292 research outputs found

    An Invasive Species Assessment Protocol: Evaluating Non-Native Plants for Their Impact on Biodiversity, Version 1

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    NatureServe, in cooperation with The Nature Conservancy and the U.S. National Park Service, developed this Invasive Species Assessment Protocol as a tool for assessing, categorizing, and listing non-native invasive vascular plants according to their impact on native species and natural biodiversity in a large geographical area such as a nation, state, province, or ecological region. This protocol is designed to make the process of assessing and listing invasive plants objective and systematic, and to incorporate scientific documentation of the information used to determine each species’ rank. NatureServe’s methodology has previously included assessments of the conservation significance of native species; this protocol extends that scope to non-native species as well. The protocol is used to assess species (or infraspecific taxa, as appropriate) individually for a specified “region of interest” and to assign each species an Invasive Species Impact Rank (I-Rank) of High, Medium, Low, or Insignificant to categorize its negative impact on natural biodiversity within that region. The protocol includes 20 questions, each with four scaled responses (A-D, plus U = unknown). The 20 questions are grouped into four sections: Ecological Impact, Current Distribution and Abundance, Trend in Distribution and Abundance, and Management Difficulty. Each species is assessed by considering these questions, with the answers used to calculate a subrank for each of the four sections. An overall I-Rank is then calculated from the subranks. Text comments and citations to information sources should be provided as documentation for each answer selected, along with a concise text summary of the major considerations leading to the overall rank. While designed for use in a specified large, contiguous, biogeographically diverse region, the protocol can be adapted to specified noncontiguous regions (such as the 50 states of the United States), and may also be applied to assess the impact in the non-native range of a species that is also present elsewhere in a region as a native. NatureServe is now using this protocol to assess the biodiversity impact of the approximately 3,500 non-native vascular plant species established outside cultivation in the United States. The protocol is offered here in generalized form for others who might wish to use it to conduct similar assessments and create lists of invasive plants for other nations, states, provinces, ecological regions, or comparable areas

    Geographical origin of dabbling ducks wintering in Iberia: Sex differences and implications for pair formation

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    Los humedales ibéricos naturales y antropógenos del sur de Europa son bien conocidos por sustentar a un gran número de aves migratorias acuáticas del Palaearctico en cada invierno. Sin embargo, la información sobre el origen geográfico de los patos de humedal que pasan el invierno en estos espacios es escasa y se limita principalmente a datos de sonar. Aquí, hemos utilizado marcadores isotópicos para determinar el origen geográfico de machos y hembras de Pintails septentrional, Anas acuta y Anas crecca euroasiática en Extremadura, en el interior de la península Ibérica, sitio clave para invernar los patos de humedal. Además, hemos instalado seis etiquetas GPSGSM en Pintails septentrional para complementar los datos derivados del análisis de isótopos estables. La mayoría (> 70%) de los Pintails septentrional, dentro del primer año calendario, fueron asignados a regiones situadas por encima de los 55° N, volando 2600-5600 km desde sus regiones de procedencia a Extremadura. Los valores promedio de δ2Hf variaron significativamente entre macho y hembra de Pintails septentrional, sugiriendo que los sexos tienen diferentes orígenes geográficos. Los datos de los adultos etiquetados Pintails septentrional apoyan los datos isotópicos, un macho volando más de 5000 km de la costa de la mar Pechora (Rusia). La mayoría (> 70%) de los Teal euroasiáticos, dentro del primer año calendario, fueron asignados a la región situada entre 48° y 60° N y viajaron 1500-4500 km para llegar en Extremadura. Los machos y hembras de Cerceta euroasiáticos mostraron diferencias marginales en valores promedio de δ2Hf. En patos de humedal migratorios, el emparejamiento se produce normalmente en las zonas de invernada, y los patos en su primer invierno pueden reproducirse en la primavera siguiente. Para Pintails septentrional, la formación de parejas en Extremadura podría suceder entre individuos con diferentes orígenes geográficos, lo que podría contribuir a la variabilidad genética de su descendencia.Natural and anthropogenic Iberian wetlands in southern Europe are well known for supporting large numbers of migratory Palaearctic waterbirds each winter. However, information on the geographical origin of dabbling ducks overwintering in these wetlands is scarce and mostly limited to data from ringing recoveries. Here, we used intrinsic isotopic markers to determine the geographical origin of male and female Northern Pintails Anas acuta and Eurasian Teal Anas crecca in Extremadura, inland Iberia, a key site for overwintering dabbling ducks. Additionally, we fitted six Northern Pintails with GPSGSM tags to complement the data derived from stable isotope analysis. Most (> 70%) first calendar-year Northern Pintails were assigned to regions above 55°N, flying 2600–5600 km from their main natal regions to Extremadura. Mean values of δ2Hf varied significantly between male and female Northern Pintails, suggesting that the sexes had different geographical origins. Data from tagged adult Northern Pintails supported the isotopic data, one male flying more than 5000 km to the coast of the Pechora Sea (Russia). Most (> 70%) first calendar-year Eurasian Teal were assigned to the region between 48° and 60°N, travelling 1500–4500 km to arrive in Extremadura. Male and female Eurasian Teal showed marginal differences in mean values of δ2Hf. In migratory dabbling ducks, pairing typically occurs on the wintering grounds, and ducks in their first winter can breed the following spring. For Northern Pintails, pair formation in Extremadura could occur between individuals with different geographical origins, which could contribute to the genetic variability of their offspring.Trabajo patrocinado por: Junta de Extremadura. Proyecto PRI 09C128 Gobierno de Extremadura y Fondos FEDER. Ayuda GR10174 Confederación Hidrográfica del Guadiana (Ministerio de Medio Ambiente). Ayuda financierapeerReviewe

