Ectomycorrhizal fungi are symbiotic associates of most temperature forest trees. Their association with the roots of trees such as pines and oaks is necessary for normal growth and reproduction of the trees. These fungi exhibit a high level of species diversity even at a single sit. Yet little is currently known about the functional significance of this diversity. %%% In this study researchers will use molecular identification methods in combination with soil core sampling, mushroom mapping, and experimental manipulations to dissect the community structure of these fungi in coastal pine forests. The sampling schemes used are designed to reveal the variation of fungal species composition in space and time at several scales, and will ultimately yield the first picture of ectomycorrhizal fungal communities in any single forest type on a regional scale. Methods for molecular identification of mycorrhizae will be further refined to facilitate widespread use and they will be adapted for the identification of fungal individuals. The latter level of identification will enable us to investigate clonal size and dissect the genetic strategies employed by selected fungal species. This work will result in a better understanding of the basic ecology of these fungi and will provide a basis for future management of pinc ecosystems.