ISSN 00978078, Water Resources, 2015, Vol. 42, No. 7, pp. 922–931. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © A.A. Medvedkov, 2014, published in Geoekologiya. Inzhenernaya Geologiya. Gidrogeologiya. Geokriologiya, 2014, No. 6, pp. 541–552.
NATURAL AND ENGINEERING–NATURAL PROCESSES
Geoenvironmental Response of the Yenisei Siberia MidTaiga
Landscapes to Global Warming during Late XX–Early XXI Centuries
A. A. Medvedkov
Faculty of Geography, Moscow State University, Moscow, 119991 Russia
Email: [email protected]
Received July 17, 2013; in final form, April 3, 2014
Abstract—The response of middle boreal landscapes in the Yenisei Siberia to climate warming is considered.
Changes in the systems of exodynamics, natural permafrost and nonpermafrost landscapes are analyzed
based on a series of studies. Permafrost landscapes are ranked by their susceptibility to climate warming.
Changes in the habitats were identified. The aggravating problems of the local population in the sphere of the
use of taiga resources, characterizing the current stage of changes in the environment and climate are dem
onstrated.
Keywords: climate warming and instability, permafrost landscapes, middle taiga, landscape indicators, exo
dynamic processes and phenomena, nature management in taiga zone
DOI: 10.1134/S0097807815070076
INTRODUCTION
The middle taiga zone is a part of the periphery of
the permafrost zone, in which natural landscapes
show highly mosaic character, since they have formed
under complex geological, geomorphological, and
geocryological conditions of the region. The study
focuses on studying the Central Siberian segment of
the area, embracing the left and rightbank areas of
the Yenisei, as well as the lower reaches of the Podka
mennaya Tunguska R. Yenisei leftbank area is a frag
ment of the West Siberian epiPaleozoic plate covered
by a continuous mantle of Quaternary deposits,
underlain in some places by continental Cretaceous
accumulations, and more often, by continental car
boniferous and marine Jurassic deposits. On the left
side of the Yenisei, the Middle and Late Mesosoic
deposits have a thickness of about 1 km [1] and rapidly
wedge out eastward. The area east of the Yenisei is the
northern part of the Baikal folded structure of the
Yenisei Ridge and the western part of the Paleozoic
Tungusskaya Syneclise of Siberian Platform. To
understand the specific landscape structure of the
region, it is important to take into account that it is
divided from the northeast to southwest by a boundary
of maximal glaciation, whose manifestation period is
taken to be the Middle Pleistocene, though it can be
younger (Late Pleistocene). In the glacial zone, the
paragenesis of glacial deposits includes a continental,
essentially bouldery moraine, widespread at elevations
of 500–600 m and higher in the northeastern part of
the region and at lower elevations of the order of 200 m
and lower in the nearYenisei zone. Here, it is more
often overlain by an aqual moraine with scattered
boulders, often with clear signs of horizontal stratal
differentiation of the bed and with individual iceberg
banks of coarse deposits on its surface. The aqual
moraine forms a low accumulative plain with eleva
tions mostly from 150 to 250 m. In the extraglacial
zone, the surface deposits of the Yenisei leftbank area
are represented by thick glacierdammed aleurite–
pelite accumulations and sands of drainage lines, ori
ented southwest into the Ob basin. The age of the
former corresponds to the manifestation time of max
imal glaciation, while that of the later corresponds to
the stage of the break of the glacial dam by waters of
the huge icedammed water body in the region where
the Ob R. flows over a valley within Siberian Spurs. In
the extraglacial zone east of the Yenisei, the occur
rence of surface deposits mostly follows the features of
the layered structure of relief. Here, the top stage
forms insular peneplain (J1–2), mostly trappean table
rocks with a common height of 500–700 m, its slopes
and high, narrowsummit mountains (400–600 m)
form an ancient stage of differentiation (J3–K1), the
main peneplanation plane (K–P2) with elevations
200–300 m and a valley network (P3–Q). Against the
background of the stage–age differentiation of relief,
intrastage surfaces of superimposed dissection and
planation (Q2–4) can be identified. This are landslides,
bluffs, scours (dellies), and glasises, galsis–floodplain
and plain, as well as a terrace–plain—an analog of a
glacierdammed plain [2].
