海拔梯度对贺兰山岩羊主要活动区植物群落特征的影响

Change in plant community characteristics along altitudinal gradients in the main browsing areas of Pseudois nayaur in the Helan Mountains

研究贺兰山岩羊主要活动区植物群落组成和物种多样性在不同海拔梯度的变化规律对贺兰山岩羊的合理管护具有重要意义。本研究通过贺兰山岩羊主要活动区植被调查,对不同海拔的数据进行单因素方差分析和回归分析,阐明1100~1500 m、1500~2000 m、2000~2500 m和大于2500 m的4个海拔段岩羊主要活动区植物物种组成和物种多样性的变化,探讨植被与岩羊等草食动物的关系及海拔对植物物种多样性的影响。结果表明:贺兰山岩羊主要活动区植被共记录到30科62属87种,主要为禾本科、蔷薇科和菊科等植物;同时,不同海拔梯度上的科、属、种的数量和组成存在差异。随着海拔上升,岩羊主要活动区的草本植物的物种丰富度升高,Pielou均匀度指数、Shannon-Wiener多样性指数和Simpson优势度指数表现为先降低后升高的特征;灌木植物物种丰富度、Pielou均匀度指数呈现出沿海拔上升而降低的特征,Shannon-Wiener多样性指数和Simpson优势度指数呈现出先增加后降低的特征。因此,针对不同海拔植物物种多样性的不同,建议对岩羊的合理管护在不同海拔地区采取不同措施,以达到防止植被退化和促进岩羊种群健康发展的目的。

In this research a vegetation survey was conducted to evaluate the changes in plant community composition and species diversity along altitudinal gradients in the main browsing areas of Pseudois nayaur(blue sheep)in the Helan Mountains.Such data is important for the successful management and protection of P.nayaur.One way ANOVA and regression analyses were performed for data from different altitudes.Changes in plant species composition and species diversity were elucidated for four altitudes(1100-1500 m,1500-2000 m,2000-2500m,and above 2500 m)in the main browsing areas of P.nayaur.The influence of altitude on plant species diversity and the relationships between vegetation and herbivores such as P.nayaur are discussed.There were found to be 87plant species,62 genera,and 30 families in total,mainly Poaceae,Rosaceae,and Asteraceae in the P.nayaur browsing areas.Meanwhile,there were differences between altitudes in the number and composition of families,genera,and species.With increasing altitude,the species richness of herbaceous plants also increased,while other indices including the Pielou evenness index,Shannon-Wiener diversity index,and Simpson dominance index all initially decreased and then increased.For shrubs,the species richness and Pielou evenness index decreased with increasing altitude;While the Shannon-Wiener diversity index and the Simpson dominance index both peaked at intermediate altitudes.Therefore,in view of the different plant species diversity patterns at different altitudes,it is suggested that different measures should be taken at different altitudes to prevent vegetation degradation and promote the sustainable conservation of the P.nayaur population.