312 research outputs found

    Spatial adaptive responses of highly threatened European mammal species under climate change

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    Current species’ range displacements are mostly triggered by climate change but European landscapes are largely dominated by human activities. In this study we identify the most promising spatial adaptive trajectories (SATs) for the thirty most threatened non volant mammal species in Europe up to 2080 (under three climate and land change scenarios) and where/when SATs of each species synchronically converge. We found large contrasts on the persistence of species in SATs, with some species largely reliant on the functionality of areas where many SATs converge. Overall, SATs and convergence centers are not adequately covered by existing conservation areas and coincide with crop and arable lands, compromising species persistence. It is important to invest in the protection of SATs and convergence centers through a mix of conventional instruments and new collaborative forms with the socio-economy. Anticipative plans at long-term coupled with risk analysis offer decision–makers templates to prevent negative surprises

    Novel physiological data needed for progress in global change ecology

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    Studies examining the underlying causes of the distributions of species and their future trajectories under climate change have benefitted from the accumulation of measurements of thermal tolerance across the tree of life. However, gaps in the global coverage of heat-tolerance data for ectotherms persist on four critical fronts. First, most large-scale analyses treat heat tolerance as a fixed species trait despite that population-level variation can equal or exceed cross-species variation. Second, terrestrial non-arthropod invertebrates and aquatic ectotherms other than bony fish have been poorly sampled, particularly in boreal and tropical regions, the Indian Ocean and the mesopelagic-deep ocean. Third, the study of climate impacts on the heat tolerance of terrestrial ectotherms has often neglected the interaction of environmental temperatures with water availability. And fourth, the mechanisms driving the dependence of heat tolerance on oxygen supply-demand remain largely unknown. We contend that filling those data and knowledge gaps requires novel strategies for the ecophysiological sampling of the range of understudied populations and species that occupy the length of climatic gradients globally. Such developments are essential for comprehensively predicting species responses to climate change across aquatic and terrestrial biomes

    Parasitismo humano por Bertiella sp. (Cestoda-Anoplocephalidae) no Estado de Goiás, Brasil

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    Relata-se o encontro de um novo caso de bertiellose humana em paciente do sexo feminino, 2 anos, natural de Goiânia, Estado de Goiás com histórico de permanência em área freqüentada por símios no Estado de Mato Grosso. A paciente apresentava inapetência, dores abdominais, emagrecimento e eliminava nas fezes ovos e proglotes que foram identificados como Bertiella sp. O objetivo do presente trabalho é registrar o encontro do terceiro caso de parasitismo humano por Bertiella sp. (Cestoda-Anoplocephalidae) no Brasil, caracterizando mais um caso de zoonose helmíntica.The authors report on a new case of human Bertiellosis in a 2-year old female patient who was born in Goiânia-Goiás (Brazil) and has had history of permanent dwelling in an area frequently visited by simians in Mato Grosso (Brazil). At the time of diagnosis the patient showed inappetence, abdominal pain, and loss of weight. Eggs and proglottids were found in her stool and were identified as Bertiella sp. The objective of this report is to register the third case of human Bertiellosis in Brazil, characterizing one more case of helminthic zoonosis

    Impacts of the SARS-CoV-2 pandemic on the global demand for exotic pets: An expert elicitation approach

