大通县退耕还林不同配置模式物种多样性的研究

研究结果表明,大通县退耕还林不同配置模式下群落物种多样性指数与丰富度、均匀度呈显著正相关,与优势度呈显著负相关。群落物种多样性指数排序,在浅山区为模式C(青杨 枸杞)>模式D(中国沙棘)>模式B(紫花苜蓿)>模式A(川赤芍)>模式E(柠条),多样性指数分别为5.309 1、5.089 4、4.657 3、4.081 6、3.410 5;在高山区为模式H(白桦 青海云杉)>模式J(青杨 中国沙棘)>模式G(华北落叶松)>模式F(青海云杉)>模式K(青海云杉 中国沙棘),多样性指数分别为5.228 9、5.071 7、4.699 2、2.780 9、2.646 2,群落乔、灌、草3层结构物种多样性指数呈现出草本层>灌木层>乔木层的规律,在优势度方面,草本层在森林中的作用远不及乔木层。

Species Diversity of Different Species Arrangement Models in Converting Cropland to Forest in Datong, Qinghai

The result of this study showed that the species diversity index of different species arrangement models was positively correlated to richness and evenness,and negatively correlated to the dominace in the converted land for forest in Datong County.The Shannon-Weiner index is as following: in low mountain areas,model C(Populus cathayana Lycium chinense >model D(Hippophae rhamnoides ssp.sinensis)>model B(Medicago saetiva)>model A(Paeonia veitchii)>model E(Caragana korshinskii).The Shannon-Weiner indexes are 5.309 1,5.089 4,4.657 3,4.081 6,3.410 5.In high mountain areas,model H(Betula platyphylla Picea crassifolia)>model J(Populus cathayana Hippophae rhamnoides ssp.sinensis)>model G(Larix principis-rupprechii)>model F(Picea crassifolia)>model K(Picea crassifolia Hippophae rhamnoides ssp.sinensis).The Shannon-Weiner indexes are 5.228 9,5.071 7,4.699 2,2.780 9,(2.646 2).The rule of species diversity index is in the order of first herb layer,second shrub layer,third tree layer,while taking dominance into account,the effect of tree layer is much better than herb layers.