Permafrost Landscape Research in the Northeast of Eurasia

Abstract

The results of permafrost landscape studies on northeastern Eurasia are presented in this review. The assessment of permafrost vulnerability to disturbances and global warming was the basis for the development of these studies. The permafrost landscape, considering the morphological features of the landscape and the permafrost together, is a timely object of study. The theoretical developments of Soviet physical geographers and landscape scientists are the basis for permafrost landscape studies. Over the past four decades, numerous permafrost landscape studies have been carried out on northeastern Eurasia (and Russia). Considering the results of these studies is the main objective of this article. The analysis of the problems of permafrost landscape identification, classification, and mapping and the study of their dynamics and evolution after disturbances and long-term development were carried out. Permafrost landscape studies employ the research methods of landscape science and geocryology. Environmental protection and adaptation of socioeconomic conditions to modern climate warming will determine the prospects for studying permafrost landscapes.

Full text



Citation: Fedorov, A.N. Permafrost
Landscape Research in the Northeast
of Eurasia. Earth 2022,3, 460–478.
https://doi.org/10.3390/
earth3010028
Academic Editor: Adriano Ribolini
Received: 31 January 2022
Accepted: 14 March 2022
Published: 18 March 2022
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations.
Copyright: © 2022 by the author.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Review
Permafrost Landscape Research in the Northeast of Eurasia
Alexander N. Fedorov
Melnikov Permafrost Institute, 677010 Yakutsk, Russia; fedorov@mpi.ysn.ru
Abstract:
The results of permafrost landscape studies on northeastern Eurasia are presented in this
review. The assessment of permafrost vulnerability to disturbances and global warming was the
basis for the development of these studies. The permafrost landscape, considering the morphological
features of the landscape and the permafrost together, is a timely object of study. The theoretical
developments of Soviet physical geographers and landscape scientists are the basis for permafrost
landscape studies. Over the past four decades, numerous permafrost landscape studies have been
carried out on northeastern Eurasia (and Russia). Considering the results of these studies is the main
objective of this article. The analysis of the problems of permafrost landscape identification, classifica-
tion, and mapping and the study of their dynamics and evolution after disturbances and long-term
development were carried out. Permafrost landscape studies employ the research methods of land-
scape science and geocryology. Environmental protection and adaptation of socioeconomic conditions
to modern climate warming will determine the prospects for studying permafrost landscapes.
Keywords:
permafrost landscape; classification; mapping; succession; evolution; northeast Eurasia;
Yakutia
1. Introduction
The landscapes of the North are unique natural formations, easily vulnerable, and
slowly restored after disturbance or impact. The cold climate, permafrost, and low biolog-
ical productivity determine the uniqueness of these landscapes. Tumel [
1
], Baranov [
2
],
Kudryavtsev [
3
], and others considered the landscape method to be one of the main meth-
ods of geocryological mapping. They relied on the characteristics of the landscape and
permafrost, which indicated the permafrost conditions.
Studying the relationship between permafrost and landscapes is associated with
protecting the northern environment. The stability of northern landscapes depends on
permafrost conditions [
4
–
6
]. The ice content and temperature of permafrost, the active
layer depth, and cryogenic processes strongly influence the functioning of landscapes.
The study of integral natural systems characterized by a single state of external and
internal properties determines the theory of the permafrost landscape. Functional links
between the components determine the use of exterior morphological features of landscapes
(mainly combinations of relief and vegetation) as indicators of permafrost conditions. The
indication method is the main method used in engineering geocryology and geocryological
mapping. The indicator properties of the external appearance of the landscape have been
well considered in the works of Tyrtikov [
7
–
9
], Melnikov et al. [
10
–
12
], Konstantinova [
13
],
and others.
Landscape indicators are used to study the relationship between relief and per-
mafrost [
14
–
18
]. Inter-component relationships between vegetation and permafrost, as
well as the temporal variability of permafrost properties, depending on vegetation dynam-
ics, were considered in the works of Tyrtikov [
7
–
9
], Lazukova [
19
], Moskalenko [
20
–
22
],
and others.
The theoretical basis of permafrost landscape studies originated in the developments
of Soviet physical geographers and landscape scientists [
23
–
27
]. Traditional classifications,
mapping techniques, and applied interpretations in landscape studies have not previously
Earth 2022,3, 460–478. https://doi.org/10.3390/earth3010028 https://www.mdpi.com/journal/earth

Earth 2022,3461
used permafrost criteria. Therefore, researchers of permafrost landscapes have used them,
eventually adapting them to the conditions of permafrost based on the goals and objectives
of the research.
For the first time, the taxonomy and classification of permafrost landscapes were com-
piled by Melnikov [
12
,
28
] (pp. 36-57 in ref. [
12
]). The landscape classification hierarchies
and principles of systematization that were established made it possible to successfully
carry out a range of studies in the northern area of Western Siberia [12,29,30].
In recent years, a significant contribution to the development of permafrost landscape
studies and to the study of the dynamics of permafrost conditions has been made by
Drozdov et al. [
31
], Varlamov et al. [
32
], Osadchaya [
33
], Tumel and Zotova [
34
], and others.
This was the beginning of environmental studies in the permafrost zone [35–38].
Permafrost landscape studies are in continuous development. The use of new methods
makes it possible to obtain new data on the distribution and evolution of permafrost [
39
–
42
].
The accumulated experience in studying permafrost landscapes has made it possible to
consider the problematic issues of their classification and functional mapping for assessing
their resistance to anthropogenic impacts.
The permafrost landscape is a relatively homogeneous natural formation that functions
under the influence of cryogenesis, with certain combinations of permafrost characteris-
tics found only in this landscape [
43
]. Permafrost landscapes are an integral part of the
landscape sphere of Earth, where the upper part of the lithosphere is permafrost. The main
factors determining the differentiation and development of permafrost landscapes are cli-
matogenic, lithogenic, biogenic, and anthropogenic factors. The term permafrost landscape
is close in meaning to periglacial landscape [
5
,
44
]. However, periglacial landscapes may
be non-permafrost. Therefore, we use the term permafrost landscape. Permafrost land-
scape identification resembles the classification of permafrost—syngenetic and epigenetic
permafrost [45].
Comprehensive landscape studies, which are the basis for monitoring, modeling, and
forecasting [
46
], are necessary to improve the effectiveness of environmental protection
measures in the field of permafrost distribution. At the same time, the permafrost landscape
acts as an integral indicator of the state of the environment. This is recognized as the main
objective in developing the concept of rational nature management in the permafrost zone.
The purpose of the article is to summarize the methodologies and results of permafrost
and landscape studies carried out in northeastern Eurasia in order to understand the fea-
tures of the natural environment and their dynamics under the influence of anthropogenic
disturbances and the modern impacts of climate change.
2. Materials and Methods
Scientific material on the permafrost and permafrost landscapes of northeastern Eura-
sia has been included in the literature and materials of the Melnikov Permafrost Institute SB
RAS since the 1940s. These materials have considered different scale permafrost maps, the
study of the dynamics of permafrost landforms and temperature regimes, the relationship
between permafrost and taliks, permafrost monitoring, heat balance studies of permafrost
ecosystems, etc. New scientific materials on the composition and properties of permafrost
have appeared, carried out in engineering–geological surveys and monitoring observations
of the permafrost dynamics.
Until the 1980s, geomorphological zoning was used in geocryological surveys to
indicate permafrost conditions [
14
,
47
]. Mapping of the permafrost in mountainous areas
was carried out by considering high-altitude landscape zones [
17
]. These works used
aerial photo interpretation, which became available in the mid-1940s in connection with
continuous topographic mapping of the northeastern USSR.
Landscape studies appeared widely in the 1980s, and they focused on studying the
spatial diversity of permafrost landscapes and their mapping [
48
–
50
]. The permafrost
characteristic combinations—ice content and ground temperature, active layer thickness,
and cryogenic processes—were mapped using landscapes.

Earth 2022,3462
The cryoindication method is the primary method for identifying permafrost land-
scapes. The study of permafrost landscapes utilizes field surveys and descriptions and
aerial and satellite image interpretation. The taxonomy and classification of permafrost
landscapes in Yakutia have been compiled, considering permafrost criteria [
43
]. Ground
temperature and active layer thickness are used as additional selection criteria in detailed
permafrost landscape studies. In medium-scale studies, cryogenic structure and ice con-
tent are used as selection criteria. In small-scale studies, along with latitudinal-zonal and
altitudinal-zonal soil–plant communities, climatic parameters are used, including freezing
and thawing indices. In recent years, the cryoindication of permafrost conditions has
employed modern methods to interpret satellite images—NDVI, LST, InSAR, and others.
Monitoring observations of the dynamics of permafrost landscapes in northeastern
Eurasia are carried out almost everywhere, but they all have different goals and objectives.
The most complex studies are carried out at stations with meteorological, heat balance, and
permafrost observations (Samoilovsky Island, Tiksi PGO, Spasskaya Pad, Neleger, etc.).
Many monitoring sites prefer studying individual permafrost characteristics or processes;
these include observation sites under the GTN-P and CALM programs, which are part
of global permafrost observation networks. There are also many observation networks
for changes in ground temperature, active layer thickness, surface subsidence due to the
melting of underground ice, etc.
The results of permafrost landscape studies are now used in GIS modeling [
39
–
41
].
The differentiation of the ground temperature and the active layer thickness in permafrost
landscapes, and the spatial distribution of these important permafrost characteristics were
modeled using the permafrost landscape map of the Yakut ASSR [
51
]. GIS and permafrost
landscape maps have provided the impetus for thematic mapping, and it is possible to
compile special geocryological maps. The interpretation of old aerial photographs and a
retrospective analysis of permafrost landscapes in comparison with modern maps based
on high-resolution satellite images have made it possible to determine the tendencies in the
development of permafrost landscapes [
52
]. Remote sensing methods have made it possible
to map the dynamic state of permafrost landscapes by the age of recovery successions after
wildfires [
53
]. The methodology for mapping permafrost landscapes is also being updated
using new remote sensing methods [54].
Existing modeling experience indicates that cartographic interpretations can be very
useful to researchers for the operational assessment of the permafrost situation, 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—has made it possible to
determine the most sensitive permafrost landscapes [55].
3. Permafrost Landscapes as an Object of Study
About a quarter of the land surface area is occupied by permafrost landscapes. In
Russia, they occupy about 65% of the territory. These landscapes mainly occupy high-
latitude and high-altitude locations, are distinguished by harsh natural conditions, and are
characterized by the development of specific cryogenic processes and phenomena.
Permafrost landscapes have been the subjects of environmental–geocryological studies
focused on studying territories’ vulnerability to technogenic impacts [
6
,
34
,
49
,
56
–
59
]. The
development of landscapes often leads to an ecological imbalance once the disturbance
becomes one of our time’s pressing problems.
The study of the main relationships between the components of the natural envi-
ronment is carried out by creating multifactorial models of the environment or integral
systems in the form of a landscape. The landscape is a set of interrelated objects and natural
phenomena representing historically established, continuously developing geographical
complexes [
60
]. In other words, this is a spatially limited set of components united by

