نتایج جستجو برای: rangeland shrubs
تعداد نتایج: 6542 فیلتر نتایج به سال:
Integrating use of seeded perennial cool-season grass pastures with native rangeland can increase available forage and provide a high plane of nutrition for grazing livestock. Our objective was to compare performance of yearling beef heifers grazing native rangeland with those grazing an integrated system that included seeded forages. Twice-replicated, 3-ha pastures seeded to either ‘Rosana’ we...
This article reports a rapid method for rangeland assessments in Kenya, Ethiopia and Uganda by harnessing pastoralists’ indigenous knowledge among the Orma, Afar and Karamojong pastoralists. The study developed and evaluated a methodological framework for conducting joint assessments with pastoralist range scouts. The framework has four components: selection of ecological and anthropogenic indi...
Livestock grazing affects over 60% of the world's agricultural lands and can influence rangeland ecosystem services and the quantity and quality of wildlife habitat, resulting in changes in biodiversity. Concomitantly, livestock grazing has the potential to be detrimental to some wildlife species while benefiting other rangeland organisms. Many imperiled grouse species require rangeland landsca...
We tested the accuracy of an atmospheric correction method that depends on clear water bodies to infer solar and atmospheric parameters for radiative transfer equations by measuring the reflectance signature of four prominent south Texas rangeland plants with the Earth Resource Technology (LANDSAT) satellite multispectral scanner (MSS) and a ground-based Exotech Model 20 spectroradiometer. The ...
Hyperspectral imagery from the airborne multispectral scanner was evaluated for discrimination and mapping of vegetation components in a semi-arid rangeland environment in Southern Australia. Automated unmixing of two image strips with 5-m resolution revealed several vegetation endmembers in the visible, near infrared (near-IR), and short-wave infrared portions of the imagery. Identity of the e...
above-ground biomass and a 20-fold increase in plant cover by Artemesia frigida, a common shrubby plant of some North American and Asian grasslands. This carbon dioxide induced enhancement of plant growth, among the highest so far reported, provides evidence from a native grassland that rising carbon dioxide levels since the onset of industrial times may have been contributing to the observed s...
Shrub encroachment in arid and semiarid rangelands, a worldwide phenomenon, results in a heterogeneous landscape characterized by a mosaic of nutrient-depleted barren soil bordered by nutrient-enriched shrubby areas known as ‘‘fertile islands.’’ Even though shrub encroachment is considered as a major contributor to rangeland degradation, little is known about mechanisms favoring the reversibili...
— This paper contributes to the debate over land tenure in rural China by extending its spatial coverage to the country’s extensive rangeland regions. Key characteristics of pastoral tenure, identified from field appraisals in western China, include group tenure and fuzzy boundaries. Although these characteristics give rise to efficiency concerns, from a new institutional economics perspective ...
Rangeland ecosystems typify physical systems having an incomplete causal theory. This paper describes CARMA, a system for rangeland pest management advising that uses model-based matching and adaptation to integrate case-based reasoning with modelbased reasoning for prediction in rangeland ecosystems. An ablation study showed that removing any part of the CARMA’s model-based knowledge dramatica...
________________________________________________________________________________ Abstract Grazing levels and rotational schemes need to be tailored to each individual farm or pasture, and more studies are needed on the resilience of rangelands and on separating the effects of grazing and climate. The direct short-term impact of three rates of stocking (4, 8 and 16 Small Stock Units-SSU/ha) was ...
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