The mean annual air temperature in the subzone of
the middle taiga in the Yenisei Siberia varies consider
ably depending on the landscape conditions and fea
tures of the area. In the nearYenisei part of the middle
922
GEOENVIRONMENTAL RESPONSE
taiga subzone, under the warming effect of the valley,
this temperature averages –4.5°C, decreasing east
ward to –7.5°C. In the northern sector of the subzone,
the mean annual temperature reaches –8.3°C, while
in the southern sector, it varies from –3.0 to –3.5°C.
The continentality index, evaluated according to
S.P. Khromov [10] is 88–90%, suggesting a high con
tinentality of climate. The mean duration of the vege
tation period with temperature above 5°C varies from
100 days in the north to 130 days in the south of the
subzone; the respective periods with a temperature
above 10°C are 65–70 and 90–100 days. The frostfree
season varies from 60 to 85 days in the same direction.
The degree of moistening of the area shows the same
regularity. The annual precipitation in the west reaches
700 mm (in the windward western part of the Central
Siberian Plateau and Yenisei Range), of which sum
mer accounts for 550–600 mm. On the eastern margin
of the zone, the precipitation is 350–400 mm. In the
western part of the Central Siberian Plateau, in its
windward part, winters are most snowy in Siberia
(except for the mountain areas of its southern part).
The mean depth of the snow cover varies from 95 to
120 cm [8]. Overall, we can conclude that the western
part of the middle taiga shows less severe and conti
nental climate conditions than its eastern part. The
middle boreal subzone is situated in the zone of dis
continuous and insular permafrost (from 30 to 60% of
the area). In the Yenisei part of the central Siberia sec
tor of the middle boreal subzone, permafrost rock
temperature at the bed of the layer of annual tempera
ture variations can be evaluated at –0.1 to –1.0°C and
their thickness, at a few meters to 25–30 m [8].
In terms of lithology and geomorphology, the terri
tory in the boreal taiga subzone is represented by
aqueoglacial plains, composed of sands and aleuroli
tes; glacial plains, composed of clays; aleurites with
inclusions of boulders, pebble, and sand lense, etc.;
high and low trappean plateaus with a discontinuous
mantle of glacial deposits in the northern part of the
subzone; and archblock folded lowmountain areas.
The soil and vegetation cover shows the predomi
nance of pine forests on illuvial–iron podzols;
spruce–fir–cedar and spruce–cedar–larch forests on
typical browntaiga and rendzina soils; thin spruce–
cedar–larch forests on cryogenic peaty–gley soils;
pine–birch forests on browntaiga thin and peaty–
skeletal soils; bushy and meadow–swamp vegetation
with thin taiga on peaty–cryogenic soils; oiseries,
meadow and sedgy vegetation of alluvial soils.
The objective of this study is a landscape–geoenvi
ronmental assessment of the state of middle boreal
landscapes in the Yenisei Siberia under changing envi
ronment and climate.
MATERIALS AND METHODS
The first stage of the study included the processing
of hydrometeorological data of local hydrometeoro
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923
logical observatories and AllRussia reference books
with the aim to reveal parameter fluctuations of the
temperature regime in the Central Siberian region
since the beginning of the XX century.
The field studies (2008–2012) included land
scape–geoenvironmental inventory of natural compo
nents on transects via the main types of forest, swamp,
and burnt catenas in the left and rightbank parts of
the Yenisei Siberia, boreal taiga subzone (Fig. 1). The
route profiling was carried out along transects across
and along the geomorphological catena, taking into
account conjugated relief surfaces, most diverse in
morpholithogenic, soil–geographic, and landscape
respects. Detail landscape descriptions along the route
were accompanied by the determination of the upper
boundary of permafrost with the use of a probe; diag
nostics of permafrost and nonpermafrost processes
was carried out. Test geobotanic sites 20 × 20 m were
analyzed on the route to determine the composition,
quality, density, and age of the timber stand (with the
use of an increment borer).