Earth 2022,3463
a relatively close interaction [
26
]. Any landscape definition implies a unified system of
morphological (external) and internal (lithogenic) factors.
In permafrost conditions, the development of landscapes and their transformation
or restoration after disturbance largely depends on the properties of the permafrost—
temperature regime, cryogenic structure, ice content, and active layer thickness. The
leading nature of the cryogenic factor in northern landscapes is determined by the specifics
of the environment of the northern regions, primarily the presence of ice in the lithogenic
base and phase transitions during freezing and thawing.
This understanding of the landscape corresponds to modern ideas about geocryolog-
ical systems, which are understood as a special type of geosystem in which energy and
mass transfer lead to the formation and existence of a specific mineral–ice [
61
]. Defining
the role of the cryogenic factor in the functioning and differentiation of the landscapes of
the north requires a certain revision of taxonomy, classification, and mapping methods. In
this regard, permafrost distribution and temperature, cryogenic structure, ice content, and
active layer thickness have been proposed as criteria for the classification and mapping
of permafrost landscapes [
43
]. Close to this definition are the cryogenic geosystems of
Melnikov et al. [62].
Gavrilova [
63
] determined which climatic parameters—the mean annual air tem-
perature, the average temperature of the coldest month, and the freezing and thawing
indices—are characteristic of landscapes of continuous, discontinuous, and sporadic dis-
tribution of permafrost zones. She also indicated the regional features: what climatic
parameters are typical for northern Eurasia, Canada, Alaska, and Fennoscandia, as well as
for the regions of Russia, such as the European territory, western and eastern Siberia, the
mountainous regions of Siberia, and the Far East.
Popov [
64
,
65
] proposed an independent type of lithogenesis–cryolithogenesis, and
Katasonov [
66
] proposed cryolithogenic formations as the basis for identifying permafrost
landscapes by their cryogenic structure and ground ice content (for example, yedoma, alas,
foothill–glacial, etc.). Furthermore, the following criteria can serve as lithological-facies
complexes: homogeneous lithological complexes in sediment composition [67].
Vegetation cover significantly influences the temperature distribution of the permafrost
and active layer thickness. The role of biogenic factors is essential in the functioning and
development of permafrost landscapes. At the present stage of environmental develop-
ment, human influence greatly affects the functioning of landscapes. Technogenic distur-
bances cause the activation of cryogenic processes, leading to restructuring of permafrost
landscapes. Permafrost conditions change significantly in technogenic systems, such as
industrial complexes, reclamation systems, agricultural lands, etc. These complexes belong
to anthropogenic (technogenic) landscapes [68,69].
The relationship between landscape morphological features and permafrost character-
istics is powerful, and this is especially true for the environmental problems of permafrost.
Therefore, the permafrost landscape, which is a complex territorial interweaving of envi-
ronmental components, ensures the equilibrium state of the natural environment in the
permafrost zone or tends to do so after a disturbance.
The permafrost landscape should be characterized by the properties of permafrost. A
distinctive feature of permafrost landscapes is that complexes with different permafrost
characteristics, such as differences in the development of ice wedges or contrasting ground
temperatures (−4 or −1◦C), represent other classification units [43].
Permafrost is the main system-forming factor. Changes in ground temperature and
active layer thickness, ice content, and cryogenic processes determine the state of the
permafrost landscape, which can lead to a loss of stability.
4. Permafrost Landscape Mapping
Normal mapping of permafrost landscapes in northeastern Eurasia began in the 1980s.
However, this was preceded by pre-landscape mapping based on physical–geographical
generalizations; these were geomorphological maps. A classic example of permafrost

Earth 2022,3464
studies based on geomorphological units is Soloviev’s work on the permafrost zone in
Central Yakutia [
14
], which is still in great demand. Ivanov [
18
] used geomorphologi-
cal zoning to assess the distribution of ground ice and the sensitivity of the surface to
anthropogenic impacts.
The ground temperature and permafrost thickness were analyzed by Nekrasov [
17
]
using landscape zonality in northeastern and southern Siberia. The schematic maps of
Nekrasov well reflect the patterns of permafrost distribution in various mountainous areas
of this immense territory.
Grave [
57
] drew up a scheme for zoning the territory of Yakutia according to the degree
of sensitivity of the surface to technogenic impacts. The accumulative plains of the Novosi-
birsk Islands and the Primorskaya lowland, with the development of thick ground ice up to
50–80 m, occupied by tundra and forest–tundra, were classified as highly vulnerable areas.
Plains, foothill and intermountain depressions, plateaus with the development of thick
underground ice up to 40 m with tundra and northern and middle taiga were classified as
moderately sensitive areas. Slightly sensitive areas are developed in mountains and high
plateaus with low ice deposits. The monograph “Surface Disturbance and Its Protection
during the Development of the North” [
6
] became the basis for environmental work in
northeastern Eurasia. The relevance of this work has increased in recent decades because
of the activation of cryogenic processes in the conditions of modern climate warming.
There are works on this topic by geomorphologists [
70
–
73
], geocryologists [
74
–
79
],
soil scientists [
80
–
85
], and botanists [
86
–
93
]. The physical–geographic zoning studies of
Mikhailov [
94
], Parmuzin [
95
,
96
], Mikheev and Pavlov [
97
], and others created the basis
for modern schemes of permafrost landscape zoning of northeastern Eurasia.
Vasiliev’s monograph, “Regularities of seasonal thawing of soils in Eastern Yaku-
tia” [
48
], is practically a permafrost landscape work, although landscape classifications were
not used. Like previous works, this study of one of the permafrost’s main characteristics—
the active layer’s depth spatial distribution—was carried out based on the physical–
geographic systematics of relief, soils, and vegetation. Compiled by Vasiliev, the “Map
of thawing soils of Eastern Yakutia” at a scale of 1:2,500,000 [
48
], presented as an inset
map to the monograph, is of value for studying permafrost landscapes. The primary
method was the imposition of two layers: geological–genetic complexes with a specific
lithological composition of 23 units and plant groups of 20 units. The map perfectly re-
flects both the latitude-zonal and altitudinal-zonal differentiation of vegetation and the
active layer thickness. This work is considered the first permafrost landscape work on
northeastern Eurasia.
Further permafrost landscape studies were carried out regularly. The monograph
“Permafrost landscapes of the development zone of the Lena-Aldan interfluve” [
49
] became
one of the first significant works on permafrost landscape studies. The monograph was
devoted to frozen landscapes and was written based on two years of field research materials
along the Tommot-Nizhny Bestyakh railway development zone (Yakutsk). The studies
were carried out at the level of terrain types (subtypes), with their identification based
on stratigraphic–genetic complexes (alluvium Q
4
, alluvium Q
2–3
, lacustrine-alluvial Q
2–3
,
eluvial Q
4
, etc.), each with a peculiar complex of ground and vegetation. Ten physical–
geographical regions were distinguished by a relatively homogeneous terrain type (subtype)
combination. Each type (subtype) of terrain in the region was assessed by sensitivity to the
activation of cryogenic processes after disturbances. Attached to the monograph was an
inset map, “Landscape-cryoindication map of the development zone of the Lena-Aldan
interfluve” from Tommot to Yakutsk, with the allocation of types (subtypes) of terrain and
regions with a table of permafrost landscape characteristics.

Earth 2022,3465
In the late 1980s and early 1990s, the Melnikov Permafrost Institute compiled a per-
mafrost and landscape map of the Yakut ASSR at a scale of 1:2,500,000 [
50
], with an
extensive explanatory note [
51
]. The map reflected 22 terrain types in terms of geological
and geomorphological features and 26 types (subtypes) of landscapes in terms of bio-
climatic features. The types of terrain—inter-alas, alas, moraine, outwash, low terrace,
glacier-water-valley, upland, slope, etc.—differed in stratigraphic–genetic complexes, cryo-
genic structures, and volumetric ice content of surface deposits. The types (subtypes) of
landscapes were characterized by relatively similar climate characteristics: freezing and
thawing indices, types of vegetation, and their productivity. Ground temperatures and
active layer thickness were systematized by overlaying the terrain types and landscape
types (subtypes). Thus, each landscape classification unit was characterized by specific
combinations of permafrost parameters. Such a classification showed a close combination
of landscape and permafrost conditions necessary for environmental assessments.
Based on combinations of terrain types and landscape types (subtypes) and geo-
logical and geomorphological structures, the permafrost landscape zoning of the Yakut
ASSR territory was compiled. A total of 54 permafrost landscape provinces were identi-
fied, with relatively homogeneous combinations of terrain types and types (subtypes) of
landscapes in three physiographic regions: central Siberia, northeastern Siberia, and the
mountains of southern Siberia. In addition to methodological descriptions of the map-
ping, the explanatory table contained a landscape cadaster comprising a combination of
geological, geomorphological, soil, and plant characteristics in types of terrain in each
of the 54 permafrost landscape provinces. Thus, the map and the explanatory note have
become reference material for those interested in the permafrost and landscape conditions
of Yakutia.
In addition, many permafrost landscape maps of various scales were compiled for
various developed territories of Yakutia. Map scales varied from detailed (1:5000–1:25,000)
to medium scale (1:100,000–1:300,000) to small scale (1:500,000–1:2,500,000). Large-scale
maps reflected permafrost landscape conditions at the taxonomic level of a facies
[98–100]
,
medium-scale maps reflected at the level of terrain types (subtypes) [
101
–
103
], and small-
scale maps overlaying terrain and landscape types [104].
In 2018, the Melnikov Permafrost Institute team updated the permafrost landscape
map [
50
] to receive new permafrost data based on satellite images and a change in the
mapping technology: the transition to GIS technologies (Figure 1). The new permafrost
landscape map of the Republic of Sakha (Yakutia) at a scale of 1:1,500,000 [
105
] showed
partially change classification, both in types of terrain and in types (subtypes) of landscapes
such as groups of vegetation. The authors identified 20 terrain types. The main difference
was that the types of terrain were not distinguished into plain and mountainous when the
stratigraphic–genetic complexes of surface deposits were the same. Instead of the types
(subtypes) of landscapes, the authors used plant groups to better show the contrast between
ground temperature and the active layer thickness. The total number of vegetation groups
was 36. The map legend shows 145 permafrost landscapes—combinations of terrain types
and plant groups—compared with 87 permafrost landscapes on the 1991 map.
Using GIS technologies, Shestakova et al. [
55
] modeled individual maps of ground
temperature, active layer thickness, ice content of surface deposits (Figure 2), and cryogenic
processes using the permafrost landscape map [
51
]. Previously, permafrost temperature
interpretations had also been modeled based on the permafrost landscape map of the Yakut
ASSR at a scale of 1:2,500,000 [
39
–
41
]. Along with permafrost landscape maps, permafrost
maps were compiled, which are necessary to determine the degree of vulnerability of
permafrost landscapes. These works include the assessment and sensitivity of carbon
accumulations in the permafrost of northeastern Yakutia [
106
], the assessment of the
stability and degradation of permafrost in eastern Chukotka [
107
,
108
], and maps of yedoma
in northeastern Eurasia and North America [109].

