Figure 1 Heat map of the importance value and niche breadth of dominant plants in different grassland types.
3.2 Relationship between species diversity and ecosystem functions
Most keystone species were significantly correlated with ecosystem functions except for the belowground biomass and ratio of organic carbon to total nitrogen (Figure S9). Species diversity indices were significantly correlated with ecosystem functions. Specifically, total nitrogen, organic carbon, alkali hydrolyzed nitrogen, and N: P were positively correlated with plant diversity indices, bacterial Chao1, and the number of rodent species, while available phosphorous was negatively correlated with plant diversity indices, bacterial Chao1, and the number of rodent species (Figure S10). For different trophic level, the plant diversity, bacterial diversity, Fungal diversity and rodent diversity yielded significantly positive and negative relationships with ecosystem functions. When the multitrophic diversity were examined, the most ecosystem functions increased along with increasing multitrophic diversity except for available phosphorus (Figure 2).