[Diversity and niche of soil moniliaceous hyphomycetes in Taibai Mountain].

Sixteen genera of soil moniliaceous hyphomycetes were isolated from 40 soil samples collected from the southern and northern slopes of Taibai Mountain, and the indices Shannon-Wiener diversity index, evenness, niche breadth, and niche overlap were used to analyze the community structure and niche of soil moniliaceous hyphomycetes in different forest types on the southern and northern slopes of Taibai Mountain. The results showed that the distribution of soil moniliaceous hyphomycetes on the study area had an obvious environmental gradient pattern. Altitude and forest type were the main determinants of the fungal community distribution. The species richness and diversity index of soil moniliaceous hyphomycetes decreased significantly with increasing altitude, but the community evenness represented an increasing trend. Among the genera of soil moniliaceous hyphomycetes, Penicillium, Aspergillus, Verticillium, Paecilomyces and Acremonium had larger niche width and greater niche overlap with other genera, suggeting that these genera had wide distribution on the southern and northern slopes of Taibai Mountain. As for Trichothecium, Gliocladium and Metarhizium, their niche width was narrower, and their niche overlap with other genera was smaller, indicating that the distribution of these genera was more affected by altitude and vegetation, with the occurrence only in special forest types.

Diversity analysis of soil dematiaceous hyphomycetes from the Yellow River source area: I.

Twenty-four soil samples of eight ecosystem-types around the Yellow River source area were investigated for the number and specific composition of soil dematiaceous hyphomycetes by dilution plate technique. And then the co-relationship between genus species of soil dematiaceous hyphomycetes and ecosystem-types was analyzed. The results show that the amount and species distribution of soil dematiaceous hyphomycetes had an obvious variability in different ecosystem-types, and that the dominant genus species varied in the eight ecosystem-types studied, with Cladosporium being the dominant genus in seven of the eight ecosystem-types except wetland. The index of species diversity varied in different ecosystem-types. The niche breadth analysis showed that Cladosporium had the highest niche breadth and distributed in all ecosystem-types, while the genera with a narrow niche breadth distributed only in a few ecosystem-types. The results of niche overlap index analysis indicated that Stachybotrys and Torula, Doratomyces and Scolecobasidium, Cladosporium and Chrysosporium had a higher niche overlap, whereas Arthrinium and Gliomastix, Phialophora and Doratomyces, Oidiodendron and Ulocladium had no niche overlap.