Macrofungal diversity in fragmented and disturbed forests of the Western Ghats of India.
Abstract
Despite their functional importance, little is known about how and where fungi can be conserved. It is important that we understand the consequences of habitat degradation and fragmentation for fungal assemblages if we are to devise successful conservation strategies. We investigated the effects of fragmentation and disturbance on the diversity and landscape distribution of fungi in tropical rain forests in the Kodagu district of the Western Ghats of India. We recorded macrofungi on three occasions over a wet season, in 0.125-ha plots in 10 forest reserve sites, 25 sacred groves and 23 coffee plantations. Despite a long history of isolation from continuous forest, sacred groves had the highest sporocarp abundance and the greatest morphotype richness per sample area, while coffee plantations had the lowest. However, coffee plantation samples were more diverse for a given number of sporocarps than a sample of a similar size from other forest types. Ordination by non-metric multidimensional scaling suggested that sacred groves had a macrofungal assemblage that was distinct from other forest types. This compositional difference was primarily because of the presence of a group of dead wood and litter decomposing fungi. Coffee plantations and forest reserve sites had very variable but overlapping compositions. Neither sacred grove size nor distances between a grove and continuous forest accounted for a significant proportion of the total variation in their macrofungal richness. There was no significant correlation between dissimilarity in macrofungal assemblage composition and geographical distance between sample sites. However, we found strong congruence between patterns of dissimilarity in macrofungi and trees between sites. Synthesis and applications. These results imply that macrofungal distribution patterns at a landscape scale are determined by habitat requirements rather than dispersal or local population dynamics. This means that habitat degradation is a more serious threat to fungal diversity than fragmentation. Sacred groves, although small, are important for fungus conservation because they provide unique types of habitat.