Climate-Driven Vegetation Distribution and Wetland Expansion at the Edge of Jiangjiadian Grassland, Northeastern China

There is a close relationship between vegetation distribution and climate pattern in grassland areas, and offering insights into the climate–vegetation relationship may provide significant references for in-depth research on the response of plant community dynamics to climate change. In this study, we took the edge of the Jiangjiadian grassland in China as the research area. Using plant plots and climate data, the climate–vegetation relationship was revealed in relation to climate change on the grassland edge. The research results show that the relative frequency (RF), density (RD), height (RH), and coverage (RC) of Phragmites australis, a typical wetland plant, are the highest among the 10 common species tested. The path coefficient of mean temperature in October (MMTO) to the RD is 0.06 (p < 0.01), and the path coefficient of precipitation in October (POct) to the relative height (RH) is 0.62 (p < 0.05), indicating that the spatial pattern of climate has a significant impact on plant distribution. The temperature and the precipitation increases are associated with the trend regarding the transformation from grassland to wetland. Overall, 34 of the 360 correlation coefficients between climate indices and plant indices reached a significant level (p < 0.05), indicating that the relationship between wetland trends and the climate spatial pattern is very complex in relation to climate change in the past 25 years.