PARENT SESSION
Poster Session #36: Mycorrhizal Fungi and Root Processes.
Thursday, August 9, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall

Multiple partners: Possible impacts on mycorrhizal community dynamics and diversity.

Golubski, Antonio¹, ¹

ABSTRACT- Although the significance of endomycorrhizal fungi in terrestrial ecosystems is widely acknowledged, the causes and consequences of diversity in these fungi are not well understood. A recent frequency dependent model suggests that dynamics within mycorrhizal mutualisms could promote the coexistence of at least two competing plant species and two competing fungal species within a community; the relative benefits each participant receives from each of its mutualistic partners determine whether or not the negative feedback responsible for this result appears. Models are developed here in which simultaneous association with multiple partners is considered to result in elevated or depressed fitness relative to association with either partner alone. This increases the range of conditions under which negative feedback occurs and coexistence of all four species is possible. Differences between plants in the relative proportions of fungi at which maximum fitness occurs may facilitate coexistence, as may differences between fungi in their abilities to establish interplant connections. These models suggest additional mechanisms by which mutualistic interactions could promote local diversity of plants and endomycorrhizal fungi.

KEY WORDS: mycorrhizae, frequency dependence, diversity, fitness