Spatiotemporal Analysis of Vegetation Dynamics in Northeast China Based on Landsat Series Imageries from 1986 to 2021

Northeast China is rich in forest resources and is one of China's most crucial forest resource areas. Due to environmental changes and human impacts, long-term monitoring of the fractional vegetation cover (FVC) in Northeast China is necessary. This study investigated the vegetation dynamics in Northeast China from 1986 to 2021 using the FVC based on kernel normalized difference vegetation index (kNDVI), and analyzed the influence of human activities on FVC. In the past 36 years, the FVC in Northeast China showed a fluctuating upward trend with high spatial heterogeneity. The mountain areas are the key regions with high vegetation coverage. However, the area with increased FVC accounted for 66.7% of Northeast China, most in densely populated areas with low FVC. In general, Northeast China experienced a high growth in FVC in the 36 years, suggesting that the effects of ecological construction and vegetation regeneration were noteworthy.