3.3 Species richness of communities and functional groups and
their relationship with climate factors
Community species richness ranged from 18 to 44 (mean 34), and declined
through time (Fig. 4a; P = 0.001;
R2 = 0.34). The average rate of loss of species
richness was 4.5 species m-2decade-1 during the period of 1981–2011. Similar to
community species richness, species richness of functional group PF
decreased during the observation period (Fig. 4d; P = 0.003;
R2 = 0.29). In contrast, we found no trend of species
richness of functional groups PR, PB, SS, and AB through time (Fig.
4b-c, e-f). The average loss rate of species richness of functional
group PF was 3.7 species m-2decade-1, community species richness was largely
related to the species richness of functional group PF (Fig. S3).