    Migration distance does not predict blood parasitism in a migratory songbird

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    Migration can influence host–parasite dynamics in animals by increasing exposure to parasites, by reducing the energy available for immune defense, or by culling of infected individuals. These mechanisms have been demonstrated in several comparative analyses; however, few studies have investigated whether conspecific variation in migration distance may also be related to infection risk. Here, we ask whether autumn migration distance, inferred from stable hydrogen isotope analysis of summer‐grown feathers (δ 2Hf) in Europe, correlates with blood parasite prevalence and intensity of infection for willow warblers (Phylloscopus trochilus ) wintering in Zambia. We also investigated whether infection was correlated with individual condition (assessed via corticosterone, scaled mass index, and feather quality). We found that 43% of birds were infected with Haemoproteus palloris (lineage WW1). Using generalized linear models, we found no relationship between migration distance and either Haemoproteus infection prevalence or intensity. There was spatial variation in breeding ground origins of infected versus noninfected birds, with infected birds originating from more northern sites than noninfected birds, but this difference translated into only slightly longer estimated migration distances (~214 km) for infected birds. We found no relationship between body condition indices and Haemoproteus infection prevalence or intensity. Our results do not support any of the proposed mechanisms for migration effects on host–parasite dynamics and cautiously suggest that other factors may be more important for determining individual susceptibility to disease in migratory bird species

    Conservation planning in an uncertain climate: Identifying projects that remain valuable and feasible across future scenarios

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    Conservation actors face the challenge of allocating limited resources despite uncertainty about future climate conditions. In many cases, the potential value and feasibility of proposed projects vary across climate scenarios. A key goal is to identify areas where conservation outcomes can balance both environmental and human needs. We developed a conservation prioritization framework that jointly considers the value and feasibility of candidate projects across future climate scenarios. We then applied this framework to the challenge of meeting environmental flow targets across the Red River basin of the south‐central United States. To estimate the conservation feasibility of meeting environmental flow goals in a river reach in each climate scenario, we used a basin‐wide hydrologic planning tool to quantify the reduction in societal water usage needed to meet environmental flow targets. To estimate the biodiversity value of each river reach in each climate scenario, we used climate‐driven species distribution models and species’ conservation status. We found that river reaches in the east‐central portion of the basin may be good candidates for conservation investments, because they had high biodiversity value and high sociopolitical feasibility in all future climate scenarios. In contrast, sites in the arid western reaches of the basin had high biodiversity value, but low feasibility of achieving environmental flow goals. Our framework should have broad applicability given that the value and feasibility of conservation projects vary across climate scenarios in ecosystems around the world. It may serve as a coarse filter to identify sites for more detailed analyses and could be integrated with complementarity‐based approaches to conservation planning to balance species’ representation across projects.This research was supported by S.M.W.'s Science to Action Fellowship through the National Climate Adaptation Science Center at the US Geological Survey. U.S. Geological Survey. Grant Number: G17AP00120 Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

