30 research outputs found

    Systematic land-cover change in KwaZulu-Natal, South Africa: Implications for biodiversity.

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    Land-cover change and habitat loss are widely recognised as the major drivers of biodiversity loss in the world. Land-cover maps derived from satellite imagery provide useful tools for monitoring land-use and land-cover change. KwaZulu-Natal, a populous yet biodiversity-rich province in South Africa, is one of the first provinces to produce a set of three directly comparable land-cover maps (2005, 2008 and 2011). These maps were used to investigate systematic land-cover changes occurring in the province with a focus on biodiversity conservation. The Intensity Analysis framework was used for the analysis as this quantitative hierarchical method addresses shortcomings of other established land-cover change analyses. In only 6 years (2005-2011), a massive 7.6% of the natural habitat of the province was lost to anthropogenic transformation of the landscape. The major drivers of habitat loss were agriculture, timber plantations, the built environment, dams and mines. Categorical swapping formed a significant part of landscape change, including a return from anthropogenic categories to secondary vegetation, which we suggest should be tracked in analyses. Longer-term rates of habitat loss were determined using additional land-cover maps (1994, 2000). An average of 1.2% of the natural landscape has been transformed per annum since 1994. Apart from the direct loss of natural habitat, the anthropogenically transformed land covers all pose additional negative impacts for biodiversity remaining in these or surrounding areas. A target of no more than 50% of habitat loss should be adopted to adequately conserve biodiversity in the province. Our analysis provides the first provincial assessment of the rate of loss of natural habitat and may be used to fulfil incomplete criteria used in the identification of Threatened Terrestrial Ecosystems, and to report on the Convention on Biological Diversity targets on rates of natural habitat loss.SP201

    Comportamento e bem-estar de peixe beta (Betta splendens) em aquário.

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    O trabalho será realizado no Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo/Campus Alegre, no laboratório de Nutrição e Produção de Espécies Ornamentais, localizado no município de Alegre, região Sul do estado do Espírito Santo, Brasil. Serão utilizados 70 exemplares machos de peixe Beta (Betta splendens) com idade entre 90 e 120 dias. Dos quais 15 exemplares de peixe Beta, machos adultos, com aproximadamente 90 dias serão manejados em aquário tipo cruzeta com quatro pontas de mesmo comprimento e distância do centro. Quatro testes serão realizados para analisar a preferência dos peixes quanto a tipo de (T1) substrato, de (T2) vegetações, de (T3) abrigos e de (T4) cores. Em cada teste será oferecido quatro tipos de preferências (P1, P2, P3 e P4) distribuídos aleatoriamente por sorteio. Serão analisados os comportamentos de frequência em cada preferência, duração em cada preferência e tempo de latência. No segundo trabalho serão utilizados 35 exemplares machos de peixe Beta com aproximadamente 90 dias distribuídos aleatoriamente em cinco tipos de alojamento (tratamentos); (T1) copos de 0,3 litros, (T2) beteiras 3 litros sem enriquecimento, (T3) beteiras 3 litros enriquecidas, (T4) aquários 38 litros sem enriquecimento e (T5) aquários 38 litros enriquecidos. Os comportamentos dos animais serão gravados durante todo o período experimental. Será realizado um total de dezesseis horas de observações para cada tratamento. Durante o mesmo período também será realizado observação focal durante cinco minutos intermitentes alternando entre os tratamentos no total de 150 minutos por período. Os comportamentos registrados serão organizados formando um etograma e comparados entre os diferentes tratamentos. No último trabalho serão utilizados os 35 exemplares machos de peixe Beta, advindos do experimento de enriquecimento, com aproximadamente 120 dias em aquário tipo labirinto. Localizado dentro do labirinto haverá quatro pontos; dois objetos estressores, espelho (E1) e predador (E2), e dois objetos recompensa ambiente enriquecido (R1) e alimento (R2). Comportamentos como lateralidade, latência, preferência, frequência e duração serão analisados durante 15 minutos na parta da manhã e 15 minutos na parte da tarde durante dois dias consecutivos. Então os animais terão cinco dias de descanso e retornarão ao labirinto para mais 15 minutos de observações comportamentais na parta da manhã e 15 minutos na parte da tarde durante dois dias consecutivos

    Coherent π0 photoproduction on the deuteron up to 4 GeV

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    The differential cross section for 2H(γ,d)π0 has been measured at deuteron center-of-mass angles of 90° and 136°. This work reports the first data for this reaction above a photon energy of 1 GeV, and permits a test of the apparent constituent counting rule and reduced nuclear amplitude behavior as observed in elastic ed scattering. Measurements were performed up to a photon energy of 4.0 GeV, and are in good agreement with previous lower energy measurements. Overall, the data are inconsistent with both constituent-counting rule and reduced nuclear amplitude predictions

    Measurements of Deuteron Photodisintegration up to 4.0 GeV

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    The first measurements of the differential cross section for the d(γ,p)n reaction up to 4.0 GeV were performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson Laboratory. We report the cross sections at the proton center-of-mass angles of 36°, 52°, 69°, and 89°. These results are in reasonable agreement with previous measurements at lower energy. The 89° and 69° data show constituent-counting-rule behavior up to 4.0 GeV photon energy. The 52° and 36° data disagree with the counting-rule behavior. The quantum chromodynamics (QCD) model of nuclear reactions involving reduced amplitudes disagrees with the present data.U.S. Department of Energy, National Science Foundatio

    Impact of livestock grazing intensity on plant diversity of montane grassland in the northern Drakensberg, South Africa

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    Communal livestock grazing is expected to impact botanical composition and plant diversity of Drakensberg montane grasslands. Accordingly, a grazing gradient extending outward from kraals, and fence-line contrasts between communal rangeland and protected areas (Golden Gate Highlands National Park and Royal Natal National Park), were studied in the QwaQwa region of South Africa. Presence of a grazing gradient was confirmed by a decrease in the amount of cattle dung with increasing distance from kraals that was independent of altitude, solar radiation, slope, or soil physico-chemical properties. Canonical correspondence analysis confirmed thatgrazing intensity had a significant influence on botanical composition although most compositional variation was unexplained. Higher grazing intensities tended to negatively affect plant species richness and diversity, and the cover of perennial graminoids, but benefitted the abundance of dwarf shrubs and alien invasive species. Similar effects were apparent across each of the fence line contrasts. Despite a long history of livestock grazing, communal rangeland supported >320 indigenous species, illustrating some contribution to biodiversity conservation, but being compromised near kraals. An improved approach for study of the impacts of livestock grazing on plant diversity is suggested that would overcome the difficulties of assessing rare and threatened species using acommunity approach. Keywords: communal rangelands, fence line contrast, functional types, grazing gradient
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