Earth 2022,3466
Earth 2022, 3, 7
Figure 1. Permafrost landscape map of the Republic of Sakha (Yakutia) on a scale of 1:1,500,000
[105].
Figure 1.
Permafrost landscape map of the Republic of Sakha (Yakutia) on a scale of 1:1,500,000 [
105
].

Earth 2022,3467
Earth 2022, 3, 8
Figure 2. Ice content of surface deposits map [55] based on the permafrost landscape map of the
Republic of Sakha (Yakutia) on a scale of 1:1,500,000 [51].
5. Study of the Dynamics and Evolution of Permafrost Landscapes
The study of the dynamics and evolution of permafrost landscapes in northeastern
Eurasia has been widely developed. A characteristic study of the dynamics of permafrost
landscapes is that of the stages of development of thermokarst landforms. The applicabil-
ity of the Yakut names in classifying the stages of thermokarst development was first no-
ticed by Efimov and Grave [110]. They noted that the initial thermokarst subsidence in its
further development turns into “eie”, subsided depressions, where the grooves between
the hillocks are filled with water. The next stage in thermokarst development is the
“duede”—a rounded lake with low but steep banks and high-centered polygons in the
Figure 2.
Ice content of surface deposits map [
55
] based on the permafrost landscape map of the
Republic of Sakha (Yakutia) on a scale of 1:1,500,000 [51].
5. Study of the Dynamics and Evolution of Permafrost Landscapes
The study of the dynamics and evolution of permafrost landscapes in northeastern
Eurasia has been widely developed. A characteristic study of the dynamics of permafrost
landscapes is that of the stages of development of thermokarst landforms. The applicability
of the Yakut names in classifying the stages of thermokarst development was first noticed
by Efimov and Grave [
110
]. They noted that the initial thermokarst subsidence in its
further development turns into “eie”, subsided depressions, where the grooves between
the hillocks are filled with water. The next stage in thermokarst development is the
“duede”—a rounded lake with low but steep banks and high-centered polygons in the

Earth 2022,3468
bottom. Over time, the “duede” turns into a water-filled lake with a flat bottom and steep
banks. The subsided lake eventually turns into an alas.
Later, Soloviev [
14
] supplemented and improved this classification of thermokarst
landforms (Figure 3). He singled out the following stages:
Earth 2022, 3, 9
bottom. Over time, the “duede” turns into a water-filled lake with a flat bottom and steep
banks. The subsided lake eventually turns into an alas.
Later, Soloviev [14] supplemented and improved this classification of thermokarst
landforms (Figure 3). He singled out the following stages:
(a) (b)
(c) (d)
(e)
Figure 3. Stages of thermokarst landforms (Central Yakutia). (a)—bylar, (b)—eie, (c)—duede, (d)—
tympy, (e)—alas.
(1) The initial bylar—slightly lowered areas deformed by separate subsidence holes and
troughs.
(2) Bylar—lowered areas where the troughs connected, forming a high-centered poly-
gon depression.
(3) Eie is a high-centered polygon depression. In the eie, the troughs between the hillocks
are filled with water [110].
(4) Duede is a depression with pronounced banks, with high-centered polygons at the
bottom and banks. Efimov and Grave [110] noted that it is filled with water.
(5) Tympy is the first stage of alas. The underground ice at the bottom of the basin
melted. The floor of the depression is leveled by alas sediments. The depression is
Figure 3.
Stages of thermokarst landforms (Central Yakutia). (
a
)—bylar, (
b
)—eie, (
c
)—duede,
(d)—tympy, (e)—alas.
(1)
The initial bylar—slightly lowered areas deformed by separate subsidence holes
and troughs.
(2)
Bylar—lowered areas where the troughs connected, forming a high-centered poly-
gon depression.
(3) Eie is a high-centered polygon depression. In the eie, the troughs between the hillocks
are filled with water [110].
(4)
Duede is a depression with pronounced banks, with high-centered polygons at the
bottom and banks. Efimov and Grave [110] noted that it is filled with water.
(5) Tympy is the first stage of alas. The underground ice at the bottom of the basin melted.
The floor of the depression is leveled by alas sediments. The depression is sharply
expressed. Usually, tympy is a completely subsided depression with a full lake [
110
].

Earth 2022,3469
(6)
Alas is a depression with a relatively flat, leveled floor and steep, sharply defined
banks. Evaporation of water forms alas from the tympy [110].
We placed the classification of thermokarst landscapes before the formation of alas.
At the same time, Soloviev [
14
] identified the further development of the alas relief from
elementary alas to complex alas, mature alas with bulgunnyakh (pingo), marginal alas,
khonu, and a relict post-alas basin. To this classification, one can add “bajdzherakhs”—
thermokarst-erosion landforms on the slopes of alas (river valleys and seacoasts) formed
when ice wedges thaw. Thanks to the classifications of Efimov and Grave [
110
] and
Soloviev [
14
], we have a coherent dynamic classification of the thermokarst landscape. In
the English language scientific literature, this classification was first described by Czudek
and Demek [111] with reference to Soloviev [112].
Permafrost landscape conditions are used in paleogeographic studies. Here, we can
trace the evolution of landscapes over a long period of development, as some landscape and
climatic conditions have been replaced by others [
113
–
117
]. During periods of warming
in northeastern Eurasia, larch woodlands with an admixture of spruce developed in the
modern tundra zone. In the contemporary larch middle taiga, larch forests combined with
spruce and pine forests grew. During periods of cooling in central Yakutia, the areas of
yerniks increased, and in Allered (until 11,500 years ago), tundra-steppes dominated.
Based on the work of palaeogeographers, we assessed permafrost conditions during
periods of Holocene warming [
118
]. The optimum ground temperature in the Holocene in
the tundra areas was 5–6.5
◦
C warmer than at present (before the current warming, or before
1980), in the northern taiga by 2.5–4
◦
C, and in the middle taiga by 1.5–2.5
◦
C. In assessing
the evolution of permafrost conditions in eastern Siberia in the Pleistocene–Holocene, one
can be guided by the work of Fotiev [
119
], which is based on the interpretation of the Baikal
chronicle of diatom deposits [120].
Permafrost landscape studies have played a significant role in determining the modern
dynamics of the natural environment during disturbances, primarily during forest fires and
deforestation. Restorative successions after disturbance reflect the restoration of permafrost
conditions. The characteristics of successional stages in the development of permafrost
landscapes and their duration have been determined [
98
,
121
–
123
]. In central Yakutia, the
complete restoration of the permafrost landscape after disturbance takes 120–130 years.
Detailed studies on the succession’s influence on the active layer thickness in central Yakutia
were carried out by Gabysheva (Lytkina) [
35
,
124
,
125
]. The study of succession stages of
development served as the basis for mapping the dynamic state of permafrost [53].
At the Neleger Station near Yakutsk City in central Yakutia, the Melnikov Permafrost
Institute experimented with clear-cutting a larch forest and studied the initial stage of
restorative succession though a detailed assessment of the dynamics of permafrost con-
ditions [
126
,
127
]. An increase in the productivity of biota serves to restore permafrost
conditions after disturbances and to measure the impact of succession stages on the state
of permafrost landscapes. To assess the aforementioned impact, boreal forests must be
studied [
128
–
131
]. Our observations in central Yakutia showed that under the conditions
of modern climate warming, successions cause a decrease in permafrost temperature [
123
],
which is quite natural.
Some researchers have noted a weak response of boreal permafrost landscapes to cli-
mate warming through ground temperature and active layer thickness and have attributed
this to the snow accumulation regime [
132
,
133
]. However, in their works, they did not
consider the biological component of the permafrost landscape, which can influence active
layer thickness.
The permafrost landscape features of the territories have impacted the increase in soil
temperature during the current climate warming. Thus, there has been an increase in soil
temperature from average long-term values of 0.5
◦
C in central Yakutia to 2–3
◦
C in Arctic
Yakutia [
134
,
135
]. Such changes have led to the degradation of permafrost landscapes on
ice-rich permafrost (Figure 4). Many researchers have noted the more intense response of
tundra permafrost landscapes, especially in the formation and expansion of thermokarst

