Land use and cover change in Northeast China and its impacts on the Xing'an permafrost in 1980s–2010s.

Boreal forest and wetland have important influences on the development and protection of the ecosystem‐dominated Xing'an permafrost. However, the responses of different ecosystems to climate change and the impacts on the underlying permafrost are still unclear. Here, based on the multi‐period land use/land cover (LULC) data and long‐time series of air temperature, combined with the ordinary least squares (OLS) and ordinary kriging (OK) methods, the effects of land use and cover change (LUCC) on the distribution of mean annual air temperature (MAAT) and permafrost in Northeast China were analyzed. From 1980s to 2010s, MAAT showed an upward trend (0.025°C per yr) and extents of permafrost showed a decreasing trend (−3668 km2yr−1) in Northeast China. Permafrost degradation mainly occurred in forested land and grassland, with areal reductions of 4.0106 × 104 and 3.8754 × 104 km2, respectively. The transformation of LULC aggravates the degradation of permafrost. The conversions of forested land and grassland to cultivated land and forested land to grassland resulted in the shrinkage of permafrost extent by 6233 km2 from 1980s to 2010s. Our results confirm the significant impacts of LUCC on the Xing'an permafrost resulting in its degradation. Additionally, they can provide a scientific basis for ecological environment protection and restoration and sustainable development of boreal forest and wetland ecosystems in permafrost regions of Northeast China. [ABSTRACT FROM AUTHOR]