Bruce E. Young

Universidad Nacional Agraria La Molina, Λίμα, Provincia de Lima, Peru

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Publications (44)312.43 Total impact

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    ABSTRACT: The effects of climate change on biodiversity are increasingly well documented, and many methods have been developed to assess species' vulnerability to climatic changes, both ongoing and projected in the coming decades. To minimize global biodiversity losses, conservationists need to identify those species that are likely to be most vulnerable to the impacts of climate change. In this Review, we summarize different currencies used for assessing species' climate change vulnerability. We describe three main approaches used to derive these currencies (correlative, mechanistic and trait-based), and their associated data requirements, spatial and temporal scales of application and modelling methods. We identify strengths and weaknesses of the approaches and highlight the sources of uncertainty inherent in each method that limit projection reliability. Finally, we provide guidance for conservation practitioners in selecting the most appropriate approach(es) for their planning needs and highlight priority areas for further assessments.
    Nature Climate Change 02/2015; 5(3):215-224. DOI:10.1038/nclimate2448 · 15.30 Impact Factor
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    ABSTRACT: Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of humaninduced habitat loss and harvesting, which are the predominant threats to reptiles.
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    ABSTRACT: New tools and approaches are becoming available for wildlife conservation managers to help support climate adaptation activities, but few studies have documented how practitioners have applied these tools and perceive their utility. We surveyed the literature and users of the NatureServe Climate Change Vulnerability Index (CCVI), a tool that is widely used in North America to assess species' vulnerability to climate change, to characterize 1) how the tool has been used; 2) the objectives addressed by projects using the tool; 3) novel approaches that might be useful to other users; 4) how the results contributed to climate change adaptation planning; and 5) needed improvements recognized by users of the tool. Responses from 25 CCVI users, representing state agencies and natural heritage programs, conservation organizations, and universities, combined with published reports from 20 CCVI assessments, indicated that the CCVI has been applied to large numbers of species from diverse taxonomic groups. Results from these assessments have been used to communicate about climate change vulnerability, select species to be prioritized for management, inform management decisions, identify monitoring needs, and inform land-acquisition decisions. Users of the CCVI have developed novel ways to address uncertainty in climate and species natural-history data, involve stakeholders, evaluate migratory species, address specific management questions, and combine outputs with the results of parallel spatial analyses. To address user needs, future iterations of the tool should address climate exposure in the full life cycle of migratory species; better examine species dependent on specific vegetation microhabitats; and improve treatment of the effects of climate on diseases, parasites, and natural enemies. © 2014 The Wildlife Society.
    Wildlife Society Bulletin 02/2015; 39(1). DOI:10.1002/wsb.478 · 1.27 Impact Factor
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    ABSTRACT: Recognizing the imperiled status of biodiversity and its benefit to human well-being, the world's governments committed in 2010 to take effective and urgent action to halt biodiversity loss through the Convention on Biological Diversity's “Aichi Targets”. These targets, and many conservation programs, require monitoring to assess progress toward specific goals. However, comprehensive and easily understood information on biodiversity trends at appropriate spatial scales is often not available to the policy makers, managers, and scientists who require it. We surveyed conservation stakeholders in three geographically diverse regions of critical biodiversity concern (the Tropical Andes, the African Great Lakes, and the Greater Mekong) and found high demand for biodiversity indicator information but uneven availability. To begin to address this need, we present a biodiversity “dashboard” – a visualization of biodiversity indicators designed to enable tracking of biodiversity and conservation pe
    PLoS ONE 11/2014; 9(11-11):e112046. DOI:10.1371/journal.pone.0112046 · 3.53 Impact Factor
