Geography of grassland ecosystems

摘要: Grasses and grasslands occur on all continents, from the equator to poles, and. together with grazing animals that coevolved diem constitute world's major food resources. 'Mankind has depended upon them for his existence ever since our remote ancestors ventured onto savannas began a new mode of (Stcbbim, 1981). seem have emerged during late Creta-ceous. by early Miocene probably assumed prominent place in earth's vegetation (de Wet. Within last few thousand years, man helped their spread very large extent, today almost 25 per cent plant cover is composed (Barnard, 1969); however, recent years extensive areas natural been ploughed raising crops. The literature truly voluminous but conspicuously uneven across continents. It beyond scope this paper review litera-ture. it also not possible describe grassland types distribution detail. Our objective here collate information origin different parts world present general picture grass-lands each continent.