PARENT SESSION
Poster Session 19: Biodiversity
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Islands in the sky: Oribatid mite communities in suspended soils of Western redcedar as model systems of island biogeography and metacommunity dynamics.

Lindo, Zoe^*,1, ¹ University of Victoria, Victoria, British Columbia, Canada

ABSTRACT- This research examines oribatid mite communities in the forest canopy (suspended soils) and forest floors associated with ancient Western redcedar trees on the southwest coast of Vancouver Island, British Columbia, Canada. These suspended soils are thought to be interconnected islands through which random movement actively disperses individuals; however, the initial source pool of these resident arboreal fauna assemblages is unknown and theorized to be the forest floor. A series of observations and experiments based on island biogeography and metacommunity dynamics test whether the forest floor is a colonizing source for canopy oribatid assemblages and explore habitat availability as a limiting resource in oribatid mite community structure. Factors affecting the diversity and abundance of arboreal microarthropods are likely to be related to tree species, elevation and suspended soil island size. Suspended soil island size and tree species are also shown to have distinct effects on a range of soil properties and processes such as C and N fluxes within these soils. These factors suggest that tree age and development stage of suspended soils are important in sustaining and supporting large, diverse communities of microarthropods in forest canopies. Well-developed suspended soils in ancient Western redcedar are unique in that they are natural model systems that lend themselves to testing resource limitations, island biogeography and metacommunity dynamics. This study provides information pertaining to the species diversity of oribatid mites in ancient temperate rainforests, and tests ecological theories to expand our understanding of patterns of biodiversity. Special emphasis is placed on the oribatid mite community as they are the dominant fauna group in these systems and new species descriptions are anticipated.

Key words: Oribatid mites, suspended soils, island biogeography, metacommunity dynamics