甜槠天然林优势种群的种间联结性研究

Interspecific association of dominant species in Castanopsis eyrei natural forests communities

根据2×2联列表,综合运用方差分析、联结系数AC、X2统计量度量,Ochiai指数、Dice指数和Jaccard指数等测度方法,计算了周宁县天然甜槠林乔木层35个主要树种的总体联结关系、种间联结系数和X2值．研究结果表明:周宁县甜槠林的种间联结测定使用上述系列技术效果很好．运用方差分析可揭示出多物种总体联结性,X2检验表示出各种对联结的量着性程度和性质,Ochiai指数、Dice指数和Jaccard指数能够表征种对的联结程度和相伴随出现的机率．同时表明:天然甜槠林种间联结较复杂,多物种总体联结性为不显著的负相关,AC值计算出正联结种对有150对,负联结298 对,其余完全独立;X2统计量检验了595对,其中0对呈现显著的正联结,2对呈现极显著的负联结,3对呈现显著的负联结．

A series of approaches including variance analysis , X^2 - test, association co-efficient, Ochiai＇ s co-efficient,Czekanowski＇s co-efficient and Jaccard＇s co-efficient were calculated on the basis of 2 × 2 contingency to determine the overall association of all species, the co-efficient of the each species-pair association and X^2 value of 35 dominant species composing the tree stratum of Castanopsis eyrei forests in the Zhouning County of China. The results showed the interspecific association of dominant species in the layer of C. eyrei forests can be adequately interpreted by using these approaches mentioned above. Especially, the variance analysis can be used to explain the overall association of all species;the X^2-test can be used to describe the statistical significance and property of the interspecific association; and the Ochiai,Czekanowski and Jaccard indices can be used to indicate association degree of any species-pair. The results showed that inter-specific association in Castanopsis eyrei natural forest was very complicated, the overall association of all species was not significantly negative. By AC values,it could be calculated that 150 species-pairs were positive and 298 species-pairs were negative,and the others were fully independent. 595 species-pairs were checked by X^2-test,in which none of species-pair was observed to have significant postitive assocition at P =0.05 and 2 species-pairs revealed significant negative assocition at P=0.01,3 species-pairs at P=0.05.