长苞铁杉林乔木层优势种群种间关联及尺度效应研究

通过设定不同尺度的样方面积,根据2×2联列表,运用方差分析、联结系数AC、2统计量度量、 Ochiai指数系列技术,测定天宝岩国家级自然保护区长苞铁杉群落乔木层10个优势种群间的总体联结关系、 种对间联结显著性和关联系数。结果表明:长苞铁杉群落乔木层10个优势种群的总体种间关联性均呈正关 联,反映该群落处于稳定的顶极阶段;10个优势种群的种间联结关系中,有26个种对在不同尺度样方设计中 均未达到一般显著水平,种对间的相互独立性较强;样方设计为100 m2时,各项指标上规律性比较明显,它的 研究结果与实际情况相吻合。群落虽处于比较稳定的顶极阶段,但应适当调整群落结构,为长苞铁杉的生长 更新提供良好的生态环境。

Study on the scale effect of interspecific association of species in tree layer of the rare plant Tsuga longibracteata community

Under conditions of given sample area,quadrats of different sizes were designed. A series of techniques including the analysis of variance, x2-test, association coefficient, Ochiai' s coefficient were calculated based upon a 2 X 2 contingency table to determine the overall association,the statistical significance and the coefficient of each species-pair association of the 10 dominant species in tree layer of the endangered and rare plant Tsuga longibracteata forest in Tianbaoyan Stated National Reserve, Fujian Province. The results showed that the overall association of 10 dominant species in tree layer of T. longibracteata community was positive, which suggested that the T. longibracteala community was stable. The x2-test showed that among 10 dominant species,26 species pairs did not show significant association in quadrats of different sizes. When 36 quadrats and 100 m2 for each quadrats were choosed,positive and negative interspecific association ratio, total multi-species x2-test, x2-test of species pairs were obviously regular. Based on study results of interspecific association analysis according to optimal quadrat number,effects of 36 quadrats and 100 m2 for each quadrat were better than that of other quadrat-designs. Although the community was at a stable late successional stage, we must adjust the structure of the community and provide well environment for T. longibracteata growth and regeneration.