In the course of route surveys, special attention was
paid to field studies of the landscape structure of key
areas, taking into account the specifics of surface
deposits and the character of their geomorphological
differentiation; landscape indication of permafrost
natural–territorial complexes (NTC) and ranking
landscape complexes into permafrost and nonperma
frost. The comprehensive analysis of such data made it
possible to identify and outline (at the level of complex
stows) the landscape complexes most vulnerable to
various external impacts (including climatic).
In addition, the field studies included monitoring
different types of permafrost and nonpermafrost stows
in terms of the specifics of their response to climate
warming, which were compared with the data
obtained by S.P. Gorshkov in the course of field studies
in the 1970s, 1980s, 1990s, and 2000s.
Special attention was paid to observations of spe
cific informative natural objects and phenomena.
—Stone streams. In the zones of occurrence of
active stone streams, the specifics of local overgrowing
by moss–lichen cover were studied, and the number of
unstable boulders was determined. For lowactivity,
closed stone streams, the degree and character of for
estation and the specifics of stand timber, in particular,
the share of inclined trees, were determined. Succes
sion changes in the taiga vegetation within the rela
tively stale covers and stonestream–defluction (block
structures with loam colmatage) were examined;
—Soliflual deposits. The signs of weakening or
degeneration of solifluction were assessed, including
the presence of inclined trees with vertical tops, as well
as the overgrowth of solifluction hollows–disruptions
in the abovesoil cover. The cases of replacement of
solifluction slopes and glacises on river banks by local
landslides–creeps because of a recession of permafrost
roof and an increase in the instability of bank massifs;
“Vorogovo” area
“Sumarokovo” area
Fig. 1. Map of key study areas in the Yenisei Siberia.
“Chapa” area
0
Transects
Model areas
5 10
20
30
“Bol’shaya Chernaya” area
“Sulomai” area
Pravaya “Lebyazh’ya” area
“Aleksis” area
40
km
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MEDVEDKOV
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GEOENVIRONMENTAL RESPONSE
RESULTS AND DISCUSSION
Climate changes. Climate warming in the Central
Siberian region has been recorded for more than
30 years since the early 1980s (Fig. 2). Warming waves
seem to be due to the stronger western transport from
the Atlantic (this is most clearly seen in winter because
of the inflow of warm air masses) and the weaker Asian
anticyclone (its western branch or the Voeikov axis)
because of a considerable decline of Arctic ice cover.
Here, the mean annual temperature increased by 1–
2°C and more compared with the previous, colder
period from the late 1940s to the late 1970s. Since the
early 1980s, the winter became warmer, and the spring
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t
Variations of mean annual air temperature
at stations Turukhansk, Bor, and Yeniseisk
2
0
–2
–4
–6
–8
–10
1900
1905
1910
1915
1920
1925
1930
1935
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
—Relic permafrost relief forms. the cryogenic
morphosculpture of the Upper Pleistocene forms of
solifluction origin, the signs of thermokarst, and the
features of their landscape occurrence were analyzed.
Analogous modern formations were sought for and
studied;
—Undergrowth of parvifoliate species (birch,
aspen). The causes of explosive rise of the undergrowth
of parvifoliate species in dark and light coniferous for
ests were studied and analyzed, in particular, in the
habitats that have not been typical of such before.
The changes in the resource–environmental func
tions of the natural systems of the middle taiga (at the
level of complex stows) under warming climate were
assessed using monitoring data based on interviews of
families of kets—representatives of a native minority
of the North. The traditional ket household is rigidly
bound to landscape, and any stress situation in the
natural complex will immediately affect their selfpro
duction and social welfare, thus making the informa
tion we have collected quite reliable. The total number
of interviewed families was 25 (as was the number of
hunting areas in the hunting community of Sulomaya
kets; the number of interviewed people was 57, about
a half of the population of Sulomai Settlement, Evenki
Municipal District, Krasnoyarsk krai).
