title: Population Density, Not Host Competence, Drives Patterns of Disease in an Invaded Community.
abstract: Generalist parasites can strongly influence interactions between native and invasive species. Host competence can be used to predict how an invasive species will affect community disease dynamics; the addition of a highly competent, invasive host is predicted to increase disease. However, densities of invasive and native species can also influence the impacts of invasive species on community disease dynamics. We examined whether information on host competence alone could be used to accurately predict the effects of an invasive host on disease in native hosts. We first characterized the relative competence of an invasive species and a native host species to a native parasite. Next, we manipulated species composition in mesocosms and found that host competence results did not accurately predict community dynamics. While the invasive host was more competent than the native, the presence of the native (lower competence) host increased disease in the invasive (higher competence) host. To identify potential mechanisms driving these patterns, we analyzed a two-host, one-parasite model parameterized for our system. Our results demonstrate that patterns of disease were primarily driven by relative population densities, mediated by asymmetry in intra- and interspecific competition. Thus, information on host competence alone may not accurately predict how an invasive species will influence disease in native species.
authors: Catherine L
authors: CL
authors: Searle
authors: Michael H
authors: MH
authors: Cortez
authors: Katherine K
authors: KK
authors: Hunsberger
authors: Dylan C
authors: DC
authors: Grippi
authors: Isabella A
authors: IA
authors: Oleksy
authors: Clara L
authors: CL
authors: Shaw
authors: Solanus B
authors: SB
authors: de la Serna
authors: Chloe L
authors: CL
authors: Lash
authors: Kailash L
authors: KL
authors: Dhir
authors: Meghan A
authors: MA
authors: Duffy
mesh_terms: D058507:Host Specificity; D006790:Host-Parasite Interactions; D058865:Introduced Species; D011156:Population Density; D011157:Population Dynamics
keywords: Daphnia; biodiversity; dilution effect; invasive species; multihost parasites; pathogen