Diversity and variability in soil fungi from a disturbed tropical rain forest

Abstract

Variation in diversity of fungi isolated from soil was studied in a ferrallitic and a hydromorphic soil, in an experimental area of the Tai National Park (SW Ivory Coast). Several experimental disturbances were produced, and the change in species diversity was observed both within and between years, over seven years. The disturbances, as well as the changes in soil moisture produced by variation of rainfall, act as extrinsic factors to the community, influencing the level of diversity. The variation of diversity within the community in time, however, seems to occur as an internal mechanism. Species with a generalist or specialist behavior were identified, in accordance with their occurrence in dry and wet periods. Two new species and two new genera found here do not seem to be rare or have limited distributions, but rather appear as generalists. Knowledge of the fungi isolated from soil is of considerable interest in tropical forests, where traditional shifting cultivation is practiced. Cultivation is currently considered responsible for ecosystem degradation. This paper, however, shows that traditional cultivation, when practiced as a short time-space disturbance, does not appear to cause serious disturbance to the fungal diversity.

Key Words:

• biological diversity
• disturbance
• microfungi
• succession
• tropical soils