Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Winter hydrology and soil erosion processes in an agricultural catchment in Norway
    Starkloff, Torsten - \ 2017
    Wageningen University. Promotor(en): C.J. Ritsema, co-promotor(en): J. Stolte; R. Hessel. - Wageningen : Wageningen University - ISBN 9789463432207 - 154
    catchment hydrology - erosion - winter - snow - norway - hydrologie van stroomgebieden - erosie - winter - sneeuw - noorwegen

    In regions with a Nordic climate, soil erosion rates in winter and early spring can exceed those occurring during other seasons of the year. In this context, this study was initiated to improve our understanding of the interaction between agricultural soils and occurring winter conditions. The main objective was to better understand how hydrological processes in a catchment are influenced by snow, ice, and freeze-thaw cycles of soils, leading to runoff and soil erosion in winter and spring conditions.

    For this purpose, detailed spatially and temporally distributed measurements and observations in a small catchment in Norway were executed during three consecutive winter/spring periods. During the winter/spring periods of 2013-2014, 2014-2015 and 2015-2016, soil water content, soil temperature, and snow cover properties were measured. In addition, numerous soil samples were taken to determine the soil hydraulic characteristics of the investigated soils and to quantify the changes in their macropore networks due to freeze-thaw events, using X-ray imaging.

    With the collected data and deduced process understanding, it was possible to model and quantify the spatial and temporal development of snow packs. Furthermore, the field observations revealed how the interaction of tillage, state of the soils and snow cover at a certain time can lead to none or extensive surface runoff and soil erosion.

    Integrating acquired data, observations and process knowledge facilitated advances in simulating and quantifying surface runoff and soil erosion rates across the catchment under investigation. The models applied and the maps and output derived are crucial elements for presenting current state and problems in the catchment to stakeholders (such as farmers), providing a starting point for discussing ways to prevent and reduce further runoff and erosion. For model calibration and validation, including interpretation of modelling results, good knowledge of the area and availability of detailed data are essential, especially when processes such as freezing-thawing of soils and ice layer and snow-pack dynamics have to be considered also.

    In order to reduce runoff and soil erosion during winter and snowmelt conditions in the future, more targeted research is required in order to address the full range of existing knowledge gaps in this field, as identified in this particular study also.

    Conceptual basis and spatial modelling to account for and conserve multiple ecosystem services in Telemark County, Norway
    Schröter, M. - \ 2015
    Wageningen University. Promotor(en): Rik Leemans; Lars Hein, co-promotor(en): D.N. Barton. - Wageningen : Wageningen University - ISBN 9789462573123 - 197
    ecosysteemdiensten - ecologie - ruimtelijke modellen - modelleren - natuurbescherming - ecosystemen - noorwegen - ecosystem services - ecology - spatial models - modeling - nature conservation - ecosystems - norway

    Ecosystem services are defined as the contributions that ecosystems make to human well-being and they are increasingly being used as an approach to analyse the relationship between humans and ecosystems. While ecosystem services are mainstreamed, operationalization of the ecosystem service concept for different policy purposes has to be further advanced. Among others, interest increases in integrating ecosystems and the services they provide into accounting schemes and into conservation planning. In this thesis, I address three challenges to operationalize the ecosystem service concept for accounting and conservation. These are first shortly described and addressed later on in the different chapters of this thesis.

    The first challenge relates to controversies around the conceptual basis of the ecosystem service concept. Ecosystem services is a normative concept and such concepts lead to controversies. These need to be clarified and addressed because contesting a concept likely reduces its acceptance and applicability. The second challenge relates to capturing the heterogeneous spatial distribution across an area of both the potential of ecosystems to provide ecosystem services (i.e. capacity) and of the actual use of ecosystem services (i.e. flow). The operationalization of ecosystem services thus requires geographic analysis. This spatial information on ecosystem services can feed into different policy purposes. Applying the ecosystem service concept in conservation planning is an evolving new practice. The third challenge is to develop appropriate methods to incorporate spatial information on ecosystem services into conservation planning.

