宁夏毛乌素沙地不同恢复措施对物种结构及多样性的影响

Influence of different recover measures on species structure and variety in Mu Us sandy land

以宁夏毛乌素沙地退化草原区为研究对象,对荒地(对照)和种植不同密度的柠条林的恢复措施条件下群落结构及多样性进行研究。结果表明,种植柠条林对退化草原的植被恢复有积极的作用,随着柠条林带间距的增加群落结构更趋稳定。由对照的不稳定一年生植物虫实、猪毛菜逐步向稳定的多年生植物白草、赖草、草木犀状黄芪演替。植物群落盖度表现为柠条10m带间距>7m带间距>对照>4m带间距。群落多样性指数表现为柠条10m带间距>4m带间距>对照>7m带间距。群落的均匀度指数变化趋势与群落多样性指数呈正相关。

The study of retrogress grassland species structure and diversity under the wasteland and Caragana forest with different density recover measures in Mu Us sandy land showed that the planting Caragana forest played a positive role in vegetation restoration.Along with the span of Caragana rows increasing,community structure tended to be more stable.Community structure succeeded from the instable annual of species of C.tylocarpum and Salsola collina in the wasteland to stable perennial species dominated by Pennisetum centrasiaticum,Leymus secalinus and Astragalus melilttoides .Vegetation coverage was in order of 10 m>7 m >4 m in terms of span width,while that of the community diversity was 10 m>4 m >7 m.There was positive correlation between the community evenness index and diversity index,while negative correlation between the dominate index and diversity index.