Ket families, which have their heritable hunting
area, collect important data on the dynamics of catch
of some animal species or the yield of berries over a
long period of several decades. Many kets (mostly old
timers) keep ecological calendars to record important
hydrometeorological and phenological phenomena.
In the absence of a reliable monitoring system in the
taiga zone of Central Siberia, such data are of impor
tance for identifying the response of the natural–envi
ronmental resources of taiga and traditional economy
of the local population to climate warming. The
author carried out route harvesting–resource observa
tions (during five field seasons starting from 2008),
including the assessment of the yield and flowering
percent of berrybeds, the resources of food plants in
different types of natural complexes (at the level of
stows).
925
Yeniseisk
Bor
Year
Turukhansk
Fig. 2. Variations of mean annual air temperature over
1900–2010 according to data of hydrometeorological sta
tions of Krasnoyarsk krai in Turukhansk V., Bor Settl.,
Kuz’movka V., and Yeniseisk T.
and autumn, longer. Years with shorter summer also
occurred.
In the cold 1974, the minimal mean monthly air
temperature in January at Bor Settlement was found to
be –35.1°C, while that in the warm 1995 was –17.8°C.
at the same time, the difference between the mean July
temperatures in the same years did not exceed 1.7°C.
The increase in the mean annual temperature in warm
years is due to both the higher temperatures in the cold
season (see Fig. 2) and the longer warm season.
Analysis of Fig. 3 suggests that the amplitude of
variations of winter temperatures is much larger than
those in other seasons, a feature that determines their
leading role in the annual temperature. It can be
clearly seen that the last 20 years of the XX century can
be distinguished by their winter maximums. Note that
a concentration of high winter temperatures falls onto
the period from the late 1980s to the mid1990s, while,
since 2009, the mean annual air temperature decreases
allove the Central Siberian region, suggesting the pos
sible end of the cycle of climate warming.
Such temperature variations can be attributed to
the character of atmospheric circulation in the middle
reach of the Yenisei and the lower reaches of the Nizh
nyaya and Podkamennaya Tunguska. The low temper
atures in the cold season in the Central Siberia are due
to the onset of the stable western branch of the Asian
anticyclone with the formation of inversions in winter
and strong cooling of the surface layer under a thin
snow cover. With the weakening of the Asian anticy
clone and the shift of its western wedge, commonly
southeastward, it is replaced by less stable and warmer
anticyclones either of local origin or arriving from the
west, southwest, or northwest. They can significantly
change the air temperature in the midwinter.
Characteristic features of permafrost landscapes
and their tolerance to climate warming. The permafrost
926
MEDVEDKOV
20
15
10
5
0
–5
–10
–15
–20
–25
winter
spring
summer
autumn
2005/06
2000/01
1995/96
1990/91
1985/86
1980/81
1975/76
1970/71
1965/66
1960/61
1955/56
1950/51
1945/46
1940/41
1935/36
1930/31
1925/26
1920/21
1915/16
1910/11
1905/06
1900/01
–32
Year
Fig. 3. Distribution of mean air temperature over seasons based on data of ZGMOS in Bor Settl. (Turukhansk raion, Krasnoyarsk
krai) over 1900–2009.
