236 research outputs found
Remembering Dr. Ben Collen, an exemplary conservation biologist
No full textRemembering Dr. Ben Collen, an exemplary conservation biologis
Language learning in Northern Ireland: teachers have their say
No full textLanguage Trends Northern Ireland surveys language teachers in Northern Ireland every two years. Its author, Dr Ian Collen, explains some of the findings
Language learning in Northern Ireland: teachers have their say
No full textLanguage Trends Northern Ireland surveys language teachers in Northern Ireland every two years. Its author, Dr Ian Collen, explains some of the findings
Meta‐corridor solutions for climate‐vulnerable plant species groups in South Korea
No full textVulnerability assessments can provide useful information for the establishment of climate change adaptation strategies. We performed spatial vulnerability assessments for multiple plant species that incorporate potential range shifts to areas of future suitable climate. We conducted the assessments at a national level for plant species organized into vulnerable species groups. We then identified a climate meta-corridor for each vulnerable group that could potentially be a pathway for multiple species. We estimated climate suitability for 2297 South Korean terrestrial plant species under current climate conditions and climate projections for 2050 using the Multivariate Adaptive Regression Splines multiresponse species distribution model. We classified the plants into five groups based on their current spatial distribution patterns: centrally located species, wide-range species, coastal mountain species, montane species, and lowland species. Three vulnerability assessment components — exposure, spatial disruption, and dispersal pressure — were used to calculate the spatial vulnerability of each species. Vulnerability values were averaged by group. We identified climate meta-corridors that would link current suitable areas to future climatically suitable areas, and tested the corridors for multi-species accessibility. The vulnerability assessment indicates that coastal mountain, montane, and lowland species groups, comprising 37% of all modelled species, are the most vulnerable to climate change. The climate meta-corridor for each group overlaps at least some portion of 83% or more of its species' current modelled ranges. The current and future climate-suitable areas for the lowland species group have very little spatial overlap, suggesting a high priority should be placed on the corridor identified for these species. We found that the destinations of the climate corridors converge, raising questions about large numbers of species moving to limited areas, and that transboundary corridor modelling is needed on the Korean Peninsula. Policy implications. Each of the three meta-corridors has unique policy implications: assisted migration for the highest elevation species for the montane; significant conservation and restoration work for the lowland; and perhaps no direct intervention but monitoring to evaluate effectiveness of the relatively intact habitats of the coastal mountain meta-corridor. Overall, implementation policies for climate connectivity will be context-dependent, requiring different approaches dependent on local and regional conditions and the species targeted
Global Biodiversity Indicators Reflect the Modeled Impacts of Protected Area Policy Change
No full textGlobal biodiversity indicators can be used to measure the status and trends of biodiversity relating to Convention on Biological Diversity (CBD) targets. Whether such indicators can support decision makers by distinguishing among policy options remains poorly evaluated. We tested the ability of two CBD indicators, the Living Planet Index and the Red List Index, to reflect projected changes in mammalian populations in sub-Saharan Africa in response to potential policies related to CBD targets for protected areas (PAs). We compared policy scenarios to expand the PA network, improve management effectiveness of the existing network, and combinations of the two, against business as usual. Both indicators showed that more effective management would provide greater benefits to biodiversity than expanding PAs alone. The indicators were able to communicate outcomes of modeled scenarios in a simple quantitative manner, but behaved differently. This work highlights both the considerable potential of indicators in supporting decisions, and the need to understand how indicators will respond as biodiversity changes
Historical drivers of extinction risk: using past evidence to direct future monitoring
No full textGlobal commitments to halt biodiversity decline mean that it is essential to monitor species' extinction risk. However, the work required to assess extinction risk is intensive. We demonstrate an alternative approach to monitoring extinction risk, based on the response of species to external conditions. Using retrospective International Union for Conservation of Nature Red List assessments, we classify transitions in the extinction risk of 497 mammalian carnivores and ungulates between 1975 and 2013. Species that moved to lower Red List categories, or remained Least Concern, were classified as ‘lower risk'; species that stayed in a threatened category, or moved to a higher category of risk, were classified as ‘higher risk'. Twenty-four predictor variables were used to predict transitions, including intrinsic traits (species biology) and external conditions (human pressure, distribution state and conservation interventions). The model correctly classified up to 90% of all transitions and revealed complex interactions between variables, such as protected areas (PAs) versus human impact. The most important predictors were: past extinction risk, PA extent, geographical range size, body size, taxonomic family and human impact. Our results suggest that monitoring a targeted set of metrics would efficiently identify species facing a higher risk, and could guide the allocation of resources between monitoring species' extinction risk and monitoring external conditions
