title: Are all seeds equal? Spatially explicit comparisons of seed fall and sapling recruitment in a tropical forest.
abstract: Understanding demographic transitions may provide the key to explain the high diversity of tropical tree communities. In a faunally intact Amazonian forest, we compared the spatial distribution of saplings of 15 common tree species with patterns of conspecific seed fall, and examined the seed-to-sapling transition in relation to locations of conspecific trees. In all species, the spatial pattern of sapling recruitment bore no resemblance to predicted distributions based on the density of seed fall. Seed efficiency (the probability of a seed producing a sapling) is strongly correlated with distance from large conspecific trees, with a >30-fold multiplicative increase between recruitment zones that are most distant vs. proximal to conspecific adults. The striking decoupling of sapling recruitment and conspecific seed density patterns indicates near-complete recruitment failure in areas of high seed density located around reproductive adults. Our results provide strong support for the spatially explicit predictions of the Janzen-Connell hypothesis.
authors.affiliation: Nicholas School of Environment, Duke University, Durham, NC, USA. vs12@duke.edu
authors.forename: Varun
authors.initials: V
authors.lastname: Swamy
authors.forename: John
authors.initials: J
authors.lastname: Terborgh
authors.forename: Kyle G
authors.initials: KG
authors.lastname: Dexter
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Best
authors.forename: Patricia
authors.initials: P
authors.lastname: Alvarez
authors.forename: Fernando
authors.initials: F
authors.lastname: Cornejo
mesh_terms: D017753:Ecosystem; D010568:Peru; D011157:Population Dynamics; D036226:Seedlings / Q000254:growth & development*; D012639:Seeds / Q000254:growth & development; D014197:Trees / Q000254:growth & development*; D014329:Tropical Climate