Collaborative Research: Dispersal Limitation as a Primary Factor in Determining Ectomycorrhizal Community Structure

Lewis And Clark College, Portland OR

Investigators

Abstract

Proposal Title: Collaborative Research: Dispersal Limitation as a Primary Factor in Determining Ectomycorrhizal Community Structure Institution: University of California-Berkeley Abstract Date: 12/04/07 Ectomycorrhizal fungi are obligate mutualists with temperate forest trees such as pines, oaks, aspens, and birch. These fungi provide mineral nutrients to the trees in exchange for sugars, and trees require them for growth and survival. Following severe disturbance such as forest fires or logging, trees need to reestablish their relationships with mycorrhizal fungi in order to survive. Prior work has shown that these fungi arrive in an ordered sequence, or "succession", after such disturbances. A new model is proposed to explain this observed pattern through differences in spore dispersal and competitive interactions among mycorrhizal fungi. Four key predictions of this model concerning limitations to aerial spore dispersal and effect of tree root density on fungal competition will be tested through a combination of field sampling and manipulative growth-chamber experiments. The broader impacts of this work are that it will help us understand an essential biotic process necessary for tree establishment, and will build a foundation of basic ecological knowledge for an important group of understudied organisms. Training of graduate and undergraduate students will be an important component of this research. In addition this work takes advantage of its location within Point Reyes National Seashore by feeding back into management decisions within the park and through outreach efforts directed towards public education.