На головну

Global grasslands under threat

The question 'Are grasslands under threat' was recently posed by the FAO (FAO, 2008) to highlight the ongoing increase in land-use pressure on grassland biomes worldwide as they compete with other land-use types, such as arable land or infrastructure development During the last decade, competition for land acreage has even increased, often to the disadvantage of grass- land, i.e. grassland has been converted into arable land. The world's largest grassland biomes, the Eur- asian steppe and the South American grasslands (Cer- rado, Campos and Pampa), are particularly threatened through changing land use. Such land-use changes are, at least partly, induced by increasing demands for high-protein feedstuff for dairy cattle nutrition. Dairy farming in north-west Europe is subjected to an ongo- ing intensification in forage production and animal husbandry, and high-input confinement systems are now becoming more typical for this region. Confine- ment dairy farms typically use large proportions of silage maize in their supply of roughage. To balance the surplus of energy from the silage maize, high amounts of imported protein-rich feedstuff such as soybean meal are fed to lactating cows. Such systems, in contrast to grassland-based, especially grass-clover- based systems, rely on the import of protein-rich feed- stuff and thus potentially contribute to land-use changes in the producing country. However, the import of feedstuff implies a virtual net import of land, which in turn means outsourcing and relocation of environmental impacts. Thus, the assessment of envi- ronmental impacts from intensified dairy farming in Europe requires the inclusion of outsourced and relo- cated forage production systems. For instance, land- use changes associated with the ongoing expansion of soybean cultivation area in South America have become a major environmental issue in the assess- ment of dairy farming systems (Gerber et al., 2010; Flysjo et al., 2012). However, there remains a lack of reliable data so that quantitative assessments suffer from inaccuracy. In the following two subsections, the threat to glo- bal grasslands is examined by highlighting the current situation and the leading research activities in two major grassland biomes of the world: (i) the Typical Steppe, a vast Eurasian steppe ecosystem of Inner Mongolia, P.R. China, and (ii) the Cerrado, a vast savannah ecosystem of Brazil

 



Sustainable intensification - changing paradigm in forage production | Land-use changes in the steppe ecosystem of Inner Mongolia Autonomous Region, P.R. China

Abstract | Materials and methods | Results | Discussion | References | Abstract | Background | Land-use change in the tropical savannah (Cerrado) of South America | Sustainable intensification of dairy farming - the specific role of grassland- based forage production | References |

© um.co.ua - учбові матеріали та реферати