Aller au contenu principal

page search

Displaying 3769 - 3780 of 4607

Assessment of soil organic carbon in semi-arid Sudan using GIS and the CENTURY model

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Soudan

Using the UNFCCC as a basis, and the objectives of estimating soil organic carbon (SOC) changes during the period 1900–2100, a spatially explicit database of climate, land cover and soil texture was compiled for a 262,000 km2 region in semi-arid Sudan. The area is characterized by low input cultivation of millet, sorghum and sesamé combined with livestock grazing.

Fertility management and landscape position: farmers' use of nutrient sources in western Niger and possible improvements

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Niger

Poor millet growth and yields in Niger are commonly attributed to rainfall deficits and low soil nutrient content. Land management by local farmers is done as a function of soil types, crops, and available resources. Farmer management practices in millet fields located on four different landscape positions were studied in a village in western Niger located near the 600 mm isohyet.

Formalizing expert judgements in land degradation assessment: a case study for Ethiopia

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Éthiopie

Expert judgements are potentially a valuable source of information in land degradation assessment, especially in areas where data paucity impedes the use of quantitative models. However, expert opinions are also much disputed because they are not tested for consistency, abstain from formal documentation, while their quantitative interpretation is inherently unidentifiable.

environmental narrative of Inland Northwest United States forests, 1800–2000

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
États-Unis d'Amérique

Fire was arguably the most important forest and rangeland disturbance process in the Inland Northwest United States for millennia. Prior to the Lewis and Clark expedition, fire regimes ranged from high severity with return intervals of one to five centuries, to low severity with fire-free periods lasting three decades or less.

Managing woodlands for income maximisation in western Queensland, Australia: clearing for grazing versus timber production

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Australie

Queensland, Australia, has a proud pastoral history; however, the private and social benefits of continued woodland clearing for pasture development are unlikely to be as pronounced as they had been in the past. The environmental benefits of tree retention in arid regions of the State are now better appreciated and market opportunities have arisen for the unique timbers of western Queensland.

set of guidance for the management of grazing Units in the cereal-sheep system of Castile-La Mancha (South-Central Spain)

LandLibrary Resource
Journal Articles & Books
Décembre, 2003

Extensive livestock farming systems in the Less Favored Areas (LFA) of the European Union (EU) are under social stress and requirement to adapt their production practices to new economic and social realities. This research argues that a restructuring plan for the cereal-sheep system of Castile-La Mancha may represent economic and ecological synergies.

Degradation and recovery processes in arid grazing lands of central Australia Part 3: implications at landscape scale

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Australie

Using data from previous studies, we tested two hypotheses about the impacts of grazing in a naturally heterogeneous landscape in arid central Australia: (1) that grazing leads to net change of resources at a paddock or landscape scale, and (2) that water and nutrients remain coupled as they move through the landscape.

Assigning life-history traits to plant species to better qualify arid land degradation in Presaharian Tunisia

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Tunisie

Apart from a decrease in total perennial plant cover, degradation of North-African arid lands is not easy to qualify. Yet, simple and comprehensive yardsticks are necessary to assess degradation. We assigned components of competitive ability (C), stress tolerance (S) and ruderality (R) to 15 common perennials of Presaharian Tunisia.

Rangeland development of the Mu Us Sandy Land in semiarid China: an analysis using Landsat and NOAA remote sensing data

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Chine

Degradation of the dry semiarid ecosystems in the Mu Us Sandy Land of north central China was explored using high-resolution satellite images from 1978, 1987 and 1996. This study monitored both changes in grassland biomass production and reclamation activities to detect the nature and scale of land degradation since major economic reforms were introduced in 1978.

causes and spatial pattern of land degradation risk in southern Mauritania using multitemporal AVHRR-NDVI imagery and field data

LandLibrary Resource
Journal Articles & Books
Décembre, 2003
Mauritanie
Tchad

Multitemporal 1 km NOAA/AVHRR Normalized Difference Vegetation Index (NDVI) maximum composite imagery was utilized in combination with rainfall, soil types, and field survey data on dominant rural activities to assess the risk of land degradation in southern Mauritania.