Acorn size and tolerance to seed predators:the multiple roles of acorns as food for seed predators,fruit for dispersal and fuel for growth  

作　　者：Andrew W.BARTLOW Salvatore JAGOSTA Rachel CURTIS Xianfeng YI Michael ASTEELE 

机构地区：[1]Department of Biology and The WIESS Institute for Environmental Science and Sustainability,Wilkes University,Wilkes Barre,Pennsylvania,USA [2]Present address:Department of Biology,University of Utah,Salt Lake City,Utah,USA [3]Center for Environmental Studies and Department of Biology,Virginia Commonwealth University,Richmond,Virginia,USA [4]Present address:Department of Veterinary Integrative Biosciences,Texas A&M University,College Station,Texas,USA [5]College of Life Sciences,Jiangxi Normal University,Nanchang,Jiangxi,China.

出　　处：《Integrative Zoology》2018年第3期251-266,共16页整合动物学（英文版）

基　　金：This study was supported by funding from the Howard Hughes Medical Institute to M.A.S.;the Natural Science Foundation of China(No.31172101)to X.F.Y.;the National Basic Research Program of China(No.2007CB109100)to X.F.Y.;the H.Fenner Research Fund of Wilkes University(M.A.S.);M.A.S also recognizes support of a Bullard Fellowship from Harvard Forest,Harvard University and the National Science Foundation(DEB 15556707);Support during final preparation of the manuscript was provided by the National Science Foundation Graduate Research Fellowship Program to A.W.B.and R.C.

摘　　要：Fitness of parents and offspring is affected by offspring size.In oaks(Quercus spp.),acorns vary considerably in size across,and within,species.Seed size influences dispersal and establishment of oaks,but it is not known whether size imparts tolerance to seed predators.Here,we examine the relative extent to which cotyledon size serves as both a means for sustaining partial consumption and energy reserves for developing seedlings during early stages of establishment.Acorns of 6 oak species were damaged to simulate acorn predation by vertebrate and invertebrate seed predators.Seedling germination/emergence and growth rates were used to assess seedling performance.We predicted that if cotyledons are important for dispersal,acorns should show tolerance to partial seed consumption.Alternatively,if the cotyledon functions primarily as an energy reserve,damage should significantly influence seedling performance.Acorns of each species germinated and produced seedlings even after removing>50%of the cotyledon.Seed mass explained only some of the variation in performance.Within species,larger acorns performed better than smaller acorns when damaged.Undamaged acorns performed as well or better than damaged acorns.There was no pattern among individual species with increasing amounts of damage.In some species,simulated invertebrate damage resulted in the poorest performance,suggesting alternative strategies of oaks to sustain damage.Large cotyledons in acorns may be important for attracting seed dispersers and sustaining partial damage,while also providing energy to young seedlings.Success of oak establishment may follow from the resilience of acorns to sustain damage at an early stage.

关 键 词：ACORNS damage tolerance dispersal QUERCUS seed size 

分 类 号：Q94[生物学—植物学]