Mycorrhizal fungi have the potential to enhance the sustainability of a revegetated site by improving the nutrient accumulation and growth rates in plants as well as increasing plant diversity and number. If the plant is compatible, the hyphae penetrate the root and form a colony between the root cells. Once inside the root, the fungi send hyphae back into the soil. These hyphae now act as an extension to the root system of the plant, increasing the volume of soil that is available for nutrient extraction. The benefit for the fungi is that the plant provides them with a source of carbohydrates.
Many nutrients required by plants, such as phosphorous, are static or poorly-mobile in the soil.
Through the mycorrhizal association, a plant can greatly increase the effective surface area of its root system for uptake of these nutrients. The plants that benefit most from the fungi are those that have a simple root system with few root hairs, and those that are phosphorous deficient. Improved phosphorous uptake increases growth and improves drought tolerance. Another advantage for the plant is that root colonisation by fungi tends to reduce the incidence of root-borne diseases. This is largely due to the fungi consuming carbohydrates in the plant root, thus reducing the energy available to pathogens.