91 research outputs found

    Population Growth and Land Use Dynamics along Urban–Rural Gradient

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    In this study we apply a spatial conditional logit model to determine factors influencing land cover change in three contiguous counties in West Georgia between 1992 and 2001 using point (pixel) based observations of land characteristics. We found that accessibility to population and population growth affect not only development of rural lands and transition between agricultural and forestry uses, but also influence changes between forest types. The model could be used to project land use–land cover change at watershed or subwatershed level and thus serve as a valuable tool for county and city planners.conditional logit, land use change, population gravity index, spatial lag, Agribusiness, Labor and Human Capital, Land Economics/Use, Q15, Q23, R14,

    Economics of controlling invasive species: a stochastic optimisation model for a spatial-dynamic process

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    Invasive species are significant threats to biodiversity, natural ecosystems and agriculture leading to large worldwide economic and environmental damage. Spread and control of invasive species are stochastic processes with important spatial dimensions. Most economic studies of invasive species control ignore spatial and stochastic aspects. This paper covers this gap in the previous studies by analysing a spatially explicit dynamic process of controlling invasive species in a stochastic setting. We show how stochasticity, spatial location of infestation and control can influence the spread, control efficiency and optimal control strategies. The main aim of this paper is to analyse the relationship between economic parameters and stochastic spatial characteristics of infestation and control. In the model used, there are two ways to control infestation: border control, under which the spread of invasive species from any of its infested neighbouring cell is prevented, and cell control, which removes the infestation from the existing cell. An integer optimisation model is applied to find the optimal strategies to deal with invasive species. Results show that it is optimal to eradicate or contain for a larger range of border control and cell control costs when the invasion is in the corner or on the edge as compared to the case where the initial infestation is in the middle of the landscape. Decrease in the probability of successful border control makes containment an unfavourable control option even for low border control costs. We show that decrease in the rate of spread can result in switching optimal strategies from containment to abandonment of control, or from eradication to containment. We also showed when the probability of successful cell control decreases, a lower eradication cost is required for eradication to remain the optimal strategy. In summary, this paper shows that in order to avoid providing misleading recommendations to environmental managers, it is important to include uncertainty in the spatial dynamic analysis of invasive species control.Spatial, Dynamics, Invasive, Economics, Stochastic, Optimisation, Environmental Economics and Policy,

    Economics of Controlling Invasive Species: A Stochastic Optimisation Model for a Spatial-Dynamic Process

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    Invasive species are significant threats to biodiversity, natural ecosystems and agriculture leading to large worldwide economic and environmental damage. Spread and control of invasive species are stochastic processes with important spatial dimensions. Most economic studies of invasive species control ignore spatial and stochastic aspects. This paper covers this gap in the previous studies by analysing a spatially explicit dynamic process of controlling invasive species in a stochastic setting. We show how stochasticity, spatial location of infestation and control can influence the spread, control efficiency and optimal control strategies. The main aim of this paper is to analyse the relationship between economic parameters and stochastic spatial characteristics of infestation and control. In the model used, there are two ways to control infestation: border control, under which the spread of invasive species from any of its infested neighbouring cell is prevented, and cell control, which removes the infestation from the existing cell. An integer optimisation model is applied to find the optimal strategies to deal with invasive species. Results show that it is optimal to eradicate or contain for a larger range of border control and cell control costs when the invasion is in the corner or on the edge as compared to the case where the initial infestation is in the middle of the landscape. Decrease in the probability of successful border control makes containment an unfavourable control option even for low border control costs. We show that decrease in the rate of spread can result in switching optimal strategies from containment to abandonment of control, or from eradication to containment. We also showed when the probability of successful cell control decreases, a lower eradication cost is required for eradication to remain the optimal strategy. In summary, this paper shows that in order to avoid providing misleading recommendations to environmental managers, it is important to include uncertainty in the spatial dynamic analysis of invasive species control.Environmental Economics and Policy, Land Economics/Use,

    Building aggregate timber supply models from individual harvest choice

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    Timber supply has traditionally been modelled using aggregate data. In this paper, we build aggregate supply models for four roundwood products for the US state of North Carolina from a stand-level harvest choice model applied to detailed forest inventory. The simulated elasticities of pulpwood supply are much lower than reported by previous studies. Cross price elasticities indicate a dominant influence of sawtimber markets on pulpwood supply. This approach allows predicting the supply consequences of exogenous factors and supports regular updating of supply models.Timber supply, harvest choice, conditional logit, elasticity, expectations, simulation.,

