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Land-use/cover dynamics in Northern Afar rangelands, Ethiopia

Journal Articles & Books
Diciembre, 2010
Etiopía

This study uses a combination of remote sensing data, field observations and information from local people to analyze the patterns and dynamics of land-use/cover changes for 35 years from 1972 to 2007 in the arid and semi-arid Northern Afar rangelands, Ethiopia. A pixel-based supervised image classification was used to map land-use/cover classes. People's perceptions and ecological time-lines were used to explain the driving forces linked to the changes. A rapid reduction in woodland cover (97%) and grassland cover (88%) took place between 1972 and 2007.

Using traits of species to understand responses to land use change: Birds and livestock grazing in the Australian arid zone

Journal Articles & Books
Diciembre, 2010
Australia

The expansion of the artificial water-point network and livestock grazing in arid and semi-arid Australia has significantly increased access to water by water limited herbivores and thus has potential to seriously negatively affect the unique endemic flora and fauna. We examined the effects of the expansion of the water-point network on the arid and semi-arid zone bird community, using data from the Atlas of Australia bird surveys of 1977-1981 and 1996-2001. We examined whether traits of species could be used to uncover the critical ecological processes altered by this land use change.

Soil carbon and nitrogen across a chronosequence of woody plant expansion in North Dakota

Journal Articles & Books
Diciembre, 2010
América Septentrional

Woody plant expansion has been documented on grasslands worldwide as a result of overgrazing and fire suppression, but changes in ecosystem structure and function accompanying this phenomenon have yet to be extensively studied in the temperate semi-arid grasslands of North America. The primary objectives of this study were to determine the influence of woody plant expansion on soil carbon (C), soil nitrogen (N), and roots to a depth of 15 cm along a 42-year (1963-2005) chronosequence encompassing grassland, woodland, and transition zones in a northern Great Plains grassland.

How much browse is available for goats that graze Mediterranean woodlands

Journal Articles & Books
Diciembre, 2010

The difficulty of determining the intake of browse grazed by goats is widely recognized. We suggest that a reasonable estimate of the amount of edible browse available to goats grazing shrubby Mediterranean vegetation can be derived from actual grazing data of goat herds that have obtained most of their annual maintenance requirements from pasture dominated by shrubs or shrubby trees. We have conducted such estimates on three forests in the Hills of Judea, two of which were grazed by milking herds and one by a herd producing mainly kids.

Crofting and bumblebee conservation: The impact of land management practices on bumblebee populations in northwest Scotland

Journal Articles & Books
Diciembre, 2010

The northwest of Scotland is a stronghold for two of the UK's rarest bumblebee species, Bombus distinguendus and Bombus muscorum. The predominant form of agricultural land management in this region is crofting, a system specific to Scotland in which small agricultural units (crofts) operate rotational cropping and grazing regimes. Crofting is considered to be beneficial to a wide range of flora and fauna. However, currently there is a lack of quantitative evidence to support this view with regard to bumblebee populations.

Multifunctional performance development and use of pasture land facilities in Europe

Policy Papers & Briefs
Diciembre, 2010
Europa

The multi-functionality of agriculture was accepted as a concept at the 1992 Rio Earth Summit. the multi-functionality of the European agriculture is a key concept. Development of a multi functional agriculture and in particular grassland agriculture of Europe promoted occurrence of the new scientific directions which investigate questions of manufacture of high-quality forages and other kinds of production with preservation of a biodiversity on agricultural arable lands and combination of rational use of natural resources with the purpose of a sustainable development.

Response of Two Sagebrush Sites to Low-Disturbance, Mechanical Removal of Piñyon and Juniper

Journal Articles & Books
Diciembre, 2010
Estados Unidos de América

In the Great Basin of the western United States, expansion of Pinus monophylla (singleleaf piñyon) and Juniperus osteosperma (Utah juniper) out of historic woodlands and into Artemisia spp. (sagebrush) shrubland communities can facilitate the invasion of exotic downy brome (Bromus tectorum) and lead to decreases in ecological and economic values of shrublands. This expansion has, therefore, been the focus of management efforts, including the thinning or removal of trees in areas that were historically shrubland.

Landscape context and plant community composition in grazed agricultural systems of the Northeastern United States

Journal Articles & Books
Diciembre, 2010
Estados Unidos de América

Temperate humid grazing lands are an important component of the landscape of the northeastern United States, as well as of the economy of this region. Unlike their European counterparts, little is known about the basic ecology of managed grasslands in this region. During an 8-year survey of 28 farms across the northeastern United States, we sampled the vegetation on 95 grazed plots, identifying 310 plant species, and collected data on topography, climate and soils.

Arbuscular mycorrhizal associations in Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands of Northern Ethiopia

Journal Articles & Books
Diciembre, 2010
Etiopía

This study assessed the arbuscular mycorrhizal (AM) status of Boswellia papyrifera (frankincense-tree) dominated dry deciduous woodlands in relation to season, management and soil depth in Ethiopia. We studied 43 woody species in 52 plots in three areas. All woody species were colonized by AM fungi, with average root colonization being relatively low (16.6% - ranging from 0% to 95%). Mean spore abundance ranged from 8 to 69 spores 100g⁻¹ of dry soil. Glomus was the dominant genus in all study sites. Season had a strong effect on root colonization and spore abundance.

Hierarchical object-based classification of ultra-high-resolution digital mapping camera (DMC) imagery for rangeland mapping and assessment

Journal Articles & Books
Diciembre, 2010
Estados Unidos de América

Ultra-high-resolution digital aerial imagery has great potential to complement or replace ground measurements of vegetation cover for rangeland monitoring and assessment. This research investigated object-based image analysis (OBIA) techniques for classifying vegetation in southwestern USA arid rangelands with 4 cm resolution digital aerial imagery. We obtained high r-square values for the regressions relating ground- to image-based measures of percent cover (r-square values: 0.82–0.92).