Almost all the world’s plants (~80% of species that have been studied) form underground partnerships with fungi. These fungi (called mycorrhizae) live in close association with the cells in plant roots, and are generally assumed to be beneficial because they provide plants with essential nutrients (e.g. nitrogen and phosphorus) and can increase drought resistance. These fungi act to increase the root surface area in the soil, boosting a plant's capacity to acquire soil resources. In exchange, the plant provides sugars to the fungi. Some plants will grow extremely poorly or not at all without the right community of fungi. However, not all mycorrhizae are beneficial to all plants and the abundance and types of mycorrhizae found in the soil can be changed by human disturbances and land management. For example, fertilization can alter the mycorrhizae community as well as decrease the benefit of the association for the plant.
Ashley Carroll, science teacher at Gull Lake Middle School, MI, joined a group of researchers investigating mycorrhizal relationships in several grass species grown for biofuel at the W K. Kellogg Biological Station (KBS) in southwestern Michigan. She helped assess the impact of crop type and fertilization on the presence of mycorrhizae and their benefit to plant growth using a variety of molecular and field research methods. She also developed an investigation in which students measure the effects of mycorrhizae on plants grown in the classroom and then use microscopes to identify the different forms of fungi associated with the plant roots.