were there any Russian studies focusing of methane emissions from permafrost?

4) What about studies on methane caters in permafrost areas?

5) I would be good to mention ideas of permafrost management by controlled grazing, e.g.
Windirsch, T., Grosse, G., Ulrich, M., Forbes, B. C., Göckede, M., Wolter, J., Macias-Fauria, M., Olofsson, J., Zimov, N., and Strauss, J.: Large Herbivores Affecting Permafrost – Impacts of Grazing on Permafrost Soil Carbon Storage in Northeastern Siberia, Biogeosciences Discuss. [preprint], https://doi.org/10.5194/bg-2021-227, in review, 2021

Comments for author File: Comments.pdf

Author Response

Thanks for you revision, at first a specially for you correction of text.

Answers for comments:

1) It would be good to also learn about the concept of "baydjarakhs" (thermokarst mounds)

I add explanation of "baydjarakhs" in ll.352-354: To this classification, one can add "baydjarakhs" - thermokarst-erosion landforms on the slopes of alas (river valleys and seacoasts), formed when ice-wedges thaws. I cannot found a good explanation, because combine text from three authors - Dubikov et al. 2003; Milkov, 1970 and Geological dictionary, 1978.

2) Were there any Russian studies focusing on permafrost temperature change upon increasing biomass in tundra? 

Added paragraph (ll.427-432):

Changes in the organic material in permafrost soils are taken into the account in geocryological modeling [144]. In Yakutia, experimental work was carried out in the tundra near Chokurdakh town in Yakutia, which found that Shrub expansion may reduce the permafrost thaw in summer [148]. In the alases of Central Yakutia, the temperature regimes of soils in meadows with a different biomass were determined [149], as well as patterns of a change during successions in boreal forests after the disturbance [124].

3-4) Were there any Russian studies focusing of methane emissions from permafrost? and 4) What about studies on methane caters in permafrost areas? 

I add in ll. 437-440: Permafrost disturbances cause an imbalance of greenhouse gases, showing the dynamism of changes in permafrost landscapes. In the permafrost landscapes of Yakutia, studies are being carried out on both carbon dioxide [150-153] and methane content in permafrost [154-156] and its emissions [157-161].

5) I would be good to mention ideas of permafrost management by controlled grazing...

I add in ll. 443-445: Recently, ideas of permafrost temperature management by controlled a grazing to ensure the permafrost sustainability and reduce greenhouse gas emissions have become interesting [149, 162-164].

Reviewer 3 Report

I read the manuscript submitted for review with great interest. It contains an overview of the existing selected publications of mainly Russian authors concerning the study of the landscape of northern Eurasia. The compilation of such papers, handbooks and maps, most of which are not familiar to English-speaking researchers, is interesting and I think it should be published.

I am not directly involved in landscape research, so perhaps the term 'permafrost landscape' proposed in the title and consistently used in the manuscript is not widely known to me, although it appears in the world literature and is even used by the author of the manuscript in his earlier, published papers. Accustomed to the term 'periglacial landscapes', I understand, however, that this is an unambiguous classification of areas with permanently frozen ground, which in the case of periglacial environments is not necessarily explicit. If possible, however, I would ask you to insert into the text an explanation why the term 'permafrost landscapes' is used instead of 'periglacial landscapes', what is the common denominator of these terms, and what is the basic difference (presumably the presence of permafrost). Since many surface, landform-forming processes operate independently of the presence of permafrost, the terms seem to intermingle.

I have no serious objections to the presented manuscript, although I will frankly admit that I am not used to texts not illustrated with any figures, diagrams or tables. As a matter of fact, one could be tempted to have one table gathering the listed publications in thematic groups, or at least illustrations of covers of the most important scientific publications from the literature review.

Author Response

Thanks for you revision.

1) Accustomed to the term 'periglacial landscapes', I understand, however, that this is an unambiguous classification of areas with permanently frozen ground, which in the case of periglacial environments is not necessarily explicit. If possible, however, I would ask you to insert into the text an explanation why the term 'permafrost landscapes' is used instead of 'periglacial landscapes', what is the common denominator of these terms, and what is the basic difference (presumably the presence of permafrost). Since many surface, landform-forming processes operate independently of the presence of permafrost, the terms seem to intermingle. 

My answer in ll. 69-73: The term permafrost landscape is close in the definition to periglacial landscapes [5, 45]. However, periglacial landscapes may be non-permafrost. Therefore, we use the term permafrost landscape. Permafrost landscapes identification is close to the classification of permafrost – syngenetic and epigenetic permafrost [46].

2) I have no serious objections to the presented manuscript, although I will frankly admit that I am not used to texts not illustrated with any figures, diagrams or tables. 

I agree with you and add four Figires in text and maps in Supplementary Materials.

Round 2

Reviewer 2 Report

My comments have been applied and the manuscript is much better now, ready for acceptance. However, there is still some need for liguistic adjucement (a native speaker should handle this issue).

Author Response

Point 1. My comments have been applied and the manuscript is much better now, ready for acceptance. However, there is still some need for liguistic adjucement (a native speaker should handle this issue).

Answer 1. We checked for native English in MDPI.

Author Response File: Author Response.docx