    This thesis aims to explore and further develop the conceptual basis of ecosystem services, and to create and apply spatial models of multiple ecosystem services for accounting, management and conservation. These interdisciplinary objectives are addressed by critically reflecting on ecosystem services, conceptual reasoning, further methodological development of spatial modelling, as well as applying the resulting spatial models in plausible conservation scenarios.

    In Chapter 2, I explore the conceptual basis of ecosystem services and describe and reflect on seven recurring critiques of the concept and respective counter-arguments. Critical arguments and counter-arguments are summarised from a literature review and they are contrasted. The seven chosen critiques are as follows. First, the concept is criticized for being too anthropocentric, whereas others argue that the concept goes beyond instrumental values and includes elements of intrinsic values that relate to ecosystem being valued for their own sake. Second, some argue that the concept promotes an exploitative human-nature relationship, whereas others state that it re-connects society to ecosystems and emphasizes humanity’s dependence on ecosystems. Third, concerns exist that the concept conflicts with biodiversity conservation objectives, whereas others emphasize complementarity between the concepts of biodiversity and ecosystem services and the practical application of both concepts in planning. Fourth, the concept is questioned because of its supposed focus on economic valuation, whereas others argue that ecosystem-services science includes various types of value systems. Fifth, the concept is criticized for promoting commodification of nature, whereas others point out that most ecosystem services are not (directly) connected to market-based instruments. Sixth, vagueness of definitions and classifications of ecosystem services are stated as a weakness, whereas others argue that vagueness enhances creativity and transdisciplinary collaboration. Seventh, some criticize the normative nature of the concept, implying that all outcomes of ecosystems and their processes are desirable. The normative nature is indeed typical for the concept, but should not be problematic when adequately acknowledged. Disentangling and contrasting different arguments contributes to a more structured debate between opponents and proponents of the ecosystem services concept and helps to further conceptualize the ecosystem service concept.

    In Chapter 3, I develop and test a framework to analyse ecosystem service capacity and flow in a spatially explicit way. This study was conducted in the overall context of ecosystem accounting. Ecosystem accounting aims to monitor extent, condition and properties of ecosystems that deliver ecosystem services over time. Guidelines and standards for ecosystem accounting are currently being developed under the auspices of the United Nations and this chapter is closely aligned to the recent System of Environmental-Economic Accounting Experimental Ecosystem Accounting (SEEA) guidelines.

    Understanding the capacity of ecosystems to generate these services and the resulting flow of ecosystem services is an essential element for understanding the sustainability of ecosystem use as well as developing ecosystem accounts. I conduct spatially explicit assessments of nine ecosystem services in Telemark county, Southern Norway. The modelled ecosystem services are moose hunting, sheep grazing, timber harvest, forest carbon sequestration and storage, snow slide prevention, recreational residential amenity, recreational hiking and existence of areas without technical interference. I conceptually distinguish capacity to provide ecosystem services from the actual flow of services and empirically assess both. This is done by means of different spatial models, developed with various available datasets and methods, including (multiple layer) look-up tables, causal relations between datasets (including satellite images), environmental regression and indicators derived from direct measurements. Capacity and flow differ both in spatial extent and in quantities. The distinction of capacity and flow of ecosystem services provides a parsimonious estimation of over- or underuse of the respective service. Assessment of capacity and flow in a spatially explicit way can thus support monitoring sustainability of ecosystem use, and this is an essential element of ecosystem accounting.