Earth 2022,3470
lakes [
136
–
138
]. Boike et al. [
139
] identified changes in lake areas, vegetation, land surface
temperatures, and the area covered by snow using data from remote sensing. Such changes
will undoubtedly have an impact on the state of permafrost landscapes.
Earth 2022, 3, 11
Arctic Yakutia [134,135]. Such changes have led to the degradation of permafrost land-
scapes on ice-rich permafrost (Figure 4). Many researchers have noted the more intense
response of tundra permafrost landscapes, especially in the formation and expansion of
thermokarst lakes [136–138]. Boike et al. [139] identified changes in lake areas, vegetation,
land surface temperatures, and the area covered by snow using data from remote sensing.
Such changes will undoubtedly have an impact on the state of permafrost landscapes.
(a) (b)
Figure 4. Ice-wedge exposure (a) and abandoned arable land from thermokarst development in the
ice-rich permafrost (b) near the Syrdakh settlement in central Yakutia.
The change in soil and vegetation cover determines the dynamic state of the perma-
frost landscape and the evolution of the environment. It is also essential for predicting the
change in permafrost in the context of global warming.
Lapenis et al. [140] noted that the biomass of green parts (leaves, needles, understory,
and green forest floor) had a steady upward trend from 1960–2000 during modern climate
change. Analysis of satellite data revealed a slight increase in the normalized difference
vegetation index (NDVI) in northern Eurasia. The development of biota productivity can
slow down the increase in ground temperature and active layer thickening in boreal land-
scapes because vegetation cover is a good heat insulator [141,142].
For example, an increase of 158% in tundra sedge meadow productivity in Canada’s
Arctic zone from 1980 to 2005, with an average increase in the mean annual air tempera-
ture by 0.8 °C per decade, resulted in a statistical decrease in the active layer thickness
from 76.8 ± 8.1 cm in the 1980s to 76.1 ± 10.6 cm in 2005 [143]. This explains the stable state
of active layer thickness obtained during the long-term monitoring of permafrost boreal
landscapes in central Yakutia from 1982 to 2012 [32]. A noticeable growth of annual larch
rings during the period of Arctic warming in the 1930s–1940s and a decrease in its growth
rates in the 1940s–1980s [144,145], noted during periods of warming and cooling of the
climate, reflect the impact of changes in biota productivity on the state of permafrost con-
ditions.
Changes in the organic material in permafrost soils are taken into account in geocry-
ological modeling [142]. In Yakutia, experimental work was carried out in the tundra near
the town of Chokurdakh in Yakutia, which found that shrub expansion may reduce per-
mafrost thaw in summer [146]. In the alases of central Yakutia, the temperature regimes
of soils in meadows with different biomasses were determined [147], as well as change
patterns during successions in boreal forests after the disturbance [123].
The stability of permafrost landscapes depends not only on permafrost conditions,
but also on the dynamics and evolution of biota. The widespread activation of forest fires
in northeastern Eurasia during climate warming in recent decades has caused a disruption
of the permafrost temperature regime and the subsequent development of restorative suc-
cessions. Permafrost disturbances cause an imbalance in greenhouse gases, illustrating the
dynamism of changes in permafrost landscapes. In the permafrost landscapes of Yakutia,
Figure 4.
Ice-wedge exposure (
a
) and abandoned arable land from thermokarst development in the
ice-rich permafrost (b) near the Syrdakh settlement in central Yakutia.
The change in soil and vegetation cover determines the dynamic state of the permafrost
landscape and the evolution of the environment. It is also essential for predicting the change
in permafrost in the context of global warming.
Lapenis et al. [
140
] noted that the biomass of green parts (leaves, needles, understory,
and green forest floor) had a steady upward trend from 1960–2000 during modern climate
change. Analysis of satellite data revealed a slight increase in the normalized difference
vegetation index (NDVI) in northern Eurasia. The development of biota productivity
can slow down the increase in ground temperature and active layer thickening in boreal
landscapes because vegetation cover is a good heat insulator [141,142].
For example, an increase of 158% in tundra sedge meadow productivity in Canada’s
Arctic zone from 1980 to 2005, with an average increase in the mean annual air temperature
by 0.8
◦
C per decade, resulted in a statistical decrease in the active layer thickness from
76.8 ±8.1 cm
in the 1980s to 76.1
±
10.6 cm in 2005 [
143
]. This explains the stable state of
active layer thickness obtained during the long-term monitoring of permafrost boreal land-
scapes in central Yakutia from 1982 to 2012 [
32
]. A noticeable growth of annual larch rings
during the period of Arctic warming in the 1930s–1940s and a decrease in its growth rates
in the 1940s–1980s [144,145], noted during periods of warming and cooling of the climate,
reflect the impact of changes in biota productivity on the state of permafrost conditions.
Changes in the organic material in permafrost soils are taken into account in geocry-
ological modeling [
142
]. In Yakutia, experimental work was carried out in the tundra
near the town of Chokurdakh in Yakutia, which found that shrub expansion may reduce
permafrost thaw in summer [
146
]. In the alases of central Yakutia, the temperature regimes
of soils in meadows with different biomasses were determined [
147
], as well as change
patterns during successions in boreal forests after the disturbance [123].
The stability of permafrost landscapes depends not only on permafrost conditions, but
also on the dynamics and evolution of biota. The widespread activation of forest fires in
northeastern Eurasia during climate warming in recent decades has caused a disruption
of the permafrost temperature regime and the subsequent development of restorative
successions. Permafrost disturbances cause an imbalance in greenhouse gases, illustrating
the dynamism of changes in permafrost landscapes. In the permafrost landscapes of
Yakutia, studies are being carried out on both carbon dioxide [
148
–
151
] and methane
content in permafrost [152–154] and their emissions [155–159].

Earth 2022,3471
The degradation processes of permafrost and the restoration of native landscapes re-
quire developing adaptation measures to life in these new conditions. Permafrost landscape
studies can benefit this development. Recently, suggestions for permafrost temperature
management by controlled grazing to ensure permafrost sustainability and reduce green-
house gas emissions have attracted interest [147,160–162].
6. Summary
Permafrost landscape studies, based on the theoretical developments of Soviet physical
geographers and landscape scientists, have become widespread in Russia. Over the past
four decades, permafrost landscape studies have been carried out widely on northeastern
Eurasia. This review summarizes the main results of these studies. The main conclusions
relate to the development of three directions, the main essence of which is as follows:
(1)
Identifying the permafrost landscape as an object of study complements the theory of
landscape science that was strongly developed in the Soviet Union (later in Russia).
The parameters of the cryogenic factor have been proposed as criteria for identifying
taxonomic units and classifying permafrost landscapes.
(2)
The development of permafrost landscape studies made it possible to create mapping
based on the classification of permafrost landscapes. Different scale permafrost
landscape maps were created that reflected the unity of the morphological parts of the
landscape and permafrost. Permafrost landscape maps are mainly used to identify
patterns of permafrost differentiation in the environmental assessment in the North.
(3)
Permafrost landscapes serve the purpose of illustrating the dynamics and evolution
of permafrost. The successional stages in the development of permafrost landscapes
indicate permafrost dynamics after disturbances; long-term changes in landscapes
relate to permafrost evolution.
Prospects for the study of permafrost landscapes in northeastern Eurasia will primarily
involve an assessment of environmental vulnerability and the adaptation of socioeconomic
conditions to modern climate warming. Understanding the concept of the permafrost
landscape, which connects all the components of the system [
43
], can solve this problem.
To do this, it is first necessary to systematize the available data. Permafrost landscape
zoning has served as the basis for compiling a cadaster of permafrost landscapes [
51
], and
it is now the basis for compiling a database of geocryological data of different scales that
will ensure environmental protection measures and adaptation in conditions of climate
change. Second, we must determine the development trends in permafrost landscapes and
permafrost in general, such as which permafrost landscapes will be the most vulnerable to
modern climate warming and anthropogenic impacts, and whether there are any mecha-
nisms for permafrost conservation. Third, it is important to determine ways of adapting
socioeconomic conditions to changes in permafrost. We see the development of permafrost
landscape research proceeding in these directions.
Funding: This work received no external funding.
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement:
Permafrost landscape maps of the Republic of Sakha (Yakutia) are
available online at https://mpi.ysn.ru/en/publications/maps (accessed on 10 March 2022).
Acknowledgments:
I thank the editors and anonymous reviewers for their helpful comments, which
improved the manuscript.
Conflicts of Interest: The author declares no conflict of interest.

