生物多様性管理と林業ジャーナル

Impact of Slash-And-Burn Agriculture on Forest Ecosystem in Garo Hills Landscape of Meghalaya, North-East India

P. K. Yadav, Mohnish Kapoor and Kiranmay Sarma

Impact of Slash-And-Burn Agriculture on Forest Ecosystem in Garo Hills Landscape of Meghalaya, North-East India

Slash-and-burn (jhum) is one of the primary causes of deforestation in tropics. In North-East India, increasing human population density has resulted in the practice of unsustainable form of slash-and-burn that includes shortening of the fallow period as well as permanent conversion of forest to permanent agricultural expansions. This unsustainable form of slashand- burn leads to soil degradation, soil erosion, loss of forest vegetation and threatens the survival of wild flora and fauna. Garo Hills has the richest reservoir of plant diversity of India and is one of the biodiversity hotspots of the world. There are numerous sacred forest patches in the Garo Hills. The prominent pressure to native forest biodiversity in the Garo Hills is the increasing anthropogenic conversion of mature and primary forest to jhum land. The decreasing fallow period has a deep impact on the life sustainability in Garo Hills and has reduced the quality of soil and thereby reducing the possibility of vegetative restoration at the locality. There was a tremendous increase in slash-and-burn land, i.e. 5.15 percentage in the year 2010 when compared to only 0.83 percentage in the year 1991. The overall reduction in the forest, mainly due to jhumming can severely affect a viable forest habitat of the endangered fauna like the Asian elephant and Hoolock Gibbon. The need to understand the effect of slash-and-burn cycle and to differentiate between the ecological sound traditional methods of jhum from the current unsustainable forms is most important.