The Population Structure And Distribution Of Rhododendron Latoucheae In Fengyangshan Nature Reserve

Using the method of plots and by the Precise positioning,25 fixed plots were established in the core area which is about 1400 meters above sea level in Fengyang Mountain Nature Reserve. By analysing the population structure and distribution pattern of Rhododendron latoucheae,and by studying on the niche of dominant tree species,species correlation and diversity,the protectional and organizational subjection were given.The conclusions as follows:(1) The community has high species diversity,the order of the species diversity in different layers was as follows:tree layer > shrub layer >herb layer.By analysing the correlations of different diversity indexes,we found the shannon-wienner was the best index to test the species diversity.(2)The distribution of the R.latoucheae population in every age class was very uneven, the proportion of the forth-class young tree was the largest, then was the third-class seedings. So the age structure of the population was growing; The distribution pattern of R.latoucheae population in the whole community was clumped, It was mainly related to the parental habits of distributing seed. The dynamic distribution pattern from seedlings to big trees were all clumped, but from seedlings to big trees, the population showed the trend of diffusion. It was related to their biological and ecological characteristics.(3)The niche breadths were measured by Levins and Shannon weiner index respectively, there were many differences between two results, but two results all showed the largest niche breadth was Schima superba, the niche similarities among the dominant species were very big, this showed that they had high similarity in using the resources. There was no obvious correlation between niche similarity and niche breadths. the niche overlap among the dominant species were very big, and the values of Lih and Lhi were almost same, If the niche similarity was big the niche overlap was big, so did the opposite.(4)The overall associations of populations were obviousely positive correlations,and the community was on a steady status. Correlation index and chi-square test were used to test the dominant populations correlations of tree layer.The results of correlations were similar between AC-value and chi-square test.In 45 species paires ,most of them were negative correlation and without correlation.