In boreal forests developed on permafrost, landslide processes are widespread. They occur primarily in years of above average summer-autumn precipitation and can cover up to 20% of total area of slopes adjacent to rivers. Permafrost landslides will escalate with climate change. These processes are the most destructive natural disturbance events and result in complete disappearance of initial ecosystems (vegetation cover and soil). We have studied sites of landslides of different ages along the Nizhnyaya Tunguska River and the Kochechum River (key site Tura) to analyze postsliding ecosystem succession. Just after the event (as at the 1-year-old site), as compared to the non-affected control site we registered a drop in soil respiration, a 3 times lower microbial respiration rate, and a 4 times smaller mineral soil C and N content at G-plots-bare soil (melkozem) at middle location of a site. Results show that regeneration of soil respiration and ecophysiological status of microbial communities in soil during post disturbance succession starts with re-establishment of the vegetation and the following accumulation of the organic soil layer. During the 35-years succession under observation the, at the oldest site the accumulated litter contained similar C and N stocks as the control sites. However, the mineral soil C and N stocks and the microbial biomass even of the oldest landslide area did not reach the value of these parameters in control plots. We conclude that forested ecosystems in permafrost area disturbed after landsliding require decades for final successful restoration. In addition, the degradation of permafrost due to landslides clearly hinders the accumulation of soil organic matter in the mineral soil.

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