Research On Population Ecology Of Cyclobalanopsis Gilva

The community of Cyclobalanopsis gilva in Jingtianyan village, Jian'ou county, Fujian province was investigated and sampled to analyze the community characteristics, age structure of Cyclobalanopsis gilva, the spatial distribution pattern of the dominant populations.Then the ecological species groups were plotted. The results could provide basis to protect and make use of Cyclobalanopsis gilva resources sustainable. The results were as follows:(1) The community structure of Cyclobalanopsis gilva was investigated in Jingtianyan village, Jian'ou county, Fujian province. Results showed that the number of species composition was rich, the species diversity was high. There were 194 species belonging to 70 families, 136 genera in the community. Cyclobalanopsis gilva was the dominant species in the community. The concomitant species were abundant, the community structure was complex.(2) Based on diameter and height data of Cyclobalanopsis gilva population in Jian'ou county of Fujian province, timespecific life tables were set up. The results showed that the analysis result based on the height data was similar with that based on diameter data meaning that the height data was suitable for age structure analysis, especially for that of the population with the diameter less than 70 cm, further proved by the fitting result of relationship between diameter and height. The mortality rates at young age stages reached 0.883 (diameter data) and 0.913 (height data), and the mortality rates at middle age stages was 0.789 (diameter data) and 0.588 (height data) meaning that this population were imposed on by the environmental pressure or disturbing. Based on the diameter data, the stability of Cyclobalanopsis gilva population maintained a steady level, and Cyclobalanopsis gilva might become a constructive species with the small loss degree and the small changing degree of survival expectation at the strong and old age stages.(3) The spatial distribution patterns of the dominant populations in Cyclobalanopsis gilva community were analysed in the paper. Results showed that the distribution of most dominant populations among layers was congregating distribution, whereas few of them were homogenous distribution. The dominant status of Cyclobalanopsis gilva was significant in this community, which proved that Cyclobalanopsis gilva played a very important role in the process of community succession.(4) Based on the population important values, 25 dominant populations were choosed, among which interspecific association were surveyed and analyzed. Then the ecological species groups were plotted. The results showed that the species pairs with significant positive associations were only 7.8 percent of the total 300 species pairs, and most of the species pairs showed weak interspecific association or without interspecific association. The investigated forest populations had characteristics of relatively independent distribution. The There results of cluster were some difference based on different indexes. Finally, according as the cluster analysis,the interspecific association coefficients and the species ecological habits,the 25 dominant populations were divided into three ecological species groups .The species composition was rich, the community structure was complex and the dominant status of Cyclobalanopsis gilva was significant in Cyclobalanopsis gilva community, Jingtianyan village. The distribution of most dominant populations among layers was congregating distribution, whereas few of them were homogenous distribution. The analysis result based on the height data was similar with that based on diameter data meaning that the height data was suitable for age structure analysis. The investigated forest populations had characteristics of relatively independent distribution, which could be divided into three ecological species groups .The results were regarded as evidences for management and protecting the mid-subtropical Cyclobalanopsis gilva forest .