Spatial patterns and drivers of ecosystem multifunctionality in China: Arid vs. humid regions.

Ecosystem multifunctionality (EMF) refers to an ecosystem's capacity to simultaneously uphold multiple ecological functions or services. In terrestrial ecosystems, the potential patterns and processes of EMF remain largely unexplored, limiting our comprehension of how ecosystems react to various driving factors. We collected environmental, soil and plant nutrient data, investigate the spatial distribution characteristics of EMF in China's terrestrial ecosystems, differentiating between arid and humid regions and examining the underlying drivers. Our findings reveal substantial spatial heterogeneity in the distribution of EMF across China's terrestrial ecosystems, with pronounced variations between arid and humid regions. In arid regions, the EMF index predominantly falls within the range of -1 to 1, including approximately 66.8 % of the total area, while in humid regions, the EMF index primarily falls within the range of 0 to 2, covering around 55.2 % of the total area. Climate, soil, and vegetation factors account for 61.4 % and 51.9 % of the total EMF variation in arid and humid regions, respectively. Notably, climate emerges as the dominant factor governing EMF variation in arid regions, whereas soil physicochemical properties take precedence in humid regions. Specifically, mean annual temperature (MAT) emerges as the primary factor influencing EMF variation in arid regions, while the normalized difference vegetation index (NDVI) and soil biodiversity index (SBI) play pivotal roles in regulating EMF variation in humid regions. Indeed, climate can exert both direct and indirect influences on EMF. In summary, our study not only compared the disparities in the spatial distribution of EMF in arid and humid regions but also unveiled the distinct controlling factors that govern EMF changes in these different regions. Our research has contributed novel insights for evaluating the drivers responsible for mediating EMF in diverse ecosystems, shedding light on the adaptability and response mechanisms of ecosystems under varying environmental conditions.