Primary plant succession on freshly degraded yedoma (ice complex) in Lena delta (Eastern Siberia)

Nikolay Laschinskiy,Christina Biasi,Alexey Faguet,E.V Banaev,M.A Tomoshevich,Y.G Zaytseva

doi:10.1051/bioconf/20202400047

Abstract

Primary plant succession was studied on freshly eroded yedoma in the southern part of Lena River Delta. Four stages of vegetation development were clearly distinguished. The first stage starts on bare ground and lasts from two-three months to one year. Its vegetation is represented only by fragmented cover of young mosses and a few seedlings of vascular plants. The most abundant moss species at this moment is Ceratodon purpureus. The second stage lasts from one to three years depending on slope steepness. Plants cover 20 to 60% of the soil surface. Main dominants are Descurainia sophioides and Tephroseris palustris. The third stage of succession presented by closed species-poor grasslands with Arctagrostis arundinacea as main dominant. This stage lasts for up to 20 years. The fourth stage is represented by species-rich herbaceous communities, which also have Arctagrostis arundinacea as main dominant but enriched with many perennial herbs. There is not enough data to determine the duration of this stage but it is at least few tens of years. This successional system requires a long time for its development. It means that IC degradation is not a recent process but accompanied yedoma deposits through all of its history.

Highlights

In course of Ice Complex (IC) degradation ice wedges melt and microbes actively consume soil organic matter
Primary plant succession was studied on freshly eroded yedoma in the southern part of Lena River Delta
Yedoma or Ice Complex (IC) is a special type of Pleistocene deposits which consists of loam or sandy loam with high organic matter content and 50 to 90% of ice

Summary

Introduction

In course of IC degradation ice wedges melt and microbes actively consume soil organic matter. On slopes this degradation is accompanied by active erosion when wet melted soil slides down slope and partly washes out into the river or lake. Newly appeared plant communities could be good indicators of certain soil processes. We picked and described sample plots 10x10 m size located in different plant communities (determined visually) on each outcrop.

Results

Conclusion