全球智库信息集成服务系统

The PAGE reports analyze quantitative and qualitative information and develops indicators of the condition of the world's freshwater, coastal, forests, grassland and agroecosystems. The condition is defined as the current and future capacity of the systems to continue providing the full range of goods and services needed or valued by humans.

The PAGE: Grassland Ecosystems focuses on a selected set of grassland goods and services: food, forage and livestock, biodiversity, carbon storage, and tourism and recreation. Each good or service is discussed in terms of its current status and modifications that have altered its condition such as cultivation, urbanization, fire, livestock grazing, and introduction of invasive species.

Results show that although the major goods and services provided by grasslands are in good to fair condition, the capacity for grassland ecosystems to continue to provide these goods and services is declining.

• There have been unambiguous declines in the extent of grasslands, especially in the temperate zones of North America and Europe where these ecosystems have been cultivated or urbanized.
• Indicators of soil condition show that more than half of the grasslands in the study have some degree of soil degradation; over 5 percent of these grasslands are strongly to extremely degraded.
• Indicators of grassland biodiversity show marked declines in grassland birds of North America, with negative effects from fragmentation and non-native species suggested for this region and others.
• Although the carbon storage potential for grasslands is large, degraded areas store less carbon and there is heavy burning of some grassland areas, especially the African savannas.
• Tourism and recreational activities in grasslands appear to make important economic contributions to some countries, with revenues generally increasing.
• Overuse of some areas, and declines in wildlife populations, however, suggest possible declines in the capacity to continue to provide these services.

Note: GIS Data Sets in ArcInfo raster Grid format. This data can be displayed in Arcview 3x. Arcview 8x, with the Spatial Analyst Extension. Interrupted Goodes Homolosine Projection.