水盐变化对荒漠植物功能多样性与物种多样性关系的影响

Effects of soil water and salinity on relationships between desert plant functional diversity and species diversity

研究植物功能多样性与物种多样性关系对土壤水盐环境的响应规律,有助于掌握胁迫环境下植物多样性的维持机理.本研究分析了艾比湖高、低土壤水盐环境下荒漠植物功能多样性、物种多样性差异及二者间关系在不同水盐环境下的变化规律.结果表明:(1)高水盐环境下植物功能离散度显著低于低水盐环境(P<0.05),物种多样性指数Fish-α显著高于低水盐环境;(2)一元与多元回归分析均表明,高水盐环境下物种多样性对功能多样性RaoQ与FRic指数有显著促进作用,低水盐环境下物种多样性对功能多样性和均匀度有显著促进作用,但对功能离散度具有显著抑制作用(P<0.05);(3)物种多样性对功能多样性的影响在低水盐环境下更显著,预测力更强;(4)功能丰富度、离散度与均匀度能较敏感地反映出荒漠植物功能多样性对水盐变化的响应.本研究有助于理解荒漠植物群落构建机制,并为荒漠植物恢复与管理提供理论参考.

Understanding the responses of the relationships between plant functional diversity and species diversity to the variation of soil water and salinity is beneficial to revealing the mechanisms underlying species coexistence in stressful environment. In this study, we analyzed plant functional diversity, species diversity, and the variation of their relationship under high and low soil water and salinity environment in a desert near Ebinur Lake. We found that:(1) Functional divergence in high soil water and salinity environment was significantly lower than that in low soil water and salinity environment, whereas the pattern of species diversity index (Fish-α) was opposite.(2) Results from both simple and multiple regression analysis showed that species diversity significantly improved functional diversity (RaoQ) and functional richness in conditions with high soil water and salinity, while in low soil water and salinity environment, species diversity improved functional diversity and functional evenness, but suppressed functional divergence.(3) Species diversity had higher predictive power for functional diversity in low soil water and salinity environment.(4) Functional richness, divergence and evenness were more sensitive to the changes of soil water and salinity. Overall, this study provides valuable clues for plant community assembly, recovery and management in desert.