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    The SARS-CoV-2 pandemic has caused immense social and economic costs worldwide. Most experts endorse the view that the virus has a zoonotic origin with the final spillover being associated with wildlife trade. Besides human consumption, wild animals are also extensively traded as pets. Information on zoonotic diseases has been reported to reduce consumer demand for exotic pets. We conducted a global survey and collected 162 responses from international experts on exotic pet trade (traders, academics, NGOs, enforcement entities) to understand how the legal and illegal trade of exotic pets is expected to be affected by the ongoing coronavirus pandemic. Our results suggest that legal purchase of exotic pets is perceived as decreasing during the first pandemic wave due to: lower availability of animals for trade, suppliers’ inability to reach consumers and social distancing measures. The general perception is that in the future (i.e., next five years), both demand and supply of legally traded exotic pets are expected to either remain unchanged or decrease only temporarily. The consumer demand for illegal exotic pets is also expected to remain unchanged following the outbreak. The top two challenges reported by respondents, when considering the consequences of the pandemic for the exotic pet trade, are inadequate enforcement of national regulations and increased illegal trade. Our results suggest that the negative consequences of a zoonotic outbreak may not dissuade consumers of exotic pets. Worldwide, the transit/storing conditions and lack of health screenings of traded live animals are conducive to spreading diseases. Consumer demand is a key driver of trade, and enforcement of trade regulations will remain challenging, unless factors driving consumer demand are adequately incorporated in problem-solving frameworks. We emphasize the complexity of trade dynamics and the need to go beyond bans on wildlife trade. Stronger law enforcement, implemented along with initiatives dissuading consumption of wild exotic pets, are essential to sustainably satisfy the market demandinfo:eu-repo/semantics/publishedVersio

    Effects of climate, species interactions, and dispersal on decadal colonization and extinction rates of Iberian tree species

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    We studied the relative importance of climate, abundance of potentially competing species, and dispersal in explaining local colonization and extinction rates of tree species throughout mainland Spain. We used a Bayesian framework to parameterize a patch occupancy model to 23 species censused in 46,596 permanent plots in a 1 × 1 km grid across most Spanish forests. For most species, dispersal was the single best predictor of colonization, whereas climate and dispersal were equally important as predictors of extinction. Precipitation was positively correlated with the colonization rate of 12 out of 13 deciduous broad-leaved species, and negatively correlated with the extinction rate of nine of them. In contrast, precipitation equally decreased colonization and extinction of five out of eight of needle-leaved species (Juniperus and Pinus spp.). There was, however, marked variation among species in the magnitude of these effects, with some species exhibiting contrasting patterns for the colonization and the extinction process. Abundance of competing tree species (= summed plot basal area) was consistently correlated with decreased colonization of all needle-leaved species, and it increased the extinction rate of 6 out of 8 of these species. It had, nonetheless, weak facilitative effect on some broad-leaved species by promoting colonization (3 of 13 species) and decreasing extinction (7 of 13 species). With local colonization and extinction data, non-equilibrial and dynamic species distribution modelling can be improved by incorporating measures of biotic interactions and dispersal effects, along with traditional climate variables.Ministerio de Economía y CompetitividadComunidad de Madri

    Effects of climate, species interactions, and dispersal on decadal colonization and extinction rates of Iberian tree species

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    We studied the relative importance of climate, abundance of potentially competing species, and dispersal in explaining local colonization and extinction rates of tree species throughout mainland Spain. We used a Bayesian framework to parameterize a patch occupancy model to 23 species censused in 46,596 permanent plots in a 1 × 1 km grid across most Spanish forests. For most species, dispersal was the single best predictor of colonization, whereas climate and dispersal were equally important as predictors of extinction. Precipitation was positively correlated with the colonization rate of 12 out of 13 deciduous broad-leaved species, and negatively correlated with the extinction rate of nine of them. In contrast, precipitation equally decreased colonization and extinction of five out of eight of needle-leaved species (Juniperus and Pinus spp.). There was, however, marked variation among species in the magnitude of these effects, with some species exhibiting contrasting patterns for the colonization and the extinction process. Abundance of competing tree species (= summed plot basal area) was consistently correlated with decreased colonization of all needle-leaved species, and it increased the extinction rate of 6 out of 8 of these species. It had, nonetheless, weak facilitative effect on some broad-leaved species by promoting colonization (3 of 13 species) and decreasing extinction (7 of 13 species). With local colonization and extinction data, non-equilibrial and dynamic species distribution modelling can be improved by incorporating measures of biotic interactions and dispersal effects, along with traditional climate variables.Ministerio de Economía y CompetitividadComunidad de Madri

    Temperature Range Shifts for Three European Tree Species over the Last 10,000 Years.

