Arbuscular mycorrhizal (AM) fungi form symbiotic associations with about 80% of terrestrial plants. One such plant is eastern red cedar (ERC), a major invasive woody species in prairie and rangelands in the central Great Plains. Because AM fungal community structure is one determinant of plant diversity, the success of ERC may hinge on its ability to form associations with existing AM fungal communities. To test this hypothesis we examined the temporal diversity of AM fungal communities associated with ERC at the Nebraska National Forest, Halsey NE. Soil and plant root samples were taken from individual seedlings in native grassland to mature ERC stands. AM fungal community structure was analyzed based on denaturing gradient gel electrophoresis (DGGE) profiles of the 18S rRNA genes. Meanwhile clone libraries of the 18S rDNA fragments were constructed and screened by DGGE, sequence information for bands from the original DGGE gel could be inferred from single clones that migrated to the identical position on DGGE. Phylogenetic analyses were conducted using the neighbor joining algorithm. Our analyses showed a temporal pattern to the diversity of AM fungi associated with ERC. The ecological significance of these adaptations is discussed.