【摘要】 为了探讨银杉的生存现状及其种间竞争机制，本研究以湖南八面山国家级自然保护区的典型银杉群落为研究对象，基于样地调查数据，对23个优势树种的重要值及生态位特征(包括生态位宽度、重叠度与相似性)进行了研究。结果表明：(1)银杉在乔木层中的重要值仅为3.14%,其Shannon-Wiener和Levins生态位宽度指数分别为1.65和0.15,显著低于云山青冈(分别为3.01、0.78)、鼠刺(分别为2.95、0.73)等优势种，反映出银杉在资源获取和种间竞争中处于弱势地位；(2)群落中53.36%的物种对的生态位重叠指数>0.3～0.8,云山青冈与鹿角杜鹃生态位重叠指数最高(0.86),而银杉与其他物种的最高生态位重叠指数仅为0.36,银杉资源的竞争压力较小；(3)仅9.09%的物种对的生态位相似性指数高于0.6,群落内物种的生态需求存在显著分异。综上，银杉濒危主要源于自身生态适应力不足。建议定向疏伐竞争树种、优化生境资源分配及深化物种生态学研究，以提升银杉群落保护成效。更多还原

【Abstract】 To explore the survival status and interspecific competition mechanisms of Cathaya argyrophylla, this study investigated a typical C.argyrophylla communities in Hunan Bamianshan National Nature Reserve.Based on plot survey data, the importance values and niche characteristics(including niche breadth, overlap, and similarity) of 23 dominant tree species were analyzed.The results showed:(1) C.argyrophylla exhibited a low importance value of 3.14% in the arborous layer, with Shannon-Wiener and Levins niche breadth indices of 1.65 and 0.15, respectively, significantly lower than those of dominant species such as Cyclobalanopsis sessilifolia(3.01, 0.78) and Itea chinensis(2.95, 0.73), reflecting C.argyrophylla was at disadvantage in resource acquisition and interspecific competition.(2) In the community, 53.36% of species pairs showed niche overlap indices >0.3 and ≤0.8.The highest niche overlap(0.86) was observed between C.sessilifolia and Rhododendron latoucheae, while the maximum niche overlap of C.argyrophylla with other species was only 0.36,indicating mild competitive pressure on C.argyrophylla.(3) Only 9.09% of species pairs demonstrated niche similarity indices above 0.6, confirming significant ecological differentiation among community members.In conclusion, the endangerment of C.argyrophylla primarily stemmed from its inherent ecological adaptability.To enhance conservation effectiveness, targeted thinning of competing tree species, optimizing habitat resource allocation, and further ecological research on C.argyrophylla are recommend.更多还原