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    ABSTRACT: 1.Despite efforts in data collection, missing values are commonplace in life-history trait databases. Because these values typically are not missing randomly, the common practice of removing missing data not only reduces sample size, but also introduces bias that can lead to incorrect conclusions. Imputing missing values is a potential solution to this problem. Here, we evaluate the performance of four approaches for estimating missing values in trait databases (K-nearest neighbour (kNN), multivariate imputation by chained equations (mice), missForest and Phylopars), and test whether imputed datasets retain underlying allometric relationships among traits.2.Starting with a nearly complete trait dataset on the mammalian order Carnivora (using four traits), we artificially removed values so that the percent of missing values ranged from 10 to 80%. Using the original values as a reference, we assessed imputation performance using normalized root mean squared error. We also evaluated whether including phylogenetic information improved imputation performance in kNN, mice, and missForest (it is a required input in Phylopars). Finally, we evaluated the extent to which the allometric relationship between two traits (body mass and longevity) was conserved for imputed datasets by looking at the difference (bias) between the slope of the original and the imputed datasets or datasets with missing values removed.3.Three of the tested approaches (mice, missForest and Phylopars), resulted in qualitatively equivalent imputation performance, and all had significantly lower errors than kNN. Adding phylogenetic information into the imputation algorithms improved estimation of missing values for all tested traits. The allometric relationship between body mass and longevity was conserved when up to 60% of data were missing, either with or without phylogenetic information, depending on the approach. This relationship was less biased in imputed datasets compared to datasets with missing values removed, especially when more than 30% of values were missing.4.Imputations provide valuable alternatives to removing missing observations in trait databases as they produce low errors and retain relationships among traits. Although we must continue to prioritize data collection on species traits, imputations can provide a valuable solution for conducting macroecological and evolutionary studies using life-history trait databases.This article is protected by copyright. All rights reserved.
    Methods in Ecology and Evolution 07/2014; 5(9). DOI:10.1111/2041-210X.12232 · 5.32 Impact Factor
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    ABSTRACT: Current economic growth models encourage natural resource-rich countries to become suppliers of raw materials for growing capital markets which severely affect conditions of large natural areas such as the western Amazon Basin, one of the most biodiverse regions on Earth. The process will accelerate as this region becomes more accessible with the development of transportation infrastructure as well as the extraction of non-renewable resources. Ameliorating these pressures in order to safeguard biodiversity and the ecosystem services it provides to humanity will require that decision-making processes are informed by relevant and up-to-date datasets. Here, we capitalize on newly available data for several species groups, aquatic and terrestrial ecological systems, and the distribution of threats and ecosystem services, to measure and map biodiversity state and pressure, and conservation response and benefits for sub-basins across a >2 million-km2 area. This information, organized according to the Pressure-State-Response-Benefits framework, should support for decisions on conservation and sustainable development investments, and monitoring their impact over the long term.
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    ABSTRACT: Current economic growth models encourage natural resource-rich countries to become suppliers of raw materials for growing capital markets which severely affect conditions of large natural areas such as the western Amazon Basin, one of the most biodiverse regions on Earth. The process will accelerate as this region becomes more accessible with the development of transportation infrastructure as well as the extraction of non-renewable resources. Ameliorating these pressures in order to safeguard biodiversity and the ecosystem services it provides to humanity will require that decision-making processes are informed by relevant and up-to-date datasets. Here, we capitalize on newly available data for several species groups, aquatic and terrestrial ecological systems, and the distribution of threats and ecosystem services, to measure and map biodiversity state and pressure, and conservation response and benefits for sub-basins across a >2 million-km2 area. This information, organized according to the Pressure-State-Response-Benefits framework, should support for decisions on conservation and sustainable development investments, and monitoring their impact over the long term.
    01/2013; 12(1):45-65.
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    ABSTRACT: Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of humaninduced habitat loss and harvesting, which are the predominant threats to reptiles.
