西藏泡核桃群落结构及物种多样性分析

The Structure Characteristics and Species Diversity of Juglans sigillata Communities in Tibet Autonomous Region

以西藏林芝县排龙乡泡核桃天然群落为对象,应用样方调查法和每木调查法调查了群落种类组成和结构特征,以及群落乔木层和灌木层的物种多样性。调查结果显示,泡核桃群落中共出现种子植物33科47属55种,群落的表征科为蔷薇科和菊科。群落层次结构明显,可分为乔木层、灌木层、草本层3个层次及层间植物,其中灌木层与乔木层的中下层个体数量占有较大优势。伴生落叶树种主要以蔷薇科、樟科植物为主,常绿阔叶树种主要以壳斗科和五加科为主。物种的重要值计算结果显示,在乔木层中核桃的重要值为161.63,占有绝对优势,通麦栎其次,但重要值仅为52.54,排在第三位的是针齿铁仔,重要值为26.08。年龄结构显示核桃种群呈双峰型,具有继续稳定发展的趋势,亚优势种通麦栎的年龄结构呈增长型发展趋势。

Field surveys were conducted on the Juglans sigillata community found in the Pailong Township,Nyingchi County,Tibet. By using methods of plots and technique of censuring every individual,we indentified and measured all trees in quadrats established in the community to quantify the community structure characteristics and the species diversity of tree and shrub layers. The results of walnut community component indicate that there are 33 families of seed plants,including 47 genera and 55 species in walnut community. The dominant families are Rosaceae and Compositae. There are three plant layers of walnut forest community,the tree,shrub and grass. The number of individuals in shrub layer and middle-under layer of tree layer are dominant. Interlayer plants are sparse. The associated deciduous trees are main Compositae and Rosaceae and associated Evergreen trees are main Araliaceae and Fagaceae.In tree layer,the important value of Juglans sigillata is 161. 63,which is the highest of all the species,the second is Quercus tungmaiensis,52. 54; the third is Myrsine semiserrata,26. 08. According to the biological and ecological characteristics,the population regeneration types of J. sigillata were Bimodal,which predict the population will develop toward the community climax as the dominant species. At the same time,the population regeneration types of Quercus tungmaiensis were Pyramid,means that its population got the increasing trend.