scholarly journals Vulnerability of the Ancient Peat Plateaus in Western Siberia

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2813
Author(s):  
Alexander Pastukhov ◽  
Tatiana Marchenko-Vagapova ◽  
Sergey Loiko ◽  
Dmitry Kaverin
Keyword(s):  
Western Siberia ◽  
Hydrological Regime ◽  
Anthropogenic Disturbances ◽  
Permafrost Degradation ◽  
Peat Accumulation ◽  
Southern Limit ◽  
Current State ◽  
Peat Deposits ◽  
Under Construction ◽  
Peat Plateaus

Based on the data of the plant macrofossil and palynological composition of the peat deposits, the evolution and current state of polygonal peatlands were analyzed at the southern limit of continuous permafrost in the Pur-Taz interfluve. Paleoreconstruction shows that peat accumulation began in the Early Holocene, about 9814 cal. year BP, in the Late Pre-Boreal (PB-2), at a rate of 1 to 1.5 mm year−1. Intensive peat accumulation continued in the Boreal and early Atlantic. The geocryological complex of polygonal peatlands has remained a stable bog system despite the predicted warming and increasing humidity. However, a rather rapid upper permafrost degradation and irreversible changes in the bog systems of polygonal peatlands occur with anthropogenic disturbances, in particular, a change in the natural hydrological regime under construction of linear objects.

Runoff generation processes in permafrost-influenced area of the Heihe River Headwater

2021 ◽  
Author(s):  
Fan Zhang ◽  
Xiong Xiao ◽  
Guanxing Wang
Keyword(s):  
Soil Water ◽  
Stream Water ◽  
Hydrological Regime ◽  
Summer Rainfall ◽  
Frozen Soil ◽  
Heihe River ◽  
The Tibetan Plateau ◽  
Permafrost Degradation ◽  
Runoff Generation ◽  
Spring Snowmelt

<p>Permafrost degradation under global warming may change the hydrological regime of the headwater catchments in alpine area such as the Tibetan Plateau (TP). In this study, he runoff generation processes in permafrost-influenced area of the Heihe River Headwater were investigated with the following results: 1) The observed stable isotope values of various water types on average was roughly in the order of snowfall and snowmelt < bulk soil water (BSW) < rainfall , stream water, mobile soil water (MSW) , and lateral subsurface flow. The depleted spring snowmelt and enriched summer rainfall formed tightly bound soil water and MSW, respectively. The dynamic mixing between tightly bound soil water and MSW resuted in BSW with more depleted and variable stable isotopic feature than MSW. 2) Along with the thawing of the frozen soil, surface runoff and shallowsubsurface flow (SSF) at 30−60 cm was the major flow pathway in the permafrost influenced alpine meadow hillslope during spring snowmelt and summer rainfall period, reapectively, with the frozen soil maintaining supra-permafrost water level. 3) Comparison between two neighouring catchments under similar precipitation conditions indicated that streamflow of the lower catchment with less permafrost proportion and earlier thawing time has larger SSF and higher based flow component, indicating the potential changes of hydrological regims subject to future warming.</p>

scholarly journals Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years

2016 ◽  
Author(s):  
Amund F. Borge ◽  
Sebastian Westermann ◽  
Ingvild Solheim ◽  
Bernd Etzelmüller
Keyword(s):  
Aerial Imagery ◽  
Aerial Images ◽  
Moderate Increase ◽  
Permafrost Degradation ◽  
Northern Norway ◽  
Temperature And Precipitation ◽  
Important Pathway ◽  
The 1950S ◽  
Lateral Erosion ◽  
Peat Plateaus

Abstract. Palsas and peat plateaus are permafrost landforms occurring in subarctic mires which constitute sensitive ecosystems with strong significance for vegetation, wildlife, hydrology and carbon cycle. We have systematically mapped the occurrence of palsas and peat plateaus in the northernmost county of Norway (Finnmark, ~ 50 000 km2) by manual interpretation of aerial images from 2005–2014 at a spatial resolution of 250 m2. At this resolution, mires and wetlands with palsas or peat plateaus occur in about 850 km2 of Finnmark, with the actual palsas and peat plateaus underlain by permafrost covering a surface area of approximately 110 km2. Secondly, we have quantified the lateral changes of the extent of palsas and peat plateaus for four study areas located along a NW–SE transect through Finnmark by utilizing repeat aerial imagery from the 1950s to the 2010s. The results of the lateral changes reveal a total decrease of 33–71 % in the areal extent of palsas and peat plateaus during the study period, with the largest lateral change rates observed in the last decade. However, the results indicate that degradation of palsas and peat plateaus in northern Norway has been a consistent process during the second half of the 20th century and possibly even earlier. Significant rates of degradation are observed in all investigated time periods since the 1950s, and thermokarst landforms observed on aerial images from the 1950s suggest that lateral degradation was already an ongoing process at this time. The results of this study show that lateral erosion of palsas and peat plateaus is an important pathway for permafrost degradation in the sporadic permafrost zone in northern Scandinavia. While the environmental factors governing the rate of erosion are not yet fully understood, we note a moderate increase in both air temperature and precipitation during the last few decades in the region.

