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Application of the state-and-transition approach to conservation management of a grazed Mediterranean landscape in Greece

Journal Articles & Books
Diciembre, 2005
Grecia

Traditionally, management of rangelands is based on the successional theory for vegetation developed by Clements. This approach, which came to be known as “the range succession model”, assumes a progressive change of vegetation towards the final (climax) stage and considers grazing as a primary driver of its dynamics. This model cannot be applied in Mediterranean rangelands, however, because they are largely modified plant communities and their final stage is usually a forest or dense woodland.

Deforestation and Shade Coffee in Oaxaca, Mexico: Key Research Findings

Policy Papers & Briefs
Diciembre, 2005
México

More than three-quarters of Mexico's coffee is grown on small plots shaded by the existing forest. Because they preserve forest cover, shade coffee farms provide vital ecological services including harboring biodiversity and preventing soil erosion. Unfortunately, tree cover in Mexico's shade coffee areas is increasingly being cleared to make way for subsistence agriculture, a direct result of the unprecedented decline of international coffee prices over the past decade.

Correlates of vascular plant species richness in fragmented indigenous forests: assessing the role of local and regional factors

Journal Articles & Books
Diciembre, 2004
Nueva Zelandia

Both local and regional factors determine local species richness. We investigated the relative role of local (13 soil and tree stand structure variables) and regional factors (19 climate, land cover and geographic location variables) in determining the richness of several vascular plant functional groups in indigenous forest fragments in southeastern New Zealand.

Modelling of non-point source pollution in a watershed using remote sensing and gis

Journal Articles & Books
Diciembre, 2004
India

Assessment of the environmental impact of Non Point Source (NPS) pollutants on a global, regional and localized scale is the key component for achieving sustainability of agriculture as well as preserving the environment. The knowledge and information required to address the problem of assessing the impact of NPS pollutants like Nitrogen (N), Phosphorus (P), etc., on the environment crosses several sub-disciplines like remote sensing, Geographical Information System (GIS), hydrology and soil science.

test of multiple hypotheses for the species richness gradient of South American owls

Journal Articles & Books
Diciembre, 2004

Many mechanisms have been proposed to explain broad scale spatial patterns in species richness. In this paper, we evaluate five explanations for geographic gradients in species richness, using South American owls as a model. We compared the explanatory power of contemporary climate, landcover diversity, spatial climatic heterogeneity, evolutionary history, and area. An important aspect of our analyses is that very different hypotheses, such as history and area, can be quantified at the same observation scale and, consequently can be incorporated into a single analytical framework.

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

Journal Articles & Books
Diciembre, 2003
Sudán

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. By integrating the database with the CENTURY ecosystem model, we were able to estimate historical, current and future pools of SOC as a function of land management and climate.