    In Chapters 4 and 5, I explore methods to operationalize the ecosystem service concept for conservation planning. These chapters are based on the models for regulating and cultural services that were developed in Chapter 3. The variation in spatial distribution between ecosystem services can be high. Hence, spatial identification of important sites for conservation planning is required. The term ‘ecosystem service hotspot’ has often been used for this purpose, but this term is defined ambiguously. An ecosystem service hotspot can refer to either areas containing high values of one service or areas with multiple services. In Chapter 4, I review and classify methods to spatially delineate hotspots. I test how spatial configuration of hotspots for a set of ecosystem services differs depending on the applied method. The outcomes are compared to a heuristic site prioritisation approach (Marxan). The four tested hotspot methods are the threshold value approach, Gi* statistic, intensity, and richness. In a conservation scenario, I set a target of conserving 10% of the quantity of five regulating and cultural services for the forest area of Telemark. Spatial configuration of selected areas as retrieved by the four hotspots and Marxan differed considerably. Pairwise comparisons were at the lower end of the scale of the Kappa statistic (-0.003 – 0.24). The outcomes also differed considerably in mean target achievement ranging from 7.7% (richness approach) to 24.9% (threshold value approach), cost-effectiveness in terms of land-area needed per unit target achievement and compactness in terms of edge-to-area ratio. Differences in spatial configuration among different hotspot methods probably lead to uncertainties for decision-making. These differences also have consequences for analysing the spatial co-occurrence of hotspots of multiple services and of services and biodiversity. While determining hotspots according to one approach might lead to high degrees of spatial overlap with another ecosystem service or biodiversity, other delineation methods might lead to considerably lower degrees of overlap.

    In Chapter 5, I analyse how the incorporation of ecosystem services as conservation features affect conservation of forest biodiversity and how different opportunity cost constraints change spatial priorities for conservation. In this study, spatially explicit cost-effective conservation scenarios for 59 forest biodiversity features and five ecosystem services in Telemark County were created with the help of the heuristic optimisation planning software Marxan with Zones. A mix of conservation instruments where forestry is either completely (non-use zone) or partially restricted (partial use zone) were combined. Opportunity costs were measured in terms of foregone timber harvest, an important provisioning service in Telemark. Including a number of ecosystem services shifted priority conservation sites compared to a case where only biodiversity was considered, and increased the area of both the partial (+36.2%) and the non-use zone (+3.2%). Furthermore, opportunity costs increased (+6.6%), which suggests that ecosystem services are not a side-benefit of biodiversity conservation in this area. Opportunity-cost levels were systematically changed to analyse their effect on spatial conservation priorities. Conservation of biodiversity and ecosystem services trades off against timber harvest. Currently designated nature reserves and landscape protection areas achieve a very low proportion (9.1%) of the conservation targets scenario, which illustrates the high importance given to timber production at present. A trade-off curve indicated that large marginal increases in conservation target achievement are possible when the budget for conservation is increased. Forty percent of the maximum hypothetical opportunity costs would yield an average conservation target achievement of 79%. This study shows how a heuristic optimisation approach can aid conservation planning for a number of ecosystem services and biodiversity.

    Based on the critiques on the ecosystem service concept, their respective counter-arguments and the conclusions from the chapters of this thesis, I suggest to further clarify, describe and develop a thick, rich and vague concept of ecosystem services. The ecosystem service concept is a thick concept as it is both descriptive, referring to flows of energy, matter and information from ecosystems to society, and normative, referring to ecosystem services being valuable and preferable to conserve. A rich ecosystem service concept envisions the concept as a platform for plural values emphasising multi-functionality of ecosystems. A rich conceptualization of ESs also includes sustainability principles, such as for instance renewability and aspects of intra- and intergenerational justice. For the purpose of interdisciplinary collaboration, the concept needs to be both vague enough to be flexibly adopted by different disciplines, and at the same time rich enough to ensure that researchers from different disciplines know they are working with the same phenomenon.

    My thesis shows that conceptual and empirically testable ways to address the critique on the ecosystem service concept exist. I conclude that a thick, rich and vague conceptualization of ecosystem services is a way forward and an adequate foundation for science that builds on the ecosystem service concept. I have proposed and empirically tested methods to spatially model ecosystem service capacity and flow and that capacity and flow differ in distribution and abundance. The distinction and empirical assessment of capacity and flow, if measured with aligned indicators, improves the understanding of over- or underuse of ecosystem services. Furthermore, I have shown possible consequences of operationalizing the ecosystem service concept for conservation. To include ecosystem services in conservation or management decisions and to bear the consequences of this inclusion is mainly a societal choice. This choice requires a societal discourse on which ecosystem services and how much of these services should be conserved. This thesis provides knowledge that can feed into such a deliberative discourse about ecosystem services. A thick, rich and vague ecosystem service concept contributes to the philosophical basis of this discourse, ecosystem accounting contributes to the cognitive basis, and the proposed methods for ecosystem service conservation can help guiding action to effectively sustain the provision of ecosystem services.

