Impacts of extreme temperature changes on fractional vegetation cover in marshes of China

China ranks third worldwide in terms of marsh areas. Marshes in China play an important role in regional aquatic ecosystem security and the carbon cycle. Understanding the impacts of extreme climatic changes on marsh vegetation is crucial for predicting the regional carbon cycle. Using the NDVI and meteorological data, we analyzed the spatiotemporal variation in fractional vegetation cover (FVC) and the impacts of extreme temperature changes on the marsh FVC in China. We observed that the marsh FVC during the growing season increased significantly ( p < 0.01) by 2.6%/decade in China from 2001 to 2021. The reduction of extreme high‐temperature and extreme low‐temperature events can both increase marsh FVC in China, but the reduction of extreme low‐temperature events has a more significant promoting effect on the increase of marsh FVC. This study highlights the asymmetric effect of extreme high and low temperature changes on the marsh FVC in China.