桂西北喀斯特常绿落叶阔叶混交林物种多样性分布格局的尺度效应  

Scale-dependent spatial patterns for species diversity in a karst evergreen and deciduous broad-leaved mixed forest of northwest Guangxi

作　　者：胡芳 曾馥平[1,2] 杜虎[1,2] 彭晚霞[1,2] 张芳[1,2] 谭卫宁 宋同清[1,2] HU Fang;ZENG Fuping;DU Hu;PENG Wanxia;ZHANG Fang;TAN Weining;SONG Tongqing(Key Laboratory of Agro-ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China;Huanjiang Observation and Research Station of Karst Ecosystem,Chinese Academy of Sciences,Huanjiaag 547100,China;Administrative Bureau of Mulun National Nature Reserve,Guangxi Zhuang Autonomous Region,Huanjiang 547200,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,环江547100 [3]广西壮族自治区木论国家级自然保护区管理局,环江547200

出　　处：《生态学报》2018年第17期6074-6083,共10页Acta Ecologica Sinica

基　　金：国家重点研发计划项目(2016YFC0502405);广西重点研发计划项目(桂科AB16380255;桂科AB17129009);国家自然科学基金项目(31770495);广西特聘专家项目

摘　　要：物种多样性的空间分布格局及其与尺度的关系研究对于了解群落物种多样性形成机制具有重要意义。为了探讨喀斯特地区物种多样性空间分布格局的尺度效应,以喀斯特常绿落叶阔叶混交林25 hm^2样地的(胸径DBH≥1)木本植物为研究对象,分析了6个空间尺度(5 m×5 m,10 m×10 m,20 m×20 m,50 m×50 m,100 m×100 m,250 m×250 m)上的多度、物种丰富度、Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数的变化规律。结果表明:物种多样性指数的空间分布均表现出较高的空间异质性;物种多样性指数的方差随取样尺度增加呈现单峰分布特征,并且在100 m×100 m尺度上达到最大值;物种多样性指数的变异系数随尺度的增加呈线性下降趋势,其中,Shannon-Wiener指数、Simpson指数以及Pielou均匀度指数均在5 m×5 m至20 m×20 m尺度上明显减小;在大于50 m×50 m的尺度上,物种丰富度与多度的正相关性不显著(P>0.05)。喀斯特常绿落叶阔叶混交林物种多样性的空间分布格局与不同空间尺度密切相关,深入解析物种多样性随空间尺度的变化模式,需要在类似的森林生态系统做更多的研究。Spatial distribution patterns of species diversity and their relationships with scale are of great significance to understand the mechanism of community species diversity formation. Here, a field survey was conducted to assess the variation in species diversity along spatial scales in a karst evergreen and deciduous broad-leaved mixed forest, Southwest China. Based on the dataset of woody plants （DBH ≥ 1） from a 25 hm2 plot, the spatial distribution patterns of species abundance, species richness, and Shannon-Wiener, Simpson, and Pielou＇s evenness indices were analyzed at six spatial scales-5 m×5 m, 10 m×10 m, 20 m×20 m, 50 m×50 m, 100 m×100 m, and 250 m×250 m. The results showed that spatial distributions of species diversity indices were highly heterogeneous. The variance of species diversity indices changed with spatial scale following a unimodal pattern, i.e., with a maximum value at the 100 m×100 m scale. Variation coefficients of species diversity decreased linearly with increasing scale. The Shannon-Wiener, Simpson, and Pielou＇s evenness indices decreased sharply at the 5 m×5 m and 20 m×20 m scales. No significant positive relationship was found between species richness and abundance at scales over 50 m×50 m （P 〉 0.05）. Our results suggest that the spatial pattern of species diversity in this evergreen and deciduous broad-leaved mixed karst forest is closely related to spatial scale. To better understand spatial variation of species diversity across spatial scales, more such studies in other similar forest ecosystems are needed.

关 键 词：物种多样性 空间分布格局 空间尺度 常绿落叶阔叶混交林 喀斯特 

分 类 号：S718.5[农业科学—林学]