Effects of sampling scale on patterns of habitat association in tropical trees

摘要: Questions: Niche differentiation is a central explanation for the co-existence and distribution patterns of numerous tree species in tropical forests, but functional equivalence leading to neutral dynamics has been proposed as an alternative explanation. This niche vs debate fuelled by highly variable results yielded studies association between distributions environmental factors, where some find strong associations others do not. Here, we ask how differences sampling scale contribute this variation. Location: Barro Colorado Island, Panama. Methods: Using maps canopy-statured individuals, evaluated habitat five on Island across wide range scales (from 50 1600 ha). We investigated scale-dependency clumping (Ripley’s K) with important variables (forest age, topography geological formation) using point pattern analyses. Results: Clump size clump density had high variances within among spatial scales. Significant were found all species, number generally increasing scale. Ignoring dispersal constraints inflated significant associations. Conclusions: that (and hence conclusions importance processes) are strongly affected choice location. Explicit inclusion effect critical main processes structure communities trees.