Survey of arbuscular mycorrhizal fungi in deforested and natural forest land in the subtropical region of Dujiangyan, southwest China

The diversity of arbuscular mycorrhizal (AM) fungi in deforested (Mantoushan) and natural forest (Banruosi) land in the subtropical region of Dujiangyan was surveyed and compared. A total of 44 taxa of AM fungi were isolated, and the same number of AM fungus taxa (34 taxa) was found in both deforested and natural forest land. Acaulospora and Glomus were the dominant genera in the two sites. Glomus convolutum and G. versiforme were the dominant species in the natural forest land, while only G. versiforme was dominant in the deforested land. There was no significant difference in total spore density of AM fungi between the two sites, but the total species richness of AM fungi was significantly higher in the deforested land than in the natural forest land. The Shannon-Weiner index of AM fungus diversity was a higher in the natural forest land (2.67) than in the deforested land (2.15). There was high AM fungus composition similarity (Sorenson's coefficient C S=0.71) between the two sites. We suggest that there was little effect of deforestation on the diversity of AM fungi, and that annual herbaceous plants play a major role in maintaining and increasing AM fungus spore density and species richness in deforested land.