Alpine grassland degradation reduced plant species diversity and stability of plant communities in the Northern Tibet Plateau

Abstract

The alpine grassland in the Northern Tibet Plateau has been degraded in recent decades. This study aimed at addressing the effects of the degree of degradation on species diversity and stability of plant communities and the relationships between diversity stability. Stability of plant communities decreased with the increasing degree of degradation probably due to the significantly decreased diversity and evenness of plant communities with degradation. Diversity (including Shannon and Simpson diversity, Pielou evenness, and species richness) was positively correlated with the corresponding stability of plant communities. This suggets that high levels of plant diversity lead to higher levels of complementary resource use via niche complementation. The relative abundance of the most dominant species was negatively correlated with the stability of the corresponding plant communities. This suggests that the stability of plant communities decreases with increasing degradation but the relative abundance of the most dominant species increases with degradation. In conclusion, diversity and the corresponding stability of plant communities decrease with increasing degradation in the alpine grassland in the Northern Tibet Plateau.