Species composition, seasonal changes and community ordination of alkalotolerant micro fungal diversity in a natural scrub jungle ecosystem of Tamil Nadu, India

One hundred and seven species of alkalotolerant fungi were isolated from different layers of litter of the Guindy Reserve Forest, Chennai, South India during a 2-year period. They comprised Zygomycota (7 species), Ascomycetes (4 species), hyphomycetes (86 species) and coelomycetes (10 species). The F1 litter layer, just beneath the recently fallen leaves, had the richest composition of fungi and the fungi were most abundant during the North East monsoons (September to November). Shannon's diversity index and Simpson diversity index. indicate F1 layer to have the maximum species. The species distribution fell into the log series model and Fishers alpha was also highest for the F1 layer. Species richness indices computed also indicated that none of the species was more predominant. Values of species evenness computed hovered around 0.6 indicating a tilt towards even distribution of the species. The fungal community is a heterogenous assembly of species derived from a homogenous habitat with a log normal pattern of distribution formed due to the interplay of many independent factors governing the relative abundance of the species. Principal component ordination analysis reveals that the greatest variation in the species composition was due to the South West monsoon. Also, detrended correspondence data put the species abundance data for the four seasons in a linear arrangement.