    Optimising the spatial pattern of landscape revegetation

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    The spatial pattern of landscape reconstruction makes a substantial difference to environmental outcomes. We develop a spatially explicit bio-economic model that optimises the reconstruction of a heavily cleared landscape through revegetation. The model determines the spatial priorities for revegetation that minimises economic costs subject to achieving particular improvements in habitat for 29 woodland-dependent bird species. The study focuses on the Avoca catchment (330 thousand ha) in North-Central Victoria. Our model incorporates spatial pattern and heterogeneity of existing and reconstructed vegetation types. The revegetation priorities are identified as being: sites in the vicinity of existing remnants, riparian areas, and parts of the landscape with diverse land uses and vegetation types. Optimal reconstruction design is affected by opportunity costs due to the loss of agricultural production and the costs of revegetation. 1 Centre for Environmental Economics and Policy, School of Agricultural and Resource Economics, University of Western Australia, Crawley, WA, 6009 2 Department of Primary Industries, Rutherglen, RMB 1145 Chiltern Valley Rd, Rutherglen, Victoria, 3685 3 North Central Catchment Management Authority, PO Box 18, Huntly, Victoria, 3551landscape reconstruction, biodiversity, optimisation, habitat, Environmental Economics and Policy, Land Economics/Use, Q57,

    Prioritising investment to enhance biodiversity in an agricultural landscape

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    The removal, alteration and fragmentation of habitat are key threats to the biodiversity of terrestrial ecosystems. Investment to protect biodiversity assets (e.g. restoration of native vegetation) in dominantly agricultural landscapes usually results in a loss of agricultural production. This can be a significant cost that is often overlooked or poorly addressed in analyses to prioritise such investments. Accounting for this trade-off is important for more successful, realistically feasible and cost-effective biodiversity conservation. We developed a spatially explicit bio-economic optimisation model that simulates the effect of conservation effort on the diversity of woodland-dependent birds in the Avoca catchment (330 thousand ha) in North-Central Victoria. The model minimises opportunity cost of agricultural production and cost of biodiversity conservation effort on a catchment level subject to achieving different levels of biodiversity outcome. We identify the locations and spatial arrangement of conservation efforts that offers the best value for money.Environmental Economics and Policy,

    Property taxes: do they affect forestry and agricultural land uses

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    Abstract , NRI point data. The model tilizes modern land use theory based on the land rent theory. In addition to the returns, we ey words: land use change, property tax, discrete choice, nested logit, Louisiana

    Observation of the B0 → ρ0ρ0 decay from an amplitude analysis of B0 → (π+π−)(π+π−) decays

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    Proton–proton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fb−1 , are analysed to search for the charmless B0→ρ0ρ0 decay. More than 600 B0→(π+π−)(π+π−) signal decays are selected and used to perform an amplitude analysis, under the assumption of no CP violation in the decay, from which the B0→ρ0ρ0 decay is observed for the first time with 7.1 standard deviations significance. The fraction of B0→ρ0ρ0 decays yielding a longitudinally polarised final state is measured to be fL=0.745−0.058+0.048(stat)±0.034(syst) . The B0→ρ0ρ0 branching fraction, using the B0→ϕK⁎(892)0 decay as reference, is also reported as B(B0→ρ0ρ0)=(0.94±0.17(stat)±0.09(syst)±0.06(BF))×10−6

    Angular analysis of the B-0 -> K*(0) e(+) e(-) decay in the low-q(2) region

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    An angular analysis of the B0K0e+eB^0 \rightarrow K^{*0} e^+ e^- decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q2q^2) interval between 0.002 and 1.120GeV2 ⁣/c4{\mathrm{\,Ge\kern -0.1em V^2\!/}c^4}. The angular observables FLF_{\mathrm{L}} and ATReA_{\mathrm{T}}^{\mathrm{Re}} which are related to the K0K^{*0} polarisation and to the lepton forward-backward asymmetry, are measured to be FL=0.16±0.06±0.03F_{\mathrm{L}}= 0.16 \pm 0.06 \pm0.03 and ATRe=0.10±0.18±0.05A_{\mathrm{T}}^{\mathrm{Re}} = 0.10 \pm 0.18 \pm 0.05, where the first uncertainty is statistical and the second systematic. The angular observables AT(2)A_{\mathrm{T}}^{(2)} and ATImA_{\mathrm{T}}^{\mathrm{Im}} which are sensitive to the photon polarisation in this q2q^2 range, are found to be AT(2)=0.23±0.23±0.05A_{\mathrm{T}}^{(2)} = -0.23 \pm 0.23 \pm 0.05 and ATIm=0.14±0.22±0.05A_{\mathrm{T}}^{\mathrm{Im}} =0.14 \pm 0.22 \pm 0.05. The results are consistent with Standard Model predictions.An angular analysis of the B0^{0} → K^{*}^{0} e+^{+} e^{−} decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb1^{−1}, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q2^{2}) interval between 0.002 and 1.120 GeV2^{2} /c4^{4}. The angular observables FL_{L} and ATRe_{T}^{Re} which are related to the K^{*}^{0} polarisation and to the lepton forward-backward asymmetry, are measured to be FL_{L} = 0.16 ± 0.06 ± 0.03 and ATRe_{T}^{Re}  = 0.10 ± 0.18 ± 0.05, where the first uncertainty is statistical and the second systematic. The angular observables AT(2)_{T}^{(2)} and ATIm_{T}^{Im} which are sensitive to the photon polarisation in this q2^{2} range, are found to be AT(2)_{T}^{(2)}  = − 0.23 ± 0.23 ± 0.05 and ATIm_{T}^{Im}  = 0.14 ± 0.22 ± 0.05. The results are consistent with Standard Model predictions.An angular analysis of the B0K0e+eB^0 \rightarrow K^{*0} e^+ e^- decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q2q^2) interval between 0.002 and 1.120GeV2 ⁣/c4{\mathrm{\,Ge\kern -0.1em V^2\!/}c^4}. The angular observables FLF_{\mathrm{L}} and ATReA_{\mathrm{T}}^{\mathrm{Re}} which are related to the K0K^{*0} polarisation and to the lepton forward-backward asymmetry, are measured to be FL=0.16±0.06±0.03F_{\mathrm{L}}= 0.16 \pm 0.06 \pm0.03 and ATRe=0.10±0.18±0.05A_{\mathrm{T}}^{\mathrm{Re}} = 0.10 \pm 0.18 \pm 0.05, where the first uncertainty is statistical and the second systematic. The angular observables AT(2)A_{\mathrm{T}}^{(2)} and ATImA_{\mathrm{T}}^{\mathrm{Im}} which are sensitive to the photon polarisation in this q2q^2 range, are found to be AT(2)=0.23±0.23±0.05A_{\mathrm{T}}^{(2)} = -0.23 \pm 0.23 \pm 0.05 and ATIm=0.14±0.22±0.05A_{\mathrm{T}}^{\mathrm{Im}} =0.14 \pm 0.22 \pm 0.05. The results are consistent with Standard Model predictions

