若尔盖高原典型草地灌丛化对植被特征和土壤养分的影响

本文以若尔盖高原高山绣线菊(Spiraea alpina)、管花忍冬(Lonicera tubuliflora)、高山柳(Salix cupularis)三类典型灌丛为研究对象,分析其林下灌丛斑块与邻近草地斑块植被特征和土壤养分差异。结果显示:相较于各自草地斑块,高山柳灌丛斑块内植被总盖度、生物量、丰富度指数、多样性指数、优势度指数均显著下降(P<0.05),土壤全量养分与速效养分含量上升;高山绣线菊灌丛斑块除丰富度指数外各项指数均上升,其中总盖度显著上升(P<0.05),土壤全量养分与速效钾含量均上升,而有效磷含量显著下降(P<0.05);管花忍冬灌丛斑块除丰富度指数外,其余植被特征指标均上升,且土壤全钾、全磷、碱解氮、有效磷、有机质含量同样上升,而土壤全氮与速效钾含量下降。本研究可为不同优势灌木的高寒草地灌丛化控制与利用提供参考。

Effects of Typical Shrub-encroached Grassland on Vegetation Characteristics and Soil Nutrients in the Zoige Plateau

In this paper,we chosed three types of typical scrub patches,Spiraea alpina,Lonicera tubuliflora and Salix cupularis,on the Zoige Plateau to analyze the vegetation characteristics and soil nutrient differences between scrub and grass patches.The results revealed that three types of shrub patches compared with the respective grassland patches,the total coverage,biomass,Margalef,Shannon-Weiner,and Simpson in the Salix cupularis shrub patches decreased significantly (P<0.05),and the total soil nutrients and available nutrients increased.In the Spiraea alpina shrub patches,all indices except richness index increased,among that total cover increased significantly (P<0.05),and the content of total soil nutrients and available potassium increased (P<0.05).Lonicera tubuliflora shrub patches had higher plant community characteristics than grass patches except for Margalef.And Lonicera tubuliflora patches had more elevated total soil potassium,total phosphorus,available nitrogen,available phosphorus,and organic matter than grass patches,while grass patches had higher total nitrogen and available potassium contents than Lonicera tubuliflora patches.This study can provide a reference for the control and utilization of different dominant shrubs in alpine grassland.