干旱区生态环境知识资源中心

This paper presents the main social and economic influences of small ruminants on the environment as well as the impact of small ruminants on natural resources in two of the most dominant world farming systems, arid add temperate. The analysis of the arid system underlined the apparent incapacity of the land to support the numbers of domestic animals that caused most of the damage in addition to that accomplished through cultivation and gathering of wood species. The ecological integrity of these systems was weakened once the strategies behind their adaptation to arid and marginal areas (diversification and mobility) were threatened. In addition, the transformation that these systems are going through (social, economical and political) has threatened the viability of these traditional systems. In temperate zones, there are concerns that both too little and too much grazing by small ruminants is leading to environmental degradation. There is a need to more fully understand the role that grazing plays in maintaining habitats and landscapes in favorable condition. Environmental concerns of small ruminant systems in intensive grassland systems are those of all intensive grassland systems, pollution from animal waste, from silage, and nitrate and phosphate discharge to water. (C) 1999 Published by Elsevier Science B.V. All rights reserved.