206,131 research outputs found
Estimating coextinction risks from epidemic tree death
At least 10% of the world's tree species are threatened with extinction and pathogens are increasingly implicated in tree threats. Coextinction and threats to affiliates as a consequence of the loss or decline of their host trees is a poorly understood phenomenon. Ash dieback is an emerging infectious disease causing severe dieback of common ash Fraxinus excelsior throughout Europe. We utilized available empirical data on affiliate epiphytic lichen diversity (174 species and 17,800 observations) among 20 ash dieback infected host tree populations of F. excelsior on the island Gotland in the Baltic Sea, Sweden. From this, we used structured scenario projections scaled with empirical data of ash dieback disease to generate probabilistic models for estimating local and regional lichen coextinction risks. Average coextinction probabilities (A - ) were 0.38 (95% CI 60.09) for lichens occurring on F. excelsior and 0.14 (95% CI 60.03) when considering lichen persistence on all tree species. A - was strongly linked to local disease incidence levels and generally increasing with lichen host specificity to F. excelsior and decreasing population size. Coextinctions reduced affiliate community viability, with significant local reductions in species richness and shifts in lichen species composition. Affiliates were projected to become locally extirpated before their hosts, illuminating the need to also consider host tree declines. Traditionally managed open wooded meadows had the highest incidence of ash dieback disease and significantly higher proportions of affiliate species projected to go extinct, compared with unmanaged closed forests and semi-open grazed sites. Most cothreatened species were not previously red-listed, which suggest that tree epidemics cause many unforeseen threats to species. Our analysis shows that epidemic tree deaths represent an insidious, mostly overlooked, threat to sessile affiliate communities in forested environments. Current conservation and management strategies must account for secondary extinctions associated with epidemic tree death
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Integrating invasion and disease in the risk assessment of live bird trade.
AimInternational trade in plants and animals generates significant economic benefits. It also leads to substantial unintended impacts when introduced species become invasive, causing environmental disturbance or transmitting diseases that affect people, livestock, other wildlife or the environment. Policy responses are usually only implemented after these species become established and damages are already incurred. International agreements to control trade are likewise usually based on selection of species with known impacts. We aim to further develop quantitative invasive species risk assessment for bird imports and extend the tool to explicitly address disease threats.LocationUnited States of America.MethodsWe use a two-step approach for rapid risk assessment based on the expected biological risks due to both the environmental and health impact of a potentially invasive wildlife species in trade. We assess establishment probability based on a model informed by historical observations and then construct a model of emerging infectious disease threat based on economic and ecological characteristics of the exporting country.ResultsWe illustrate how our rapid assessment tool can be used to identify high-priority species for regulation based on a combination of the threat they pose for becoming established and vectoring emerging infectious diseases.Main conclusionsOur approach can be executed for a species in a matter of days and is nested in an economic decision-making framework for determining whether the biological risk is justified by trade benefits
Rethinking Regional Energy Policy Do Threats Matter in Supply and Generation Process?
The study investigates potential threats to energy security and sustainable electricity production
from a regional perspective, after identifying a host of factors that are likely to affect sustainable
energy production and supply using seemingly unrelated regression estimation, which produces
efficient estimates. Our results show that energy security which we described as the level of
diversification in regional specific energy generating sources is probably being affected by
regional specific level of industrialization and domestic energy consumption. Issues of over
dependence on specific sources of energy supply (particularly nuclear production sources) were
also found to have a negative effect on energy security and probably increase the risk of future
failure in energy supply. Energy policy was also found to have a significant effect on energy
security. The impacts of various constraints on electricity production were also considered. It
was found that many factors affect electricity output production in regions particularly
environmental factors that affect consumption and generation
The Development of an Assault Directed Infrared Countermeasures (DIRCM) Program
The purpose of this thesis is to document the history of the development of an Assault Directed Infrared Countermeasures (DIRCM) Program as well as Navy Program Office (PMA272) efforts to date, to initiate a new start ACAT II Program for Navy and Marine Corps helicopters starting in Fiscal Year (FY) 2006. It concentrates on the programmatic aspects of Assault DIRCM and does not go into detail on the design or technical aspects of the development of the system. This thesis will introduce emerging threats to helicopters operating in theater and describe the requirement for a DIRCM technology. It will also highlight program issues based on observations made over the past year as well as provide a recommended path forward for immediate program execution considering internal and external program and acquisition constraints both real and perceived
The Intersections of Biological Diversity and Cultural Diversity: Towards Integration
There is an emerging recognition that the diversity of life comprises both biological and cultural diversity. In the past, however, it has been common to make divisions between nature and culture, arising partly out of a desire to control nature. The range of interconnections between biological and cultural diversity are reflected in the growing variety of environmental sub-disciplines that have emerged. In this article, we present ideas from a number of these sub-disciplines. We investigate four bridges linking both types of diversity (beliefs and worldviews, livelihoods and practices, knowledge bases and languages, and norms and institutions), seek to determine the common drivers of loss that exist, and suggest a novel and integrative path forwards. We recommend that future policy responses should target both biological and cultural diversity in a combined approach to conservation. The degree to which biological diversity is linked to cultural diversity is only beginning to be understood. But it is precisely as our knowledge is advancing that these complex systems are under threat. While conserving nature alongside human cultures presents unique challenges, we suggest that any hope for saving biological diversity is predicated on a concomitant effort to appreciate and protect cultural diversity
Child–parent interaction in relation to road safety education : Part 2 – main report
• Children and young people are particularly vulnerable road users. • Child pedestrian injury rates are poor compared with the rest of Europe. • The factors that impact on children’s road safety and their capability in traffic are numerous, multi-faceted and complex. • • The systematic review conducted by Cattan et al. (2008) as the initial phase of this study shows that: • parents see themselves as being responsible for developing their children’s road safety awareness and skills; • holding hands is the most common road-crossing interaction between parents and children; • adults rarely make use of road-crossing events to give oral instructions; • few parents and children are consistent in their road-crossing behaviour; • roadside training by volunteer parents for groups of children can lead to significant improvements in children’s road safety behaviour; • belief in fate seems to influence the likelihood of parents using restraints, such as seat belts or car seats, with their children; and • parents’ understanding of the child’s perspective in carrying out road safety tasks and their motivation to actively involve their child in making decisions at the roadside can be improved through training. • Social Cognitive Theory (Bandura, 1986) suggests that the modelling role of parents can make a significant contribution to children’s learning about road use and their development of traffic competence whether or not parents are aware of this. • The main aim of this study was to explore the way parents influence children and young people aged 0–16 years to be safer road users. • This study included children and young people aged 5–16 and parents of children aged 0–16 years old
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