landscapes are very sensitive to climate warming,
though to a different degree. Of importance in this sit
uation are their indication and the identification of
occurrence specifics. Permafrost processes in boreal
landscapes often manifest themselves under favorable
substrate conditions, irrespective of the heat supply to
relief elements. Thus, the lithological–geomorpho
logical and landscape–geographic analyses showed
that permafrost stows in the lower reaches of the Pod
kamennaya Tunguska occur in the surface deposits of
aleurite–pelite composition [5]. This demonstrates
the priority role of the lithological factor. Of great
demarcation importance in terms of landscape is the
southern boundary of the Upper Pleistocene glacia
tion, which separates the modern boreal natural com
plexes into the landscapes of glacial and nonglacial
zones. In the glacial zone, permafrost landscapes
dominate within the upper stage of the relief, where
they occur on the summit plains, nearsummit slopes,
and the slopes and beds of valleys, where disperse
rocks overlie traprock outcrops. The situation in the
nonglacial zone is different: here, permafrost land
scapes are confined to the lower stage of relief (a com
bination of erosion valley network and waterdivide
depressions) because of their higher watering due to
the concentration of surface runoff, high occurrence
of subsoil water, etc. (Fig. 4). The next is the aspect
factor: permafrost lies on the slopes of cold aspect
(northern and eastern) with traprock outcrops. These
areas show higher watering, the development of stone
stream–creep and, at the most developed stage of the
process, peat bed increase [5]. An example of a combi
nation of several factors, leading to the formation of
permafrost stows, is a hanging bog. Hanging bogs are
mostly situated on steep nearriver slopes with low
heat supply. A stone flow underlies a thin peat layer in
each such bog. The permafrost peatery shows high
segregation ice content. The most impressive are ice
inclusions with a size of a walnut. The permafrost layer
is overlain by ground vegetation, consisting of mosses,
lichens, and dwarf shrubs with abundance of ledum
and dwarf arctic birch. However, under the conditions
of global warming, the permafrost in the area can
aggradate because of the longer vegetation period,
resulting in a thicker peat–vegetation layer, which
serves as a heat insulator.
Our studies show that permafrost rocks manifest
themselves in different stows, which feature dystrophy,
suppression, and species poverty, appreciable distur
bances of the day surface, specific soil profile with gley
signs, higher watering of soils and surface deposits,
and the manifestation of cryogenic processes and phe
nomena (Fig. 4).
Thus, the key characteristics of permafrost land
scapes include
(1) vegetation character: suppressed thin taiga with
appreciable tilt of trees, sparse stands and dwarf birch
thickets, moss–brush vegetation with the predomi
nance of sphagnum mosses (Sphagnopsida);
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L10°
60 t/ha
“Drunk” forest
Dead wood
Other denotations
Kurumdecerption
Solifluction
Permafrost complexes
Alder
Vegetation
AIIV
L5–7°
48 t/ha
E
L15°
L13–15°
Skeleton browntaiga peaty
Calcareous leached
Lowthickness peatypermafrost
Accumulativehumus peatypermafrost
Alluvial gley
Browntaiga peaty
Soils
Browntaiga gley
L20°
45 t/ha
75 t/ha
87 t/ha
Elements of
geological structure
242 m
L2–3°
Loams
solifluction
and defluction
Skarns
AIIV Age and genesis index
L4°
90 t/ha
Fig. 4. Schematic landscape–indication profile over the Bol’shaya Chernaya R. valley (the lefthand tributary of the Podkamennaya Tunguska R.).
Fir
Larch
Birch
Cedar
L2–3°
LgIII
Spruce
107 m
L2°
Bol’shaya Chernaya R.
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W
5 km
GEOENVIRONMENTAL RESPONSE
927
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MEDVEDKOV
Fig. 5. Solifluction hole–break in ground vegetation filled with cold water on the surface of a high (14–17 m) floodplain of the
Podkamennaya Tunguska. Water is a sign of the presence of a permafrost aquiclude near the day surface.
(2) specific soils: cryogenic peat–gley, alluvial–
swamp with signs of gley and cryogenic skeletal
(stonestream soils);
(3) relief microforms: solifluction windows–breaks
(holes–breaks) (Fig. 5), solifluction ledges, frost
mounds, thermokarst subsidence;
(4) relief mesoforms and their outline: solifluction
swells (foot plumes); watered and lowmobility stone
streams; hanging bogs; ditchtype channels of creeks
and rivers with landslide signs;
(5) the state of surface deposits: viscous–flow con
sistency of disperse soils; active and watered stone
streams (individual boulders are unstable);
(6) the composition of surface deposits: moraine
clays, loams, lacustrine–glacial and alluvial clays,
aleurites, frozen peat, solifluction disperse deposits,
highly watered boulders of stonestream fields;
(7) higher watering of a stow due to groundwater
outcrops.
