冀北沙荒地不同坡位黄柳生物沙障对物种组成及多样性的影响

Effect of Hebei Areas at Different Slope Salix gordejevii Sand Barrier on Species Composition and Diversity

【目的】为冀北沙漠化土地生物多样性保护提供基础资料和实验证据。【方法】以冀北承德地区植被退化的沙漠化土地为研究对象,通过调查沙荒坡地不同坡位带状黄柳生物沙障内物种组成和数量特征,计算物种多样性指数,分析不同坡位黄柳沙障对物种结构及多样性影响。【结论】不同坡位建立黄柳生物沙障,植被恢复效果明显,从坡顶到坡底,群落物种数量逐渐增加,群落优势物种发生了显著的变化,逐渐从一年生草本地肤(Kochia scoparia(L.)Schrad.)变为多年生花苜蓿(Medicago ruthenica(L.))、多花胡枝子(Lespedeza floribunda Bunge)。【结果】不同坡位的群落内共出现植物物种7科11属17种,其中坡顶出现4科6属8种植物,坡中出现植物共4科8属8种,坡底出现植物共7科10属15种。坡顶、坡中、坡底物种丰富度指数表现为坡底>坡顶>坡中,Shannon-wiener多样性指数随海拔的增加而减小,Pielou均匀度指数和Simpson多样性指数伴随海拔的升高先降低后升高,坡底物种多样性明显高于坡顶和坡中。

【Objective】To provide basic data and experimental evidence for biodiversity protection in northern Hebei sandy desertification land.【Method】The vegetation degraded sandy desertification land in Chengde region of northern Hebei was used as the object of study to investigate the species composition and quantitative characteristic in the banding Salix gordejuvi i biological sand barriers at different slope positions of the sandy wasteland,calculate the species diversity index,and analyze the influence of Salix gordejuvii at different slopes on the species structure and diversity.【Conclusions】Salix gordejuvii biological barriers are constructed at different slope positions,which lead to obvious vegetation recovery effect.From the top of slope to the lower foot of slope,the community species amount is gradually increased,and the community dominant species have been significantly changed from the annual herb(Kochia scoparia)to the perennial herb(Medicago ruthenica and Lespedeza floribunda).【Results】A total of 17 plant species belong to 10 genera of 7 families occurred in the community at different slope positions,including 8 plant species of 6 genera of 4 families in the top of slope,8 plant species of 8 genera of 4 families in the middle of slope,and 15 plant species of 10 genera of 7 families in the lower foot of slope.The species abundance index in the plant community within the Salix gordejuvii sand barriers at different slope positions followed the order of lower foot of slope>top of slope>middle of slope.Besides,the Simpson diversity index and Pielou evenness index were first decreased and then increased with the increased in altitude,while the Shannon-wiener diversity index was decreased with the increase in altitude,and the species diversity in the lower foot of slope was remarkably higher than those in the top of slope and the middle of slope.