title: Succession of ephemeral secondary forests and their limited role for the conservation of floristic diversity in a human-modified tropical landscape.
abstract: Both local- and landscape-scale processes drive succession of secondary forests in human-modified tropical landscapes. Nonetheless, until recently successional changes in composition and diversity have been predominantly studied at the patch level. Here, we used a unique dataset with 45 randomly selected sites across a mixed-use tropical landscape in central Panama to study forest succession simultaneously on local and landscape scales and across both life stages (seedling, sapling, juvenile and adult trees) and life forms (shrubs, trees, lianas, and palms). To understand the potential of these secondary forests to conserve tree species diversity, we also evaluated the diversity of species that can persist as viable metapopulations in a dynamic patchwork of short-lived successional forests, using different assumptions about the average relative size at reproductive maturity. We found a deterministic shift in the diversity and composition of the local plant communities as well as the metacommunity, driven by variation in the rate at which species recruited into and disappeared from the secondary forests across the landscape. Our results indicate that dispersal limitation and the successional niche operate simultaneously and shape successional dynamics of the metacommunity of these early secondary forests. A high diversity of plant species across the metacommunity of early secondary forests shows a potential for restoration of diverse forests through natural succession, when trees and fragments of older forests are maintained in the agricultural matrix and land is abandoned or set aside for a long period of time. On the other hand, during the first 32 years the number of species with mature-sized individuals was a relatively small and strongly biased sub-sample of the total species pool. This implies that ephemeral secondary forests have a limited role in the long-term conservation of tree species diversity in human-modified tropical landscapes.
authors.affiliation: Center for Tropical Forest Science, Smithsonian Tropical Research Institute, Ciudad de Panamá, República de Panamá
authors.forename: Michiel
authors.initials: M
authors.lastname: van Breugel
authors.affiliation: Center for Tropical Forest Science, Smithsonian Tropical Research Institute, Ciudad de Panamá, República de Panamá
authors.forename: Jefferson S
authors.initials: JS
authors.lastname: Hall
authors.affiliation: Center for Tropical Forest Science, Smithsonian Tropical Research Institute, Ciudad de Panamá, República de Panamá ; Yale School of Forestry and Environmental Studies, New Haven, Connecticut, United States of America.
authors.forename: Dylan
authors.initials: D
authors.lastname: Craven
authors.affiliation: Center for Tropical Forest Science, Smithsonian Tropical Research Institute, Ciudad de Panamá, República de Panamá
authors.forename: Mario
authors.initials: M
authors.lastname: Bailon
authors.affiliation: Center for Tropical Forest Science, Smithsonian Tropical Research Institute, Ciudad de Panamá, República de Panamá
authors.forename: Andres
authors.initials: A
authors.lastname: Hernandez
authors.affiliation: Yale School of Forestry and Environmental Studies, New Haven, Connecticut, United States of America.
authors.forename: Michele
authors.initials: M
authors.lastname: Abbene
authors.affiliation: Forest and Landscape Centre, Faculty of Life Sciences, Copenhagen University, Frederiksberg C, Denmark.
authors.forename: Paulo
authors.initials: P
authors.lastname: van Breugel
mesh_terms: D044822:Biodiversity; D003247:Conservation of Natural Resources; D017753:Ecosystem; D006801:Humans; D010176:Panama; D014197:Trees; D014329:Tropical Climate