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  • 1
    Publication Date: 2011-08-29
    Description:    The emerging interest in the biological and conservation significance of locally rare species prompts a number of questions about their correspondence with other categories of biodiversity, especially global rarity. Here we present an analysis of the correspondence between the distributions of globally and locally rare plants. Using biological hotspots of rarity as our framework, we evaluate the extent to which conservation of globally rare plants will act as a surrogate for conservation of locally rare taxa. Subsequently, we aim to identify gaps between rarity hotspots and protected land to guide conservation planning. We compiled distribution data for globally and locally rare plants from botanically diverse Napa County, California into a geographic information system. We then generated richness maps highlighting hotspots of global and local rarity. Following this, we overlaid the distribution of these hotspots with the distribution of protected lands to identify conservation gaps. Based on occupancy of 1 km 2 grid cells, we found that over half of Napa County is occupied by at least one globally or locally rare plant. Hotspots of global and local rarity occurred in a substantially smaller portion of the county. Of these hotspots, less than 5% were classified as multi-scale hotspots, i.e. they were hotspots of global and local rarity. Although, several hotspots corresponded with the 483 km 2 of protected lands in Napa County, some of the richest areas did not. Thus, our results show that there are important conservation gaps in Napa County. Furthermore, if only hotspots of global rarity are preserved, only a subset of locally rare plants will be protected. Therefore, conservation of global, local, and multi-scale hotspots needs serious consideration if the goals are to protect a larger variety of biological attributes, prevent extinction, and limit extirpation in Napa County. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10531-011-0137-6 Authors Benjamin J. Crain, Department of Biological Sciences, Humboldt State University, 1 Harpst Street, Arcata, CA 95521, USA Jeffrey W. White, Department of Biological Sciences, Humboldt State University, 1 Harpst Street, Arcata, CA 95521, USA Steven J. Steinberg, Department of Environmental Science and Management, Humboldt State University, 1 Harpst Street, Arcata, CA 95521, USA Journal Biodiversity and Conservation Online ISSN 1572-9710 Print ISSN 0960-3115
    Print ISSN: 0960-3115
    Electronic ISSN: 1572-9710
    Topics: Biology
    Published by Springer
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  • 2
    Publication Date: 2011-03-30
    Description:    Nitrous oxide (N 2 O) emissions from grazed grasslands are estimated to be approximately 28% of global anthropogenic N 2 O emissions. Estimating the N 2 O flux from grassland soils is difficult because of its episodic nature. This study aimed to quantify the N 2 O emissions, the annual N 2 O flux and the emission factor (EF), and also to investigate the influence of environmental and soil variables controlling N 2 O emissions from grazed grassland. Nitrous oxide emissions were measured using static chambers at eight different grasslands in the South of Ireland from September 2007 to August 2009. The instantaneous N 2 O flux values ranged from -186 to 885.6 μg N 2 O-N m −2  h −1 and the annual sum ranged from 2 ± 3.51 to 12.55 ± 2.83 kg N 2 O-N ha −1  y −1 for managed sites. The emission factor ranged from 1.3 to 3.4%. The overall EF of 1.81% is about 69% higher than the Intergovernmental Panel on Climate Change (IPCC) default EF value of 1.25% which is currently used by the Irish Environmental Protection Agency (EPA) to estimate N 2 O emission in Ireland. At an N applied of approximately 300 kg ha −1  y −1 , the N 2 O emissions are approximately 5.0 kg N 2 O-N ha −1 y −1 , whereas the N 2 O emissions double to approximately 10 kg N ha −1 for an N applied of 400 kg N ha −1  y −1 . The sites with higher fluxes were associated with intensive N-input and frequent cattle grazing. The N 2 O flux at 17°C was five times greater than that at 5°C. Similarly, the N 2 O emissions increased with increasing water filled pore space (WFPS) with maximum N 2 O emissions occurring at 60–80% WFPS. We conclude that N application below 300 kg ha −1  y −1 and restricted grazing on seasonally wet soils will reduce N 2 O emissions. Content Type Journal Article Pages 1-20 DOI 10.1007/s10021-011-9434-x Authors Rashad Rafique, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Deirdre Hennessy, Department of Animals &, Grassland Science Research, Teagasc-Moorpark, Fermoy, Ireland Gerard Kiely, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840
    Print ISSN: 1432-9840
    Electronic ISSN: 1435-0629
    Topics: Biology
    Published by Springer
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  • 3
    Publication Date: 2012-02-02