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    We quantified the degree to which the relationship between the geographic distribution of three major European tree species, Abies alba, Fagus sylvatica and Picea abies and January temperature (Tjan) has remained stable over the past 10,000 years. We used an extended data-set of fossil pollen records over Europe to reconstruct spatial variation in Tjan values for each 1000-year time slice between 10,000 and 3000 years BP (before present). We evaluated the relationships between the occurrences of the three species at each time slice and the spatially interpolated Tjan values, and compared these to their modern temperature ranges. Our results reveal that F. sylvatica and P. abies experienced Tjan ranges during the Holocene that differ from those of the present, while A. alba occurred over a Tjan range that is comparable to its modern one. Our data suggest the need for re-evaluation of the assumption of stable climate tolerances at a scale of several thousand years. The temperature range instability in our observed data independently validates similar results based exclusively on modeled Holocene temperatures. Our study complements previous studies that used modeled data by identifying variation in frequencies of occurrence of populations within the limits of suitable climate. However, substantial changes that were observed in the realized thermal niches over the Holocene tend to suggest that predicting future species distributions should not solely be based on modern realized niches, and needs to account for the past variation in the climate variables that drive species ranges

    Evaluating the combined effects of climate and land-use change on tree species distributions

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    A large proportion of the world's biodiversity is reportedly threatened by habitat loss and climate change. However, there are few studies that investigate the interaction between these two threats using empirical data.Here, we investigate interactions between climate change and land use change in the future distribution of 23 dominant tree species in mainland Spain. We simulated changes up to year 2100 using a climate-dependent Stochastic Patch Occupancy Model, parameterized with colonization and extinction events recorded in 46 569 survey plots.We estimated that the distribution of 17 out of 23 tree species are expanding, and hence not at equilibrium with the climate. However, climate change will make the future occupancy of 15 species lower than expected if climate, and habitat, remained stable (baseline scenario).Climate change, when combined with 20% habitat loss, was estimated to reduce species occupancy by an average of 23% if habitat loss is spatially clumped, relative to baseline projections, and by 35% if scattered. If habitat loss occurred in areas already impacted by human activities, species occupancy would be reduced by 26%. Land-use changes leading to habitat gain (i.e. creation through e.g. reforestation), could slightly mitigate the effects of climate change; but a 20% increment in habitat would reduce climate-change-driven losses in species occupancy by only ~3%.Synthesis and applications. The distributions of the most common tree species in mainlandSpain are expanding, but climate change threatens to reduce this expansion by 18% for 15of the 23 studied species. Moreover, if the habitat of these species is simultaneously lost, theoccupancies of all of them will be reduced further, with variation depending on the spatialpattern of the lost habitats. However, we did not detect synergies between climate change andhabitat loss. The combined effect (with 20% habitat loss) was 5–13% less than what it wouldbe if the effects were additive. Importantly, reforestation could partially offset the negativeeffects of climate change, but complete mitigation would require an increase in forested landof 80%, and the prioritization of territories that are less impacted by human activities.Ministerio de Economía y CompetitividadComunidad de Madri

    The Lemaitre Model and the Generalisation of the Cosmic Mass

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    We consider the spherically symmetric metric with a comoving perfect fluid and non-zero pressure -- the Lemaitre metric -- and present it in the form of a calculational algorithm. We use it to review the definition of mass, and to look at the apparent horizon relations on the observer's past null cone. We show that the introduction of pressure makes it difficult to separate the mass from other physical parameters in an invariant way. Under the usual mass definition, the apparent horizon relation, that relates the diameter distance to the cosmic mass, remains the same as in the Lemaitre-Tolman case.Comment: latex, 16 pages, Revision has minor changes due to referee's comments
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