Earth 2022,3472
References
1. Tumel, V.F. About permafrost survey. Izv. AN USSR Ser. Geogr. Geophys. 1945,9, 135–144. (In Russian)
2.
Baranov, I.Y. Goals, and objectives of geocryological survey. In Field Geocryological (Permafrost) Research; Publishing House of the
Academy of Sciences of the USSR: Moscow, Russia, 1961; pp. 15–36. (In Russian)
3.
Kudryavtsev, V.A. Permafrost survey as the main type of permafrost research. In Permafrost Research; Kudryavtsev, V.A., Ed.;
Moscow State University: Moscow, Russia, 1961; Issue 1, pp. 3–10. (In Russian)
4. Washburn, A.L. Periglacial Processes and Environment; St. Martin’s Press: New York, NY, USA, 1973; p. 320.
5. French, H.M. The Periglacial Environment, 3rd ed.; Wiley: New York, NY, USA, 2007; p. 458.
6.
Brown, J.; Grave, N.A. The Surface Disturbance and its Protection at Reclamation of North; Nauka: Novosibirsk, Russia, 1981; p. 88.
(In Russian)
7.
Tyrtikov, A.P. The Influence of Vegetation on Freezing and Thawing of Soils; Moscow State University: Moscow, Russia, 1969; p. 192.
(In Russian)
8.
Tyrtikov, A.P. Vegetation Dynamics and Development of Permafrost in Western Siberia; Moscow State University: Moscow, Russia,
1974; p. 198. (In Russian)
9. Tyrtikov, A.P. Vegetation Dynamics and Development of Permafrost Landforms; Nauka: Moscow, Russia, 1979; 116p. (In Russian)
10.
Melnikov, E.S.; Veisman, L.I.; Kritsuk, L.N.; Moskalenko, N.G.; Tagunova, L.N.; Todosiichuk, I.V. Landscape Indicators of Engineering
Geocryological Condition of the North of the Western Siberia and Their Interpretive Signs; Nedra: Moscow, Russia, 1974; p. 132.
(In Russian)
11.
Melnikov, E.S.; Kritsuk, L.N.; Moskalenko, N.G. Landscape-Indication Method for Engineering-Geocryological Research in
Western Siberia. In Landscape Indication of Natural Processes; Nauka: Moscow, Russia, 1976; pp. 88–95. (In Russian)
12.
Melnikov, E.S.; Veisman, L.I.; Moskalenko, N.G.; Tagunova, L.N.; Ukraintseva, N.G.; Chekrygina, S.N.; Ananieva, G.V.;
Goralchuk, M.I.
; Kritsuk, L.N.; Lazareva, N.A.; et al. Landscapes of Cryolithozone of the West Siberian Gas-Bearing Province; Nauka:
Novosibirsk, Russia, 1983; p. 165. (In Russian)
13.
Konstantinova, G.S. Permafrost and landscapes. In Second Intern. Conf. Permafrost. Reports And Messages. Issue. 2. Regional
Geocryology; Book Publishing House: Yakutsk, Russia, 1973; pp. 116–120. (In Russian)
14.
Soloviev, P.A. The Cryolithozone of Northern Part of the Lena-Amga Interfluve; Academy of Sciences: Moscow, Russia, 1959; p. 144.
(In Russian)
15. Lugovoi, P.N. Features of the Mountain Permafrost Regions Condition; Nauka: Moscow, Russia, 1970; p. 135. (In Russian)
16.
Fotiev, S.M.; Danilova, N.S.; Sheveleva, N.S. Geocryological Conditions of the Middle Siberia; Nauka: Moscow, Russia, 1974; p. 148.
(In Russian)
17.
Nekrasov, I.A. Permafrost of the North-East and the South of Siberia and the Regularities of Its Development; Book Publishing House:
Yakutsk, Russia, 1976; p. 246. (In Russian)
18.
Ivanov, M.S. The Cryogenic Structure of Quarternary Deposits of the Leno-Aldan Depression; Nauka: Novosibirsk, Russia, 1984; p. 125.
(In Russian)
19.
Lazukova, G.G. Use of vegetation as indicators of permafrost conditions. Bulletin of Moscow State University, Ser. 5. Geography
1967,4, 54–58. (In Russian)
20.
Moskalenko, N.G. On the influence of vegetation disturbances on the dynamics of seasonal thawing of soils in the northern taiga
of Western Siberia. In Landscape Indication of Natural Processes; Chikishev, A.G., Ed.; Nauka: Moscow, Russia, 1976; pp. 144–149.
(In Russian)
21.
Moskalenko, N.G. Landscape research in the tundra of the Tazovsky Peninsula. In Proceedings Of VSEGINGEO: Regional
Geocryological Research; Zilberbord, A.F., Gravis, G.F., Eds.; VSEGINGEO: Moscow, Russia, 1977; Volume 113, pp. 50–58.
(In Russian)
22.
Moskalenko, N.G. Anthropogenic Dynamics of Vegetation in the Plains of the Russian Permafrost; Nauka: Novosibirsk, Russia, 1999;
p. 280. (In Russian)
23.
Solntsev, N.A. On the morphology of the natural geographical landscape. In Questions of Geography; Baransky, N.N., Ed.;
Geografgiz: Moscow, Russia, 1949; Volume 16, pp. 61–96. (In Russian)
24. Isachenko, A.G. Landscape Science and Physical-Geographical Zoning; Higher School: Moscow, Russia, 1965; p. 328. (In Russian)
25. Milkov, F.N. Landscape Geography and Practice Questions; Mysl: Moscow, Russia, 1966; p. 156. (In Russian)
26. Armand, D.L. Landscape Science; Mysl: Moscow, Russia, 1975; p. 287. (In Russian)
27. Sochava, V.B. Introduction to the Study of Geosystems; Nauka: Novosibirsk, Russia, 1978; p. 318. (In Russian)
28.
Melnikov, E.S. Scientific Bases and Methods of Regional Engineering-Geological Studies of Cryolithozone’s Plains (on the Example
of Western Siberia). Ph.D. Thesis, VSEGINGEO, Moscow, Russia, 1985; p. 44. (In Russian).
29.
Melnikov, E.S.; Goralchuk, M.I.; Kritsuk, L.N.; Ananieva, G.V.; Andrianov, V.N.; Veisman, L.I.; Drozdov, D.S.; Nevecherya, V.L.;
Tagunova, L.N.; Ukraintseva, N.G.; et al. Geocryological Conditions of the West Siberian Gas-Bearing Province; Melnikov, E.S., Ed.;
Nauka: Novosibirsk, Russia, 1983; p. 199. (In Russian)

Earth 2022,3473
30.
Grechischev, S.E.; Moskalenko, N.G.; Shur, Y.L.; Slavin-Borovsky, V.B.; Nevecherya, V.L.; Melnikov, E.S.; Kritsuk, L.N.;
Sheshin, Y.B.
; Veisman, L.I.; Malevsky-Malevich, S.P.; et al. Geocryological Forecast for the West Siberian Gas-Bearing Province;
Grechischev, S.E., Ed.; Nauka: Novosibirsk, Russia, 1983; p. 182. (In Russian)
31.
Drozdov, D.S.; Ukraintseva, N.G.; Tsarev, A.M.; Chekrygina, S.N. Changes in the temperature field of permafrost and the state of
geosystems on the territory of the Urengoy field over the past 35 years (1974–2008). Earth Cryosphere
2010
,14, 22–31. (In Russian)
32.
Varlamov, S.; Skachkov, Y.; Skryabin, P. Current climate change effects on the ground thermal regime in Central Yakutia. Sci. Cold
Arid. Reg. 2014,6, 282–292.
33.
Osadchaya, G.G. Permafrost Landscapes of the Bolshezemelskaya Tundra as a Basis for Rational Nature Management. Ph.D.
Thesis, Yakutsk University, Ukhta, Russia, 2018; p. 35. (In Russian).
34.
Tumel, N.; Zotova, L. Diagnostics and Mapping of Geoecological Situations in the Permafrost Zone of Russia. Geosciences
2019
,
9, 353. [CrossRef]
35.
Lytkina, L.P. Post-fire dynamics of forest growth conditions in the larch forests of Central Yakutia. Geogr. Nat. Resour.
2008
,2,
181–185. (In Russian)
36.
Nikolaev, A.N. Dendrochronological Analysis of Natural Processes in the Cryolithozone (on the Example of Central Yakutia).
Ph.D. Thesis, Yakutsk University, Yakutsk, Russia, 2011; p. 40. (In Russian).
37. Isaev, A.P. Stability of permafrost forests to anthropogenic factors. Successes Mod. Nat. Sci. 2012,11, 41–43. (In Russian)
38.
Iijima, Y.; Fedorov, A.N. Permafrost-Forest Dynamics. In Ecological Studies. Analysis and Synthesis. Vol. 236. Water and Carbon
Dynamics in Eastern Siberia; Takeshi, O., Ed.; Springer Nature: Singapore, 2019; pp. 175–206.
39.
Romanovsky, V.E.; Sazonova, T.S.; Balobaev, V.T.; Shender, N.I.; Sergueev, D.O. Past and recent changes in air and permafrost
temperatures in eastern Siberia. Glob. Planet. Chang. 2007,56, 399–413. [CrossRef]
40.
Beer, C.; Fedorov, A.N.; Torgovkin, Y. Permafrost temperature and active-layer thickness of Yakutia with 0.5-degree spatial
resolution for model evaluation. Earth Syst. Sci. Data 2013,5, 305–310. [CrossRef]
41.
Beer, C.; Porada, P.; Ekici, A.; Brakebusch, M. Effects of short-term variability of meteorological variables on soil temperature in
permafrost regions. Cryosphere 2018,12, 741–757. [CrossRef]
42.
Li, A.; Xia, C.; Bao, C.; Yin, G. Using MODIS Land Surface Temperatures for Permafrost Thermal Modeling in Beiluhe Basin on
the Qinghai-Tibet Plateau. Sensors 2019,19, 4200. [CrossRef] [PubMed]
43.
Fedorov, A.N. Permafrost Landscapes of Yakutia. Classification and Mapping Issues; Permafrost Institute: Yakutsk, Russia, 1991; p. 140.
(In Russian)
44. Murton, J.B. What and where are periglacial landscapes? Permafr. Periglac. Process. 2021,32, 186–212. [CrossRef]
45.
van Everdingen, R. Multi-language glossary of permafrost and related ground-ice terms. In National Snow and Ice Data Center/World
Data Center for Glaciology; World Wide Web Adress: Boulder, CO, USA, 2005.
46.
Grave, N.A. On improving the efficiency of environmental protection measures in the permafrost region. In Methodological
Problems of the Development of Science in the Region; Derevyanko, A.P., Solomonov, N.G., Eds.; Nauka: Novosibirsk, Russia, 1987;
pp. 129–137. (In Russian)
47.
Zolnikov, V.G. Topography and soil forming deposits in the eastern part of Central Yakutia. In Materials on Environmental
Conditions and Agriculture in Central Yakutia; Academy of Science USSR: Moscow, Russia, 1954; Issue 1, pp. 7–54. (In Russian)
48. Vasiliev, I.S. The Regularities Seasonal Thawing in Eastern; Nauka: Novosibirsk, Russia, 1982; p. 133. (In Russian)
49.
Bosikov, N.P.; Vasiliev, I.S.; Fedorov, A.N. Permafrost Landscapes of Reclaimed Zone of Leno-Aldan Interfluve; Permafrost Institute:
Yakutsk, Russia, 1985; p. 124. (In Russian)
50.
Fedorov, A.N.; Botulu, T.A.; Vasiliev, I.S.; Varlamov, S.P.; Gribanova, S.P.; Dorofeev, I.V. Permafrost-Landscape Map of the Yakut ASSR,
Scale 1:2,500,000; Melnikov, P.I., Ed.; Gosgeodezia: Moscow, Russia, 1991; 2 Sheet. (In Russian)
51.
Fedorov, A.N.; Botulu, T.A.; Varlamov, S.P.; Vasiliev, I.S.; Gribanova, S.P.; Dorofeev, I.V.; Klimovsky, I.V.;
Samsonova, V.V.
;
Soloviev, P.A.
Permafrost Landscapes in Yakutia. Explanation Note to the Permafrost-Landscape Map of the Yakut ASSR at a
1:2,500,000 Scale; GUGK: Novosibirsk, Russia, 1989; p. 170. (In Russian)
52.
Gorokhov, A.N.; Fedorov, A.N.; Skorve, J.; Makarov, V.S. Assessment of anthropogenic variability of landscapes in the vicinity of
the Churapcha setttlement (Central Yakutia) based on remote sensing data. Probl. Reg. Ecol. 2011,4, 7–13. (In Russian)
53.
Shestakova, A.A. Mapping of Permafrost Landscapes Taking into Account Vegetation Successions (on the Example of the
Prilensky Plateau). Ph.D. Thesis, Permafrost Institute, Yakutsk, Russia, 2011; p. 20. (In Russian).
54.
Kalinicheva, S.V.; Fedorov, A.N.; Zhelezniak, M.N. Mapping Mountain Permafrost Landscapes in Siberia Using Landsat Thermal
Imagery. Geosciences 2018,9, 4. [CrossRef]
55.
Shestakova, A.; Fedorov, A.; Torgovkin, Y.; Konstantinov, P.; Vasyliev, N.; Kalinicheva, S.; Samsonova, V.; Hiyama, T.; Iijima, Y.;
Park, H.; et al. Mapping the Main Characteristics of Permafrost on the Basis of a Permafrost-Landscape Map of Yakutia Using
GIS. Land 2021,10, 462. [CrossRef]
56.
Grave, N.A. Sensitivity of the surface to technogenic impact in the permafrost region, techniques and methods for reflecting it
on maps. In Methods of Engineering-Geological Research and Mapping of the Permafrost Region; Kudryavtsev, V.A., Ed.; Permafrost
Institute: Yakutsk, Russia, 1978; pp. 16–33. (In Russian)

