Spatial differentiation and temporal dynamics of drained raised bogs in Western Siberia

Anna Sinyutkina,G.M Tsybulski Gennady,M.V Noskov,Yu.A Maglinets

doi:10.1051/e3sconf/202133302015

Abstract

This study analysed the influence of drainage on the vegetation cover of raised bogs in the taiga zone of Western Siberia. The study was based on a temporal analysis of Landsat satellite imagery data using the normalised difference vegetation index (NDVI) for the period from 1975–2020. We investigated four key sites within drained raised bogs. The analysis was not carried out using absolute NDVI values; rather, the ratio of the NDVI values of drained bogs to the NDVI values of a similar pristine bog was used. Four stages of the vegetation dynamics of drained bogs were determined. In the first stage, including the period before drainage, the NDVI values were close to those of the pristine site, which confirms that there are similar conditions before drainage. The second stage, from 1989–2001(2002), is characterised by a decrease in NDVI values relative to the pristine bog. This was probably due to the degradation of moss vegetation, which is a sensitive indicator of a decrease in the water table level in the absence of a significant growth of the tree layer. Furthermore, since the 2000s, there has been an increase in the NDVI values and they have stabilised at the level of a pristine bog.

Highlights

In the taiga zone of Western Siberia, the drainage of raised bogs was carried out from the 1960s to the1980s, mainly for agricultural and forestry activities, and for peat extraction
We investigated five key sites within drained and pristine raised bogs in the south-eastern part of Western Siberia within the Tomsk region
Since the 2000s, there has been an increase in normalised difference vegetation index (NDVI) values and they have stabilised at the level of a pristine bog

Summary

Introduction

In the taiga zone of Western Siberia, the drainage of raised bogs was carried out from the 1960s to the1980s, mainly for agricultural and forestry activities, and for peat extraction. Drained mires occupy more than 500 km (less than 1% of the total wetland area), and among them, pine dwarf-shrub sphagnum raised bogs cover only 130 km. Drained mires occupy more than 500 km (less than 1% of the total wetland area), and among them, pine dwarf-shrub sphagnum raised bogs cover only 130 km2 Despite their small area, these sites are at risk from peat fires. Within the drained mires of the taiga zone of Western Siberia, there are no long-term field studies to assess the impact of drainage and the further development of vegetation cover. Despite its prospects and high scientific and practical significance, for the territory of the taiga zone of Western Siberia, studies on monitoring ecosystem processes using satellite data within wetlands are not numerous [10]

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