Soil aggregation (the arrangement of pore spaces and solid matter in soil) is a critically important process in natural and managed ecosystems, affecting a wide range of soil and ecosystem functions and biota. Management practices and erosion threaten soil structure on a national and global scale. Fungi, and in particular arbuscular mycorrhizal fungi (AMF), are of great significance in soil aggregation. However, there is little known about of the basic biological characteristics of AMF in relation to soil aggregation. This research tests several fundamental biological (physiological and architectural) characteristics of AMF for their relationship with soil aggregation. It is hypothesized that there fungal traits correlate with soil aggregation across a number of fungal species. The research also places soil aggregation in the context of other functions carried out by these symbiotic fungi, and investigates how different species of fungi can interact in maintaining stable soil aggregates. An aspect of the educational component of this research is participation of graduate students and PI in the Montana Teachers Investigate Ecology program, a partnership with Western Montana High School teachers.