Hydrological and gas regime of swamps in the conditions of forest reclamation

2021 ◽  
Vol 0 (6) ◽  
pp. 39-44
Author(s):  
Lidiya Inisheva ◽  
Leh Shaydak ◽  
Boris Babikov
Keyword(s):  
Western Siberia ◽  
Drainage System ◽  
Southern Taiga ◽  
The State ◽  
Natural State ◽  
Forest Steppe ◽  
Peat Deposits ◽  
Forest Reclamation

The effective of forest reclamation in oligotrophic and eutrophic swamps in the southern taiga and forest-steppe zones of Western Siberia are described. The state of the hydrological and gas regime of peat deposits is analyzed. It is concluded that forest reclamation 60 years ago on oligotrophic and eutrophic swamps has little effect on the hydrological and gas regime of the reclaimed territory at this moment. These regimes are approaching to their natural state, which indicates that the area is re-waterlogged in the absence of operation of the drainage system.

The modern hydrological regime of the northern part of Western Siberia fromin situand satellite observations

2009 ◽  
Vol 66 (4) ◽  
pp. 447-463 ◽  
Author(s):  
E.A. Zakharova ◽  
A.V. Kouraev ◽  
M.V. Kolmakova ◽  
N.M. Mognard ◽  
V.A. Zemtsov ◽  
...  
Keyword(s):  
Western Siberia ◽  
Hydrological Regime ◽  
Satellite Observations

scholarly journals Monitoring of agrophysical properties of the active layer of drained long-frozen peat deposits in Western Siberia

2020 ◽  
Vol 164 ◽  
pp. 07016
Author(s):  
Vasily Novokhatin ◽  
Nadezhda Osipova
Keyword(s):  
Western Siberia ◽  
Soil Reclamation ◽  
Hydromorphic Soils ◽  
Investment Projects ◽  
Long Term Study ◽  
Peat Deposits ◽  
Changes Over Time ◽  
Reclaimed Soils ◽  
Over Time

In this study, the authors considered the dynamics of the main agrophysical properties of hydromorphic geosystems in Western Siberia. In the process of evolution, as well as in the conditions of technogenic impact, the soils of natural-territorial complexes, their properties are subject to significant changes. New hydromorphic geosystems are formed, the soils of which are characterized by changed agrophysical properties. Modern technologies for developing investment projects for soil reclamation of hydromorphic geosystems should be based on agrophysical characteristics of reclaimed soils, on the basis of which it is possible to create the necessary parameters of drainage systems and, as a result, provide optimal soil regimes for agricultural crops for a long period. The difficulty is that these soil characteristics are variable over time. Until recently, agrophysical characteristics of soils obtained in other regions of the country were used in the development of reclamation projects for hydromorphic soils in Western Siberia. The attempt to borrow them has led to the fact that large areas of drained soil have become completely unsuitable and to restore their project productivity, a number of agro-reclamation activities and the attraction of large financial resources are currently required. In this regard, there is a need for a comprehensive, long-term study of the main properties of hydromorphic soils used for agricultural purposes, and especially their changes over time under the influence of anthropogenic load.

A thawing boreal peat landscape along the southern limit of permafrost presently is carbon neutral

2020 ◽  
Author(s):  
Oliver Sonnentag ◽  
Julien Fouché ◽  
Manuel Helbig ◽  
Gabriel Hould Gosselin ◽  
Matteo Detto ◽  
...  
Keyword(s):  
Land Cover ◽  
Eddy Covariance ◽  
Black Spruce ◽  
Mean Value ◽  
Permafrost Region ◽  
Southern Limit ◽  
Organic C ◽  
Land Cover Types ◽  
Ecosystem Carbon ◽  
Peat Plateaus

