摘要
通过样地调查方法、Jaccard相异性指数、Spearman回归分析和非度量多维标度(NMDS)排序分析,研究了千岛湖154个岛屿上不同植物群落β多样性及其主要影响因素。结果表明不同的景观参数对不同植物生长型有不同程度的影响,其中(1)藤本、灌木的β多样性形成的主导因素是面积,即面积差越大的区域间的β多样性越高;(2)乔木的β多样性主要受到岛屿间距离的限制,岛屿间距离越远,β多样性越高;(3)草本植物的β多样性分布与岛屿面积差及岛屿间距离并未呈现出显著相关,即其分布不受这两种因素限制;(4)NMDS分析结果显示岛屿面积、形状、边缘面积比和岛屿到大陆最小距离等特征对千岛湖岛屿上植物β多样性起决定性的作用。千岛湖陆桥岛屿组成的片段化生境中植物β多样性受扩散限制和生态位假说的共同影响。
Beta diversity reflects the variation of species composition across different sites, within a region of interest or along environmental gradients. It is a key concept of the understanding of ecosystem function, the conservation of biodiversity and the design of natural reserves. There are two main current hypotheses about the forming and maintaining mechanisms of beta diversity： dispersal limitation and niche differentiation. The dispersal hypothesis addressed that the differences of species distribution are created through spatially limited dispersal. The niche hypothesis emphasizes the variations of environmental condition among sites, which can offer suitable habitats for different species to settle. These two processes differently affect the respective patterns of plant groups （e.g. including tree, shrub, herb and liana） and drive them playing different roles in the formation of beta diversity. However, most current studies primarily focus on improving the analytical approaches of beta diversity and calculating various indices of beta diversity in different sites. Thousand Island Lake （TIL） is a large man-made hydroelectric reservoir with over 1078 land-bridge islands in western Zhejiang province, China, which is an ideal fragmented landscape for researching beta diversity and its drivers.
We studied the pattern of beta diversity of vascular plants on 154 islands in the TIL and its major causes by using quadrat method, Jaccard dissimilarity, Spearman correlation analysis and Non-metric Multidimensional Scaling （NMDS） ordination analysis. The results showed that the impacts on beta diversity from different environmental characteristics varied with different plant groups. The beta diversity of liana and shrubs is significantly correlated with island area, which means their beta diversity mainly due to the area differences among islands. The more the area lost, the higher the beta diversity of these two plant groups. The beta diversity of trees, in contrast, was mainly influenced by the distance b
出处
《生态学报》
CAS
CSCD
北大核心
2014年第14期3866-3872,共7页
Acta Ecologica Sinica
基金
国家自然科学基金(30770371)
浙江省自然科学基金(Z51000053)
关键词
维管植物
Β多样性
陆桥岛屿
Jaccard指数
非度量多维标度
vascular plants
β diversity
land-bridge islands
jaccard dissimilarity
non-metric multidimensional scaling