Earth 2022,3474
57.
Grave, N.A. Principles of surface sensitivity evaluation on anthropogenic impacts. In Nature Protection of Yakutia; Andreev, V.N.,
Sherbakov, I.P., Eds.; Yakutsk Branch of USSR Academy of Sciences: Yakutsk, Russia, 1979; pp. 91–94. (In Russian)
58.
Grave, N.A. Place and direction of geocryological research in the problem of environmental protection and rational use of natural
resources in the permafrost region. In Sustainability of the Surface to Technogenic Impacts in the Permafrost Region; Grave, N.A.,
Turbina, M.I., Eds.; Permafrost Institute: Yakutsk, Russia, 1980; pp. 6–12. (In Russian)
59.
Parmuzin, S.Y.; Sukhodolsky, S.E. Experience in zoning a territory with highly ice-rich deposits in terms of resistance to
technogenic impacts (on the example of the Middle Yamal. In Sustainability of the Surface to Technogenic Impacts in the Permafrost
Region; Grave, N.A., Turbina, M.I., Eds.; Permafrost Institute: Yakutsk, Russia, 1980; pp. 108–127. (In Russian)
60. Milkov, F.N. Landscape Sphere of the Earth; Mysl: Moscow, Russia, 1970; p. 207. (In Russian)
61.
Ershov, E.D.; Garagulya, L.S. The main directions of geocryological research at the present stage. In Geocryological Research;
Ershov, E.D., Ed.; Moscow State University: Moscow, Russia, 1987; pp. 3–17. (In Russian)
62.
Melnikov, V.P.; Khimenkov, A.N.; Brushkov, A.B.; Vlasov, A.N.; Volkov-Bogorodsky, D.B.; Samsonova, V.V. Cryogenic Geosystems:
Research and Modeling Problems; Geo: Novosibirsk, Russia, 2010; p. 390. (In Russian)
63. Gavrilova, M.K. Modern Climate and Permafrost on the Continents; Nauka: Novosibirsk, Russia, 1981; p. 112. (In Russian)
64.
Popov, A.I. Permafrost Phenomena in the Earth‘s Crust (Cryolithology); Moscow State University: Moscow, Russia, 1967; p. 307.
(In Russian)
65.
Popov, A.I. Cryolithogenesis as a zonal type of lithogenesis. In Problems of Geocryology; Nauka: Moscow, Russia, 1983; pp. 35–43.
(In Russian)
66.
Katasonov, E.M. Cryolithogenic deposits, their permafrost formation complexes. In Problems of Geocryology; Nauka: Moscow,
Russia, 1983; pp. 162–169. (In Russian)
67.
Drozdov, D.S. Identification and Delimitation of Geological Bodies in Medium-Scale Engineering-Geological Mapping Using
Mathematical Methods (on the Example of the North of Western Siberia). Ph.D. Thesis, VSEGINGEO, Moscow, Russia, 1983;
p. 17. (In Russian).
68. Milkov, F.N. Man and Landscapes: Essays on Anthropogenic Landscape Science; Mysl: Moscow, Russia, 1973; p. 224. (In Russian)
69.
Milkov, F.N. Anthropogenic landscape science, the subject of study and the current state. In Questions of Geography;
Kovalev, S.A., Ed.; Mysl: Moscow, Russia, 1977; Volume 106, pp. 11–27. (In Russian)
70.
Dolgushin, I.Y. Geomorphology of the Western Part of the Aldan Highlands; Publishing House of the Academy of Sciences of the USSR:
Moscow, Russia, 1961; p. 206. (In Russian)
71. Baranova, Y.P.; Biske, S.F. Northeast of the USSR; Nauka: Moscow, Russia, 1964; p. 290. (In Russian)
72. Timofeev, D.A. Middle and Lower Olekma; Nauka: Moscow-Leningrad, Russia, 1965; p. 138. (In Russian)
73.
Rusanov, B.S.; Borodenkova, Z.F.; Goncharov, V.F.; Grinenko, O.V.; Lazarev, P.A. Geomorphology of Eastern Yakutia; Book Publishing
House: Yakutsk, Russia, 1967; p. 376. (In Russian)
74.
Belokrylov, I.D.; Efimov, A.I. Permafrost of the Zone of Iron Ore and Coal Deposits of Yakutia; Publishing House of the Academy of
Sciences of the USSR: Moscow, Russia, 1960; p. 75. (In Russian)
75.
Kachurin, S.P. Thermokarst on the Territory of the USSR; Publishing House of the Academy of Sciences of the USSR: Moscow, Russia,
1961; p. 290. (In Russian)
76.
Trush, N.I.; Chizhov, A.B.; Chizhova, N.I.; Vsevozhskaya, M.A.; Pavlova, O.P.; Khrutsky, S.F.; Piotrovsky, M.V.; Kondratieva, K.A.;
Melentiev, V.S.; Gavrilov, A.V.; et al. South Yakutia; Kudryavtsev, V.A., Ed.; Moscow State University: Moscow, Russia, 1975; p. 444.
(In Russian)
77.
Katasonov, E.M.; Ivanov, M.S.; Pudov, U.U.; Katasonova, E.G.; Siegert, C. Structure and Absolute Geochronology of Alas Deposits in
Central Yakutia; Katasonov, E.M., Ed.; Nauka: Novosibirsk, Russia, 1979; p. 95. (In Russian)
78.
Ospennikov, E.N.; Trush, N.I.; Chizhov, A.B.; Chizhova, N.N. Exogenous Geological Processes and Phenomena (South Yakutia); Moscow
State University: Moscow, Russia, 1980; p. 227. (In Russian)
79.
Tomirdiaro, S.V. Loess-ice formation of Eastern Siberia in the Late Pleistocene and Holocene; Nauka: Moscow, Russia, 1980; p. 184.
(In Russian)
80.
Zolnikov, V.G. Soils of the eastern half of Central Yakutia and their use. In Materials on Environmental Conditions and Agriculture in
Central Yakutia; Academy of Science USSR: Moscow, Russia, 1954; Issue 1, pp. 55–221. (In Russian)
81.
Zolnikov, V.G.; Elovskaya, L.G.; Teterina, L.V.; Chernyak, E.I. Soils of the Vilyui Basin and Their Use; Academy of Science USSR:
Moscow, Russia, 1962; p. 204. (In Russian)
82. Karavaeva, N.A. Tundra soils of Northern Yakutia; Nauka: Moscow, Russia, 1969; p. 205. (In Russian)
83. Savvinov, D.D. The Hydrothermal Regime of Soils in the Permafrost Zone; Nauka: Novosibirsk, Russia, 1976; p. 254. (In Russian)
84.
Elovskaya, L.G.; Petrova, E.I.; Teterina, L.V. Soil map of Yakutia. In Study of Biological Resources in Yakutia; Yakutsk Branch
Academy of Sciences: Yakutsk, Russia, 1978; pp. 4–13. (In Russian)
85.
Desyatkin, R.V. Soils of the Alasses of the Lena-Amga Interfluve; Yakutsk Branch Academy of Sciences: Yakutsk, Russia, 1984; p. 168.
(In Russian)
86. Sheludyakova, V.A. Vegetation of the Verkhoyansk Region of the Yakut ASSR.; YakutGIZ: Yakutsk, Russia, 1948; p. 68. (In Russian)

