Diversity and ecological distribution of macrofungi in the Laojun Mountain region, southwestern China
Surveys of the macrofungi associated with eight different vegetation types in the Laojun Mountain region of southwestern China yielded approximately 520 species belonging to 175 genera. Species richness and diversity were highest in mixed conifer and broadleaf forests and deciduous broadleaf forests. In typical forests of temperate regions of the world, there are five dominant genera of ectomycorrhizal macrofungi. The distribution patterns of species in these genera for the different vegetation types indicate that they are able to associate with a wide variety of different trees. Analysis of data for common macrofungal species and taxonomic similarity of the communities present in the eight vegetation types suggest that the greater the differences in the plant species that comprise the vegetation, the less similar are the common macrofungal species associated with the most common host plants. These same data also show that some species of macrofungi occur only in one or two vegetation types. There were 156 species of edible fungi recorded from the different vegetation types, and these fungi appear to be abundant in the Laojun Mountain region. At different positions along the elevation gradient, positive correlations existed with respect to the relationship between species richness and diversity, and the general trend was for macrofungal species richness and diversity to decrease with increasing elevation, with the numbers of species recorded being significantly lower at the very highest elevation. The relative dominance of certain taxa in the assemblage of species present was found to increase with increasing elevation, and variation in the evenness component of diversity was slight. As such, the differences in dominance and evenness were also not significant (P > 0.05). Macrofungal species richness was slightly more diverse on shaded slopes than on more exposed (sunny) slopes, and the differences in species diversity, dominance and evenness were relatively minor. This suggests that slope aspect may only weakly influence the distribution of macrofungal species in the Laojun Mountain region.