Nestedness in insular floras:spatiotemporal variation and underlying mechanisms

作     者：Lloyd W.Morrison 

作者机构：Department of BiologyMissouri State University901 S.National AvenueSpringfieldMO 65897USA 

出 版 物：《Journal of Plant Ecology》 (植物生态学报（英文版）)

年 卷 期：2013年第6卷第6期

页      面：480-488页

核心收录：

学科分类：07[理学] 0701[理学-数学] 070101[理学-基础数学] 

基　　金：This work was supported by National Geographic Society grants(7447-03 and 8137-06)to the author 

主　　题：Bahamas environmental gradient insular floras nestedness NODF metric 

摘      要：Aims Nestedness is a characteristic of insular metacommunity *** few studies,however,have attempted to evaluate temporal changes in nestedness,or elucidate the mechanisms underlying nestedness.I evaluated both spatial and temporal patterns of nestedness in the insular floras of four archipelagoes of small islands in the Bahamas and the potential underlying environmental *** The NODF(a nestedness metric based on overlap and decreasing fill)and the matrix temperature measure,T,were used to quantify nestedness in insular floras on small islands near Abaco,Andros,Great Exuma and the Exuma Cays,*** different null models were employed for each nestedness *** environmental variables were evaluated in relation to nestedness by ordering islands according to gradients and recalculating NODF *** Findings All archipelagoes were significantly *** among sites contributed more to overall nestedness than did nestedness among *** scores varied among archipelagoes,but were surprisingly constant over *** islands by vegetated area yielded the highest nestedness scores for three archipelagoes;ordering islands by protection from exposure yielded the highest nestedness score for one *** scores varied little over time even though species compositions changed,indicating that extinctions occurred in a deterministic *** relative importance of area suggests extinction is an important mechanism in producing *** to determine the relative importance of immigrations or extinctions requires some assumptions,however,and both processes are likely cumulative in most cases.