The diversity of arbuscular mycorrhizal fungi: Functional and ecological responses to stressful soil conditions.

摘要

Arbuscular mycorrhizal (AM) fungi mediate interactions between plants and soils, and are important where nutrient or metal concentrations limit plant growth. Variation in fungi in response to edaphic conditions and the fungal community composition may influence the effectiveness of the plant-mycorrhizal associations in some soil environments. For this thesis, I performed two studies to investigate the diversity of AM fungi: (1) Intraspecific variation among fungal species to confer A1 tolerance to a host plant and (2) Shifts in population structure of AM fungi following succession in a serpentine grassland. Results of the first study demonstrate functional differences across three AM fungal species, but more importantly, these differences varied considerably amongst fungal isolates, regardless of origin. My second study revealed an altered fungal community due to changes in soil chemical characteristics. Both of these studies suggest that the diversity of mycorrhizal fungal communities may be important for plant community stability as ecosystems undergo change.