干旱区生态环境知识资源中心

Land degradation has recently been exacerbated in rangelands of Mexico by heavy grazing pressures, In the country, the grazing stock (cattle, goats, sheep and hogs) increased from 22 million in the early 1950’s to approximately 50 million in the mid 1980’s. Recorded local grazing pressures are surpassing from two to six times the recommended stocking rates of most rangelands of northern Mexico. Signals of deterioration of natural resources vary in time and space mainly because of ecosystem diversity, recurrent drought spells of different magnitudes, and economic and political issues. Estimates of carrying capacities and overgrazing rates are out of date, and very few quantitative parameters of desertification processes are available. However, there are qualitative and perceptual evidences of changes in soil and vegetation patterns, as well as socioeconomic issues, such as land tenure and forms of organization, that deserve to be discussed. Management practices, research, and social issues are addressed in this review from the desertification perspective, with the objective of highlighting the main causes of overgrazing and desertification. Needs for research and future tasks to achieve the sustainable management of rangelands of northern Mexico, with especial emphasis on those of the northeastern region, are also pointed out.