title: Confronting species distribution model predictions with species functional traits.
abstract: Species distribution models are valuable tools in studies of biogeography, ecology, and climate change and have been used to inform conservation and ecosystem management. However, species distribution models typically incorporate only climatic variables and species presence data. Model development or validation rarely considers functional components of species traits or other types of biological data. We implemented a species distribution model (Maxent) to predict global climate habitat suitability for Grass Carp (Ctenopharyngodon idella). We then tested the relationship between the degree of climate habitat suitability predicted by Maxent and the individual growth rates of both wild (N = 17) and stocked (N = 51) Grass Carp populations using correlation analysis. The Grass Carp Maxent model accurately reflected the global occurrence data (AUC = 0.904). Observations of Grass Carp growth rate covered six continents and ranged from 0.19 to 20.1 g day(-1). Species distribution model predictions were correlated (r = 0.5, 95% CI (0.03, 0.79)) with observed growth rates for wild Grass Carp populations but were not correlated (r = -0.26, 95% CI (-0.5, 0.012)) with stocked populations. Further, a review of the literature indicates that the few studies for other species that have previously assessed the relationship between the degree of predicted climate habitat suitability and species functional traits have also discovered significant relationships. Thus, species distribution models may provide inferences beyond just where a species may occur, providing a useful tool to understand the linkage between species distributions and underlying biological mechanisms.
authors.affiliation: Department of Biological Sciences University of Notre Dame Notre Dame Indiana 46556; Department of Biology University of Nevada Reno Reno Nevada 89509.
authors.forename: Marion E
authors.initials: ME
authors.lastname: Wittmann
authors.affiliation: Department of Biological Sciences University of Notre Dame Notre Dame Indiana 46556; Environmental Change Initiative University of Notre Dame Notre Dame Indiana 46556; Department of Natural Resources Management Texas Tech University Lubbock Texas 79409.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Barnes
authors.affiliation: Department of Biological Sciences University of Notre Dame Notre Dame Indiana 46556; Department of Biology University of Nevada Reno Reno Nevada 89509; Environmental Change Initiative University of Notre Dame Notre Dame Indiana 46556.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Jerde
authors.affiliation: Fisheries and Oceans Canada Great Lakes Laboratory for Fisheries and Aquatic Sciences Burlington ON L7S 1A1 Canada.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Jones
authors.affiliation: Department of Biological Sciences University of Notre Dame Notre Dame Indiana 46556; Environmental Change Initiative University of Notre Dame Notre Dame Indiana 46556.
authors.forename: David M
authors.initials: DM
authors.lastname: Lodge
keywords: Environmental niche model; Maxent; grass carp; managed species; model validation; species biogeography; species functional traits