1,072 research outputs found
Quantification of habitat fragmentation reveals extinction risk in terrestrial mammals
Although habitat fragmentation is often assumed to be a primary driver of extinction, global patterns of fragmentation and its relationship to extinction risk have not been consistently quantified for any major animal taxon. We developed high-resolution habitat fragmentation models and used phylogenetic comparative methods to quantify the effects of habitat fragmentation on the world's terrestrial mammals, including 4,018 species across 26 taxonomic Orders. Results demonstrate that species with more fragmentation are at greater risk of extinction, even after accounting for the effects of key macroecological predictors, such as body size and geographic range size. Species with higher fragmentation had smaller ranges and a lower proportion of high-suitability habitat within their range, andmost high-suitability habitat occurred outside of protected areas, further elevating extinction risk. Our models provide a quantitative evaluation of extinction risk assessments for species, allow for identification of emerging threats in species not classified as threatened, and provide maps of global hotspots of fragmentation for the world's terrestrial mammals. Quantification of habitat fragmentation will help guide threat assessment and strategic priorities for global mammal conservation
Reducing the burden of injury: An intersectoral preventive approach is needed
Injuries constitute the second largest contributor to the Western Cape burden of disease (BoD), after major infectious diseases caused by HIV/AIDS and tuberculosis and ahead of mental health disorders and cardiovascular and childhood diseases. The Provincial Health Department instituted the BoD Reduction Project to improve health surveillance for planning and resource allocation, review risk factors, and prioritise interventions to reduce the overall BoD
Global inequities and political borders challenge nature conservation under climate change
Underlying sociopolitical factors have emerged as important determinants of wildlife population trends and the effectiveness of conservation action. Despite mounting research into the impacts of climate change on nature, there has been little consideration of the human context in which these impacts occur, particularly at the global scale. We investigate this in two ways. First, by modeling the climatic niches of terrestrial mammals and birds globally, we show that projected species loss under climate change is greatest in countries with weaker governance and lower Gross Domestic Product, with loss of mammal species projected to be greater in countries with lower CO2 emissions. Therefore, climate change impacts on species may be disproportionately significant in countries with lower capacity for effective conservation and lower greenhouse gas emissions, raising important questions of international justice. Second, we consider the redistribution of species in the context of political boundaries since the global importance of transboundary conservation under climate change is poorly understood. Under a high-emissions scenario, we find that 35% of mammals and 29% of birds are projected to have over half of their 2070 climatic niche in countries in which they are not currently found. We map these transboundary range shifts globally, identifying borders across which international coordination might most benefit conservation and where physical border barriers, such as walls and fences, may be an overlooked obstacle to climate adaptation. Our work highlights the importance of sociopolitical context and the utility of a supranational perspective for 21st century nature conservation
Linked indicator sets for addressing biodiversity loss
The target adopted by world leaders of significantly reducing the rate of biodiversity loss by 2010 was not met but this stimulated a new suite of biodiversity targets for 2020 adopted by the Parties to the Convention on Biological Diversity (CBD) in October 2010. Indicators will be essential for monitoring progress towards these targets and the CBD will be defining a suite of relevant indicators, building on those developed for the 2010 target. Here we argue that explicitly linked sets of indicators offer a more useful framework than do individual indicators because the former are easier to understand, communicate and interpret to guide policy. A Response-Pressure-State-Benefit framework for structuring and linking indicators facilitates an understanding of the relationships between policy actions, anthropogenic threats, the status of biodiversity and the benefits that people derive from it. Such an approach is appropriate at global, regional, national and local scales but for many systems it is easier to demonstrate causal linkages and use them to aid decision making at national and local scales. We outline examples of linked indicator sets for humid tropical forests and marine fisheries as illustrations of the concept and conclude that much work remains to be done in developing both the indicators and the causal links between them
On the Link between Martian Total Ozone and Potential Vorticity
