Study On Quantitative Ecology Of Carpinus Cordata Communities In Lishan Nature Reserve, Shanxi

Carpinus cordata distributes widely in Northeast of and North China; and also existences in Korea and Japan. The speceis always growes on mountain slope or mixed forest in the valley, and sometimes formes into a piece of pure forest. Based on the field investigation, the Carpinus cordata communities in Lishan Nature Reserve were studied by the methodology of quantitative vegetation ecology, including their classification and ordination, species diversity and interspecific segregations respectively. During this study, we had understanding the law of their composition and species diversity changes and revealing the succession stage of them, and hope to provide the theoretical and scientific basis for the Carpinus cordata community about their research and protection.Based on the40plots dataset from the field, Carpinus cordata communities were investigated by TWINSPAN and DCA. The Results from TWINSPAN indicated that40plots were divided into7asscoiations, and reflected the relationship between the communities and environmental factors. The results from DCA showed that:the first axis (abscissa) on the DCA diagram reflected the changes of Carpinus cordata communities with aspect from left to right slope, that trend was from semi-sunnyâ†'semi-shadyâ†'shady. It suggested the difference of illumination in the environment also affect the communities within the temperature and humidity changes. However, the second axis (vertical axis) don’t reflected the connection of the communities and environmental factors obviously. Moreover, the diagonal of this two-dimensional ordination diagram reflected the extent of interference in40plots. The ordination of the dominant species showed the same relationships between axis and environmental factors. The combination of the two ordination axes reflected that the dominant species in the community distribution patterns largely determine the distribution pattern of the community types.The species diversity and the three layers of the7associations the communities were studied by the use of the richness index (Patrick abundance index), diversity index (Simpson diversity index and Shannon-Wiener diversity index) and evenness index (Pielou evenness index and Alatalo evenness index). The results showed that:the richness index and diversity index of Ass. â…  and â…£ are higher than the others, indicating that species of these two groups are rich. However, the richness, diversity index and evenness of Ass. â…¡ are lower than the others relatively. The results from ANOVA for the indices showed that:the differences among richness index, diversity indices and evenness indices were not significant among the7associations (P>0.05).Carpinus cordata communities were studyed by using nearest neighbor method, the NXN nearest neighbor contingency table, χ--test and separation index, the results show:(1) There were905pairs separation significantly,41pairs not separation significantly in946pairs;(2) there were349species-pair positive segregation,90species-pair negative and507species-pair random segregation accounting for36.89%,9.52%, and53.59%respectively;(3) The result fromχ--test for NXN nearest-neighbor contingency table indicated that44species in the communities were mosaic distribution and overall non-segregation. Moreover, the results of species segregation suggested that the Carpinus cordata communities were in the early stage of succession.