Soil Sliding in Continuous Permafrost Terrain of Siberia: The Case Study of Soil Respiration and Soil Microbial Activity Dynamics During Ecosystem Re-establishment

摘要

In forested ecosystems developed on permafrost, solifluction processes are widespread, occur in years of above average summer-autumn precipitation and can cover up to 20 % of total area of slopes adjacent to rivers. This process is the most destructive natural disturbance event resulting in complete disappearance of initial ecosystems (vegetation cover and soil). To analyze postsliding ecosystem succession, sites of two ages (5 and 35 years old) after solifluction were chosen along with Nizhnyaya (Lower) Tunguska River valley. Results show that regeneration of soil respiration and eco-physiological status of microbial communities in soil during postsolifluction succession starts with vegetation re-establishment. As long as ecosystems regenerate, accumulated litter contains the main pool of microorganisms, though microbial biomass of 35-year-old solifluction area does not reach the value of microbial biomass in control plots. Therefore, forested ecosystems in permafrost zone after landsliding requires decades for final successful restoration of soil respiration and the microbial community.