title: The relative influences of climate and competition on tree growth along montane ecotones in the Rocky Mountains.
abstract: Distribution shifts of tree species are likely to be highly dependent upon population performance at distribution edges. Understanding the drivers of aspects of performance, such as growth, at distribution edges is thus crucial to accurately predicting responses of tree species to climate change. Here, we use a Bayesian model and sensitivity analysis to partition the effects of climate and crowding, as a metric of competition, on radial growth of three dominant conifer species along montane ecotones in the Rocky Mountains. These ecotones represent upper and lower distribution edges of two species, and span the distribution interior of the third species. Our results indicate a greater influence of climate (i.e., temperature and precipitation) than crowding on radial growth. Competition importance appears to increase towards regions of more favorable growing conditions, and precise responses to crowding and climate vary across species. Overall, our results suggest that climate will likely be the most important determinant of changes in tree growth at distribution edges of these montane conifers in the future.
authors.affiliation: Program in Ecology and Department of Botany, 3165, University of Wyoming, 1000 E. University Avenue, Laramie, WY, 82071, USA. pcopenha@uwyo.edu.
authors.forename: Paige E
authors.initials: PE
authors.lastname: Copenhaver-Parry
authors.affiliation: Department of Biology, Kalamazoo College, 1200 Academy Street, Kalamazoo, MI, 49006-3295, USA.
authors.forename: Ellie
authors.initials: E
authors.lastname: Cannon
mesh_terms: D001499:Bayes Theorem; D002980:Climate; D057231:Climate Change; D013696:Temperature; D064028:Tracheophyta
keywords: Bayesian model; Distribution edge; Distribution shift; Plant performance; Sensitivity analysis