    [Letter] Present and future biodiversity risks from fossil fuel exploitation

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    Currently, human society is predominantly powered by fossil fuels—coal, oil and natural gas—yet also ultimately depends on goods and services provided by biodiversity. Fossil fuel extraction impacts biodiversity indirectly through climate change and by increasing accessibility, and directly through habitat loss and pollution. In contrast to the indirect effects, quantification of the direct impacts has been relatively neglected. To address this, we analyse the potential threat to > 37,000 species and > 200,000 protected areas globally from the locations of present and future fossil fuel extraction in marine and terrestrial environments. Sites that are currently exploited have higher species richness and endemism than unexploited sites, whereas known future hydrocarbon activities will predominantly move into less biodiverse locations. We identify 181 ‘high‐risk’ locations where oil or gas extraction suitability coincides with biodiversity importance, making conflicts between extraction and conservation probable. In total, protected areas are located on US$3‐15 trillion of unexploited hydrocarbon reserves, posing challenges and potentially opportunities for protected area management and sustainable financing

    Protecting Endangered Species: Do the Main Legislative Tools Work?

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    It is critical to assess the effectiveness of the tools used to protect endangered species. The main tools enabled under the U.S. Endangered Species Act (ESA) to promote species recovery are funding, recovery plan development and critical habitat designation. Earlier studies sometimes found that statistically significant effects of these tools could be detected, but they have not answered the question of whether the effects were large enough to be biologically meaningful. Here, we ask: how much does the recovery status of ESA-listed species improve with the application of these tools? We used species' staus reports to Congress from 1988 to 2006 to quantify two measures of recovery for 1179 species. We related these to the amount of federal funding, years with a recovery plan, years with critical habitat designation, the amount of peer-reviewed scientific information, and time listed. We found that change in recovery status of listed species was, at best, only very weakly related to any of these tools. Recovery was positively related to the number of years listed, years with a recovery plan, and funding, however, these tools combined explain <13% of the variation in recovery status among species. Earlier studies that reported significant effects of these tools did not focus on effect sizes; however, they are in fact similarly small. One must conclude either that these tools are not very effective in promoting species' recovery, or (as we suspect) that species recovery data are so poor that it is impossible to tell whether the tools are effective or not. It is critically important to assess the effectiveness of tools used to promote species recovery; it is therefore also critically important to obtain population status data that are adequate to that task

    Local factors mediate the response of biodiversity to land use on two African mountains

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    Land-use change is the single biggest driver of biodiversity loss in the tropics. Biodiversity models can be useful tools to inform policymakers and conservationists of the likely response of species to anthropogenic pressures, including land-use change. However, such models generalize biodiversity responses across wide areas and many taxa, potentially missing important characteristics of particular sites or clades. Comparisons of biodiversity models with independently collected field data can help us understand the local factors that mediate broad-scale responses. We collected independent bird occurrence and abundance data along two elevational transects in Mount Kilimanjaro, Tanzania and the Taita Hills, Kenya. We estimated the local response to land use and compared our estimates with modelled local responses based on a large database of many different taxa across Africa. To identify the local factors mediating responses to land use, we compared environmental and species assemblage information between sites in the independent and African-wide datasets. Bird species richness and abundance responses to land use in the independent data followed similar trends as suggested by the African-wide biodiversity model, however the land-use classification was too coarse to capture fully the variability introduced by local agricultural management practices. A comparison of assemblage characteristics showed that the sites on Kilimanjaro and the Taita Hills had higher proportions of forest specialists in croplands compared to the Africa-wide average. Local human population density, forest cover and vegetation greenness also differed significantly between the independent and Africa-wide datasets. Biodiversity models including those variables performed better, particularly in croplands, but still could not accurately predict the magnitude of local species responses to most land uses, probably because local features of the land management are still missed. Overall, our study demonstrates that local factors mediate biodiversity responses to land use and cautions against applying biodiversity models to local contexts without prior knowledge of which factors are locally relevant
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