Earth 2022,3475
87.
Sheludyakova, V.A. Steppe vegetation of the Yakut Arctic. In Proceedings of the Institute of Biology of Yakut branch Academy of
Sciences of the USSR. Issue 3: Materials for the Study of the Vegetation of Yakutia; Publishing House of the Academy of Sciences
of the USSR: Moscow, Russia, 1957; pp. 68–82. (In Russian).
88.
Kuvaev, V.B. Vegetation of the eastern Verkhoyansk region. In Vegetation of the Far North of the USSR and its Development; Publishing
House of the Academy of Sciences of the USSR: Moscow-Leningrad, Russia, 1956; Issue 2, pp. 133–186. (In Russian)
89.
Kuvaev, V.B. Regularities in the distribution of vegetation cover in Western Verkhoyansk region. In Problems of Botany. Vol.5:
Materials for the Study of Flora and Vegetation of High Mountains; Tolmachev, A.I., Ed.; Publishing House of the Academy of Sciences
of the USSR: Moscow-Leningrad, Russia, 1960; pp. 72–84. (In Russian)
90.
Kuvaev, V.B. Vegetation classification of the southern part of Yakutia on a landscape basis. Bot. J.
1966
,51, 1564–1579. (In Russian)
91.
Sheludyakova, V.A.; Galaktionova, T.F.; Dobretsova, L.A.; Permyakova, A.A.; Usanova, V.M. Vegetation of the Vilyui River Basin;
Shcherbakov, I.P., Ed.; Publishing House of the Academy of Sciences of the USSR: Moscow-Leningrad, Russia, 1962; p. 136.
(In Russian)
92. Shcherbakov, I.P. Forest cover of the North-East of the USSR; Nauka: Novosibirsk, Russia, 1975; p. 344. (In Russian)
93.
Andreev, V.N.; Galaktionova, T.F.; Karpel, B.A.; Perfilieva, V.I.; Chugunova, R.V.; Shurduk, I.F. Vegetation map. In Agricultiral
Atlas of Yakut ASSR; Matveev, I.A., Ed.; GUGK: Moscow, Russia, 1989; pp. 42–43. (In Russian)
94.
Mikhailov, N.I. Physical-geographical zoning of the Yakut ASSR. In Materials on the Physical-Geographical Zoning of the USSR
(Siberia and The Far East); Gvozdetsky, N.A., Ed.; Moscow State University: Moscow, Russia, 1964; pp. 71–129. (In Russian)
95.
Parmuzin, Y.P. Central Siberia. In Physico-Geographical Zoning of the USSR; Gvozdetsky, N.A., Ed.; Moscow State University:
Moscow, Russia, 1968; pp. 341–381. (In Russian)
96.
Parmuzin, Y.P. Central Yakut country. In Physical-Geographical Zoning of the USSR; Gvozdetsky, N.A., Ed.; Moscow State University:
Moscow, Russia, 1968; pp. 382–395. (In Russian)
97.
Mikheev, V.S.; Pavlov, P.D. Physical-geographical zoning. In Atlas of the Yakut ASSR; Sivtsev, T.D., Ed.; GUGK: Moscow, Russia,
1981; p. 22. (In Russian)
98.
Fedorov, A.N. The role of logging in the development of permafrost landscapes in Central Yakutia. In Regional and Engineering
Permafrost Investigations in Yakutia; Klimovsky, I.V., Kuzmin, G.P., Eds.; Permafrost Institute: Yakutsk, Russia, 1985; pp. 111–117.
(In Russian)
99.
Varlamov, S.P. Landscape typological mapping as a basis for stationary research extrapolation. In Regional and Engineering
Geocryological Studies; Klimovsky, I.V., Kuzmin, G.P., Eds.; Permafrost Institute: Yakutsk, Russia, 1985; pp. 132–137. (In Russian)
100.
Fedorov, A.N.; Maximov, T.C.; Gavriliev, P.P.; Skachkov, Y.B.; Ugarov, I.S.; Desyatkin, R.V.; Isaev, A.P.; Vasiliev, I.S.;
Konstantinov, P.Y.
; Rusakov, V.G.; et al. Spasskaya Pad: Comprehensive Studies of Permafrost Landscapes; Gavrilova, M.K.,
Konstantinov, P.Y., Shats, M.M., Eds.; Permafrost Institute: Yakutsk, Russia, 2006; p. 210. (In Russian)
101.
Shats, M.M.; Dorofeev, I.V.; Fedorov, A.N. Experience the landscape and permafrost mapping SouthernYakutia. In Natural
Conditions Reclaimed Regions of Siberia; Klimovsky, I.V., Pozdnyakova, E.S., Eds.; Permafrost Institute: Yakutsk, Russia, 1987; pp.
49–55. (In Russian)
102.
Torgovkin, Y.I. Landscape Indication and Mapping Permafrost Conditions of the Lena River Basin. Ph.D. Thesis, Permafrost
Institute, Yakutsk, Russia, 2005; p. 20. (In Russian).
103.
Gorokhov, A.N.; Makarov, V.S.; Vasiliev, N.F.; Fedorov, A.N. Methodical approaches to compiling a landscape map based on GIS
technologies (on the example of the Neryungri industrial complex of Yakutia). Probl. Reg. Ecol. 2009,3, 15–19. (In Russian)
104.
Fedorov, A.N.; Torgovkin, Y.I. Variety of permafrost landscapes of the Lena river basin. In Scientific Readings Devoted to the 100th
Anniversary of the Birth of Academician Viktor Borisovich Sochava: Materials of the International Conference, Irkutsk, 20–21 June 2005;
Snytko, V.A., Ed.; Institute of Geography of the Siberian Branch of the Russian Academy of Sciences: Irkutsk, Russia, 2005;
pp. 39–42. (In Russian)
105.
Fedorov, A.N.; Vasilyev, N.F.; Torgovkin, Y.I.; Shestakova, A.A.; Varlamov, S.P.; Zheleznyak, M.N.; Shepelev, V.V.;
Konstantinov, P.Y.
; Kalinicheva, S.V.; Basharin, N.I.; et al. Permafrost-landscape map of the Republic of Sakha (Yakutia)
at scale 1:1,500,000. Geosciences 2018,8, 465. [CrossRef]
106.
Shmelev, D.; Veremeeva, A.; Kraev, G.; Kholodov, A.; Spencer, R.G.M.; Walker, W.S.; Rivkina, E. Estimation and Sensitivity of
Carbon Storage in Permafrost of North-Eastern Yakutia. Permafr. Periglac. Process. 2017,28, 379–390. [CrossRef]
107.
Maslakov, A.; Zotova, L.; Komova, N.; Grishchenko, M.; Zamolodchikov, D.; Zelensky, G. Vulnerability of the Permafrost
Landscapes in the Eastern Chukotka Coastal Plains to Human Impact and Climate Change. Land 2021,10, 445. [CrossRef]
108.
Maslakov, A.; Shabanova, N.; Zamolodchikov, D.; Volobuev, V.; Kraev, G. Permafrost Degradation within Eastern Chukotka
CALM Sites in the 21st Century Based on CMIP5 Climate Models. Geosciences 2019,9, 232. [CrossRef]
109.
Strauss, J.; Laboor, S.; Schirrmeister, L.; Fedorov, A.N.; Fortier, D.; Froese, D.; Fuchs, M.; Günther, F.; Grigoriev, M.; Harden, J.;
et al. Circum-Arctic Map of the Yedoma Permafrost Domain. Front. Earth Sci. 2021,9, 758360. [CrossRef]
110.
Efimov, A.I.; Grave, N.A. Buried ice in the area of Abalakh lake. In Socialist Construction; SNK & GosPlan YaASSR: Yakutsk,
Russia, 1940; pp. 65–78. (In Russian)
111.
Czudek, T.; Demek, J. Thermokarst in Siberia and Its Influence on the Development of Lowland Relief. Quat. Res.
1970
,1, 103–120.
[CrossRef]

Earth 2022,3476
112.
Soloviev, P.A. Alas relief of Central Yakutia and its origin. In Permafrost and Accompanying Phenomena on the Territory of the Yakut
ASSR; Grave, N.A., Ed.; Publishing House of the Academy of Sciences of the USSR: Moscow, Russia, 1962; pp. 38–53. (In Russian)
113. Khotinsky, N.A. Holocene of Northern Eurasia; Nauka: Moscow, Russia, 1977; p. 199. (In Russian)
114.
Andreev, A.A. History of vegetation and climate of Central Yakutia in the Holocene and Late Glacial. In Lakes of Cold Regions,
Proceedings of Int. Conf. Part 4: Issues of Paleoclimatology, Paleolimnology and Paleoecology; Yakutsk State University: Yakutsk, Russia,
2000; pp. 15–29. (In Russian)
115.
Andreev, A.A.; Klimanov, V.A.; Sulerzhitskiy, L.D. The history of vegetation and climate of central Yakutia over the past
11,000 years. In Geochronology of the Quaternary; Ivanova, I.K., Kind, I.V., Eds.; Nauka: Moscow, Russia, 1992; pp. 113–117.
(In Russian)
116.
Andreev, A.; Klimanov, V.; Sulerzhitsky, L. Vegetation and climate history of the Yana River lowland, Russia, during the last
6400yr. Quat. Sci. Rev. 2001,20, 259–266. [CrossRef]
117.
Klimanov, V.A. Paleoclimate of Northern Eurasia with an increase in mean global temperature of 0.6–0.8oC or less. In Climates and
Landscapes of Northern Eurasia in a Global Warming Condition. Retrospective Analysis and Scenarios. Atlas-Monograph “Development of
Landscapes and Climate of Northern Eurasia. Late Pleistocene—Holocene—Prediction Elements”; Velichko, A.A., Ed.; GEOS: Moscow,
Russia, 2010; Volume 3, pp. 70–86. (In Russian)
118.
Fedorov, A.N.; Novopriezzhaya, V.A.; Fedorov, N.A.; Konstantinov, P.Y.; Samsonova, V.V. Retrospective Analysis of Permafrost
Landscape Evolution in Yakutia during the Holocene Warm Intervals. Land 2020,9, 463. [CrossRef]
119.
Fotiev, S.M. Modern conceptions of the evolution of cryogenic area of West and East Siberia in Pleistocene and Holocene (report 2).
Earth Cryosphere 2006,10, 3–26. (In Russian)
120.
Karabanov, E.B.; Kuzmin, M.I.; Williams, D.F.; Khursevich, G.K.; Bezrukova, E.V.; Prokopenko, A.A.; Kerber, E.A.;
Gvozdkov, A.N
.; Geletyi, V.F.; Veil, D.; et al. Global cooling of Central Asia in the Late Cenozoicaccording to the sedi-
mentary record from Lake Baikal. Doklady RAS 2000,370, 61–66. (In Russian)
121.
Stashenko, A.I. Study of transformation of permafrost conditions during of reclamation of forest natural complexes in the south
of the Central Yakutia. In Cryogenic Physio-Geological Processes and Methods for the Study Their Development; Grechishev, S.E., Ed.;
USSR’s Scientific Institute of Hydrology and Engineering Geology: Moscow, Russia, 1987; pp. 93–100. (In Russian)
122.
Varlamov, S.P.; Skryabin, P.N. Post-fire changes in the hydrothermal state of permafrost in Yakutia. Adv. Curr. Nat. Sci.
2016
,5,
105–110. (In Russian)
123.
Fedorov, A.; Konstantinov, P.; Vasilyev, N.; Shestakova, A. The influence of boreal forest dynamics on the current state of
permafrost in Central Yakutia. Polar Sci. 2019,22, 100483. [CrossRef]
124.
Lytkina, L.P.; Mironova, C.I. Post-fire succession in permafrost forests (on the example of Central Yakutia). Ecology
2009
,3,
168–173. (In Russian)
125.
Gabysheva, L.P. Changes in the phytomass of the living ground cover after fires in the larch forests of Central Yakutia. Sci. Educ.
2013,4, 62–65. (In Russian)
126.
Iwahana, G.; Machimura, T.; Kobayashi, Y.; Fedorov, A.; Konstantinov, P.; Fukuda, M. Influence of forest clear-cutting on the
thermal and hydrological regime of the active layer near Yakutsk, eastern Siberia. J. Geophys. Res.
2005
,110, GO2004. [CrossRef]
127.
Fedorov, A.N.; Iwahana, G.; Konstantinov, P.Y.; Machimura, T.; Argunov, R.; Efremov, P.V.; Lopez, L.M.C.; Takakai, F. Variability
of Permafrost and Landscape Conditions Following Clear Cutting of Larch Forest in Central Yakutia. Permafr. Periglac. Process.
2017,28, 331–338. [CrossRef]
128.
Usoltsev, V.A. Forest Biomass of Northern Eurasia: Mensuration Standards and Geography; Ural Branch of RAS: Yekaterinburg, Russia,
2002; p. 763. (In Russian)
129.
Shvidenko, A.Z.; Schepaschenko, D.G.; Nilsson, S.; Buluy, Y.I. Tables and Models of Growth and Productivity of Forests of Major Forest
Forming Species of Northern Eurasia (Standard and Reference Materials), 2nd ed.; Federal Agency of Forest Management: Moscow,
Russia, 2006; p. 803. (In Russian)
130.
Berner, L.T.; Beck, P.S.A.; Loranty, M.M.; Alexander, H.D.; Mack, M.C.; Goetz, S.J. Cajander larch (Larix cajanderi) biomass
distribution, fire regime and post-fire recovery in northeastern Siberia. Biogeosciences 2012,9, 3943–3959. [CrossRef]
131.
Alexander, H.D.; Natali, S.M.; Loranty, M.; Ludwig, S.; Spektor, V.; Davydov, S.; Zimov, N.; Trujillo, I.; Mack, M.C. Impacts of
increased soil burn severity on larch forest regeneration on permafrost soils of far northeastern Siberia. For. Ecol. Manag.
2018
,
417, 144–153. [CrossRef]
132.
Varlamov, S.P.; Skachkov, Y.B.; Skryabin, P.N. Results of 35-year monitoring studies of the permafrost zone at the Chabyda station
(Central Yakutia). Sci. Educ. 2017,2, 34–40. (In Russian)
133. Varlamov, S.P.; Skachkov, Y.B.; Skryabin, P.N. Monitoring of the Thermal Regime of Grounds in Central Yakutia; Permafrost Institute:
Yakutsk, Russia, 2021; p. 156. (In Russian)
134.
Fedorov, A.; Ivanova, R.; Park, H.; Hiyama, T.; Iijima, Y. Recent air temperature changes in the permafrost landscapes of
northeastern Eurasia. Polar Sci. 2014,8, 114–128. [CrossRef]
135.
Romanovsky, V.E.; Drozdov, D.S.; Oberman, N.G.; Malkova, G.V.; Kholodov, A.L.; Marchenko, S.; Moskalenko, N.G.;
Sergeev, D.O.
; Ukraintseva, N.G.; Abramov, A.; et al. Thermal state of permafrost in Russia. Permafr. Periglac. Process.
2010
,
21, 136–155. [CrossRef]

