不同退化程度高寒草甸植物物种多样性与生态系统多功能性关系

为探究高寒草甸不同退化程度生态系统多功能性的变化，本研究综合考虑了植物物种多样性和多种生态系统功能如生产力、养分循环和固存能力、土壤涵养水分能力等，运用降维因子分析的方法计算了生态系统多功能性，综合分析了植物物种多样性与生态系统功能和多功能性间的关系。结果表明：高寒草甸退化显著降低了Margalef指数、Shannon-weiner指数、Simpson指数和Pielou指数(P<0.05)，各生态系统功能趋于恶化。高寒草甸退化导致生态系统多功能性的下降，综合统计量结果为轻度退化(21.9955)＞中度退化(8.7295)＞重度退化(—30.7245)。植物物种多样性与生态系统多功能性之间均存在正相关关系，其中Simpson指数与生态系统多功能性指数拟合的结果最好，说明高寒草甸生态系统多功能性受植物物种多样性的制约。本研究可为青藏高原草地退化及恢复的过程和机理研究提供理论依据。

Relationship Between Plant Species Diversity and Ecosystem Multifunctionality in Alpine Meadow with Different Degradation Degrees

In order to explore the changes in ecosystem multifunctionality in an alpine meadow with different degrees of degradation,this study comprehensively considered plant species diversity and various ecosystem functions,such as productivity,nutrient circulation,and storage capacity,soil water conservation capacity,etc. The multi-functionality of the ecosystem was calculated by dimension reduction factor analysis,and the relationship between plant species diversity and ecosystem functions and multifunctionality was comprehensively analyzed. The results showed that the degradation of the alpine meadow significantly reduced the Margalef index,Shannon Weiner index,Simpson index,and Pielou index (P<0.05),and each function of the ecosystem tended to deteriorate. The degradation of the alpine meadow led to the decline of ecosystem multifunctionality. The comprehensive statistical results were:Lightly degraded (21.995 5)>Moderately degraded (8.729 5)>Severely degraded (-30.724 5). There was a positive correlation between plant species diversity and ecosystem multifunctionality,among which the Simpson index and ecosystem multifunctionality index fitted best,indicating that the alpine meadow ecosystem multifunctionality was restricted by plant species diversity. This study can provide a theoretical basis for the study of the process and mechanism of grassland degradation and restoration in the Qinghai Tibet Plateau.