title: Emergence and accumulation of novel pathogens suppress an invasive species.
abstract: Emerging pathogens are a growing threat to human health, agriculture and the diversity of ecological communities but may also help control problematic species. Here we investigated the diversity, distribution and consequences of emerging fungal pathogens infecting an aggressive invasive grass that is rapidly colonising habitats throughout the eastern USA. We document the recent emergence and accumulation over time of diverse pathogens that are members of a single fungal genus and represent multiple, recently described or undescribed species. We also show that experimental suppression of these pathogens increased host performance in the field, demonstrating the negative effects of emerging pathogens on invasive plants. Our results suggest that invasive species can facilitate pathogen emergence and amplification, raising concerns about movement of pathogens among agricultural, horticultural, and wild grasses. However, one possible benefit of pathogen accumulation is suppression of aggressive invaders over the long term, potentially abating their negative impacts on native communities.
authors.affiliation: Agronomy Department, University of Florida, Gainesville, FL, 32611.
authors.forename: Kerry Bohl
authors.initials: KB
authors.lastname: Stricker
authors.affiliation: Plant Pathology Department, University of Florida, Gainesville, FL, 32611.
authors.forename: Philip F
authors.initials: PF
authors.lastname: Harmon
authors.affiliation: Plant Pathology Department, University of Florida, Gainesville, FL, 32611.|Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32610.
authors.forename: Erica M
authors.initials: EM
authors.lastname: Goss
authors.affiliation: Department of Biology, Indiana University, Bloomington, IN, 47405.
authors.forename: Keith
authors.initials: K
authors.lastname: Clay
authors.affiliation: Agronomy Department, University of Florida, Gainesville, FL, 32611.
authors.forename: S
authors.initials: S
authors.lastname: Luke Flory
mesh_terms: D017753:Ecosystem; D005658:Fungi / Q000502:physiology*; D058865:Introduced Species; D010572:Pest Control, Biological; D006109:Poaceae / Q000382:microbiology* / Q000502:physiology*
keywords: Bipolaris; Microstegium vimineum; enemy release hypothesis; fungal pathogens; non-native invasive plant; spillover; stiltgrass