The Study On Community Characteristics In Relation With Influence Factors Of Taxus Cuspidata

Taxus cuspidata is a class Ⅰ protected plant in China.Due to human interference,its natural population has been severely damaged in recent years because of its medicinal and ornamental value.It has been listed as a national minimum population species protection plant.This paper takes the plant communities in the habitat of Taxus cuspidata in Northeast China as the research object.Based on field surveys,the principles and methods of ecology are applied to study the species composition characteristics,species diversity characteristics,and the distribution of Taxus cuspidata population in the communities of Taxus cuspidata.Factors and other content are studied.It is expected to provide data support for the habitat selection of in situ and ex situ conservation of Taxus cuspidata.Research indicates:(1)There are five community types in the community types of Taxus cuspidata:Pinus koraiensis-Tilia amurensis forest,Pinus koraiensis-Abies nephrolepis forest,Pinus koraiensis-Ulmus laciniata fore st,Pinus koraiensis-Betula costata forest,and Mixed forest community.Among the 21 survey sites,80.95%of the community types belong to Pinus koraiensis-Tilia amurensis forest,and Pinus koraiensis-Abies nephrolepis forest.Taxus cuspidata was the most abundant species in the forest of Pinus koraiensis-Tilia amurensis forest,and the distribution frequency was the highest in the forest of Pinus koraiensis-Abies nephrolepis forest,and even the distribution of patches was found.(2)After indoor identification and statistics,it was found that there were 48 families,,91 genera and 108 species of plants in the distribution community of Taxus cuspidata.Among them,there are 30 species of 21 genera in 14 families of arbors,24 species of 20 genera in 12 families of shrubs,and 54 species of 52 families in 29 families of herbs.The subjects with a large number and number of species within the family are Rosaceae,Liliaceae,Ranunculaceae,Saxifragaceae,Umbelliferae,Pinaceae..The plant community in the distribution community of Taxus cuspidata is rich in plant species with high buds,less shoots on the ground,and more ground buds and cryptophytes.(3)In the species diversity of the community,the species diversity index in the arbor layer and herb layer of the Pinus koraiensis-Tilia amurensis forest,and Pinus koraiensis-Abies nephrolepis forest were significantly higher than the other three types of communities.Among the shrub layers,the species diversity index of Pinus koraiensis-Abies nephrolepis forest and Pinus koraiensis-Ulmus laciniata forest were higher than the other three types of communities.Taken together,the species diversity index of Pinus koraiensis-Abies nephrolepis forest is the highest.(4)Ecological factors such as elevation,aspect,slope position and slope have significant effects on the population distribution of Taxus cuspidata.The correlation analysis of the number of individuals and ecological factors in the main forest layer of Taxus cuspidata showed that the degree of canopy was significantly negatively correlated with the number of individual individuals,and the slope gradient was positively correlated with its elevation.The results of the analysis show that the highest altitude range of the Taxus cuspidata population ranges from 700m to 900m above sea level.In terms of slope direction,the number of populations on the shady slope is significantly greater than that on the sunny slope;in the selection of slope position,the northeastern red beans are selected.The fir is more suitable for growing in the middle and upper part of the mountain.The population of Taxus cuspidata is mostly distributed in the mountainous areas below 100 to 20°.With the increase or decrease of the slope,the number of populations is significantly reduced.