title: Agricultural land-use history causes persistent loss of plant phylogenetic diversity.
abstract: Intensive land use activities, such as agriculture, are a leading cause of biodiversity loss and can have lasting impacts on ecological systems. Yet, few studies have investigated how land-use legacies impact phylogenetic diversity (the total amount of evolutionary history in a community) or how restoration activities might mitigate legacy effects on biodiversity. We studied ground-layer plant communities in 27 pairs of Remnant (no agricultural history) and Post-agricultural (agriculture abandoned >60 yr ago) longleaf pine savannas, half of which we restored by thinning trees to reinstate open savanna conditions. We found that agricultural history had no impact on species richness, but did alter community composition and reduce phylogenetic diversity by 566 million years/1,000 m2. This loss of phylogenetic diversity in post-agricultural savannas was due to, in part, a reduction in the average evolutionary distance between pairs of closely related species, that is, increased phylogenetic clustering. Habitat restoration increased species richness by 27% and phylogenetic diversity by 914 million years but did not eliminate the effects of agricultural land use on community composition and phylogenetic structure. These results demonstrate the persistence of agricultural legacies, even in the face of intensive restoration efforts, and the importance of considering biodiversity broadly when evaluating human impacts on ecosystems.
authors.affiliation: Department of Plant Biology, Michigan State University, 612 Wilson Road, Room 368, East Lansing, Michigan, 48824, USA.
authors.forename: Nash E
authors.initials: NE
authors.lastname: Turley
authors.affiliation: Department of Plant Biology and Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, 612 Wilson Road, Room 368, East Lansing, Michigan, 48824, USA.
authors.forename: Lars A
authors.initials: LA
authors.lastname: Brudvig
mesh_terms: D000383:Agriculture; D044822:Biodiversity; D003247:Conservation of Natural Resources; D017753:Ecosystem; D004784:Environmental Monitoring; D010802:Phylogeny; D028223:Pinus
keywords: biodiversity conservation; community ecology; community phylogenetics; longleaf pine savanna; restoration ecology