3.4 Plant species dominance
Warming significantly decreased plant community evenness, but warming had differential impacts on species dominance (Fig. 4, and Tables S4 and S5). The RDA analysis with treatment and environmental variables accounted for 41% of the variation in species dominance (Fig. S5). In general, species with a greater extension in growing season length and flower duration tended to increase their dominance (Fig. 5). The positive relations were also observed between warming-induced shifts in last flower and leaf senescence dates and warming-induced changes in species dominance (Fig. 5). Specifically, warming-induced changes in last flower, leaf senescence, flower duration and growing season length explained 16, 8, 27 and 22% variance of warming-induced changes in species dominance, respectively. By contrast, there was no relation between warming-induced changes in leaf out and first flower dates and warming-induced changes in species dominance (Fig. S6).