ACTIVITY AND SPECIES COMPOSITION OF ARBUSCULAR MYCORRHIZAL FUNGI FOLLOWING SOIL REMOVAL

Large areas of the Everglades National Park have been invaded by exotic plant species, particularly Schinus terebinthifolius. In an attempt to return these areas to the former wetland vegetation, an experimental site was subjected to soil removal (SR). The objective of this study was to document the effect of SR on the activity-estimated by total propagule and spore numbers, and root colonization-and species composition of arbuscular mycorrhizal (AM) fungi. Soil and plant samples were collected in the spring (following the dry season) and fall (following the wet season) for 2 yr from full- and partial-SR plots, an adjacent site dominated by schinus, and the mature undisturbed glade. The mature glade had the lowest mycorrhizal activity, while the SR plots had the highest activity. Mycorrhizal activity in SR plots increased over the 2-yr period. These plots also had greater plant species richness than the mature glade. No relationship was found between root colonization and plant hydrological category. A total of 22 fungal species, belonging to four genera, were present as the most abundant AM species in individual plots. Temporal changes observed in these species were likely related to changes in host plants and the edaphic environment. We suggest that the complexity of both AM and vegetation succession on these plots will decrease with time after species richness of AM and plants peak and the site conditions stabilize.