708 research outputs found

    Not only the butterflies: managing ants on road verges to benefit Phengaris (Maculinea) butterflies

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    Obligate myrmecophilic butterfly species, such as Phengaris (Maculinea) teleius and P. nausithous, have narrow habitat requirements. Living as a caterpillar in the nests of the ant species Myrmica scabrinodis and M. rubra, respectively, they can only survive on sites with both host ants and the host plant Great Burnet Sanguisorba officinalis. After having been reintroduced into a nature reserve in the Netherlands in 1990, both butterfly species expanded their distribution to linear landscape elements such as road verges and ditch edges outside this reserve. As additional habitat of both butterfly species, vegetation management of these landscape elements became important. Our results show that a management beneficial for Phengaris butterflies should aim to increase the nest density of Myrmica species, at the same time reducing the density of nests of the competitor Lasius niger or at least keeping them at a low density. Unfavourable grassland management under which L. niger thrives, includes not mowing or flail-cutting the grass, or depositing dredgings along the side of the ditch. Management favourable for the two Myrmica species differs, demanding some flexibility if both species are to benefit. M. scabrinodis is best supported with early mowing of the road verge vegetation or late mowing in the nature reserve, both of which result in an open vegetation and warm microclimate. In contrast, the nest sites of M. rubra should be left undisturbed during the summer, and mown in late autumn. Mowing of butterfly habitat should be avoided between mid-June and mid-September as this would remove the flowerheads of the Sanguisorba plants, on which the butterflies lay their eggs

    Fluidized beds as turbulence promoters in the concentration of food liquids by reverse osmosis

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    Fluidized beds offer a potential improvement of reverse osmosis processes for food liquids, less fouling of the membrane, and reduced energy consumption. Our experiments were concerned with tubular systems in which fluidized beds of glass, steel, and lead beads were used. Glass beads appeared to be preferable, since they caused little damage to the membrane. Only with the larger glass beads (3 mm) did the membrane skin become corrugated, so that the rejection decreased. The permeate flux for Gouda cheese whey was almost equal to that of an empty tube for which the velocity was about thirty times higher. The erosive action of the glass beads on the fouling layer was partially responsible for this effect. For reverse osmosis of skim milk and potato fruit water the bed did not reduce the fouling layer to a sufficient extent and, therefore, had a lower permeate flux than an empty tube

    Tracking butterflies for effective conservation

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    Dit proefschrift bestaat uit drie delen: het volgen van veranderingen in de verspreiding van vlinders, het volgen van veranderingen in de populatiegrootte van vlinders en hoe deze kennis te gebruiken voor hun bescherming

    High Nature Value Farmland in Europe - An Estimate of the Distribution Patterns on the Basis of Land Cover and Biodiversity Data

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    Europe's agricultural landscapes provide highly varied living conditions for many plants and animals. Baldock et al. (1993) and Beaufoy et al. (1994) described the general characteristics of low-input farming systems in terms of biodiversity and management practices and introduced the term high nature value farmland. Typical high nature value farmland areas are the extensively grazed uplands in the UK, alpine meadows and pasture, steppic areas in eastern and southern Europe and dehesas and montados in Spain and Portugal. The more intensively farmed areas in lowland western Europe can also host concentrations of species of particular conservation interest, such as migratory waterfowl. The need for measures to prevent the loss of high nature value farmland is widely acknowledged. Conservation of biodiversity on agricultural land is an explicit objective of the pan-European Biodiversity and Landscape Strategy, the Bern Convention, the European Landscape Convention, and, at EU level, the Habitats and Birds Directives and the Rural Development Policy (Community Strategic Guidelines for Rural Development Programming Period 2007-2013). In their 6th Environment Action Programme, the EU committed itself to halting biodiversity decline by 2010. Conserving High Nature Value farmland is key to achieving this 2010 biodiversity target. Pan-European data on distribution and conservation status of HNV farmland, however, were largely lacking. In their 2003 "Kyiv" declaration, the European Environment Ministers have therefore set the goal to fill this data gap and take adequate conservation measures. In support of this policy process, EEA and UNEP published a Joint Message (EEA 2004), presenting a preliminary map of HNV farmland and analysing the targeting of agricultural policy instruments. The Joint Message used the concept as developed by Andersen et al. (2003) that describes HNV farmland as: "Those areas in Europe where agriculture is a major (usually the dominant) land use and where that agriculture supports, or is associated with, either a high species and habitat diversity or the presence of species of European conservation concern, or both". The aim of estimating HNV farmland distribution at European level according to a standardised method is primarily to gain insight in the current status, as well as enabling analysis of European trends and targeting of relevant policy instruments, such as Less Favoured Area (LFA) support. In order to increase accuracy, JRC and the EEA have been preparing the first EU27 map of High Nature Value farmland, on the basis of new land cover data, refined and regionally differentiated selection criteria, and additional biodiversity datasets.JRC.H.5-Rural, water and ecosystem resource

    Limited variability in biological durability of thermally modified timber using vacuum based technology

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    The SmartHeat® thermal timber treatment is a new technology based on the process parameters being steered very precisely mainly due to the vacuum applied and heating system involved. Timber treated with this technology shows a potential for less variability of biological durability in one batch. Several batch treatments were sampled and assessed on statistical variability of decay resistance against Basidiomycetes and soft rotting micro-fungi according to lab testing as described in the standards CEN/TS 15083 part 1 and 2 respectively (only Basidiomycetes test results are reported in this paper). By means of Weibull distribution assessment it was possible to show that variability in biological durability of each treated beam is well controlled and that this variability is limited compared to natural durability of wood species. Lower treatment variability due to precise parameter control for each beam and limited deviations of process parameters within the treating vessel are considered the main contributing factors. The paper also states that lower control of process parameters of some heat treatment processes might induce higher variability of the obtained biological durability than a customer might expect

