Fig. 4 Changes in species richness of (a) community, (b) PR, (c) PB, (d) PF, (e) SS, and (f) AB from 1981‑2011. Asterisks indicate significant changes in species richness (*P<0.05, **P < 0.01). Abbreviations: perennial rhizome grass (PR), perennial bunchgrasses (PB), perennial forbs (PF), shrubs and semi-shrubs (SS), and annuals and biennials (AB).
The dynamics of species richness were also related to climate factors (Table 1). The species richness of the community and functional group PF were positively correlated with P7 and P6-9, and negatively correlated with T6 and T6-7, respectively. In addition, a positive correlation was also observed between P1-9 and species richness of functional group PF. The species richness of functional groups PR and PB were positively correlated with T7 and P7-9, respectively. Additionally, P5 and P7 were positively correlated with species richness of functional group AB. The species richness of functional group SS was not related to any of the climate factors investigated.