37 research outputs found

    Impacts of logging, hunting, and conservation on vocalizing biodiversity in Gabon

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    Tropical forests support two-thirds of the world's biodiversity, contribute to global climate regulation, and support the culture and livelihoods of forest-dependent people. Much of extant tropical forest is subject to selective logging and hunting - extractive activities that potentially alter ecosystem function and species diversity. However, the collective impact of these threats, especially in the context of protected vs unprotected areas, is not fully understood. Here we assess how vocalizing biodiversity responds to logging and hunting, across the diel cycle, seasonally, and between protected and unprotected landscapes in Gabon. We compared soundscape saturation across 109 sites in national parks, Forest Stewardship Council (FSC) certified, and non-certified logging concessions. We estimated hunting pressure by quantifying gunshots and relative accessibility per site. Overall, we found that the soundscapes of FSC-certified concessions resembled national parks (selectively logged 20+ years ago) more so than non-certified concessions. We also found that never logged sites, part of a proposed community conserved area, had different soundscapes than all other categories, including national parks. Unlogged sites had higher saturation than logging concessions at dusk and dawn. Soundscapes and hunting pressure were highly variable across different concessions. We found that higher gunshot rates and recent logging were associated with lower soundscape saturation overall. Based on our findings, we recommend that (i) the very few never logged forests that remain (and are not yet protected) should be urgently withdrawn from selective logging, and (ii) FSC or other certification schemes should be promoted in Gabon, with an emphasis on sustainable hunting

    Co-limitation towards lower latitudes shapes global forest diversity gradients

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    The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

    Co-limitation towards lower latitudes shapes global forest diversity gradients

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    The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

    Co-limitation towards lower latitudes shapes global forest diversity gradients

    Get PDF
    The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

    Designing analytical approaches for interactive competitive intelligence

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    Der Begriff der Resilienz erfĂ€hrt aktuell eine starke Resonanz in der Wirtschaftsgeographie. Das Platzen der Dotcom-Blase und die Finanz- und Wirtschaftskrise Ende der 2000er Jahre werfen Fragen dazu auf, wie ökonomische Krisen entstehen und wie sie vermieden oder gemeistert werden können. Auch Herausforderungen des Klimawandels, der Ressourcenverknappung oder des demographischen Wandels wirken sich auf ökonomische Systeme aus. Staaten und Regionen sind von Krisen nicht nur in unterschiedlichem Maße betroffen, auch ihre Reaktionen darauf unterscheiden sich erheblich. Einige gehen gestĂ€rkt aus Krisen hervor, andere werden in ihrer Entwicklung zurĂŒckgeworfen, und wieder andere scheinen kaum betroffen zu sein. Ist dieser Umstand begrĂŒndet in einer unterschiedlich starken Resilienz? Und wenn j a, welche Prozesse bedingen oder beeinflussen eine mehr oder weniger starke Resilienz von rĂ€umlichen Einheiten

    Mapping between the Dublin Core Abstract Model DCAM and the TMDM

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    Sheet hyaloclastite: density-current deposits of quench and bubble-burst fragments from thin, glassy sheet lava flows, Seamount Six, Eastern Pacific Ocean

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    New observations with the submersible ALVIN and deep-tow camera show that bedded sheet-hyaloclastites are common deposits between 2024 and 1723 m depth on the upper flank of Seamount Six, located on the Cocos plate at 12°45â€ČN, 102°35â€ČW. The individual sheets are highly localized and of small areal extent (<200 m2), though no vent sites were found. Several facies associations of hyaloclastite, with pillow talus, knobbly fist-sized lava fragments and thin sheet lava (<10 cm) underlying hyaloclastite, are identified. Recovered samples consist of angular, polyhedral sand-sized sideromelane shards and thin, bent, plate-like sideromelane fragments called Limu O'Pelee. Limu are solidified fragments of burst magma bubbles, which formed by vapourization of water entrapped by lava. Analysis of lava and hyaloclastite shards including limu shows three geochemically distinct populations, depleted MORB (N1), more evolved NMORB (N2) and hawaiite (H) of diverse composition. In individual hyaloclastite samples, shards of two or three different types may occur in various proportions, though in samples of hyaloclastite associated with sheet lava the predominant shards are of the same geochemical type as the sheet lava. Deposition of hyaloclastites occurred from lateral density currents formed by transformation from convective suspension settling. Grain size distribution, settling behaviour of different co-deposited shard types and sedimentary structures, together with pelagic ooze in the matrix and geochemically mixed shard populations, indicate some erosion, traction reworking and turbulence during transport. Critical observations are that contorted sheet lava protrudes through hyaloclastite and that sheet lava flow vugs commonly contain pelagic ooze. Facies associations plus consideration of limu formation allow the establishment of a new, multi-component model of hyaloclastite formation. It is inferred that the formation of limu-bearing sheet hyaloclastite involves entrapment of pelagic sediment beneath or within lava. This leads to limu bubble formation and suppressed tephra jetting. Together with convectively rising water heated by the lava flow, these processes loft shards slightly into the water column, from which they settle singly or in vertical sediment gravity flows that are redirected to flow along the seafloor

    A semantic web faceted search system for facilitating building of biodiversity and ecosystems services

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    To address biodiversity issues in ecology and to assess the consequences of ecosystem changes, large quantities of long-term observational data from multiple datasets need to be integrated and characterized in a unified way. Linked open data initiatives in ecology aim at promoting and sharing such observational data at the web-scale. Here we present a web infrastructure, named Thesauform, that fully exploits the key principles of the semantic web and associated key data standards in order to guide the scientific community of experts to collectively construct, manage, visualize and query a SKOS thesaurus. The study of a thesaurus dedicated to plant functional traits demonstrates the potential of this approach. A point of great interest is to provide each expert with the opportunity to generate new knowledge and to draw novel plausible conclusions from linked data sources. Consequently, it is required to consider both the scientific topic and the objects of interest for a community of expertise. The goal is to enable users to deal with a small number of familiar and conceptual dimensions, or in other terms, facets. In this regard, a faceted search system, based on SKOS collections and enabling thesaurus browsing according to each end-users requirements is expected to greatly enhance data discovery in the context of biodiversity studies

    A semantic web faceted search system for facilitating building of biodiversity and ecosystems services

    No full text
    To address biodiversity issues in ecology and to assess the consequences of ecosystem changes, large quantities of long-term observational data from multiple datasets need to be integrated and characterized in a unified way. Linked open data initiatives in ecology aim at promoting and sharing such observational data at the web-scale. Here we present a web infrastructure, named Thesauform, that fully exploits the key principles of the semantic web and associated key data standards in order to guide the scientific community of experts to collectively construct, manage, visualize and query a SKOS thesaurus. The study of a thesaurus dedicated to plant functional traits demonstrates the potential of this approach. A point of great interest is to provide each expert with the opportunity to generate new knowledge and to draw novel plausible conclusions from linked data sources. Consequently, it is required to consider both the scientific topic and the objects of interest for a community of expertise. The goal is to enable users to deal with a small number of familiar and conceptual dimensions, or in other terms, facets. In this regard, a faceted search system, based on SKOS collections and enabling thesaurus browsing according to each end-users requirements is expected to greatly enhance data discovery in the context of biodiversity studies
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