HUMAN USE OF THE SAND DUNE ECOSYSTEM IN THE SEMIARID ZONE OF THE RAJASTHAN DESERT, INDIA

Sand dunes form one of the most fragile terrestrial ecosystems. In Raj asthan they have a diverse vegetation and are often utilized by consid erable human and livestock populations. A thorough knowledge of the re source utilization by the human and animal populations is essential if the future potential of the ecosystem and its physical stability unde r changing environmental conditions are to be accurately assessed. Thi s study examines the socio-economic aspects of land degradation at fou r sites in Churu and Jhunjhunu districts, northwest Rajasthan. An atte mpt is made to assess the socio-economic factors leading to land degra dation. Data on human use of the Rajasthan (Thar) Desert semiarid ecos ystem were collected through individual interviews, group discussions and field measurements. The present exploitation of soil and vegetatio n resources, possible future biomass deficiency, its impact on sustain able development and role in land degradation are examined. The averag e number of people in each household in the study area, and the number of livestock each household maintains are too high to allow a satisfa ctory income to be sustained. The annual income of 50-90 per cent of h ouseholds was less than 10 000 rupees ($US 1 = 17 rupees in 1987). Sal e and consumption of milk, wool, surplus animals and wood provide live lihood, supplemented with income from wage labour. Rain-fed marginal l and cultivation produces poor yields and the per capita production is too low to justify the huge soil erosion losses occurring. The number of goats, sheep and cattle owned by the inhabitants has increased trem endously in recent years. Stocking rates vary from 1.63 to 12.08 anima ls per hectare. The grazing pressure during the dry season, when forag e availability decreases, reaches 34.9 animals per hectare. As a resul t of overgrazing, the land productivity has decreased considerably. Th e annual fodder deficit values in the study area are enormous. Demand for fuelwood at all the study sites is increasing, yet available fores ts have already largely been cut down. The distance travelled to colle ct fuelwood has been increasing, whereas the amount and quality of fue lwood is decreasing. Use of cattle dung to supplement fuelwood during the summer dry season and in drought periods has been decreasing due t o low fodder availability and high livestock mortality. Human numbers are increasing, and livestock numbers are also multiplying (except in drought periods) and consequently the available resources are decreasi ng. Soil erosion and desertification will continue to increase during the next decade unless effective counter measures are undertaken.