Seed arrival, ecological filters, and plant species richness: a meta-analysis

• Published in: Ecology letters Vol. 12; no. 11; pp. 1250 - 1260
• Main Authors: Myers, Jonathan A, Harms, Kyle E
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.11.2009; Blackwell Publishing Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biodiversity; Biological and medical sciences; Botany; Coexistence; Community assembly; correlation; disturbance; Ecology; Filters; forests; functional diversity; Fundamental and applied biological sciences. Psychology; General aspects; Grasslands; Heterogeneity; immigration; Meta-analysis; Nutrient availability; physiology; Plant communities; Plant Development; Plant species; Population Density; Population Dynamics; prediction; propagule supply; Resource availability; Savannahs; savannas; seed addition; seed dispersal; seed limitation; Seeds; Seeds - physiology; species coexistence; Species diversity; species pool; Species richness; Theory; Water availability; Wetlands; disturbance; Seeds; seed addition; Supply; Ecology; Coexistence; Perturbation; Biodiversity; propagule supply; Dispersion; Metaanalysis; Species diversity; seed limitation; species pool; seed dispersal; Immigration; Community assembly; Community; Species richness; species coexistence
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/j.1461-0248.2009.01373.x

Theoretical models predict that effects of dispersal on local biodiversity are influenced by the size and composition of the species pool, as well as ecological filters that limit local species membership. We tested these predictions by conducting a meta-analysis of 28 studies encompassing 62 experiments examining effects of propagule supply (seed arrival) on plant species richness under contrasting intensities of ecological filters (owing to disturbance and resource availability). Seed arrival increased local species richness in a wide range of communities (forest, grassland, montane, savanna, wetland), resulting in a positive mean effect size across experiments. Mean effect size was 70% higher in disturbed relative to undisturbed communities, suggesting that disturbance increases recruitment opportunities for immigrating species. In contrast, effect size was not significantly influenced by nutrient or water availability. Among seed-addition experiments, effect size was positively correlated with species and functional diversity within the pool of added seeds (species evenness and seed-size diversity), primarily in disturbed communities. Our analysis provides experimental support for the general hypothesis that species pools and local environmental heterogeneity interactively structure plant communities. We highlight empirical gaps that can be addressed by future experiments and discuss implications for community assembly, species coexistence, and the maintenance of biodiversity.