<p>Along the southern limit of permafrost in northwestern Canada rising air temperatures have caused widespread land cover changes at unprecedented rates. A prominent change includes thermokarst wetland expansion at the expense of black spruce-dominated boreal forest stands due to the permafrost thaw-induced collapse of peat plateaus. We present a multi-year (2013 – 2017) net ecosystem carbon (C) balance (NECB, g C m<sup>-2</sup>year<sup>-1</sup>) at Scotty Creek near Fort Simpson, NT. The highly fragmented study site is dominated by permafrost-free wetlands and forested permafrost peat plateaus. Eddy covariance  measurements of net ecosystem carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>) exchanges (2013 – 2017) are complemented by discharge (2014 – 2016) and water chemistry monitoring (2015 and 2016) at the outlets of three small headwater catchments (<0.5 km<sup>2</sup>) draining the eddy covariance footprint area. In addition to net ecosystem CO<sub>2</sub>and CH<sub>4</sub>exchanges, the NECB includes the export of dissolved C (DC) as the sum of inorganic and organic C (DIC and DOC), free CO<sub>2</sub>and CH<sub>4</sub>through runoff, and the estimated import of DOC through precipitation. We use absorbance spectroscopy for dissolved organic matter (DOM) characterization to distinguish different DOM sources among catchments and characteristic land cover types. Between 2013 and 2017, the NECB varied between a weak net C source (~16 ±5 g C m<sup>-2</sup>year<sup>-1</sup>) and sink (~-22 ±5 g C m<sup>-2</sup>year<sup>-1</sup>) in 2015 and 2013, respectively, with a mean value of -1 ±7 g C m<sup>-2</sup>year<sup>-1</sup>. The net C sink-source strength was largely controlled by variations in net CO<sub>2</sub>exchange, ranging between a weak net CO<sub>2 </sub>sink (~-29 ±3 g C m<sup>-2</sup>year<sup>-1</sup>) and source (~8 ±4 g C m<sup>-2</sup>year<sup>-1</sup>) in 2015 and 2013, respectively. In contrast, our study site was a persistent annual net CH<sub>4</sub>source (~8 ±1 g C m<sup>-2</sup>year<sup>-1</sup>). Compensated by the import of DOC through precipitation, DC exported from the three catchments was a negligible component of the NECB. There were no significant differences in DOC concentrations and absorbance indices among catchments, and thawed and frozen land cover types, overall illustrating high DOM aromaticity (SUVA<sub>254</sub>= 3.3 ± 0.6 L mg<sup>-1</sup>m<sup>-1</sup>) and high molecular weight (a254:a365 = 4.3 ± 0.3) characteristic for peatlands and peat-dominated landscapes outside the circumpolar permafrost region. We conclude that a rapidly thawing boreal peat landscape along the southern limit of permafrost presently appears to be C neutral.</p>

The Holocene evolution of permafrost near the tree line, on the eastern coast of Hudson Bay (northern Quebec)

1987 ◽  
Vol 24 (11) ◽  
pp. 2206-2222 ◽  
Author(s):  
Michel Allard ◽  
Maurice K. Seguin
Keyword(s):  
Climatic Conditions ◽  
Snow Accumulation ◽  
Eastern Coast ◽  
Permafrost Degradation ◽  
Tree Line ◽  
Stratigraphic Sequence ◽  
Forest Tundra ◽  
Discontinuous Permafrost ◽  
Shrub Tundra ◽  
Peat Plateaus

Permafrost evolution in postglacial marine silts near the tree line was reconstructed using landform analysis, 14C dating, and palynostratigraphic analysis of peat sections. In the forest–tundra, below the tree line, four sites in peat plateaus have a stratigraphic sequence indicating an alluvial plain environment from 6000 to 4800 BP followed by a wetland supporting trees and shrubs with deep snow accumulation and without permafrost. Ground heave occurred between 1900 and 1200 BP as peat plateaus and palsas were formed. In the shrub–tundra, above the tree line, three permafrost sites with buried peat beds suggest that climatic conditions were cold enough for discontinuous permafrost in the surrounding landscape starting from land emergence, about 5800 BP; however, fen expansion and sedge peat accumulation continued over unfrozen ground until 2300, 1560, and 1400 BP. At these dates, the sites were buried with silt, probably as a result of mass wasting on nearby permafrost mounds and then permafrost aggraded under the sites. Generally, the palynostratigraphic data reflect a marked cooling of climate starting by 3200–2700 BP and culminating in a major period of permafrost aggradation between 1900 and 1200 BP. Permafrost degradation has been dominant since then despite other possible cold intervals. Nowadays, the permafrost in marine silts is twice as thick and three times more widespread in the shrub–tundra than in the forest–tundra.

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