176 research outputs found

    Analysis of the Conservation of Central American Mangroves Using the Phytosociological Method

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    Our study of mangrove swamps revealed a total of 120 species, of which 13 are characteristics of mangrove swamps, and 38 of flooded areas with low salt. All the others are invasive species which have taken advantage of the degradation of these natural ecosystems. The scenario is not very different in Laguna de Tres Palos in Mexico. The frequent fires in the low-growing semi-deciduous rainforest (dry forest) have caused intense erosion, with the consequence that the site has silted up. As a result, the first vegetation band of Rhizophora mangle is extremely rare. Instead, Laguncularia racemosa and Conocarpus erectus are dominant, along with a band of Phragmito-Magnocaricetea with a high occurrence of Phragmites australis (Cav.) Trin., which acts as an indicator of sediment silting. It is extremely frequent for several reasons: as it is the decrease of the salinity of the water, the scarce depth due to the accumulation of sediments and the contamination by the entrance of residual waters of the nearby populations. When the depth and salinity of the water are suitable, the dominant species are Rhizophora mangle, Laguncularia racemosa, and Avicennia germinans

    Comparative analysis of ephemeral river ecosystem services in agricultural and natural landscapes in Mediterranean environments. A Practical Approach to Caia River

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    Comparative analysis of ephemeral river ecosystem services in agricultural and natural landscapes in Mediterranean environments. A Practical Approach to Caia River. A comparison study between agricultural and natural Mediterranean environments landscapes

    Climatology, bioclimatology and vegetation cover: tools to mitigate climate change in olive groves

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    This work establishes the relationship between bioclimatology and agronomy. Bioclimatic indices are obtained for several areas under olive cultivation and correlated with olive yields. Due to the effect of climate change on cultivation and the high economic losses it produces, we propose a sustainable development model for the territorial classification of crops based on bioclimatic knowledge. Bioclimatic diagrams are prepared to provide information on water stress in crops so that irrigation can be carried out at the most effective time, a measure that has been shown to lead to water and energy savings for growers. In addition to this development model, we propose the application of non-aggressive cultivation techniques such as the use of living plant cover to ensure the protection of the soil and avoid losses due to climate irregularities. Studies conducted up to the present on applied bioclimatology have yielded promising results in the fields of farming and forestry. The maps and bioclimatic indices of Professor Rivas-Martínez, Ic, Io and It/Itc, are essential for bioclimatic classification. The agricultural development model with a bioclimatic basis ensures economic savings for growers and minimizes the environmental impact of cultivation. In the case of olive cultivation we detected that in 2005 all the cultivated areas that were not in their thermoclimatic optimum were damaged by frost. The widespread cultivation of olive groves in the Mediterranean basin, and mainly in the south of Spain, is reason enough to establish a relationship between its production and its bioclimatic environment. The ombroclimatic study in certain localities under olive cultivation shows that areas with Io Stellarietea mediae constitutes the basis for establishing either natural or sown vegetation cover.info:eu-repo/semantics/publishedVersio

    Forest and arborescent scrub habitats of special interest for SCIs in Central Spain

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    The habitat of the several territories in Ciudad Real (Castilla-La Mancha, Spain) are studued through the and mapping (scale 1:10.000) and vegetation analysis. The distribution and surface of the habitat presents in the Sites of Community Interest (SCIs), as well as pressures, threats, trends, and state of conservation are described. These site contributes significantly to the maintenance or restoration at a favourable conservation status of a natural habitat type or of a species of community intesess.These specially protected areas are part of the Natura 2000 network. We discuss the diversity of forest habitats characterized by species of the genus Quercus L., focusing only on the plant communities in the Habitats Directive 92/43/EEC of 1992, regarding the conservation of fauna and flora and habitats of interest owing to their endemic or rare character. Habitats and species must be studied in combination to ensure the maximum reliability of the results. We concentrate on habitats with low representation in the territory as a consequence of their rarity or endemicity. We study the following habitats of special interest: 9230—Mediterranean-Ibero-Atlantic and Galaico-Portuguese oak woods of Quercus robur and Quercus pyrenaica; 9240—Iberian oaks of Quercus faginea and Quercus canariensis; 9320—Thermomediterranean forests of Olea and Ceratonia (Iberian Peninsula, Balearic and Canary Islands); 9540—Mediterranean pine forests of endemic Pinus pinaster (Pinus pinaster subsp. acutisquama); 9560—Endemic forests with Juniperus spp.; 5210. Arborescent scrub with Juniperus spp.info:eu-repo/semantics/publishedVersio

    Interactions between surrounding landscape biodiversity and intermittent rivers in mediterranean environments – case study of the Caia River

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    Landscape is a dynamic mosaic of various structures interacting together. Neglecting or overusing one part of this mosaic may boost up or damage the development of others. For instance, overgrazing may increase soil erosion process which may clog a river/stream. In this regard land use changes, climate change and landscape management may lead to increase the intermittency of the surface watercourses, as well as in the ecosystem services provided by riverscapes for humans. Therefore, the present research focus on the existing interactions between the Caia River, an intermittent river located in the Mediterranean region, and its surrounding agricultural and natural landscapes. The performed analyses considered the identification of the existing interaction between natural and agricultural landscapes with the Caia River defining the predictable ecosystem services provided by each element of the landscape and assessing the potential decrease of the ecosystem services provided in case of landscape changes, which according to the performed research might enclose significant impacts both in ecologic and socioeconomic terms.info:eu-repo/semantics/publishedVersio

    Measurement of the differential cross-section of B+B^{+} meson production in pp collisions at s\sqrt{s} = 7 TeV at ATLAS

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    The production cross-section of B+ mesons is measured as a function of transverse momentum pT and rapidity y in proton--proton collisions at center-of-mass energy sqrt(s) = 7 TeV, using 2.4 fb-1 of data recorded with the ATLAS detector at the Large Hadron Collider. The differential production cross-sections, determined in the range 9<pT<120 GeV and y<2.25, are compared to next-to-leading-order theoretical predictions.Peer Reviewe

    Dynamics of isolated-photon plus jet production in pp collisions at (s)=7\sqrt(s)=7 TeV with the ATLAS detector

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    The dynamics of isolated-photon plus jet production in pp collisions at a centre-of-mass energy of 7 TeV has been studied with the ATLAS detector at the LHC using an integrated luminosity of 37 pb^-^1. Measurements of isolated-photon plus jet bin-averaged cross sections are presented as functions of photon transverse energy, jet transverse momentum and jet rapidity. In addition, the bin-averaged cross sections as functions of the difference between the azimuthal angles of the photon and the jet, the photon-jet invariant mass and the scattering angle in the photon-jet centre-of-mass frame have been measured. Next-to-leading-order QCD calculations are compared to the measurements and provide a good description of the data, except for the case of the azimuthal opening angle.Peer Reviewe

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

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    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H→γγH\rightarrow\gamma\gamma, H→ZZ∗→4ℓH\rightarrow ZZ^{*}\rightarrow 4 \ell and H→WW→ℓνℓνH\rightarrow W W \rightarrow \ell\nu\ell\nu. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of about 25 fb−1^{-1}. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson.Peer Reviewe

    Observation of an Excited Bc±B_c^\pm Meson State with the ATLAS Detector

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    A search for excited states of the Bc± meson is performed using 4.9  fb-1 of 7 TeV and 19.2  fb-1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay Bc±→J/ψπ±. The state appears in the m(Bc±π+π-)-m(Bc±)-2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5  MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the Bc± meson, Bc±(2S).Peer Reviewe
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