Host-Generalist Phytopathogens and the Maintenance of Forest Diversity on Barro Colorado Island

Résumé fourni par la source

Spatiotemporal analyses of plant communities suggest that pathogens contribute to the maintenance of local forest diversity. However, such analyses cannot identify the mechanisms driving observed conspecific negative density/distance-dependent mortality. Particularly, is conspecific negative density/distance-dependence (CNDD) caused by pathogens with narrow or broad host ranges? We review Barro Colorado Island–based studies that identified phytopathogens and assessed their host ranges and fitness impacts with culture-based approaches. These studies suggest that phytopathogens with host ranges spanning plant families and orders are common; generalist phytopathogens exert host-specific impacts, unevenly affecting recruitment across hosts; and tree species vary in susceptibility to infection and impacts postinfection. We discuss mechanisms for generalist phytopathogens to promote local and regional forest diversity: host affinities, host-specific coinfections, age-dependent impacts, and host-specific impacts. These mechanisms, which expand and diverge from those proposed in the Janzen–Connell hypothesis, are pivotal future research directions. To counteract anthropogenic threats, we must understand the processes maintaining tropical forest diversity.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.