A new method for identifying rapid decline dynamics in wild vertebrate populations
No full textTracking trends in the abundance of wildlife populations is a sensitive method for assessing biodiversity change due to the short time-lag between human pressures and corresponding shifts in population trends. This study tests for proposed associations between different types of human pressures and wildlife population abundance decline-curves and introduces a method to distinguish decline trajectories from natural fluctuations in population time-series. First, we simulated typical mammalian population time-series under different human pressure types and intensities and identified significant distinctions in population dynamics. Based on the concavity of the smoothed population trend and the algebraic function which was the closest fit to the data, we determined those differences in decline dynamics that were consistently attributable to each pressure type. We examined the robustness of the attribution of pressure type to population decline dynamics under more realistic conditions by simulating populations under different levels of environmental stochasticity and time-series data quality. Finally, we applied our newly developed method to 124 wildlife population time-series and investigated how those threat types diagnosed by our method compare to the specific threatening processes reported for those populations. We show how wildlife population decline curves can be used to discern between broad categories of pressure or threat types, but do not work for detailed threat attributions. More usefully, we find that differences in population decline curves can reliably identify populations where pressure is increasing over time, even when data quality is poor, and propose this method as a cost-effective technique for prioritizing conservation actions between populations
Resolving hiatus in (isi)Ndebele: An optimality theoretic account
No full textAbstractVowel hiatus is a dispreferred phenomenon in many languages. When vowel sequences arise through morphophonological concatenations in (isi)Ndebele, hiatus may be resolved in one of three processes: (i) one of the two vowels undergoes elision; (ii) one of the vowels (mostly the first vowel in the sequence) undergoes glide formation; and (iii) the two vowels undergo vowel coalescence – the merging of the two vowels into a neutral vowel that has the qualities of both the two initial vowels straddling a word boundary. This article examines these vowel hiatus resolution strategies in (isi)Ndebele, through the theoretical explications of Optimality Theory (OT) and CV Phonology. In (isi)Ndebele, the featural qualities of the two vowels straddling a word boundary and the morphological contexts at which the hiatal configurations occur determine what process repairs vowel hiatus. Hiatus resolution is also invariably ONSET and feature driven: driven by Preferred Syllable Structure Rules(PSSRs) and constraints
A global analysis of the determinants of alien geographical range size in birds
No full textAim: Determining the causes of range size variation in the distributions of alien species is important for understanding the spread of invasive species. Factors influencing alien range size have been explored for some species at a regional level, but to date there has been no global analysis of an entire class. Here, we present such an analysis for birds, testing for the effects of introduction event, location and species-level variables on alien range sizes. Location Global. Methods: We used a novel dataset on the global distributions of alien bird species to test for relationships between alien range size and colonization pressure, residence time, extent of the global climatic niche, native range size, body mass and specialization, using a statistical approach based on phylogenetic generalized least squares models. We performed this analysis globally, and for separate biogeographical realms. Results: Approximately half of the variation in alien bird range size is explained by colonization pressure in univariate analysis. We identified consistent effects of higher colonization pressure at global and realm levels, as well as support for effects of native range size and residence time. We found less support for effects of body mass, specialization or extent of the global climatic niche on alien range size. Main conclusions: Alien bird range sizes are generally small relative to their native range sizes, and many are continuing to expand. Nevertheless, current variation is predictable, most strongly by the event-level factor of colonization pressure. Whether a species is widespread is a better predictor of alien range size than whether a species could be widespread (estimated by global climatic niche extent), while we also find effects of residence time on alien range size. These relationships may help to identify those alien species that are more likely to spread and hence have greater environmental and economic impacts where they have been introduced.Ellie E. Dyer, Victoria Franks, Phillip Cassey, Ben Collen, Robert C. Cope, Kate E. Jones, Ҫagan H. Ṣekercioğlu and Tim M. Blackbur
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