AbstractWe demonstrate for the first time that total ozone in the martian atmosphere is highly correlated with the dynamical tracer, potential vorticity, under certain conditions. The degree of correlation is investigated using a Mars global circulation model including a photochemical model. Potential vorticity is the quantity of choice to explore the dynamical nature of polar vortices because it contains information on winds and temperature in a single scalar variable. The correlation is found to display a distinct seasonal variation, with a strong positive correlation in both northern and southern winter at poleward latitudes in the northern and southern hemisphere respectively.The identified strong correlation implies variations in polar total ozone during winter are predominantly controlled by dynamical processes in these spatio-temporal regions. The weak correlation in northern and southern summer is due to the dominance of photochemical reactions resulting from extended exposure to sunlight. The total ozone/potential vorticity correlation is slightly weaker in southern winter due to topographical variations and the preference for ozone to accumulate in Hellas basin. In northern winter, total ozone can be used to track the polar vortex edge.The ozone/potential vorticity ratio is calculated for both northern and southern winter on Mars for the first time. Using the strong correlation in total ozone and potential vorticity in northern winter inside the polar vortex, it is shown that potential vorticity can be used as a proxy to deduce the distribution of total ozone where satellites cannot observe for the majority of northern winter. Where total ozone observations are available on the fringes of northern winter at poleward latitudes, the strong relationship of total ozone and potential vorticity implies that total ozone anomalies in the surf zone of the northern polar vortex can potentially be used to determine the origin of potential vorticity filaments
Improvements to the Red List Index
The Red List Index uses information from the IUCN Red List to track trends in the projected overall extinction risk of sets of species. It has been widely recognised as an important component of the suite of indicators needed to measure progress towards the international target of significantly reducing the rate of biodiversity loss by 2010. However, further application of the RLI (to non-avian taxa in particular) has revealed some shortcomings in the original formula and approach: It performs inappropriately when a value of zero is reached; RLI values are affected by the frequency of assessments; and newly evaluated species may introduce bias. Here we propose a revision to the formula, and recommend how it should be applied in order to overcome these shortcomings. Two additional advantages of the revisions are that assessment errors are not propagated through time, and the overall level extinction risk can be determined as well as trends in this over time
Employment mobility in high-technology agglomerations: the cases of Oxfordshire and Cambridgeshire
This paper examines labour market behaviour of the highly skilled in high-tech local economies, taking the UK examples of Oxfordshire and Cambridgeshire as case studies. It reports on data from a survey of members of three scientific institutes to compare rates of employee mobility in the two locations and considers the likely explanations and implications of those patterns
Hot and Diffuse Clouds near the Galactic Center Probed by Metastable H3+
Using an absorption line from the metastable (J, K) = (3, 3) level of H3+
together with other lines of H3+ and CO observed along several sightlines, we
have discovered a vast amount of high temperature (T ~ 250 K) and low density
(n ~ 100 cm-3) gas with a large velocity dispersion in the Central Molecular
Zone (CMZ) of the Galaxy, i.e., within 200 pc of the center. Approximately
three fourths of the H3+ along the line of sight to the brightest source we
observed, the Quintuplet object GCS 3-2, is inferred to be in the CMZ, with the
remaining H3+ located in intervening spiral arms. About half of H3+ in the CMZ
has velocities near ~ - 100 km s-1 indicating that it is associated with the
180 pc radius Expanding Molecular Ring which approximately forms outer boundary
of the CMZ. The other half, with velocities of ~ - 50 km s-1 and ~ 0 km s-1, is
probably closer to the center. CO is not very abundant in those clouds. Hot and
diffuse gas in which the (3, 3) level is populated was not detected toward
several dense clouds and diffuse clouds in the Galactic disk where large column
densities of colder H3+ have been reported previously. Thus the newly
discovered environment appears to be unique to the CMZ. The large observed H3+
column densities in the CMZ suggests an ionization rate much higher than in the
diffuse interstellar medium in the Galactic disk. Our finding that the H3+ in
the CMZ is almost entirely in diffuse clouds indicates that the reported volume
filling factor (f ≥ 0.1) for n ≥ 104 cm-3 clouds in the CMZ is an
overestimate by at least an order of magnitude.Comment: 33 pages, 5 figures, 3 table
An unexpected disruption of the atmospheric quasi-biennial oscillation
One of the most repeatable phenomena seen in the atmosphere, the quasi-biennial oscillation (QBO) between prevailing eastward and westward wind jets in the equatorial stratosphere (approximately 16 to 50 kilometers altitude), was unexpectedly disrupted in February 2016. An unprecedented westward jet formed within the eastward phase in the lower stratosphere and cannot be accounted for by the standard QBO paradigm based on vertical momentum transport. Instead, the primary cause was waves transporting momentum from the Northern Hemisphere. Seasonal forecasts did not predict the disruption, but analogous QBO disruptions are seen very occasionally in some climate simulations. A return to more typical QBO behavior within the next year is forecast, although the possibility of more frequent occurrences of similar disruptions is projected for a warming climate
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