天宝岩国家级自然保护区长苞铁杉群落乔木层的生态位特征

采用样方法对天宝岩国家级自然保护区长苞铁杉群落特征进行调查,系统分析了不同长苞铁杉群落乔木层的生态位特征。优势种长苞铁杉在3个群落中生态位宽度均较大,Levins指数依次为:长苞铁杉—猴头杜鹃混交林(0.83)>长苞铁杉—青冈混交林(0.95)>长苞铁杉纯林(0.93);Hurlbert指数依次为:长苞铁杉—青冈混交林(0.96)>长苞铁杉—猴头杜鹃混交林(0.84)>长苞铁杉纯林(0.75)。各类型长苞铁杉群落生态位重叠分配格局增减不一,总体上呈先增后减趋势。3个群落的生态位重叠指数分布趋势也不同,整体平均生态位重叠指数依次为:长苞铁杉—猴头杜鹃混交林(20.42%)>长苞铁杉纯林(20.16%)>长苞铁杉—青冈混交林(19.78%),差异不明显。研究区内长苞铁杉生态位宽度及与其他物种间的生态位重叠均较大,其利用环境资源的程度高,对环境的适应与竞争能力强。

Species niche characteristics of the tree layer of different Tsuga longibracteata communities in the Tianbaoyan National Nature Reserve

It is important for the community of ecological niche in the system to be restored and rebuilt as well as the natural productivity improvement.A quadrat method is used to investigate different longibracteata community species niche characteristics in the Tianbaoyan National Nature Reserve.The niche characteristics of different longibracteata are compared systematically.The results show that the dominant species of longibracteata has a larger niche breadth in this three communities.Levins index(from small) are longibracteata and Hericiumerinaceus cuckoo mixed forests(0.83),Tsuga longibracteata and Cyclobalanopsis glauca mixed forests(0.95),longibracteata pure forest(0.93).Hurlbert index(from small) are longibracteata and C.glauca mixed forests(0.96),longibracteata and Hericiumerinaceus cuckoo mixed forests(0.84),longibracteata pure forest(0.75).The distribution pattern of niche overlap of main arbor species plant population in these forests communities are different,the mainsrtream is first increased and then decreased trend.These 3 communities niche overlap index distribution trends are different,the overall average niche overlap index from small is as follows: longibracteata and Hericiumerinaceus mixed forest(20.42%)>longibracteata pure forest(20.16%)>longibracteata and C.glauca mixed forests(19.78%),but the difference is not very significant.longibracteata niche breadth is larger as well as its niche overlap.The degree in using environment resources is high,it also has a strong adaption and competition ability.