Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines.
Résultats de la recherche
Showing items 1 through 9 of 34.-
Library ResourceArticles et Livresaoût, 2014France, Royaume-Uni, Kenya, États-Unis d'Amérique, Afrique orientale, Amérique septentrionale, Europe septentrionale, Europe occidentale
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Library ResourceArticles et Livresdécembre, 2015Cameroun
Baillonella toxisperma, Pentaclethra macrophylla and Trichoscypha abut are important foods for communities living around forests in Cameroon. Information on the nutritional value and bioactive content of these foods is required to establish their contribution to the nutrition and health of the communities. Samples of the three foods were obtained from four villages in east and three villages in south Cameroon. The foods were analyzed for proximate composition, minerals and bioactive content using standard chemical analysis methods. T.
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Library ResourceArticles et Livresdécembre, 2009Somalie
Soil loss is a major concern for land managers due to its influence on biomass production, surface water quality and landscape beauty. In Somalia, the risk of soil loss is accelerated by the removal of vegetation, bad land use practices and negative impacts of urbanization. The political upheavals and consequent insecurity in the country are major limitations for detailed database and research in soil loss.
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Library ResourceArticles et Livresdécembre, 2009Zimbabwe
Three smallholder villages located in typical communal (from 1948), old (1987) and new (2002) resettlement areas, on loamy sand, sandy loam and clay soils, respectively, were selected to explore differences on natural resource management and land productivity. Focus group discussions and surveys were carried out with farmers. Additionally, farmers in three wealth classes per village were chosen for a detailed assessment of their main production systems.
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Library ResourceArticles et Livresdécembre, 2009Algérie, Maroc, Afrique
The design of public policy related to irrigation sectors in North Africa was often based on the state view. Local farmers' organizations, made up of family farms, did not contribute to building the legal framework, which was in turn unable to propose specific solutions for family farming. Legal reforms currently underway in Morocco and Algeria show how difficult it is to integrate field realities. Access to land and water resources is often obtained through informal local coordination modes.
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Library ResourceArticles et Livresdécembre, 2016Afrique du Sud, Afrique, Afrique australe
To establish the significance of Henry Bernstein's theoretical work on the dynamics of agrarian class struggles in Africa, this paper discusses two important political debates in which he has been both observer and participant, and that have oriented much of the subsequent Marxist work done in Africa on agrarian change. The first was the heated discussion begun over 40âyears ago around Nyerere's âAfrican socialismâ and the failures of the ujamaa policy of villagization. The second is the still unsettled debate around programmes of redistributive land reform in South Africa.
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Library ResourceArticles et Livresdécembre, 2014Éthiopie
The combined effects of erosive rains, steep slopes and human land use have caused severe land degradation in the Ethiopian Highlands for several thousand years, but since the 1970s, however, land rehabilitation programmes have been established to try to reverse deterioration. In order to characterize and quantify the transformations in the north Ethiopian Highlands, a study was carried out over 8884 km² of the Tigray Highlands of northern Ethiopia.
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Library ResourceArticles et Livresdécembre, 2015Maroc, Afrique septentrionale
Atriplex nummularia has been extensively planted in Northern Africa to combat desertification. However, few studies evaluated the effectiveness of these interventions. This study aimed at assessing the dynamic performance of a number of Atriplex plantations located in the Marrakech province in terms of multitemporal dry biomass production. Three SPOT 5 images (2004, 2008 and 2012) and field biomass measurements were integrated to quantify the dry biomass production dynamics of plantations established from 1996 to 2007. Different plant ages covered the whole plant life cycle curve.
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Library ResourceArticles et Livresdécembre, 2016Afrique australe, Afrique
The Okavango catchment in southern Africa is subject to environmental as well as socio‐economic transformation processes such as population growth and climate change. The degradation of soil and vegetation by deforestation and overgrazing is one of the downsides of this development, reducing the capacity of the land to provide ecosystem functions and services. In this study, climate simulations are brought together with secondary socioeconomic, pedologic and remote‐sensing data in a GIS‐based assessment of the factors commonly associated with land degradation risk.
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Library ResourceArticles et Livresdécembre, 2016Éthiopie
Soil quality (SQ) assessment from farmers' point of view can be used as a primary indicator for planning sustainable agriculture. Despite this fact, limited information is documented with regard to SQ indicators, for example weed species, crop types and management practices from farmers' knowledge perspectives. The aims of this study are to analyse factors that determine farmers' knowledge of SQ, identify SQ indicators of weed species and crop types across different SQ status and assess soil‐and‐crop management practices that maintain SQ in the Mai‐Negus catchment, northern Ethiopia.
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