243 research outputs found

    Grazing as a conservation management tool:Responses of voles to grazer species and densities

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    Grazing is a widely applied conservation management tool, but the optimal regime for biodiversity conservation is still unknown. The effects of grazers on small mammals are not yet fully understood and mostly restricted to studies which compare grazed with ungrazed areas. We determined the effect of different livestock grazers and densities and a rotation regime, on voles in a conservation area in The Netherlands. We used a 7-year grazing experiment with horse and cattle grazing at two densities namely 0.5 and 1 animal ha(-1) (equivalent to 0.4 and 0.8 LSU), including a rotation regime i.e. 1 year summer grazing with 1 cattle ha(-1) followed by 1 ungrazed year. We recorded vole activity signs as a measure for presence (i.e. presence of burrow entrances, droppings, runways and plant clippings) in circular 2 m(2) plots along transects. Low grazer densities, regardless of species, corresponded to higher vole presence. Vole presence tended to be greater with cattle grazing than with horse grazing, but the difference was not significant. The increase in vole presence was greater in the rotation regime than with low or high density cattle grazing. The different vole activity signs provided similar results to each other with the exception of burrow entrances, suggesting that this measure is less accurate in predicting vole presence. Hence, voles clearly responded to the different grazing regimes. Our results have high relevance for conservation, in particular in systems where small mammals contribute to important ecological processes (e.g. bioturbation, seed dispersal) and play a crucial role in the survival of (iconic) higher trophic level taxa such as raptors or mammalian predators. In such systems, conservation management may best implement low-density cattle or rotation grazing. (C) 2018 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved

    Physical properties analysis of uv-crosslinked sulfonated Poly Ether Ether Ketone and Methyl Cellulose / Nordiana Nabilla Ramly … [et al.]

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    Proton exchange membrane materials based on sulfonated Poly Ether Ether Ketone with Methyl Cellulose are developed in this study. The hybrid membrane is exposed to UV radiation with photoinitiator to improve the membrane dimensional stability up to 50%. The hybrid membranes characterized by FTIR shows the crosslinking occurs by formation of C-C bond from BEE instead of the consumption of SO3H group. This new crosslinked hybrid membrane shows good prospect for the use as proton exchange membrane in fuel cell

    Livestock as a potential biological control agent for an invasive wetland plant

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    Invasive species threaten biodiversity and incur costs exceeding billions of US$. Eradication efforts, however, are nearly always unsuccessful. Throughout much of North America, land managers have used expensive, and ultimately ineffective, techniques to combat invasive Phragmites australis in marshes. Here, we reveal that Phragmites may potentially be controlled by employing an affordable measure from its native European range: livestock grazing. Experimental field tests demonstrate that rotational goat grazing (where goats have no choice but to graze Phragmites) can reduce Phragmites cover from 100 to 20% and that cows and horses also readily consume this plant. These results, combined with the fact that Europeans have suppressed Phragmites through seasonal livestock grazing for 6,000 years, suggest Phragmites management can shift to include more economical and effective top-down control strategies. More generally, these findings support an emerging paradigm shift in conservation from high-cost eradication to economically sustainable control of dominant invasive species

    Effects of grazing management on biodiversity across trophic levels–The importance of livestock species and stocking density in salt marshes

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    European coastal salt marshes are important for the conservation of numerous species of specialist plants, invertebrates, breeding and migratory birds. When these marshes are managed for nature conservation purposes, livestock grazing is often used to counter the dominance of the tall grass Elytrigia atherica, and the subsequent decline in plant species richness. However, it remains unclear what is the optimal choice of livestock species and stocking density to benefit biodiversity of various trophic levels. To fill this knowledge gap, we set up a triplicate, full factorial grazing experiment with cattle and horse grazing at low and high stocking densities (0.5 or 1 animal ha−1) at the mainland coast of the Dutch Wadden Sea. Here, we present the results after 4 years and integrate these with previously published results from the same experiment to assess effects of livestock grazing on various trophic groups. Stocking density affected almost all measured variables: high stocking densities favoured plant species richness and suppression of E. atherica, whereas low stocking densities favoured abundances of voles, pollinators and flowers. Densities of different functional groups of birds showed no significant response to the regimes, but tended to be somewhat higher under 0.5 horse and 1 cattle ha−1. Choice of livestock species had fewer and smaller effects than stocking density. Horse grazing was detrimental to vole density, and showed an interactive effect with stocking density for Asteraceae flower abundance. Multidiversity, a synthetic whole-ecosystem biodiversity measure, did not differ among regimes. These results are discussed in the light of other results from the same experiment. Because of these contrasting effects on different trophic groups, we advise concurrent application of different grazing regimes within a spatial mosaic, with the inclusion of long-term abandonment. High density horse grazing, however, is detrimental to biodiversity

    Monitoringonderzoek proefverkweldering Noard-Fryslân Bûtendyks : Tussenrapportage 2004

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    Gegevens betreffende: vernatting en grondwatersamenstelling, verzilting (bodemvochtigheid en saliniteit), vegetatie-ontwikkeling, ganzen en broedvogels. Gezamenlijk onderzoek van: Altenburg & Wymenga, koeman en bijkerk, Rijksuniversiteit Groningen, en Alterra-Texe

    Global-change effects on early-stage decomposition processes in tidal wetlands – implications from a global survey using standardized litter

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    Tidal wetlands, such as tidal marshes and mangroves, are hotspots for carbon sequestration. The preservation of organic matter (OM) is a critical process by which tidal wetlands exert influence over the global carbon cycle and at the same time gain elevation to keep pace with sea-level rise (SLR). The present study assessed the effects of temperature and relative sea level on the decomposition rate and stabilization of OM in tidal wetlands worldwide, utilizing commercially available standardized litter. While effects on decomposition rate per se were minor, we show strong negative effects of temperature and relative sea level on stabilization, as based on the fraction of labile, rapidly hydrolyzable OM that becomes stabilized during deployment. Across study sites, OM stabilization was 29 % lower in low, more frequently flooded vs. high, less frequently flooded zones. Stabilization declined by ∼ 75 % over the studied temperature gradient from 10.9 to 28.5 ∘C. Additionally, data from the Plum Island long-term ecological research site in Massachusetts, USA, show a pronounced reduction in OM stabilization by > 70 % in response to simulated coastal eutrophication, confirming the potentially high sensitivity of OM stabilization to global change. We therefore provide evidence that rising temperature, accelerated SLR, and coastal eutrophication may decrease the future capacity of tidal wetlands to sequester carbon by affecting the initial transformations of recent OM inputs to soil OM
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