First World Congress of International Consortium on Geo-disaster Reduction (1st ICGdR World Congress)

Permafrost and vegetation are intricately linked in their dynamics, are key to cold-region ecosystems and sensitive to climate change. To investigate the spatiotemporal relationships between vegetation type conversion and permafrost change, an observational study was conducted in Northeast China from 2000 to 2024 based on geospatial data. This study quantified the frequency of changes in permafrost stability type (FCT) and assessed the development trend of permafrost stability, calculated the comprehensive and single vegetation type dynamic ratios (CV and SV). Results show that CV and FCT exhibit a synchronous upward trend, with a strong linear relationship (R²=0.9532). CV is most pronounced in zones where permafrost development is strengthened, reaching 15.88%. Within the study area, 67.47% of the permafrost has undergone at least one change in stability type, with the FCT =2 being the predominant type. The conversion from grassland to cropland and deciduous broad-leaved forest (DBF) is the main path. Grassland experienced the largest net area loss (7,556.94 km²), while cropland and DBF increased by 2,965.46 km² and 4,534.01 km² respectively, being the vegetation types with the largest net increase. This work will contribute to informing ecosystem management and policy-making in cold regions under climate change.
 

Permafrost changes; Vegetation type conversions; Northeast China; Remote sensing; Spatiotemporal analysis