Land-use Changes and Resource Degradation in South–West Masailand, Tanzania

Abstract

This study uses sequential aerial photography to identify environmental changes. The interpreted aerial photos constitute a data-bank of past and present land cover/uses.* Substantial changes have been observed in the areas of cultivation, woody cover, and bare ground.An increased 449.9% of the surveyed area has been cleared for cultivation during the last 30 years, while 77.2% of the former woodland has been destroyed during the same period, contributing to a 15.6% increase in grassland. Bare ground increased by 33.1%. Increased cultivation is caused by increase in the population of subsistence farmers and mechanization. Expansion of cultivation and overexploitation of woody resources (fuel-wood and building materials) are the causes of decline in the woody vegetation. As consumption of woody resources exceeds natural regeneration, woody cover is gradually replaced by grasslands.Diminution of the woody vegetation results in shortage of fuel-wood and building materials and consequent misery to the local people. Expansion of cultivation reduces grazing-land, leading to overstocking and overgrazing. Extensive cultivation, based on soil ‘mining’, subjects more and more land to physical and chemical soil degradation, leading in turn to decline in soil fertility and crop yields. Both overgrazing and extensive cultivation accelerate soil erosion in the area, reducing available cropland, while siltation and flooding cause serious damage to property and infrastructure.Lack of effective land-use planning, uncontrolled population growth, and introduction of the Tanzanian village agricultural production system in a semi-arid area, have contributed to the present deplorable state of affairs. In general, the area shows increasing environmental degradation and resource depletion, while very little conservation effort is being made to reverse the trend. These results indicate that a sustainable resource management plan is urgently needed for the area.