Drainage consequences and self-restoration of drained raised bogs in the south-eastern part of Western Siberia: Peat accumulation and vegetation dynamics

This study analysed the drainage influence on vegetation and peat deposit and assessed the self-restoration of ecological functions of Western Siberia bogs. As a case study, we selected four raised bogs - two are the east-northern spurs of the Great Vasyugan Mire and two are small, raised bogs on the terrace of the Bakchar River and the Ob River. The consequences of drainage and the ability to self-restore are influenced by the moisture conditions before drainage, bog size, distance between ditches and microtopography characteristics. The dominant species under wet conditions, such as Sphagnum magellanicum and Sphagnum balticum, changed with drainage to Sphagnum fuscum, and the peat accumulation rate increased. The sites with more dry conditions and dominated by Sphagnum fuscum were characterised by the intense degradation of Sphagnum, Bryidae and lichen growth and a low peat accumulation rate. Large raised bogs are relatively stable and capable of self-restoration. The drainage effect was more significant within some parts of the small bogs. Drainage consequences were less dramatic for large bogs, even in the marginal parts and near the ditches. A distance between ditches of 40 m and less is critical for self-restoration. Our study demonstrates that modern peat accumulation occurred in most parts of the plots; the mean peat accumulation rate over the last 35 years was 0.43 cm per year. Drainage influence in the south-eastern part of Western Siberia is less significant than in European bogs, not only because of the high stability of raised bogs but also because of the lower drainage intensity as well as the absence of forest planting, fertilisation and peat mining.

Automated summary

This study investigated the drainage impact on vegetation and peat deposit in Western Siberia bogs, finding that large raised bogs are relatively stable and capable of self-restoration, while small bogs are more susceptible to drainage effects.