PARENT SESSION
Poster Session 31: Rare, Threatened, and Endangered Species
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
The effect of ecological context on species abundance patterns: A comprehensive framework to define rarity.
Jacobs, Lee Anne1, 1 University of North Carolina, Chapel Hill, NC, lajacobs@unc.edu
ABSTRACT- Understanding patterns of species distribution and the mechanisms that shape those patterns has long been a fundamental objective in ecology and is critical for conservation planning. However, despite many studies that have sought causes for rarity, few consistent trends have emerged. This lack of consistency is due, in part, to two factors. First, studies treat but often do not distinguish different forms of rarity, making comparisons among studies difficult. Second, most studies focus on inherent species traits as a basis of comparison, which neglects the effects of environmental and biotic context within which species interact. As a step toward a more cohesive approach to the study of rarity, I propose two solutions to the problems stated above. Reference to a single comprehensive set of definitions of rarity will provide a common currency for comparison among studies and will allow more effective communication of results. Consideration of the effect of ecological context on species distribution patterns, to complement the effect of traits, will provide a more complete understanding of the mechanisms that produce, maintain, and change species abundance patterns through time. To illustrate these solutions, I reformulate an existing framework of definitions to associate forms of rarity with mechanisms that produce them and demonstrate how biological interactions cause species to change from rare to common or common to rare as ecological context changes. This comprehensive approach will allow us to predict changes in abundance, prevent such changes if they threaten species of concern, and restore populations that have already experienced such change.
Key words: rarity, relative abundance