Nonpermafrost landscapes show
(a) the presence of fullscale erect tree vegetation;
(b) the high occurrence of hard rocks under a thin
mantle of surface deposits;
(c) relatively good drainage.
As to the stability of permafrost landscapes, it was
found to show some differentiation of occurrence
toward the south. If some type of permafrost stows
occurs furthest to the south, then, other conditions
being the same, it can be regarded as the most tolerant
to climate warming [5]. In this context, three types of
stows can be identified in the region under study by
their tolerance to climate warming:
—lowstability stows of glacises with good water
supply and slopes with open stone flows and summit
plains;
1
—stable stows of slopes, glacises and glacis–flood
2
plains ;
—highly stable—polyfactor permafrost stows on
slopes with poor heat supply: hanging bogs and for
ested floodplains of large rivers.
Thus the most stable permafrost stows are hanging
bogs of cold slopes and forested floodplains of major
rivers.
The response of permafrost landscapes. In the lower
reaches of the Podkamennaya Tunguska, the least sta
ble permafrost is confined to the landscapes of low
(200–250 m) summit plains and gentle slopes, com
posed of clays, loams with inclusion of individual
boulders, and aleurolites–finesand deposits of glacial
complex [3]. Common in such places are bog com
plexes with low thin (crown density of 40–50%)
cedar–fir taiga with birches and larches on peaty–gley
cryogenic soil with most–brush and, sometimes,
lichen ground cover.
At the depth of zero annual temperature variations,
the cryogenic soil is cooled to 1°C and even to frac
1 Glacises
are accumulative surfaces with slopes from a few
degrees to a few tens of minutes, composed of decerption, solif
luction, and diluvium, forming foot plumes or occupying valley
beds.
2 Glacis–floodplain includes areas of glacises near river bed,
which are inundated during spring flood, under meadow–bog or
dwarf birch vegetation on alluvial–gley and peaty–permafrost
soils.
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GEOENVIRONMENTAL RESPONSE
929
Fig. 6. A kurum overgrown by lichen and young birches on the righthand bank in the middle reaches of the Bol’shaya
Chernaya R. (the lefthand tributary of the Podkamennaya Tunguska).
tions of degree below zero. The active layer in loams
and clays is the layer of seasonal freezing and thawing,
which is 0.8–1.0 m in thickness [3, 6]. Since the mid
1990s until now, the top of permafrost shifted 1.5–2 m
and more down, demonstrating the process of perma
frost degradation because of the warming of its strata.
The beginning of permafrost degradation had an
immediate effect on the appearance of permafrost
landscapes, i.e., the disappearance of water in solifluc
tion holesbreaks; fallen trees can be seen with the
entire spreadingroot assemblage torn out of the earth,
because they fall more easily under wind impact, and
their root base lost the support of the solid frozen sub
strate. The result was an increase in the occurrence of
relief forms of biogenic origin (the socalled, iskor’s)
in the landscapes of insularpermafrost subzone.
Local replacement of solifluction by landslide pro
cesses was observed in the zones of intensification of
river erosion. Because of draining, some plants, pri
marily, horsetail, lose their green color, making the
ground vegetation cover yellowish–golden. Small
thaw lakes with collapssed and dead forest stand.
In the basements of stone streams and detritus,
called kurums, the permafrost retreats downward
faster than in the areas of permafrost thin forest. Stud
ies in key areas show that baldpeak ice melted, small
depressions formed, and cold subsurface creeks disap
peared in the kurums, primarily on slopes with south
ern and western aspects. The kurums overgrow with
lichens, dwarf shrubs, and individual trees (Fig. 6). In
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the low reaches of the Podkamennaya Tunguska R.,
the kurums not covered by forest, even on slopes with
poor heat supply, on valley beds, on slopes and summit
plains with elevations not exceeding 400 m, have lost
their baldpeak ice. Warm kurums are common in the
northern part of the Yenisei Range and the western
part of Central Siberian Plateau up to the Nizhnyaya
Tunguska R. in the zone of Severnyi kamen' trappean
massif, which is as close as 70 km south of the polar
circle. The permafrost on the beds of deep valleys and
on steep slopes of northern and eastern aspects with
low heat supply is more tolerant to warming. The per
mafrost roof is still stable on the upper plateau of the
western Central Siberia with absolute elevations of
550–700 m.
