000			02201cam a2200265 4500500
005			20250121101515.0
041			_afre
042			_adc
100	1	0	_aBrossard, Michel _eauthor
700	1	0	_a López-Hernández, Danilo _eauthor
245	0	0	_aSoil and Environmental Sustainability Indicators for South America’s Savannas
260			_c2005.
500			_a16
520			_aSouth American savannas cover some 2.69 million sq km across Brazil, Colombia, Venezuela and Bolivia. On a world-wide scale they represent one of the most extensive land areas with agricultural potential for crop and forestry production. Besides, these vast stretches of land are also the main alternative for avoiding the extension of agriculture to fragile tropical areas of higher ecological risk, such as the tropical rain forests and hillsides. Over the past four decades introduced pastures consisting chiefly of African species, in particular from the genus Brachiaria and Andropogon, and cropland have replaced the natural vegetation having low nutrient requirement in the savannas (Llanos) of Colombia and Venezuela, as well as in the Cerrado (Brazil). Intensive reforestation schemes have also taken place with alien species such as Pinus and Eucalyptus for pulpwood and timber production. The introduction of African grassland species and annual and perennial crops were made possible through the use of intensive fertilization, particularly with inorganic amendments. Following a preliminary comparative review of the colonization process by agriculture in the Llanos and Cerrado and a survey of some soil biogeochemical features, we show the crucial relation between these environments and current environmental stakes and the need to generate new indicators for the use of savanna areas.
690			_aCerrado
690			_aColombia
690			_aLlanos
690			_aVenezuela
690			_aland use
690			_aBrazil
690			_asoil biogeochemical cycle
690			_asavanna
786	0		_nNatures Sciences Sociétés | 13 | 3 | 2005-09-01 | p. 266-278 | 1240-1307
856	4	1	_uhttps://shs.cairn.info/journal-natures-sciences-societes-2005-3-page-266?lang=en&redirect-ssocas=7080
999			_c524853 _d524853