    Vibriose in aquacultuur: een internationale workshop van de European Association of Fish Pathologists (EAFP)
    Haenen, O.L.M. - \ 2014
    Aquacultuur 29 (2014)4. - ISSN 1382-2764 - p. 29 - 34.
    aquacultuur - visziekten - vibrio - vibrio vulnificus - bacterieziekten - spanje - noorwegen - kroatië - nederland - aquaculture - fish diseases - vibrio - vibrio vulnificus - bacterial diseases - spain - norway - croatia - netherlands
    De wereldwijde groei van de aquacultuur had een toename tot gevolg van de vraag naar cysten van Artemia (voor het voeden van larven van vissen en garnalen in een hatchery). Mondiaal worden cysten van zoutwaterkreeftje Artemia gewonnen in natuurlijke, zoute wateren. De beschikbaarheid van cysten is echter beperkt; niet alleen stijgt de vraag, de hoeveelheid te oogsten cysten is ook onvoorspelbaar door de wisselende klimatologische omstandigheden. De wetmatigheden van vraag en aanbod veroorzaken daarom fluctuaties in de prijs.
    Ecosystem Services and Opportunity Costs Shift Spatial Priorities for Conserving Forest Biodiversity
    Schroter, M. ; Rusch, G.M. ; Barton, D.N. ; Blumentrath, S. ; Nordén, B. - \ 2014
    PLoS ONE 9 (2014)11. - ISSN 1932-6203 - 12 p.
    protected areas - trade-offs - rich forests - conservation - landscapes - strategies - payments - benefits - science - norway
    Inclusion of spatially explicit information on ecosystem services in conservation planning is a fairly new practice. This study analyses how the incorporation of ecosystem services as conservation features can affect conservation of forest biodiversity and how different opportunity cost constraints can change spatial priorities for conservation. We created spatially explicit cost-effective conservation scenarios for 59 forest biodiversity features and five ecosystem services in the county of Telemark (Norway) with the help of the heuristic optimisation planning software, Marxan with Zones. We combined a mix of conservation instruments where forestry is either completely (non-use zone) or partially restricted (partial use zone). Opportunity costs were measured in terms of foregone timber harvest, an important provisioning service in Telemark. Including a number of ecosystem services shifted priority conservation sites compared to a case where only biodiversity was considered, and increased the area of both the partial (+36.2%) and the non-use zone (+3.2%). Furthermore, opportunity costs increased (+6.6%), which suggests that ecosystem services may not be a side-benefit of biodiversity conservation in this area. Opportunity cost levels were systematically changed to analyse their effect on spatial conservation priorities. Conservation of biodiversity and ecosystem services trades off against timber harvest. Currently designated nature reserves and landscape protection areas achieve a very low proportion (9.1%) of the conservation targets we set in our scenario, which illustrates the high importance given to timber production at present. A trade-off curve indicated that large marginal increases in conservation target achievement are possible when the budget for conservation is increased. Forty percent of the maximum hypothetical opportunity costs would yield an average conservation target achievement of 79%.
    Unexpectedly high catch-and-release rates in European marine recreational fisheries: implications for science and management
    Ferter, K. ; Weltersbach, M.S. ; Strehlow, H.V. ; Graaf, M. de; Hammen, T. van der - \ 2013
    ICES Journal of Marine Science 70 (2013)7. - ISSN 1054-3139 - p. 1319 - 1329.
    salmon salmo-salar - atlantic salmon - length limits - circle hooks - mortality - anglers - fish - harvest - recall - norway
