title: Species with greater seed mass are more tolerant of conspecific neighbours: a key driver of early survival and future abundances in a tropical forest.
abstract: Multiple niche-based processes including conspecific negative density dependence (CNDD) determine plant regeneration and community structure. We ask how interspecific and intraspecific density-dependent interactions relate to plant life histories and associated functional traits. Using hierarchical models, we analysed how such interactions affected first-year survival of seedling recruits of 175 species in a tropical forest, and how species abundances and functional traits are related to interspecific variation in density-dependent effects. Conspecific seedling neighbour effects prevailed over the effects of larger conspecific and all heterospecific neighbours. Tolerance of seedling CNDD enhanced recruit survival and subsequent abundance, all of which were greater among larger seeded, slow-growing and well-defended species. Niche differentiation along the growth-survival trade-off and tolerance of seedling CNDD strongly correlated with regeneration success, with manifest consequences for community structure. The ability of larger seeded species to better tolerate CNDD suggests a novel mechanism for CNDD to contribute to seed-size variation and promote species coexistence through a tolerance-fecundity trade-off.
authors.affiliation: Department of Biology and Environment, University of Haifa - Oranim, Tivon, Israel.|Department of Forest Resources, University of Minnesota, 1530 Cleveland Avenue North, St. Paul, MN, 55108, USA.|Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa Ancón, Panama.
authors.forename: Edwin
authors.initials: E
authors.lastname: Lebrija-Trejos
authors.affiliation: Department of Forest Resources, University of Minnesota, 1530 Cleveland Avenue North, St. Paul, MN, 55108, USA.|Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, 2753, Australia.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Reich
authors.affiliation: Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa Ancón, Panama.
authors.forename: Andres
authors.initials: A
authors.lastname: Hernández
authors.affiliation: Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa Ancón, Panama.
authors.forename: S Joseph
authors.initials: SJ
authors.lastname: Wright
mesh_terms: D044822:Biodiversity; D008954:Models, Biological; D010176:Panama; D011157:Population Dynamics; D065947:Rainforest; D012639:Seeds / Q000502:physiology*; D013045:Species Specificity; D014197:Trees / Q000254:growth & development / Q000502:physiology*; D014329:Tropical Climate
keywords: Conspecific; density dependence; functional traits; growth-survival trade-off; heterospecific; niche differentiation; seed mass; seed-size-seed-number trade-off; seedling survival; tolerance-fecundity trade-off