Relationships among shrub leaf traits in Inner Mongolia and comparison in different spatial scales

Based on the sampling and measurement along a 1 100 km shrubbiome transect across the arid and semiarid region in Inner Mongolia, northern China, we examined the relationships of leaf mass and areabased leaf mass per area (LMA), net photosynthetic rate, N and P content, and compared the leaf trait relationships in this study with shrub trait data across Chinese grassland and global scales. The main results were as follows: 1) In Inner Mongolia，LMA was significantly and negatively correlated with massbased net photosynthetic rate, N and P content, and was positively related to areabased N and P content. Mass or areabased, leaf net photosynthetic rate, N and P content were positively correlated with each other. 2) LMA, N and P content showed an isometric scaling relationship with each other, and areabased traits were more tightly related with each other than massbased ones. The scaling relationships between leaf photosynthetic rate and LMA, N and P content were allometric, and massbased traits were more tightly correlated than areabased traits. 3) Leaf traits showed stronger scaling relationships with increasing spatial scales, and the scaling exponents also revealed systematically change with increasing spatial scales. Our results strongly support that there is a global general scaling relationship among key functional leaf traits.