补播对中度退化高寒草地群落特征和多样性的影响

Effects of Reseeding on Plant Community Composition and Diversity of Moderately Degraded Alpine Grassland in Qinghai-Tibetan plateau

为研究补播对高寒草地群落特征和植被多样性的影响,本研究以黑土滩中度退化草地为对象,利用免耕补播机通过近自然补播措施进行了恢复,测定了恢复后草地的群落组成及多样性特征。结果表明:经人工补播后,退化草地的植被盖度,地上、地下生物量,禾本科牧草比例和根冠比都显著上升(P<0.05),补播措施起到了很好的修复效果。从物种组成上看,退化草地经过补播之后,其植被群落组成和物种重要值都发生了变化。其中,禾本科牧草和莎草科牧草占据了重要地位。此外,物种丰富度指数、Shannon-Weiner指数、均匀度指数经人工补播后都有所上升,但差异不显著。综上所述,人工补播是高寒地区黑土滩中度退化草地修复一种快速有效的措施,能够有效的提高可食牧草的比例,同时也有利于高寒地区草地植被恢复。

In order to study the effects of reseeding on the characteristics and vegetation diversity of alpine grassland,the moderately degraded"black beach”areas were chosen to study in this paper.The near-natural replanting methods(reseeding),which was conducted by no-tillage reseeding machine,was used to recover this degraded grassland.The community composition and diversity of the grassland after restoration were determined.Our results showed that,the coverage,aboveground and underground biomass,Poaceae herbage ratio and root-shoot ratio of degraded grassland increased significantly(P<0.05)after artificial reseeding,indicating that the reseeding had a good repairing effect.For species composition,its species community composition and important values of individual species changed after artificial reseeding.And the Poaceae and Cyperaceae herbage took an important position in the community.In addition,the species richness,Shannon-Weiner and evenness index all increased after artificial reseeding,but there’s no significant difference between reseeding and the control.Overall,artificial reseeding is a quick-acting measure for the restoration of moderately degraded grassland in"black beach"land in alpine regions,which can effectively increase the proportion of edible pasture and improve grassland vegetation restoration in alpine regions.