    Biological Conservation 01/2013; 157:372-385. · 4.04 Impact Factor
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    ABSTRACT: Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human induced habitat loss and harvesting, which are the predominant threats to reptiles.
    Biological Conservation 01/2013; 157:372-385. DOI:10.1016/j.biocon.2012.07.015 · 4.04 Impact Factor
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    ABSTRACT: Background: The Andes-Amazon basin of Peru and Bolivia is one of the most data-poor, biologically rich, and rapidly changing areas of the world. Conservation scientists agree that this area hosts extremely high endemism, perhaps the highest in the world, yet we know little about the geographic distributions of these species and ecosystems within country boundaries. To address this need, we have developed conservation data on endemic biodiversity (~800 species of birds, mammals, amphibians, and plants) and terrestrial ecological systems (~90; groups of vegetation communities resulting from the action of ecological processes, substrates, and/or environmental gradients) with which we conduct a fine scale conservation prioritization across the Amazon watershed of Peru and Bolivia. We modelled the geographic distributions of 435 endemic plants and all 347 endemic vertebrate species, from existing museum and herbaria specimens at a regional conservation practitioner's scale (1:250,000-1:1,000,000), based on the best available tools and geographic data. We mapped ecological systems, endemic species concentrations, and irreplaceable areas with respect to national level protected areas. Results: We found that sizes of endemic species distributions ranged widely (< 20 km 2 to > 200,000 km
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    ABSTRACT: The Andes-Amazon basin of Peru and Bolivia is one of the most data-poor, biologically rich, and rapidly changing areas of the world. Conservation scientists agree that this area hosts extremely high endemism, perhaps the highest in the world, yet we know little about the geographic distributions of these species and ecosystems within country boundaries. To address this need, we have developed conservation data on endemic biodiversity (~800 species of birds, mammals, amphibians, and plants) and terrestrial ecological systems (~90; groups of vegetation communities resulting from the action of ecological processes, substrates, and/or environmental gradients) with which we conduct a fine scale conservation prioritization across the Amazon watershed of Peru and Bolivia. We modelled the geographic distributions of 435 endemic plants and all 347 endemic vertebrate species, from existing museum and herbaria specimens at a regional conservation practitioner's scale (1:250,000-1:1,000,000), based on the best available tools and geographic data. We mapped ecological systems, endemic species concentrations, and irreplaceable areas with respect to national level protected areas. We found that sizes of endemic species distributions ranged widely (< 20 km2 to > 200,000 km2) across the study area. Bird and mammal endemic species richness was greatest within a narrow 2500-3000 m elevation band along the length of the Andes Mountains. Endemic amphibian richness was highest at 1000-1500 m elevation and concentrated in the southern half of the study area. Geographical distribution of plant endemism was highly taxon-dependent. Irreplaceable areas, defined as locations with the highest number of species with narrow ranges, overlapped slightly with areas of high endemism, yet generally exhibited unique patterns across the study area by species group. We found that many endemic species and ecological systems are lacking national-level protection; a third of endemic species have distributions completely outside of national protected areas. Protected areas cover only 20% of areas of high endemism and 20% of irreplaceable areas. Almost 40% of the 91 ecological systems are in serious need of protection (= < 2% of their ranges protected). We identify for the first time, areas of high endemic species concentrations and high irreplaceability that have only been roughly indicated in the past at the continental scale. We conclude that new complementary protected areas are needed to safeguard these endemics and ecosystems. An expansion in protected areas will be challenged by geographically isolated micro-endemics, varied endemic patterns among taxa, increasing deforestation, resource extraction, and changes in climate. Relying on pre-existing collections, publically accessible datasets and tools, this working framework is exportable to other regions plagued by incomplete conservation data.
    BMC Ecology 01/2012; 12:1. DOI:10.1186/1472-6785-12-1
  • 01/2012: pages 73; NatureServe.
  • Wildlife Conservation in a Changing Climate, Edited by Jedediah F. Brodie, Eric Post, Daniel F. Doak, 01/2012: chapter 7: pages 129-152; University of Chicago Press., ISBN: 9780226074641
  • P J Comer, B Young, K Schulz
