Successional pathways after peatland draining: remote sensing and predictive modelling of landscape dynamics

Peatlands are key contributors to carbon storage and hydrological regulation but their role and ecosystem functions and services have been substantially altered by anthropogenic interference, primarily through drainage and peat extraction. This study focuses on the Tarmanskoe peatland in Western Siberia, where large areas were drained for peat extraction and agricultural use from the 1960s to 1970s. Using Landsat satellite imagery from 1984 to 2024 - complemented by high-resolution Unmanned Aerial Vehicle (UAV) data - we applied object-based classification (Random Forest) to assess historical land-cover changes. We then employed a hybrid CA-Markov (Cellular Automata-Marcov) model to project future landscape transformations over the next three decades (2034–2054). Results indicate that formerly drained peatlands followed two main successional pathways: an initial phase of meadow formation with varying levels of waterlogging, followed by a gradual expansion of mixed forests. By 2024, about half of the drained peatland areas transitioned from meadows to forest cover, suggesting a dominant trend toward forest succession. Simultaneously, lakes in the region underwent significant water losses - nearly a 50% reduction in total area since 2013 - driven by natural aging processes, drainage-induced lowering of water levels, and rising mean annual temperatures. The CA-Markov projections reveal a continued, albeit slower, increase in forested areas and a further reduction in water bodies, reaching only 17.4% of their 1984 extent by 2054. These findings underscore the lasting ecological impacts of drainage and peat extraction, as evidenced by spatially heterogeneous successional processes and widespread fragmentation of ecosystems. They also highlight emerging risks, including further water-level declines, increased fire hazard, and ongoing landscape fragmentation. From a conservation perspective, proactive management and the restoration of hydrological functions in disturbed peatlands may help mitigate long-term ecological and climate-related vulnerabilities.