9420141 Parker A pivotal mutualism in the dynamics and productivity of natural and agricultural ecosystems is the plant/fungus ectomycorrhizal symbiosis. This study joins two distinct approaches and investigator backgrounds, field ecology and molecular biology, to provide the first rigorous field test of the hypothesis that specificity in plant-fungal mycorrhizal interactions may influence forest succession rates and patterns. Ectomycorrhizal community structure and plant-fungus specificity patterns will be determined by a combination of soil coring, seedling bioassays, mushroom collections, and molecular methods. By working in conifer forests that span a successional age series, long-term dynamics of the mycorrhizal fungi can be assessed. Experiments are planned that (1) determine the diversity and dynamics of fungi that can form ectomycorrhizae in 3 age classes of conifer stands, (2) statistically test conflicting hypotheses regarding mycorrhizal specificity, (3) test conflicting hypotheses regarding the nature of early vs. late fungi in a disturbance ecosystem, and (4) determine whether mycorrhizal fungi are partitioning along spatial/temporal gradients. This study will provide a first glimpse into ectomycorrhizal community structure and dynamics in mixed conifer forests on a regional scale, and will provide insight into its importance in conifer forests. This research will also provide expanded and refined molecular methods to investigate mycorrhizae for widespread use by ecologists.
