Adaptation strategies to pasture degradation： Gap between government and local nomads in the eastern Tibetan Plateau

In the last decade, there has been increasing interest in climate change, pasture degradation and its driving forces, and innovations in nomadic pastoralism on the Tibetan Plateau. However, little is known of indigenous strategies of adaptation to pasture degradation, which limits the effectiveness of adaptation strategies planned by local government. This paper analyzes nomads＇ strategies of adaptation to pasture degradation on the basis of a field survey of three townships of Dalag County in the source regions of the Yangtze and Yellow rivers. Pastures there have evidently degraded, with pastures in Wasai mainly in a state of slight or medium degradation and those in Manzhang and Jianshe in a state of medium or severe degradation. With the degradation of pasture, the grazing time is reduced, which af- fects the livelihoods of nomads. Although the Four-Package Project has commenced in this region, there is still severe fodder shortage in winter and spring. The traditional hay storage strategy does not work because of pasture degradation, and few nomads establish fenced and artificial pastures. Therefore, nomads have employed other strategies, such as renting pasture, providing supplementary feed, and diversifying their livelihoods. Local strategies taken by nomads can provide valuable insights into ecological restoration and livelihood improvement in the region and suggest changes to means promoted by local government. It is necessary to seek new means that combine the best aspects of nomadic pastoralism with modern stockbreeding technologies to help nomads adapt to pasture degeneration and improve their livelihoods.

The expansion of Brazilian agriculture:Soil erosion scenarios

During the next 10 years Brazil's agricultural area will expand to meet increased domestic and worldwide demand for food,fuel,and fiber.Present choices regarding land use will determine to what degree this expansion will have adverse effects that include soil erosion,reservoir siltation,water quality problems,loss of biodiversity and social conflict,especially around indigenous reservations.This paper presents an up-to-date inventory of soil erosion in Brazil caused by crop and livestock activities and provides estimates based on three different hypothetical land-use scenarios to accommodate the expansion of Brazilian agricultural activity by 2020:Scenario 1-expansion of cropping into areas of natural vegetation,without adoption of conservation practices;Scenario 2-expansion of cropping into areas of degraded pasture,without adoption of conservation practices;Scenario 3-expansion of cropping into areas of degraded pasture,together with conservation practices in 100%of the expanded area.The worst-case scenario involves expansion of agriculture into areas of native vegetation in the Brazilian Savannah(Cerrado)and Brazilian rainforest(Amazon)biomes,and could increase total soil erosion in Brazil(currently about 800 million metric tons a year)by as much as 20%.In the best-case scenar-io,crop expansion under a conservation agriculture model would utilize currently degraded pasture,especially in the Savannah(circa 40 million hectares),reducing soil erosion in Brazil by around 20%.For this to occur,however,a national soil and water conservation policy needs to be implemented in Brazil to support a sustainable model of agriculture in which the environment can be preserved as much as possible.