Reduced vegetation cover caused by grassland degradation results in the interception of solar illuminance significantly decreasing, then leading to an increase in ground temperature, which has a significant impact on biological growth and regional climate. Based on the field experiment, we explore the interception of solar illuminance by grasslands with three degrees of degradation and its effect on the soil temperature. Solar illuminance at various heights and times was measured to obtain the interception by vegetation, which included reduction by physical shielding and consumption by the plants’ life activities. Solar illuminance in the subareas sprayed with herbicide was merely reduced by physical shielding, and the difference in solar illuminance interception between normally growing grasslands and fatal grasslands was used for the plants’ life activities. This method described above was almost the first to be used for the exploration of the functional allocation of solar illuminance interception. The percentage of solar illuminance interception was largest in the non-degraded grassland (80–95% at different times), including a 50–60% reduction on account of physical shielding and a 20–45% consumption by the grass’s life activities. Light interception by grassland vegetation directly reduced the grassland temperature. The increment of ground temperature reaches 4–13 °C when a non-degraded grassland turns into a severely degraded grassland.
Precipitation is a fundamental element in terrestrial water circulation and ecosystem hydrological balance. The occurrence of concentrated precipitation is closely linked to vegetation growth and soil fertility rather than accumulated or averaged precipitation. Despite its importance, the characteristics of continuous precipitation and its specific effects on vegetation cover remain uncertain. In this study, we formulated a new continuous precipitation index system, including (continuous precipitation days); (annual continuous precipitation times); (continuous precipitation amount); and (frequency in different ranges of ). We utilized daily precipitation data from 467 meteorological stations across China, which were divided into eight vegetation type regions. We observed that the spatial distribution of continuous precipitation differed to varying degrees from accumulated precipitation. The national average of for a single event was 16.7 mm, ranging from 3.8 mm in the temperate desert region to 37.1 mm in the tropical monsoon forest and rainforest region. Similarly, the national average of () for a single event was approximately 2.3 or 9 days. At the regional level, the tropical monsoon forest and rainforest region experienced the longest . Furthermore, the national average of occurrences for 1 year was 57.7 times, varying from 29.8 times in the temperate desert region to 77.9 times in the tropical monsoon forest and rainforest region. Vegetation responses to precipitation regimes exhibit significant regional heterogeneity across China. Our analysis reveals that and show markedly positive correlations with vegetation growth. In subtropical monsoon climate zones, particularly the Yunnan–Guizhou Plateau and Qinling Mountains, demonstrates strong positive correlations (r = 0.6–1.0) with NDVI, where sustained rainfall provides stable moisture availability for vegetation. While a positive correlation between vegetation (NDVI) and mean annual consecutive precipitation is observed in some arid northern regions, in ecosystems such as the Loess Plateau (TG/TM), vegetation growth shows greater dependence on , highlighting the crucial role of total precipitation amount in water-limited ecosystems. Notably, extreme precipitation events display dual effects on vegetation dynamics. Prolonged heavy rainfall (/) exhibits significant negative impacts on NDVI (r = −1.0 to −0.6) in topographically complex regions, including the Hengduan Mountains and Yangtze River Basin (SE), likely due to induced soil erosion and waterlogging stress. Our findings underscore the importance of incorporating continuous precipitation indices to evaluate and forecast the influence of precipitation on ecosystem stability. This understanding is vital for developing informed conservation and management strategies to address current and future climate challenges.