第九届青年地学论坛

Carrying out research on grassland ecological changes caused by shrub invasion at the regional scale is of great significance for a deeper understanding of the phenomenon of shrub encroachment. This paper takes Xilin Gol League as the research area, based on the shrub-encroached grassland (SEG) classification results in five periods from 2000 to 2020, and uses regression analysis to explore the relationship between vegetation coverage, surface temperature, landscape index, and the SEG area. Results show that from 2000 to 2020, vegetation coverage increased by approximately 0.067 and 0.058 at the 1-km and 3-km scales, respectively. There is a significant linear relationship between the increased SEG area and vegetation coverage change at the 1 km scale (R²>0.67, p<0.005), while their linear relationship is weaker at the 3 km scale. During the same study period, the daily average temperature at the 1-km and 3-km scales decreased by approximately 1.128°C and 2.76°C, respectively, indicating that shrub invasion brought significant cooling effects. In addition, changes in landscape patterns showed nonlinear relationships with the SEG area. The relationships between SEG area and landscape fragmentation, complexity, and spatial heterogeneity first increasing and then decreasing. Our findings can provide a reference for grassland protection and management.

shrub encroachment; ecological environment; landscape pattern