Grassland biodiversity encompasses a wide range of goods useful to humans.
Grasslands have been the seedbeds for the ancestors of major cereal crops, including wheat, rice, rye, barley, sorghum, and millet. They continue to provide the genetic material necessary to breed cultivated varieties that are resistant to crop diseases. Grasslands also provide habitat for plants and animals-soil microfauna and large mammals alike.
Global and regional datasets identify biodiversity in the world’s grasslands. The PAGE analysis reviews these datasets, paying special attention to areas designated as especially important for preserving grassland biodiversity.
The following summarizes key findings of the PAGE study regarding the condition of grassland ecosystems, as well as the quality and availability of data.
PAGE measures and indicators
Data sources and comments
Areas of designated importance Centers of Plant Diversity Compilation of information on centers of plant diversity worldwide through fieldwork and expert judgment from IUCN-The World Conservation Union, spatial, electronic database by World Wildlife Fund (WWF-U.S) (Davis et al 1994 and 1995). Endemic Bird Areas Worldwide documentation of breeding ranges of restricted-range bird species developed by Birdlife International through fieldwork and expert judgment (Stattersfield et al 1998). Global 200 Ecoregions Designation of 200-plus ecoregions in the world by WWF-U.S., selected as outstanding examples of diverse ecosystems based on expert opinion (Olson and Dinerstein 1998). Biological Distinctiveness Index Index of ecoregions based on species richness, species endemism, rarity of habitat type, rare phenomena, and beta diversity developed by WWF-U.S. for North and Latin America (Dinerstein et al. 1995, Ricketts et al 1999). Protected Areas Global database of protected areas in management categories I-VI produced by IUCN-World Conservation Union and WCMC (WCMC 1999).
Grassland bird populations Long-term trend data on breeding birds of North America found along more than 3,500 survey routes over approximately 30 years beginning in 1966, now reported by the U.S. Geological Survey (USGS) (Sauer et al 1997 and 1999).
Large grassland herbivores Long-term population trend data from the Serengeti (Campbell and Borner 1995).
Key areas for threatened birds in the Neotropics Dataset for Latin America with extensive documentation, identifying key areas of threatened species through fieldwork and expert judgment, presented by Birdlife International (Wege and Long 1995).
Fragmentation and road densities Spatial, electronic database of road networks worldwide from Digital Chart of the World (DCW) (ESRI 1993); fragmentation index developed by the World Wildlife Fund (Dinerstein et al. 1995; Ricketts et al 1997) presented in chapter on grassland extent and change.
Non-Native species Species Dataset for North America aggregating county-level statistics on non-native species to ecoregions, compiled by WWF-US (Ricketts et al. 1997). County lists do not distinguish invasive or harmful introductions from those that are benign or beneficial.