Earth 2022,3477
136.
Walter, K.M.; Zimov, S.A.; Chanton, J.P.; Verbyla, D.; Chapin, F.S. Methane Bubbling from Siberian Thaw Lakes as a Positive
Feedback to Climate Warming. Nature 2006,443, 71–75. [CrossRef]
137.
Morgenstern, A.; Grosse, G.; Gunther, F. Spatial analyses of thermokarst lakes and basins in Yedoma landscapes of the Lena Delta.
The Cryosphere 2011,5, 849–867. [CrossRef]
138. van Huissteden, J.; Mi, Y.; Gallagher, A.; Budishev, A. The importance of ecosystem covery for quantification of greenhouse gas
fluxes from permafrost degradation. In Proceedings of the 1st International Conference Global Warming and the Human Nature
Dimension in Siberia: Social Adaptation to the Changes of the Terrestrial Ecosystem, with an Emphasis on Water Environments,
Kyoto, Japan, 7–9 March 2012; pp. 48–50.
139.
Boike, J.; Grau, T.; Heim, B.; Günther, F.; Langer, M.; Muster, S.; Gouttevin, I.; Lange, S. Satellite-derived changes in the permafrost
landscape of central Yakutia, 2000–2011: Wetting, drying, and fires. Glob. Planet. Change 2016,139, 116–127. [CrossRef]
140.
Lapenis, A.; Shvidenko, A.; Shepaschenko, D.; Nilsson, S.; Aiyyer, A. Acclimation of Russian forests to recent changes in climate.
Glob. Change Biol. 2005,11, 2090–2102. [CrossRef] [PubMed]
141.
Kudryavtsev, V.A.; Garagulya, L.S.; Kondratieva, K.A.; Romanovskyi, N.N.; Maksimova, L.N.; Chizhov, A.B. Methods of Permafrost
Survey; Moscow State University: Moscow, Russia, 1979; p. 358. (In Russian)
142.
Feldman, G.M.; Tetelbaum, A.S.; Shender, N.I.; Gavriliev, R.I. Guidelines for Predicting the Ground Temperature Regime in Yakutia;
Permafrost Institute: Yakutsk, Russia, 1988; p. 240. (In Russian)
143.
Hill, G.B.; Henry, G.H.R. Responses of High Arctic wet sedge tundra to climate warming since 1980. Glob. Change Biol.
2010
,
17, 276–287. [CrossRef]
144.
Vaganov, A.A.; Shiyatov, S.G.; Mazepa, V.S. Dendroclimatic Research in the Ural-Siberian Subarctic; Nauka: Novosibirsk, Russia,
1996; p. 244. (In Russian)
145.
Esper, J.; Frank, D.; BãNtgen, U.; Verstege, A.; Hantemirov, R.M.; Kirdyanov, A.V. Trends and uncertainties in Siberian indicators
of 20th century warming. Glob. Chang. Biol. 2009,16, 386–398. [CrossRef]
146.
Blok, D.; Heijmans, M.M.P.D.; Schaepman-Strub, G.; Kononov, A.; Maximov, T.C.; Berendse, F. Shrub expansion may reduce
summer permafrost thaw in Siberian tundra. Glob. Change Biol. 2010,16, 1296–1305. [CrossRef]
147.
Makarov, V.; Savvinov, G.; Gavrilieva, L.; Gololobova, A. The Effect of Grazing on the Temperature Regime of the Alas Soils of
Central Yakutia. Land 2020,9, 365. [CrossRef]
148.
Takakai, F.; Desyatkin, A.R.; Lopez, C.M.L.; Fedorov, A.N.; Desyatkin, R.V.; Hatano, R. Influence of forest disturbance on CO
2
,
CH
4
and N
2
O fluxes from larch forest soil in the permafrost taiga region of eastern Siberia. Soil Sci. Plant Nutr.
2008
,54, 938–949.
[CrossRef]
149.
Loranty, M.M.; Berner, L.T.; Taber, E.D.; Kropp, H.; Natali, S.M.; Alexander, H.D.; Davydov, S.P.; Zimov, N.S. Understory
vegetation mediates permafrost active layer dynamics and carbon dioxide fluxes in open-canopy larch forests of northeastern
Siberia. PLoS ONE 2018,13, e0194014. [CrossRef]
150.
Masyagina, O.V.; Menyailo, O.V. The impact of permafrost on carbon dioxide and methane fluxes in Siberia: A meta-analysis.
Environ. Res. 2020,182, 109096. [CrossRef]
151.
Shepelev, A.G.; Kizyakov, A.; Wetterich, S.; Cherepanova, A.; Fedorov, A.; Syromyatnikov, I.; Savvinov, G. Sub-Surface Carbon
Stocks in Northern Taiga Landscapes Exposed in the Batagay Megaslump, Yana Upland, Yakutia. Land 2020,9, 305. [CrossRef]
152.
Brouchkov, A.; Fukuda, M. Preliminary measurements on methane content in permafrost, Central Yakutia, and some experimental
data. Permafr. Periglac. Process. 2002,13, 187–197. [CrossRef]
153.
Kraev, G.N.; Schultze, E.D.; Rivkina, E.M. Cryogenesis as a factor of methane distribution in layers of permafrost. Dokl. Earth Sci.
2013,451, 882–885. [CrossRef]
154.
Yang, J.-W.; Ahn, J.; Iwahana, G.; Han, S.; Kim, K.; Fedorov, A. Brief Communication: The reliability of gas extraction techniques
for analyzing CH4and N2O compositions in gas trapped in permafrost ice wedges. Cryosphere 2020,14, 1311–1324. [CrossRef]
155.
Desyatkin, A.R.; Takakai, F.; Fedorov, P.P.; Nikolaeva, M.C.; Desyatkin, R.V.; Hatano, R. CH4emission from different stages of
thermokarst formation in Central Yakutia, East Siberia. Soil Sci. Plant Nutr. 2009,55, 558–570. [CrossRef]
156.
Desyatkin, A.P.; Takakai, F.; Hatano, R. Flood effect on CH
4
emission from the alas in Central Yakutia, East Siberia. Soil Sci. Plant
Nutr. 2014,60, 242–253. [CrossRef]
157.
Morozumi, T.; Shingubara, R.; Suzuki, R.; Kobayashi, H.; Tei, S.; Takano, S.; Fan, R.; Liang, M.; Maximov, T.C.; Sugimoto, A.
Estimating methane emissions using vegetation mapping in the taiga-tundra boundary of a north-eastern Siberian lowland. Tellus
B Chem. Phys. Meteorol. 2019,71, 1581004. [CrossRef]
158.
Anisimov, O.A.; Zimov, S.A.; Volodin, E.M.; Lavrov, S.A. Emission of methane in the permafrost zone of Russia and assessment of
its impact on the global climate. Russ. Meteorol. Hydrol. 2020,5, 131–143. (In Russian)
159.
Hughes-Allen, L.; Bouchard, F.; Laurion, I.; Séjourné, A.; Marlin, C.; Hatté, C.; Costard, F.; Fedorov, A.; Desyatkin, A. Seasonal
patterns in greenhouse gas emissions from thermokarst lakes in Central Yakutia (Eastern Siberia). Limnol. Oceanogr.
2020
,66.
[CrossRef]
160.
Zimov, S.A.; Zimov, N.S.; Tikhonov, A.N.; Chapin, F.S., III. Mammoth steppe: A high-productivity phenomenon. Quat. Sci. Rev.
2012,57, 26–45. [CrossRef]

Earth 2022,3478
161.
Beer, C.; Zimov, N.; Olofsson, J.; Porada, P.; Zimov, S. Protection of Permafrost Soils from Thawing by Increasing Herbivore
Density. Sci. Rep. 2020,10, 1–10. [CrossRef]
162.
Windirsch, T.; Grosse, G.; Ulrich, M.; Forbes, B.C.; Göckede, M.; Wolter, J.; Macias-Fauria, M.; Olofsson, J.; Zimov, N.; Strauss, J.
Large Herbivores Affecting Permafrost—Impacts of Grazing on Permafrost Soil Carbon Storage in Northeastern Siberia. Biogeosci.
Discuss. 2021; in review. [CrossRef]