Vulnerability of the Ancient Peat Plateaus in Western Siberia.

Alexander Pastukhov,Tatiana Marchenko-Vagapova,Sergey Loiko,Dmitry Kaverin

doi:10.3390/plants10122813

Abstract

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.

Highlights

Peatlands, occupying only 3% of the land surface, contain about 15–30% of global soil organic carbon reserves [1], thereby playing a significant role in the regulation of general planetary processes, such as biogeochemical and biogeophysical cycles, greenhouse gases, and activity and species diversity of vegetation and soil biota
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
Polytrichum strictum, Pleurozium schreberi, and Dicranum elongatum mostly grow in these communities

Summary

Introduction

Peatlands, occupying only 3% of the land surface, contain about 15–30% of global soil organic carbon reserves [1], thereby playing a significant role in the regulation of general planetary processes, such as biogeochemical and biogeophysical cycles, greenhouse gases, and activity and species diversity of vegetation and soil biota. In Western Siberia, peatlands cover 592,440 km, exceeding 50% of all regional area in the taiga zone, and have the peat thickness up to 8–10 m [2]. In western Siberia, climate warming, increased precipitation, and permafrost thaw are accompanied by an increase in the frequency of full or partial drainage of thermokarst lakes. Highly productive plant communities on nutrient-rich sediments may develop, increasing the influencing greening trends of Arctic tundra [7]. Thermokarst features, such as thaw ponds of thermokarst lakes, are hotspots for methane emissions in warming lowland tundra [8]

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