541 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
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
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
Predicting incident delirium diagnoses using data from primary-care electronic health records
Importance
risk factors for delirium in hospital inpatients are well established, but less is known about whether delirium occurring in the community or during an emergency admission to hospital care might be predicted from routine primary-care records.
Objectives
identify risk factors in primary-care electronic health records (PC-EHR) predictive of delirium occurring in the community or recorded in the initial episode in emergency hospitalisation. Test predictive performance against the cumulative frailty index.
Design
Stage 1: case-control; Stages 2 and 3: retrospective cohort.
Setting
clinical practice research datalink: PC-EHR linked to hospital discharge data from England.
Subjects
Stage 1: 17,286 patients with delirium aged â„60 years plus 85,607 controls. Stages 2 and 3: patientsââ„â60 years (n =â429,548 in 2015), split into calibration and validation groups.
Methods
Stage 1: logistic regression to identify associations of 110 candidate risk measures with delirium. Stage 2: calibrating risk factor weights. Stage 3: validation in independent sample using area under the curve (AUC) receiver operating characteristic.
Results
fifty-five risk factors were predictive, in domains including: cognitive impairment or mental illness, psychoactive drugs, frailty, infection, hyponatraemia and anticholinergic drugs. The derived model predicted 1-year incident delirium (AUCâ=â0.867, 0.852:0.881) and mortality (AUCâ=â0.846, 0.842:0.853), outperforming the frailty index (AUCâ=â0.761, 0.740:0.782). Individuals with the highest 10% of predicted delirium risk accounted for 55% of incident delirium over 1 year.
Conclusions
a risk factor model for delirium using data in PC-EHR performed well, identifying individuals at risk of new onsets of delirium. This model has potential for supporting preventive interventions
Connectivity between countries established by landbirds and raptors migrating along the AfricanâEurasian flyway
The conservation of long-distance migratory birds requires coordination between the multiple countries connected by the movements of these species. The recent expansion of
tracking studies is shedding new light on these movements, but much of this information
is fragmented and inaccessible to conservation practitioners and policy makers. We synthesized current knowledge on the connectivity established between countries by landbirds
and raptors migrating along the AfricanâEurasian flyway. We reviewed tracking studies to
compile migration records for 1229 individual birds, from which we derived 544 migratory links, each link corresponding to a speciesâ connection between a breeding country in
Europe and a nonbreeding country in sub-Saharan Africa. We used these migratory links
to analyze trends in knowledge over time and spatial patterns of connectivity per country
(across species), per species (across countries), and at the flyway scale (across all countries
and all species). The number of tracking studies available increased steadily since 2010 (particularly for landbirds), but the coverage of existing tracking data was highly incomplete.
An average of 7.5% of migratory landbird species and 14.6% of raptor species were tracked
per country. More data existed from central and western European countries, and it was
biased toward larger bodied species. We provide species- and country-level syntheses of the
migratory links we identified from the reviewed studies, involving 123 populations of 43
species, migrating between 28 European and 43 African countries. Several countries (e.g.,
Spain, Poland, Ethiopia, Democratic Republic of Congo) are strategic priorities for future
tracking studies to complement existing data, particularly on landbirds. Despite the limitations in existing tracking data, our data and results can inform discussions under 2 key
policy instruments at the flyway scale: the AfricanâEurasian Migratory Landbirds Action Plan and the Memorandum of Understanding on the Conservation of Migratory Birds of
Prey in Africa and Eurasia.Fundação para a CiĂȘncia e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio
Measuring Terrestrial Area of Habitat (AOH) and Its Utility for the IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species includes assessment of extinction risk for 98 512 species, plus documentation of their range, habitat, elevation, and other factors. These range, habitat and elevation data can be matched with terrestrial land cover and elevation datasets to map the speciesâ area of habitat (AOH; also known as extent of suitable habitat; ESH). This differs from the two spatial metrics used for assessing extinction risk in the IUCN Red List criteria: extent of occurrence (EOO) and area of occupancy (AOO). AOH can guide conservation, for example, through targeting areas for field surveys, assessing proportions of speciesâ habitat within protected areas, and monitoring habitat loss and fragmentation. We recommend that IUCN Red List assessments document AOH wherever practical
