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

Journal Articles & Books
декабря, 2003
Mauritania
Chad

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. Mauritania is one of eight continental West African Sahel countries that stretch from Chad to the northwestern Atlantic coast, and from the southern fringe of the Sahara Desert to the northern limit of the Sudanian climatic zone.

Scale-dependent effects of grazing on rangeland degradation in northern Kenya: a test of equilibrium and non-equilibrium hypotheses

Journal Articles & Books
декабря, 2003
Kenya

This study employs scale-dependence as an analytical approach to understanding effects of livestock grazing on rangeland degradation in northern Kenya. It used extensive datasets previously collected from 13 200 km2 rangelands where grazing pressure gradients of livestock (varied from none, light, moderate, heavy and very heavy grazing) in conjunction with seasonality across different ecological scales influenced plant responses and probably contributed to land degradation.

assessment of restoration of biodiversity in degraded high mountain grazing lands in northern Ethiopia

Journal Articles & Books
декабря, 2003
Ethiopia

Loss of biodiversity is the single most important threat to the conservation and sustainable use of drylands in northern Ethiopia due to many centuries of cultivation and heavy livestock grazing pressure. The current study assessed the restoration of biodiversity in highly degraded areas in eastern Tigray, northern Ethiopia using area enclosures (AEs). The study assessed whether the differences in biodiversity between AEs and open management schemes and time of land abandonment influenced diversity of plant life forms (i.e. herbs, shrubs and trees).

Comparison of 2 techniques for monitoring vegetation on military lands

Journal Articles & Books
декабря, 2003

The U.S. Army is responsible for preparing a well-trained combat force while maintaining the ecological diversity and integrity of the lands it manages. The ability to efficiently collect data that accurately capture plant community diversity and percent composition is imperative to proper monitoring and land management of military lands. To ensure that the dual goals of military training and land stewardship are met on an army-wide basis, the U.S. Army Land Condition-Trend Analysis (LCTA) Program was developed.

Degradation and recovery processes in arid grazing lands of central Australia. Part 2: vegetation

Journal Articles & Books
декабря, 2003
Australia

In a naturally heterogeneous landscape in arid central Australia, a previous study found that grazing changed the distribution of water and nutrients amongst different geomorphic strata of the landscape. In this concurrent study, we show that herbage biomass, cover and composition responded primarily to these geomorphic strata and not to grazing. The cover of palatable species as a group proved the exception, and decreased with increasing grazing. The quantity of shrubs responded to both strata and grazing, and was greatest under least grazing.

Degradation and recovery processes in arid grazing lands of central Australia. Part 1: soil and land resources

Journal Articles & Books
декабря, 2003
Australia

The distribution and quality of soil and land resources in heterogeneous grazing lands of central Australia were changed by grazing. Sites located at increasing distances from livestock watering points showed greater degrees of landscape organization and soil productive potential. The depositional strata, where resources tended to accumulate, occupied a larger proportion of the landscape as distance increased. Physical and nutrient cycling soil properties improved.

Case studies in the conservation of biodiversity: degradation and threats

Journal Articles & Books
декабря, 2003

The rating of biodiversity in arid and semiarid regions on the basis of ecological function and genetic traits of adaptation to severe environmental stresses produces significantly higher values, than that based solely on the commonly applied structural criteria of forms of life and levels of organization.