title: Multispecies coexistence of trees in tropical forests: spatial signals of topographic niche differentiation increase with environmental heterogeneity.
abstract: Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity.
authors.affiliation: School of Geosciences, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, UK. calum.brown@ed.ac.uk
authors.forename: C
authors.initials: C
authors.lastname: Brown
authors.forename: D F R P
authors.initials: DF
authors.lastname: Burslem
authors.forename: J B
authors.initials: JB
authors.lastname: Illian
authors.forename: L
authors.initials: L
authors.lastname: Bao
authors.forename: W
authors.initials: W
authors.lastname: Brockelman
authors.forename: M
authors.initials: M
authors.lastname: Cao
authors.forename: L W
authors.initials: LW
authors.lastname: Chang
authors.forename: H S
authors.initials: HS
authors.lastname: Dattaraja
authors.forename: S
authors.initials: S
authors.lastname: Davies
authors.forename: C V S
authors.initials: CV
authors.lastname: Gunatilleke
authors.forename: I A U N
authors.initials: IA
authors.lastname: Gunatilleke
authors.forename: J
authors.initials: J
authors.lastname: Huang
authors.forename: A R
authors.initials: AR
authors.lastname: Kassim
authors.forename: J V
authors.initials: JV
authors.lastname: Lafrankie
authors.forename: J
authors.initials: J
authors.lastname: Lian
authors.forename: L
authors.initials: L
authors.lastname: Lin
authors.forename: K
authors.initials: K
authors.lastname: Ma
authors.forename: X
authors.initials: X
authors.lastname: Mi
authors.forename: A
authors.initials: A
authors.lastname: Nathalang
authors.forename: S
authors.initials: S
authors.lastname: Noor
authors.forename: P
authors.initials: P
authors.lastname: Ong
authors.forename: R
authors.initials: R
authors.lastname: Sukumar
authors.forename: S H
authors.initials: SH
authors.lastname: Su
authors.forename: I F
authors.initials: IF
authors.lastname: Sun
authors.forename: H S
authors.initials: HS
authors.lastname: Suresh
authors.forename: S
authors.initials: S
authors.lastname: Tan
authors.forename: J
authors.initials: J
authors.lastname: Thompson
authors.forename: M
authors.initials: M
authors.lastname: Uriarte
authors.forename: R
authors.initials: R
authors.lastname: Valencia
authors.forename: S L
authors.initials: SL
authors.lastname: Yap
authors.forename: W
authors.initials: W
authors.lastname: Ye
authors.forename: R
authors.initials: R
authors.lastname: Law
mesh_terms: D017753:Ecosystem; D016468:Forestry; D008962:Models, Theoretical; D014197:Trees / Q000502:physiology*; D014329:Tropical Climate
keywords: cross-pair overlap distribution; neutral theory; niche differentiation; spatial pattern; species coexistence; tropical forest