'High-co-occurrence genera': weak but consistent relationships with global richness, niche partitioning, hybridization and decline

摘要

Aim Many biologists explain the global richness of lineages and local co-occurrence of lineage members by distinct processes: speciation/extinction versus ecological interactions. Moreover, allopatric distribution, rarity and local competition limit local co-occurrence of species even within species-rich lineages. However, whether and why the global richness of lineages relates to local co-occurrence of lineage members has not been tested. We study angiosperms, and hypothesize that in globally species-rich genera species frequently encounter congeners locally, reflecting (1) random sampling of species pools into local communities and (2) processes of global species production and local survival such as hybridization, niche filling and a reduced risk of extinction.