Age structure in neutral theory resolves inconsistencies related to reproductive-size threshold

作     者：James Rosindell Patrick A.Jansen Rampal S.Etienne 

作者机构：Institute of Integrative and Comparative BiologyFaculty of Biological SciencesUniversity of LeedsLeeds LS29JTWest YorkshireUK Institute of Bioinformatics and Evolutionary StudiesUniversity of IdahoMoscowID 83844USA Center for Tropical Forest ScienceSmithsonian Tropical Research InstitutePO Box 0843-03092BalboaAnconRepublic of Panama Centre of Ecosystem StudiesWageningen UniversityPO Box 476700 AA Wageningenthe Netherlands Community and Conservation EcologyCentre for Ecological and Evolutionary StudiesUniversity of GroningenPO Box 111039700 CC Groningenthe Netherlands 

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

年 卷 期：2012年第5卷第1期

页      面：64-71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：Engineering and Physical Sciences Research Council overseas postdoctoral research fellowship at the life sciences interface(EP/F043112/1 to J.R.) the Netherlands Organization for Scientific Research(NWO-ALW 864-07-007 to R.S.E.,NWOALW 863-07-008 to P.A.J.) 

主　　题：neutral theory age structure sampling DBH 

摘      要：Aims Neutral theory consists of a suite of models that assume ecological equivalence among individual *** have been most commonly applied to tropical forest tree communities either as null models or as *** models typically only include reproductive adults;therefore,fitting to empirical tree community data requires defining a reproductive-size threshold,which for trees is usually set arbitrarily to a diameter at breast height(DBH)of 100 *** inevitable exclusion of some reproductive adults and inclusion of some saplings cause a non-random sampling bias in neutral model ***,we investigate this problem and resolve it by introducing simple age structure into a neutral *** We compared the performance and sensitivity of DBH threshold of three variants of a spatially explicit neutral model:the traditional model,a model incorporating random sampling and a model with two distinct age classes—reproductive adults and *** the age-structured model,saplings are offspring from adults that disperse according to a Gaussian dispersal kernel around the *** only extra parameter is the ratio of adults to saplings,which is not a free parameter but directly *** used species–area relationships(SARs)to explore the predicted effect of saplings on the species richness at different scales in our *** then evaluated the three model variations to find the parameters required to maintain the observed level of species richness in the 50-ha plot on Barro Colorado Island(BCI).We repeated our analysis filtering the data at different minimum tree-size thresholds in order to find the effect this threshold has on our ***,we used empirical species–individual relationships(SIRs)to test the pre-existing hypothesis that environmental filtering is the primary cause of differences between the assemblage of saplings and that of adults on *** Findings Our age-structured neutral model was characterized by SARs that