Three forest reserves, with highly degraded areas, are open to visitors in Maringá, Paraná, Brazil. Impact caused by tree cutting, heavy traffic and visitors on the establishment of arbuscular mycorrhizal fungi (AMF) was evaluated in two areas with different degradation stages of the Dr. Luis Teixeira Mendes Forest Garden, a remnant of semideciduous forest. Soil samples were removed from three locations within each area; spores were isolated from the soil by wet sieving and sucrose centrifugation and mounted on permanent slides. Spores were counted and identified taxonomically under a microscope. Diversity, dominance, equitability and similarity indexes were calculated from abundance data. The degraded area had the highest number of spores and featured communities with the lowest rates in richness, diversity and equitability. However, high spore density was caused by the frequent presence of G. sinuosum sporocarps. Ten to 12 species were verified in each site from the preserved area while this number varied from 6 to 12 in the degraded area. In the degraded area, Site II, lying in the most protected area of the forest fragment, diversified and equilibrated communities existed, similar to sites in the preserved area. Results suggest that environmental degradation had negative effects on the establishment and diversity of AMF.
diversity; Glomeromycetes; forest fragmentation
