【摘要】 祁连山是中国西部地区重要的安全屏障和水源涵养区，灌丛群落在水源涵养和安全屏障中起着重要的作用。为了探究祁连山灌丛群落结构随海拔和经度的变化规律，选取了甘肃省永登县奖俊埠林场（祁连山东段）、甘肃省古浪县夏玛林场（祁连山中东段）、甘肃省民乐县海潮坝森林公园（祁连山中段），分析灌丛群落Shannon-Wiener多样性指数、Pielou均匀度、物种重要值、地上生物量和盖度在海拔2 700—3 100 m的变化。结果发现，（1）随着海拔的升高，银露梅（Potentilla glabra）的优势度逐渐下降，金露梅（Potentilla fruticosa）的优势度增加，高山绣线菊（Spiraea alpina）和山生柳（Salix oritrepha）在3个海拔梯度的优势度变化不显著。（2）随着海拔的升高，Shannon-Wiener多样性指数、地上生物量和盖度递增，且各海拔之间差异显著。（3）随着经度的增加（自西向东），地上生物量和盖度呈递增趋势，而Pielou均匀度呈递减趋势；ShannonWiener多样性指数在海拔2 700 m呈递减趋势，在海拔2 900 m和3 100 m呈递增趋势。（4）Shannon-Wiener多样性指数与海拔高度、地上生物量、盖度、Pielou均匀度都存在显著相关性。以上结果表明海拔梯度和经度对灌丛群落结构直接或间接产生影响。该研究将为祁连山区灌丛的保护与开发提供一定的理论基础。更多还原

【Abstract】 Qilian Mountain is an important safety barrier and water conservation area in western China. Shrub communities play an important role in water conservation and safety protection. In order to investigate the changes of shrub community structure in Qilian Mountains with altitude and longitude. This paper selected the Jiangjunbu Forest Farm in Yongdeng County(the eastern part of Qilian Mountain), the Xiama Forest Farm in Gulang County(the middle-eastern part of Qilian Mountain), and the Haichaoba Forest Park in Minle County(the middle part of Qilian Mountain). The Shannon-Wiener index, Pielou evenness, species importance value, shrub biomass, and shrub coverage were used to reflect the changes of shrub community structure at the altitude of 2 700–3 100 m. The results showed that,(1) At the altitude of 2 700–3 100 m, Potentilla glabra decreased and Potentilla fruticosa increased, while Spiraea alpina and Salix oritrepha in three altitudinal gradients did not change significantly.(2) With the increase of altitude, the Shannon-Wiener index, aboveground biomass, and the coverage of shrubs increased and varied significantly with altitude.(3) With the increase of longitude(from west to east), the aboveground biomass and coverage of shrub increased, while the Pielou evenness decreased; the Shannon-Wiener index showed a decrease at 2 700 m and increases at 2 900 m and 3 100 m;(4) The Shannon-Wiener index was significantly correlated with altitude, aboveground biomass, coverage, and Pielou evenness. These results indicate that the altitudinal gradient and longitude have direct or indirect effects on the shrub community structure. This study will provide a theoretical basis for the protection and development of shrubs in Qilian Mountains.更多还原