The analysis of the collected material allows us to
suggest that protection response in the form of nega
tive feedbacks form in the kurums of the boreal taiga
subzone. At the first stage, baldpeak ice melts and
kurums overgrow with mosses, lichens, and tree spe
cies. At the gradual overgrowth of a kurum, fine soil
accumulates, filling gaps between boulders and form
ing more impressive soil profile A1–AB–C of brown
taiga skeletal soil. The accumulation of fine earth and
the rate of kurum overgrowth were found to increase in
the zones of concentration of black cristose lichens. At
the farther accumulation of fine earth, the brown taiga
skeletal soil transforms into peaty brown taiga soil, the
share of disperse deposits and the thickness of peat–
vegetation layer increase, and the watering of kurum
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MEDVEDKOV
and its isolation from the lower air layer grow. The for
mation of hanging peat bogs at the second stage is
accompanied by aggradation of permafrost because of
a growth of icy rocks.
Our studies show that in 1980–2012 in Central
Siberia, only hightemperature permafrost experi
enced degradation: kurums in all subzones of the per
mafrost zone, though not including the upper pene
plain, and the hightemperature permafrost in pelite
rocks—only in insularpermafrost zone and further
southward.
Changes in habitats. Changes were found to have
taken place in the habitats of encephalitic tick, which
has been detected as far as 63° N [3, 9]. Ixodid (Ixodes
perculcatus) have shifted 250 km northward over the
past 25 years, covering the subzone of central taiga in
the zone of our studies. The probability of tick
induced diseases increased. Tick activity has been
especially high in the recent decade. Our interviews
show that this worries the inhabitants of Vorogovo V.,
Bor Settl. in the southern Turukhanskii raion, Sulo
main V., Kuz’movka V. in the southwestern Evenkiiskii
district, and other populated localities in Krasnoyarsk
krai, who repeatedly request tickborne encephalitis
vaccination. Many insects in the forest steppe and
southern taiga have been described by A.V. Kuvaev in
the lower reaches of the Podkamennaya Tunguska and
the middle reaches of the Yenisei R. in the central
taiga subzone.
In the third quarter of the XX century (a period
with stable cold winter), there were nearly no vipers
(Vipera berus L.) in the central taiga part of the Yenisei
rightbank area. The expansion of those poisonous
snakes became the topic for the local population after
anomalously warm years of the second half of the
1990s, which coincides with the period of mass thaw
ing of baldrock ice in kurums. Now vipers are almost
everpresent on thawed kurums.
Coney (Ochotona), which plays a significant part in
the nutrition of sables, leaves kurums. This is facili
tated by late spring cold spells and the loss of subsur
face water resources at the base of kurums.
Problems of conventional nature development. Cli
mate warming, which features more frequent warm
winters and prolonged springs and autumns had a
strong effect on taiga biological resources. Thus, in
1997 and 1998, there were almost no berries of black
berry, blueberry, cowberry, honeysuckle, red and black
currant in the Central Siberian Reserve (within one of
the largest wildlife reserves of the planet with a size
equal to the territory of Lebanon or Jamaica). Their
yields were also scarce in 1999, the situation remaining
nearly the same now, as follows from the data of mon
itoring studies and interviews with local people. They
note that pine nuts were difficult to find in years with
cool summer and warm winter, despite the ubiquitous
presence of cedars in the dark coniferous forest. Simi
lar trends were recorded in the yield of berry beds.
Thus a relationship was found to exist between the
yield of cowberry and the weight of its leaves in sum
mers of different type [4]. The weight of leaves is min
imal in warm and moderately humid summer because
of water consumption by the growing fruits, while,
during cold summers, the situation is inverse (the ber
ries are few, so they do not compete with leaves for
matter); dry or very humid summer also is not favor
able for fruit formation.
