Changes of plant species diversity and interspecific correlation in a degraded swamp community along drainage gradients on the Zoigê Plateau of China
若尔盖高原退化沼泽群落植物多样性及种间相关性沿排水梯度的变化

Aims Plant species diversity and interspecific correlation are central topics in phytocoenology and biodiversity science.Our objective is to study the dynamics and interrelationships of plant species diversity and interspecific correlation in a Zoigê Plateau swamp community at different stages of degradation caused by anthropogenic drainage.Methods Spearman’s rank correlation and regression analysis were employed to analyze plant species diversity and interspecific correlation as well as their relationship.Important findings Along drainage gradients from relatively pristine swamp to extremely degraded swamp,different plant species had restricted ecological distributions.The total number of species,species richness per quadrat,Shannon-Wiener index and Whittaker index all increased monotonically,and the intensity of interspecific correlation increased in general.The proportion of species pairs with positive correlation increased gradually with increasing level of degradation.The proportion of species pairs with negative correlation showed an opposite trend.Shannon-Wiener index showed significant linear correlation with the proportion of species pairs with positive or negative correlation(p < 0.05),but Whittaker index showed no significant correlation(p > 0.05).The positive interspecific correlation and plant species diversity of the swamp community were promoted by habitat heterogeneity caused by anthropogenic drainage.