    Description:    Land use change and human population growth are accelerating the fragmentation and insularization of wildlife habitats worldwide. The conservation and management of wildlife in the resultant ‘island’ ecosystems in the context of global warming is challenging due to the isolation and reduced size of the ecosystems and hence the scale over which ecosystem processes can operate. We analyzed trends in numbers of nine large herbivores in Kenya’s Lake Nakuru National Park to understand how rainfall and temperature variability, surrounding land use changes, and boundary fencing affected wildlife population dynamics inside the park during 1970–2011. Buffalo, zebra and Thomson’s gazelle numbers increased persistently. Grant’s gazelle and impala increased initially then gradually declined. Waterbuck and warthog numbers progressively declined to levels that potentially threatened their local population persistence. The total biomass of ungulates tripled from 1970 to 2011, with buffalo replacing waterbuck as the predominant species in biomass. Increased competition from buffalo and zebra, heightened predation and illicit human harvests probably all contributed to the declines by waterbuck and warthog. Density-dependent limitation of population growth within the park confines was evident for buffalo, impala, eland, giraffe, Grant’s and Thomson’s gazelles. Fluctuations in the lake level related to varying rainfall affected changes in animal abundance through expansion of the lake area and flooding of grasslands bordering the lake. Unusually, the most stressful conditions were associated with high water levels following high rainfall. There was also evidence of carry-over effects from prior habitat conditions affecting all species. The relatively stable populations of all species except warthog and waterbuck demonstrate the remarkable capacity of this small, insularized park to retain viable populations of most of the large herbivores, without much management intervention. Content Type Journal Article Category Original Paper Pages 1-21 DOI 10.1007/s10531-012-0239-9 Authors Joseph O. Ogutu, International Livestock Research Institute, P.O. Box 30709, Nairobi, 00100 Kenya Norman Owen-Smith, Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Wits, 2050 South Africa Hans-Peter Piepho, Bioinformatics Unit, Institute for Crop Science, University of Hohenheim, Fruwirthstrasse 23, 70599 Stuttgart, Germany Bernard Kuloba, Kenya Wildlife Service, Lake Nakuru National Park, P.O. Box 539, Nakuru, Kenya Joseph Edebe, Kenya Wildlife Service, Lake Nakuru National Park, P.O. Box 539, Nakuru, Kenya Journal Biodiversity and Conservation Online ISSN 1572-9710 Print ISSN 0960-3115
    Print ISSN: 0960-3115
    Electronic ISSN: 1572-9710
    Topics: Biology
    Published by Springer
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  • 4
    Publication Date: 2011-02-04
    Description:    Agricultural drainage is thought to alter greenhouse gas emissions from temperate peatlands, with CH 4 emissions reduced in favor of greater CO 2 losses. Attention has largely focussed on C trace gases, and less is known about the impacts of agricultural conversion on N 2 O or global warming potential. We report greenhouse gas fluxes (CH 4 , CO 2 , N 2 O) from a drained peatland in the Sacramento-San Joaquin River Delta, California, USA currently managed as a rangeland (that is, pasture). This ecosystem was a net source of CH 4 (25.8 ± 1.4 mg CH 4 -C m −2  d −1 ) and N 2 O (6.4 ± 0.4 mg N 2 O-N m −2  d −1 ). Methane fluxes were comparable to those of other managed temperate peatlands, whereas N 2 O fluxes were very high; equivalent to fluxes from heavily fertilized agroecosystems and tropical forests. Ecosystem scale CH 4 fluxes were driven by “hotspots” (drainage ditches) that accounted for less than 5% of the land area but more than 84% of emissions. Methane fluxes were unresponsive to seasonal fluctuations in climate and showed minimal temporal variability. Nitrous oxide fluxes were more homogeneously distributed throughout the landscape and responded to fluctuations in environmental variables, especially soil moisture. Elevated CH 4 and N 2 O fluxes contributed to a high overall ecosystem global warming potential (531 g CO 2 -C equivalents m −2  y −1 ), with non-CO 2 trace gas fluxes offsetting the atmospheric “cooling” effects of photoassimilation. These data suggest that managed Delta peatlands are potentially large regional sources of greenhouse gases, with spatial heterogeneity in soil moisture modulating the relative importance of each gas for ecosystem global warming potential. Content Type Journal Article Pages 1-15 DOI 10.1007/s10021-011-9411-4 Authors Yit Arn Teh, Environmental Change Research Group, School of Geography & Geosciences, University of St Andrews, St Andrews, KY16 9 AL Scotland, UK Whendee L. Silver, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Oliver Sonnentag, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Matteo Detto, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Maggi Kelly, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Dennis D. Baldocchi, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840
    Print ISSN: 1432-9840
    Electronic ISSN: 1435-0629
    Topics: Biology
    Published by Springer
    Location Call Number Limitation Availability
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