PARENT SESSION
Contributed Oral Session 118: Biogeography: Community Composition
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 519 B, Level 5, Palais des congrès de Montréal

Regional effects on the assembly of the Yellowstone mammalian species pool.

Bruzgul, Judsen^*,1, Hadly, Elizabeth¹, ¹ Stanford University, Stanford, CA, USA

ABSTRACT- Understanding the processes fundamental to patterns of biodiversity has been a goal since the beginning of ecology. We used the assembly of the biota of Yellowstone National Park over the past 10,000 years as a natural experiment for investigating the processes that generated the modern species pool. Our approach enabled us to investigate the myriad of processes working at a variety of spatial and temporal scales. We applied null models to generate the local species pool, and used a vector-based approach to determine biogeographic affinity of species. Our results indicate that the Yellowstone fauna is composed of a non-random subset of mammals from different body size categories and with different biogeographic affinities. We found a general bias towards species that demonstrate affinity to the northern Rocky Mountain region. This result is counter to the more general pattern of south-to-north colonization following glacial retreat of continental ice in Canada. This pattern is driven by an overrepresentation of Carnivora from the north. We also found significantly fewer Rodentia with biogeographic affinity to the Great Basin region than expected from random assembly from all regions. Using a spatially explicit approach, our results demonstrate that the Yellowstone biota is differentially affected by physical and biological factors, and our approach holds promise for alternative methods to predict ecosystem response to future environmental changes.

Key words: biogeography, body size, biodiversity, national parks