| Abstract Detail
Integration of Spatial and Ecological Data in Evolutionary Studies Feria, Teresa Patricia [1], Trisha, Consiglio [2], Espinosa-Organista, David Nahum [3], Jimenez, Ivan [4]. Niche breadth and niche position predict global and regional range size across Bursera species (BURSERACEAE). Understanding the determinants of species’ range sizes is a key question in ecology and biogeography. Two major hypotheses contend that properties of ecological niches determine geographic range size. The niche breadth hypothesis proposes that the breadth of environmental conditions in which a species is able to survive and reproduce determines range size. It predicts a positive relationship between niche breadth and geographic range size. In contrast, the niche position hypothesis poses that range size is determined by the spatial frequency of the environmental conditions in which a species is able to survive and reproduce. It predicts a negative relationship between niche position and range size. Niche position is the absolute distance between the mean of the environmental conditions where a species occurs and the mean of the environmental conditions across a geographic region. We confronted these predictions against data on the global and regional (within the Balsas Basin) distribution of 26 Bursera tree species. We measured niche breadth and niche position in terms of precipitation, temperature and soil properties, both in univariate and multivariate space. We related these measures to range size using multiple regression, and phylogenetic independent contrasts when necessary. Niche breadth, measured both in univariate and multivariate space, was significantly and positively related to both global and regional range size. At the regional scale the relationship was weaker than at global scale. Niche position measured in multivariate, but not in univariate space, was weakly but significantly negatively related to global and regional range size. Therefore, Bursera species that had broad environmental tolerances tended to be more widely distributed, at both global and regional scales, than species with narrower tolerances. In addition, Bursera species that occupied habitats that were uncommon across geographic space tended to have more restricted global and regional distributions than species with lower niche position. Log in to add this item to your schedule
1 - University of Missouri-St. Louis and Center for Conservation and Susta, Biology, One University Boulevard, St. Louis, Missouri, 63121, USA 2 - Missouri Botanical Garden, Center for Conservation and Sustainable Development, 4344 Shaw Boulevard, St. Louis, Missouri, 63110, USA 3 - Facultad de Estudios Superiores Zaragoza, UNAM, Museo/Herbario, Batalla 5 de mayo s/n Esq. Fuerte de Loreto. Col. Ejército de Oriente, Mexico, D. F., 09230, Mexico 4 - Missouri Botanical Gardens, Center for Conservation and Sustainable Development, 4344 Shaw Boulevard, Saint Louis, MO, 63110, United States
Keywords: range size Bursera trees Niche breadth Niche position Balsas Basin Mexico ENFA.
Presentation Type: Symposium or Colloquium Presentation Session: C02 Location: Stevens 2/Hilton Date: Wednesday, July 11th, 2007 Time: 9:30 AM Number: C02006 Abstract ID:2126 |