黄河上游重大生态功能区草地逆型演替植物多样性变化研究

Species Diversity Changes in Converse Successions of Grassland in Important Eco-function Area in the Upper Reaches of the Yellow River

基于5个样地、90个样方的野外调查资料,研究了玛曲县不同退化程度草地群落植物多样性和地上生物量变化情况。结果表明:多样性指数与丰富度指数、均匀度指数及地上生物量有显著线性关系,而与优势度指数呈显著负相关。原生地带性群落以及演替早期类群多样性、均匀度、盖度及地上总生物量最高,在极度退化阶段,地上总生物量最低,优势度指数最大,随着退化程度加剧,草地群落的盖度、物种多样性指数、均匀度指数均下降,毒杂草、莎草增多,禾草急剧下降,最终导致草地初级生产力的降低。

Based on the data from 5 sampling sites and 90 quadrats, the plant diversity and above ground biomass of degenerated in different degree were studied . The result indicated that the diversity indices have the remarkable linear relations with the abundance index, the uniformity index and the above ground biomass , but have the remarkable inverse correlation with the dominance index.Original zonal communities and slightly degraded succession communities had the highest species diversity,evenness index, coverage and above-ground biomass;the above—ground biomass was the lowest ,while the dominant index was the greatest at extremely degraded grassland.With increasing degradation of the alpine grassland,the plant coverage, species diversity index,evenness index are decreasing,the forbs and sedges are increasing , the graminoids significantly decreased,lead to the decrease of reproductivity of grassland.