Analysis On Community Characteristics Of The Ephedra Equisetina In Shanxi

In Wu Lu Mountain,Zhou Hong Mountain,Wu Taishan and Heng Shan of Shanxi Province,the sample plots were set up separately in these areas where Ephedra equisetina was distributed concentratedly,which has 89 plots with 2225m~2in total.Based on field surveys and combined with relevant quantitative ecological method,this paper analyses the specie composition and Ephedra equisetina community,life style spectrum,the dynamics of population structures,species diversity,inter-specific association and other basic characteristics,which pursues to understand the composition and dynamics of community and evaluate the status of community development in order to provide a reference to the protection of Ephedra equisetina community.The results show:(1)A total of 127 species were recorded in 41 families and 97 genera in Shan Xi province.Among them,gymnosperms are 2 families,2 genera and 2 species;angiosperms are38 families 95 genera and125 species.There are 6 distribution areas and 3 variants.The distribution area of the family is the most in the world.There are 12 distribution areas and 4variations of the genus.There are 8 types of temperate distribution and 6 types of tropical species.It can be seen that the geographical distribution of the community is from temperate to tropic.The percent of Hemicryptophyte plant and high proportion takes the first two in the community life.It reflects the climate of research area is damp and rains heaviy in summer,but is cold and lasts long in winter,which is consistent with the geographical environment in Shan Xi province.(2)There are four research areas(Wu Lu Mountain,Zhou Hong Mountain,Wu Taishan,Heng Shan),with plots in order:24 families,5 genera and 58 species,15 families,28genera and 31species,14 families,23 genera and 24 species,10 families,13 genera and 14species.The number of plots is influenced by the number of quadrat investigation.But to a certain extent,it represents the Ephedra equisetina community species composition in this region.There were 14,10,10,and 5 species of casuarina in the four study areas,which are mainly distributed in the world.In the classification of life form,according to the results of five deer mountains,hemicryptophyte predominates is the top plant populationwhile high plant is the second in Zhou Hong mountain and Wu Taishan.High bud and geophyte take the first place andhemicryptophyte and chamaephytes are also growing in Hengshan.Among the four research areas,perennial herbs were dominant,followed by shrubs and half shrubs,with no tree species.(3)In this thesis,Ward's minimum variance clustering was adopted to classify the 89 samples of the Ephedra equisetina community in Shan Xi province,which was divided into 10 groups.The results show that the species diversity of group A(Ass.Ephedra equisetina-Carexlanceolata)andgroupD(Ass.Ephedraequisetina-Carex lanceolata+Glycyrrhiza uralensis)in Wulu mountain is the highest,and the last group I is located in Wu Taishan.In the comparison of species diversity in the four research areas,the species diversity index of Wu Lu Mountain and Zhou Hong Mountain was large,and the community of the Wu Taishan and the Heng Shan are seriously disturbed.(4)Analysing population age structure and population dynamics of Ephedra equisetina in the four research areas,the results shows that Ephedra equisetina species is stable and the epopulation tends to Deevey-?type in Wu Lu Mountain and Zhou Hong Mountain;Ephedra equisetina species belongs to the growing type and the population tends to Deevey-?in Wu Taishan and Heng Shan.(5)Analyzing the interspecific association between the main species in Ephedra equisetina community in Wu Hu Mountain,Zhou Hong Mountain,Wu Taishan and Heng Shan,the results show that the most of all are associated with each other.There is a significant positive correlation between Wu Lu Mountain and Wu Taishan,and there is no significant negative correlation between Zhou Hong Mountain and Heng Shan.The results shows that the positive and negative correlation ratios of Wu Lu Mountain,Zhou Hong Mountain.Wu Taishan and Hengshan are 1.07,0.83,0.77 and 0.64 respectively.In the test of Person correlation coefficient,the positive and negative correlation ratios are 0.85,0.67,0.88 and0.62 respectively;In Spearman rank correlation coefficient test,positive and negative correlation ratios are 0.96,0.96,0.88,0.83 respectively.