Authors: Gijsman, A.J.
General - 1992
Clearing of tropical rainforest for agricultural purposes largely contributes to the decline in land area under undisturbed virgin forest. The development of more sustainable land use systems, allowing a prolonged economically viable production on the currently cultivated land, may contribute to reducing the pressure on the remaining forest reserves. The rapid decline in productivity of recently cleared land due to soil degradation, however, hampers the establishment of such production systems. This study provides a literature survey dealing with the decline in soil physical conditions due to various land clearing and subsequent land use practices. This decline is brought in relation with changes in soil faunal populations and soil faunal activity. The potential to slow down or reverse the soil degradation by manipulation of soil fauna through providing favourable microclimatic conditions, increasing food supply and/or introducing new species is also investigated. It is well known that the chemical soil fertility rapidly declines after removal of the forest cover, since the tight nutrient cycling which provided for the high biomass production of the forest, is interrupted. In contrast, hardly any attention has been paid to the decline in physical condition of the soil, although degeneration of the soil structure may strongly limit root penetration and root functioning in the soil, and may also increase losses of fertile soil through erosion. As soil faunal activity is a major structure forming and stabilising factor in the soil, soil fauna are crucial for the establishment and/or maintenance of a physical soil condition favourable for plant growth.