A global model of the response of tropical and sub-tropical forest biodiversity to anthropogenic pressures
Habitat loss and degradation, driven largely by agricultural expansion and intensification, present the greatest immediate threat to biodiversity. Tropical forests harbour among the highest levels of terrestrial species diversity and are likely to experience rapid land-use change in the coming decades. Synthetic analyses of observed responses of species are useful for quantifying how land use affects biodiversity and for predicting outcomes under land-use scenarios. Previous applications of this approach have typically focused on individual taxonomic groups, analysing the average response of the whole community to changes in land use. Here, we incorporate quantitative remotely sensed data about habitats in, to our knowledge, the first worldwide synthetic analysis of how individual species in four major taxonomic groupsâinvertebrates, âherptilesâ (reptiles and amphibians), mammals and birdsârespond to multiple human pressures in tropical and sub-tropical forests. We show significant independent impacts of land use, human vegetation offtake, forest cover and human population density on both occurrence and abundance of species, highlighting the value of analysing multiple explanatory variables simultaneously. Responses differ among the four groups considered, andâwithin birds and mammalsâbetween habitat specialists and habitat generalists and between narrow-ranged and wide-ranged species
Multimodel climate and variability of the stratosphere
The stratospheric climate and variability from simulations of sixteen chemistryâclimate models is evaluated. On average the polar night jet is well reproduced though its variability is less well reproduced with a large spread between models. Polar temperature biases are less than 5 K except in the Southern Hemisphere (SH) lower stratosphere in spring. The accumulated area of low temperatures responsible for polar stratospheric cloud formation is accurately reproduced for the Antarctic but underestimated for the Arctic. The shape and position of the polar vortex is well simulated, as is the tropical upwelling in the lower stratosphere. There is a wide model spread in the frequency of major sudden stratospheric warnings (SSWs), late biases in the breakup of the SH vortex, and a weak annual cycle in the zonal wind in the tropical upper stratosphere. Quantitatively, âmetricsâ indicate a wide spread in model performance for most diagnostics with systematic biases in many, and poorer performance in the SH than in the Northern Hemisphere (NH). Correlations were found in the SH between errors in the final warming, polar temperatures, the leading mode of variability, and jet strength, and in the NH between errors in polar temperatures, frequency of major SSWs, and jet strength. Models with a stronger QBO have stronger tropical upwelling and a colder NH vortex. Both the qualitative and quantitative analysis indicate a number of common and longâstanding model problems, particularly related to the simulation of the SH and stratospheric variability
TESSA: A toolkit for rapid assessment of ecosystem services at sites of biodiversity conservation importance
Sites that are important for biodiversity conservation can also provide significant benefits (i.e. ecosystem services) to people. Decision-makers need to know how change to a site, whether development or restoration, would affect the delivery of services and the distribution of any benefits among stakeholders. However, there are relatively few empirical studies that present this information. One reason is the lack of appropriate methods and tools for ecosystem service assessment that do not require substantial resources or specialist technical knowledge, or rely heavily upon existing data. Here we address this gap by describing the Toolkit for Ecosystem Service Site-based Assessment (TESSA). It guides local non-specialists through a selection of relatively accessible methods for identifying which ecosystem services may be important at a site, and for evaluating the magnitude of benefits that people obtain from them currently, compared with those expected under alternative land-uses. The toolkit recommends use of existing data where appropriate and places emphasis on enabling users to collect new field data at relatively low cost and effort. By using TESSA, the users could also gain valuable information about the alternative land-uses; and data collected in the field could be incorporated into regular monitoring programmes
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