喀斯特常绿落叶阔叶林个体死亡对空间格局及种间关联性的影响  

Effects of tree mortality on the spatial patterns and interspecific associations of individuals in karst ever-green deciduous broad-leaved mixed forests.

作　　者：鲁梦珍 曾馥平[1,2,3] 宋同清 彭晚霞[1,2] 苏樑[1,2] 刘坤平 谭卫宁[4] 杜虎 LU Meng-zhen;ZENG Fu-ping;SONG Tong-qing;PENG Wan-xia;SU Liang;LIU Kun-ping;TAN Wei-ning;DU Hu(Key Laboratory of Agro-ecologi-cal Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China;Guangxi Key Laboratory of Karst Ecological Processes and Services,Huanjiang Observation and Research Station of Karst Ecosystem,Huanjiang 547100,Guangxi,China;University of Chinese Academy of Sciences,Beijing 100049,China;Management Center for Guangxi Mulun National Nature Reserve,Huanjiang 547100,Guangxi,China)

机构地区：[1]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [2]中国科学院环江喀斯特生态系统观测研究站,广西喀斯特生态过程与服务重点实验室,广西环江547100 [3]中国科学院大学,北京100049 [4]广西木论国家级自然保护区管理中心,广西环江547100

出　　处：《应用生态学报》2022年第10期2679-2686,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(42071073,31971487);广西重点研发计划项目(桂科AB17129009);中国科学院青年创新促进会项目(2021366);河池市特聘专家项目资助。

摘　　要：树木死亡作为森林生态系统中一个重要的生态学过程,研究其如何影响物种的空间分布格局及种间关联性,可以为揭示树木死亡机制及群落动态变化规律提供重要参考。本研究根据木论25 hm2喀斯特常绿落叶阔叶林动态监测样地两次木本植物调查数据,采用点格局分析方法,分析了树木死亡前后空间格局和种间关系的变化。结果表明:样地内个体死亡前后主要表现为聚集分布,但死亡后聚集分布的物种比例较死亡前略微下降,小尺度上呈现随机分布的物种比例有所增加,个体的死亡呈非随机性死亡。在物种水平上,13个优势种的死树和活树之间在0~30 m各尺度上呈显著正关联,表明样地内优势物种个体之间种内和种间竞争作用不激烈;树木死亡前后种间关联性主要为正关联,且大部分物种种间关系在死亡前后并未发生变化,表明群落已发展到相对稳定的阶段;死亡后,在1~30 m尺度上表现为正关联的物种对比例有所增加,负关联和无关联的物种对在大部分尺度上有所减少,说明个体死亡发生后,各个物种之间的竞争压力在一定程度上有所缓解。Tree mortality is an important ecological process in forests.It is crucial to understand how tree mortality affects spatial patterns and interspecific associations for revealing the mechanisms of tree mortality and community dynamics.We employed the correlation method of spatial point pattern analysis to analyse the variations in spatial patterns and interspecific relations before and after mortality using data obtained from two surveys of a 25 hm2 plot in the Mulun National Natural Reserve,China.The results showed that most species had an aggregated distribution both pre-and post-mortality.The proportion of species with aggregated distribution reduced slightly post-mortality compared with that for pre-mortality.Increases in the number of species with random distribution at small scale indi-cated that tree death was not random.At the species level,there were significant positive associations between dead and live trees of the 13 common species at different levels of 0-30 m range,suggesting weak intraspecific and inter-specific competition among dominant species.Pre-and post-mortality interspecific associations were mostly positive,which remained stable during the period of two surveys for most species,indicating that the community had reached a rather stable stage.Following tree mortality,the number of species with positive associations increased at 1-30 m scales,whereas the number of species with negative and no associations decreased at most scales.These results indicated that the pressure of interspecific competition was relieved to some extent after individual death.

关 键 词：树木死亡 点格局分析 空间格局 种间关联 喀斯特生态系统 

分 类 号：S718.5[农业科学—林学]