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    ABSTRACT: ... Citation: Comer , PJ, B . Young , K . Schulz , G . Kittel, B . Unnasch, D. Braun, G . Hammerson, L. Smart, H. Hamilton, S. Auer, R. Smyth, and J . Hak.. 2012. Climate Change Vulnerability and Adaptation Strategies for Natural Communities : Piloting methods in the Mojave and Sonoran ...
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    ABSTRACT: Motivated by the need for a means to rapidly assess the vulnerability of species to climate change, NatureServe developed a Climate Change Vulnerability Index. The Index uses a scoring system that integrates a species’ predicted exposure to climate change within an assessment area and three sets of factors associated with climate change sensitivity, each supported by published studies: 1) indirect exposure to climate change, 2) speciesspecific factors (including dispersal ability, temperature and precipitation sensitivity, physical habitat specificity, interspecific interactions, and genetic factors), and 3) documented response to climate change. Assessing species with this Index facilitates grouping taxa by their relative risk to climate change, and by sensitivity factors, which we expect will help users to identify adaptation options that could benefit multiple species. Our primary goal for the Index is to provide valuable input for key planning documents, such as revisions of state wildlife action plans, such that climate change impacts can be addressed and integrated with other stressors. Further, we hope that this tool will help land managers develop and prioritize strategies for climate change adaptation that lead to actions that increase the resilience of species to climate change. This document explains the Index, how to use it, and how to interpret the results.
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    PLoS Biology 10/2010; · 12.69 Impact Factor
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    ABSTRACT: Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.
    Science 10/2010; 330(6010):1503-9. DOI:10.1126/science.1194442 · 31.48 Impact Factor
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    ABSTRACT: Background/Question/Methods Resource managers increasingly seek to identify which species are most vulnerable to climate change-induced declines. To meet this need, we developed a practical, multifaceted rapid assessment tool, the "climate change vulnerability index." The index considers climate change exposure and species sensitivity. Exposure is the magnitude of projected climate change across the species' range within the assessment area. Species sensitivity includes intrinsic factors such as natural and life history traits that may reduce resilience (such as habitat specialization or a strong potential for disruption of key species interactions) and traits that suggest potential inability to adapt (such as low dispersal ability or reduced genetic diversity). The index also includes extrinsic factors related to a species' distribution, such as dispersal barriers and proximity to predicted sea level rise. Exposure and sensitivity are combined to generate a categorical vulnerability score (Extremely Vulnerable, Highly Vulnerable, Moderately Vulnerable, Not Vulnerable/Presumed Stable, or Not Vulnerable/Increase Likely). Results/Conclusions Preliminary results from a study of 216 vertebrates and mollusks in Nevada show that the index effectively sorted species, with the majority being Moderately Vulnerable or Not Vulnerable/Presumed Stable. 100% of mollusks, 80% of fish, 38% of amphibians, 30% of reptiles, 35% of mammals, and 4% of birds assessed were at least Moderately Vulnerable. Key vulnerability factors included limited hydrological niche, impacts from climate change mitigation-related land use changes, migration to or through a few vulnerable locations or lack of facultative distribution shifts, and dependence on vulnerable aquatic/wetland habitats. Good dispersal ability, broad physical habitat, migration to broad geographical areas or tendency to facultatively shift distribution, and broad temperature tolerance were factors that decreased vulnerability. The importance of limited hydrological niche and dependence on vulnerable aquatic/wetland habitats highlights the need for further exploration of the interaction among increasing temperatures, moisture, and wildlife habitats in Nevada. Further testing of the index at the state/province level is warranted, as well as testing at larger spatial scales.
    95th ESA Annual Convention 2010; 08/2010

Publication Stats

4k Citations
312.43 Total Impact Points

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Institutions

  • 2009
    • Universidad Nacional Agraria La Molina
      • Department of Forestry Management
      Λίμα, Provincia de Lima, Peru
  • 2008
    • Tulane University
      • Department of Ecology and Evolutionary Biology
      New Orleans, Louisiana, United States
    • International Union for Conservation of Nature
      Vaud, Switzerland
  • 1213
    • Southern Illinois University Carbondale
      • Department of Zoology
      Carbondale, IL, United States