Years with low reproduction of gameanimal
resources have become a standard, rather than excep
tion, especially in areas east of the Yenisei. This can be
attributed to the higher degree of freezehazard of the
rightbank areas as compared with leftbank areas
because of the geomorphological features of the area:
its high roughness, the presence of deep valleys, higher
absolute elevations, etc. Cold air enters the valleys;
recurrent frosts in springs are more frequent. An
important feature is the lesser thickness of the snow
cover on the rightbank compared with the leftbank
area. Thaws became more frequent in the period of
climate warming. For example, the kets, representa
tives of indigenous peoples of Siberia, note that 20–
25 years ago, frosts lasted for at least a month, while
now they last not more than 2–3 weeks. Ket’s observa
tions are supported by the data of meteorological sta
tions in the area, showing an increase in the frequency
of thaws and a warmer winter period (see Fig. 3). The
result is the lesser thickness of snow cover, which could
not but affect the yields of berry beds. A decrease in
snow cover thickness is known to increase the likeli
ness of freezing of blueberry and blackberry. Ket hunt
ers also notice that the thickness of snow cover has
decreased, making it more difficult to hunt for elk. The
result is the phenomenon of “hungry taiga” observed
in the two recent decades. I.I. Krupnik [7] called such
phenomena “life crises,” commenting that, according
to interviews and chronicles, they occur in years with
extreme weather conditions, which mostly accom
pany the periods of warming and climate instability.
The decrease in the lifesupporting function of the
feeding landscape (as L.N. Gumilev called it) requires
us to focus on the comprehensive development of tra
ditional types of taiga nature development and their
diversification; support of their resource and produc
tion–technological base; and the organization of pro
cessing of conventional trades [9].
CONCLUSIONS
A vast body of data was obtained suggesting the
beginning of permafrost degradation in the middle
boreal subzone in the Yenisei basin (not less than 70%
of the area it occupies within the ecotone).
The most significant response processes to climate
warming in the boreal landscapes of the Middle
Yenisei area include
an increase in the thickness of the active permafrost
layer (10–15 cm/year within lowstability stows) and
the intensification of solifluction;
WATER RESOURCES
Vol. 42
No. 7
2015
GEOENVIRONMENTAL RESPONSE
cases of local replacement of solifluction by land
slide motion of soils in the zones of active river ero
sion;
anomalously frequent fall of trees that have spread
ingtype root systems in areas where clay soils are
waterlogged, have viscoplastic consistency, and are
1.5 or more meters in thickness;
better drainage on summit plains and adjacent gen
tle slopes;
higher mobility of large boulders on kurums (NTCs
that are most vulnerable to climate warming) because
of melting of baldpeak ice, as well as the number and
area of overgrowth spots of mosses and lichens;
depletion of subsurface streams under kurum boul
der cover;
the intensification of thermokarst processes within
swampy areas;
the deterioration of forest and game resources
because of an increase in the share of birch and aspen
in the dark coniferous taiga;
more frequent episodes of forest diseases and their
spreading over wider areas, poor yields of berries and
pignoli nuts, a drop in the populations of game ani
mals;
changes in the habitats and northward displace
ment of some representatives of the animal kingdom
(ixodids, adder, etc.);
a decrease in the efficiency of nature development
by the local population.
The ecotone under consideration is situated in the
western part of the Central Siberian Plateau and the
eastern margin of the West Siberian Plain. The
response to climate warming causes changes in the
permafrost–landscape conditions, exodynamic pro
cesses, the production of natural systems and affects
the life support of the local population. The under
standing of processes taking place in a permafrost eco
tone is of importance for assessing the changes in
modern boreal landscapes in the Northern Eurasia
and the state of its natural–environmental resources
in the future.
WATER RESOURCES
Vol. 42
No. 7
2015
931
ACKNOWLEDGMENTS
The author is grateful to Prof. S.P. Gorshkov for his
help in field studies and processing the obtained mate
rial underlying this article.
The study was financed by the RF Presidents Sci
entific grant (project 7614.2015.5).
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