    There is a trade‑off between forest productivity and animal biodiversity in Europe

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    While forest productivity and biodiversity are expected to be correlated, prioritizing either forest productivity or biodiversity can result in different management. Spatial quantification of the congruence between areas suitable for either one can inform planning. Here we quantify the relationship between net primary productivity of European forests and biodiversity of mammals, birds, reptiles, amphibians, and butterflies both separately and in combination, and map their spatial congruence. We used richness maps obtained by stacking species distribution models for these animal species, and average net primary production from 2000 to 2012 using moderate resolution imaging spectroradiometer (MODIS) data. We tested how biodiversity and primary productivity are correlated and quantified the spatial congruence of these two sources. We show the areas where high or low productivity co-occur with high or low biodiversity using a quantile-based overlay analysis. Productivity was positively correlated to overall biodiversity and mammal, herptile and butterfly biodiversity, but biodiversity of birds showed a weak negative correlation. There were no significant differences in the strength of relationship across species groups, while herptiles had stronger relationships with productivity compared to other groups. Overlap analysis revealed significant spatial overlap between productivity and biodiversity in all species groups, except for birds. High value areas for both productivity and biodiversity in all species groups, except birds, co-occurred in the Mediterranean and temperate regions. The areas with high biodiversity of birds are mainly found in the boreal areas of Europe, while for all other species groups these areas are mostly located on the Iberian Peninsula and the Balkan ranges. Based on the presented maps, areas where regulating wood production activities to conserve species can be identified. But the maps also help to identify areas where either biodiversity or productivity is high and focusing on just one aspect is more straightforward

    Natuurkwaliteit van het agrarisch gebied

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    Dit werkdocument geeft een beschrijving van de methode en de eerste resultaten van de natuurkwaliteit van het agrarisch gebied. Hiermee is een eerste kaart en graadmeter van de natuurkwaliteit van het agrarisch gebied op nationaal schaalniveau gereedgekomen. Het beeld vormt een aanvulling op de kaart van de actuele natuurkwaliteit van natuurreservaten, die al eerder beschikbaar is gekomen. De nu beschikbare indicator en kaart van de natuurkwaliteit van het agrarisch gebied voorziet in een belangrijke kennisleemte. Het belang van het agrarisch gebied in het behoud van biodiversiteit kan nu worden geduid. De ruimtelijke variatie in de natuurkwaliteit is ook inzichtelijk gemaakt. Het beleid kan bij het leggen van prioriteiten voor het behoud en bescherming van agrarische biodiversiteit nu rekening houden met het voorkomen van huidige natuurwaarden. Een van de belangrijkste conclusies is dat de natuurkwaliteit van het agrarisch gebied veel lager is dan in de natuurgebieden. Laagveengebieden hebben binnen het agrarische gebied de hoogste natuurkwaliteit, terwijl de centrale en noordelijke zeekleigebieden de laagste natuurkwaliteit bevatten. De aanwezige natuurkwaliteit in het agrarisch gebied, wordt voornamelijk bepaald door de aanwezigheid van broedvogels en veel minder door vaatplanten en dagvlinders. Het ruimtelijke patroon van aanwezige kwaliteit komt overeen binnen de verschillende soortgroepen broedvogels, vaatplanten en dagvlinders. De resterende natuurkwaliteit in het agrarisch gebied bevindt zich vooral in natuurlijke elementen zoals heggen, bosjes, sloten, dijken en perceelranden. Voor weidevogels is juist de mate van openheid van belang. Beschikbare landelijk dekkende verspreidingskaarten van doelsoorten dagvlinders, broedvogels en vaatplanten zijn gebruikt om de natuurkwaliteit te bepalen. Om dekkende landelijke verspreidingskaarten te maken zijn interpolatiemodellen gebruikt. De natuurkwaliteit is afgemeten aan een natuurlijke referentie, conform de systematiek van het Handboek Natuudoeltypen en daarmee ook coform de methode gebruikt voor de bepaling van de natuurkwaliteit van natuurreservaten. Elke 10-15 jaar zijn de verspreidingskaarten van dagvlinders, broedvogels en vaatplanten voldoende gedekt om een update van het landelijke beeld en de graadmeter mogelijk te maken. Tussentijdse veranderingen in de natuurkwaliteit kunnen worden gevolgd met het Netwerk Eologische Monitoring. De methode en resultaten hebben een voorlopig karakter. Er zijn nog een aantal methodische verbeteringen noodzakelijk om tot een definitief resultaat te komen. Tevens is het wenselijk om de natuurkwaliteit ook af te meten aan de hand van een meer cultuurlijke referentie

    Probing bacterial-fungal interactions at the single cell level.

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    Interactions between fungi and prokaryotes are abundant in many ecological systems. A wide variety of biomolecules regulate such interactions and many of them have found medicinal or biotechnological applications. However, studying a fungal-bacterial system at a cellular level is technically challenging. New microfluidic devices provided a platform for microscopic studies and for long-term, time-lapse experiments. Application of these novel tools revealed insights into the dynamic interactions between the basidiomycete Coprinopsis cinerea and the bacterium Bacillus subtilis. Direct contact was mediated by polar attachment of bacteria to only a subset of fungal hyphae suggesting a differential competence of fungal hyphae and thus differentiation of hyphae within a mycelium. The fungicidal activity of B. subtilis was monitored at a cellular level and showed a novel mode of action on fungal hyphae
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