    Study of the rare B-s(0) and B-0 decays into the pi(+) pi(-) mu(+) mu(-) final state

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    A search for the rare decays Bs0π+πμ+μB_s^0 \to \pi^+\pi^-\mu^+\mu^- and B0π+πμ+μB^0 \to \pi^+\pi^-\mu^+\mu^- is performed in a data set corresponding to an integrated luminosity of 3.0 fb1^{-1} collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/c2c^2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0π+πμ+μB_s^0 \to \pi^+\pi^-\mu^+\mu^- and the first evidence of the decay B0π+πμ+μB^0 \to \pi^+\pi^-\mu^+\mu^- are obtained and the branching fractions are measured to be B(Bs0π+πμ+μ)=(8.6±1.5(stat)±0.7(syst)±0.7(norm))×108\mathcal{B}(B_s^0 \to \pi^+\pi^-\mu^+\mu^-)=(8.6\pm 1.5\,({\rm stat}) \pm 0.7\,({\rm syst})\pm 0.7\,({\rm norm}))\times 10^{-8} and B(B0π+πμ+μ)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×108\mathcal{B}(B^0 \to \pi^+\pi^-\mu^+\mu^-)=(2.11\pm 0.51\,({\rm stat}) \pm 0.15\,({\rm syst})\pm 0.16\,({\rm norm}) )\times 10^{-8}, where the third uncertainty is due to the branching fraction of the decay B0J/ψ(μ+μ)K(890)0(K+π)B^0\to J/\psi(\to \mu^+\mu^-)K^*(890)^0(\to K^+\pi^-), used as a normalisation.A search for the rare decays Bs0→π+π−μ+μ− and B0→π+π−μ+μ− is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5–1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0→π+π−μ+μ− and the first evidence of the decay B0→π+π−μ+μ− are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0→π+π−μ+μ−)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))×10−8 and B(B0→π+π−μ+μ−)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8 , where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→μ+μ−)K⁎(892)0(→K+π−) , used as a normalisation.A search for the rare decays Bs0→π+π−μ+μ− and B0→π+π−μ+μ− is performed in a data set corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5–1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0→π+π−μ+μ− and the first evidence of the decay B0→π+π−μ+μ− are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0→π+π−μ+μ−)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))×10−8 and B(B0→π+π−μ+μ−)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8 , where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→μ+μ−)K⁎(892)0(→K+π−) , used as a normalisation.A search for the rare decays Bs0π+πμ+μB_s^0 \to \pi^+\pi^-\mu^+\mu^- and B0π+πμ+μB^0 \to \pi^+\pi^-\mu^+\mu^- is performed in a data set corresponding to an integrated luminosity of 3.0 fb1^{-1} collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/c2c^2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0π+πμ+μB_s^0 \to \pi^+\pi^-\mu^+\mu^- and the first evidence of the decay B0π+πμ+μB^0 \to \pi^+\pi^-\mu^+\mu^- are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0π+πμ+μ)=(8.6±1.5(stat)±0.7(syst)±0.7(norm))×108\mathcal{B}(B_s^0 \to \pi^+\pi^-\mu^+\mu^-)=(8.6\pm 1.5\,({\rm stat}) \pm 0.7\,({\rm syst})\pm 0.7\,({\rm norm}))\times 10^{-8} and B(B0π+πμ+μ)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))×108\mathcal{B}(B^0 \to \pi^+\pi^-\mu^+\mu^-)=(2.11\pm 0.51\,({\rm stat}) \pm 0.15\,({\rm syst})\pm 0.16\,({\rm norm}) )\times 10^{-8}, where the third uncertainty is due to the branching fraction of the decay B0J/ψ(μ+μ)K(890)0(K+π)B^0\to J/\psi(\to \mu^+\mu^-)K^*(890)^0(\to K^+\pi^-), used as a normalisation
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