    While catch-and-release (C&R) is a well-known practice in several European freshwater recreational fisheries, studies on the magnitude and impact of this practice in European marine recreational fisheries are limited. To provide an overview of the practice and magnitude of C&R among marine recreational anglers in Europe, the existing knowledge of C&R and its potential associated release mortality was collected and summarized. The present study revealed that in several European countries over half of the total recreational catch is released by marine anglers. High release proportions of >60% were found for Atlantic cod (Gadus morhua), European sea bass (Dicentrarchus labrax), pollack (Pollachius pollachius), and sea trout (Salmo trutta) in at least one of the studied European countries. In the case of the German recreational Baltic Sea cod fishery, release proportions varied considerably between years, presumably tracking a strong year class of undersized fish. Reasons for release varied between countries and species, and included legal restrictions (e.g. minimum landing sizes and daily bag limits) and voluntary C&R. Considering the magnitude of C&R practice among European marine recreational anglers, post-release mortalities of released fish may need to be accounted for in estimated fishing mortalities. However, as the survival rates of European marine species are mostly unknown, there is a need to conduct post-release survival studies and to identify factors affecting post-release survival. Such studies could also assist in developing species-specific, best-practice guidelines to minimize the impacts of C&R on released marine fish in Europe.
    Screening of lipophilic marine toxins in shellfish and algae: Development of a library using liquid chromatography coupled to orbitrap mass spectrometry
    Gerssen, A. ; Mulder, P.P.J. ; Boer, J. de - \ 2011
    Analytica Chimica Acta 685 (2011)2. - ISSN 0003-2670 - p. 176 - 185.
    mussels mytilus-edulis - fatty-acid esters - okadaic acid - protoceratium-reticulatum - norway - pectenotoxin-2 - yessotoxin - discovery - analogs
    Most liquid chromatography (LC) mass spectrometric (MS) methods used for routine monitoring of lipophilic marine toxins focus on the analysis of the 13 toxins that are stated in European Union legislation. However, to date over 200 lipophilic marine toxins have been described in the literature. To fill this gap, a screening method using LC coupled to high resolution (HR) orbitrap MS (resolution 100 000) for marine lipophilic toxins has been developed. The method can detect a wide variety of okadaic acid (OA), yessotoxin (YTX), azaspiracid (AZA) and pectenotoxin (PTX) group toxins. To build a library of toxins, shellfish and algae samples with various toxin profiles were obtained from Norway, Ireland, United Kingdom, Portugal and Italy. Each sample extract was analyzed with and without collision induced dissociation fragmentation. Based on their mass and specific fragmentation pattern, 85 different toxins were identified comprising 33 OA, 26 YTX, 18 AZA and 8 PTX group toxins. A major complication of full scan HRMS is the huge amount of data generated (file size), which restricts the possibility of a fast search. A software program called metAlign was used to reduce the orbitrap MS data files. The 200-fold reduced data files were screened using an additional software tool for metAlign: ‘Search_LCMS’. A search library was constructed for the 85 identified toxins. The library contains information about compound name, accurate mass, mass deviation (
    Dialogue between farmers and experts regarding farm animal welfare. Farmers' juries in Norway, the Netherlands and Italy
    Bock, B.B. ; Swagemakers, P. ; Jacobsen, E. ; Ferrari, P. - \ 2010
    Cardiff : Cardiff University Press (Welfare quality reports no. 17) - ISBN 9781908442017 - 142
    varkenshouderij - veehouders - houding van boeren - dierenwelzijn - mens-dier relaties - italië - noorwegen - nederland - dierlijke productie - varkens - pig farming - stockmen - farmers' attitudes - animal welfare - human-animal relationships - italy - norway - netherlands - animal production - pigs
    The main objective of this report is to evaluate farmers' responses to and acceptance of the Welfare Quality assessment and monitoring system, its grading system and use for product information. It is important to determine how farmers perceive the tool because they will be among main users, and their acceptance is essential for its successful implementation. The Welfare Quality team developing this tool also needs to know which aspects evoke farmers' interest and trust as well as those causing concern and distrust. We also need insight into their reasoning and motives for acceptance or refusal. Since opinions on and understanding of animal welfare differ between Northern, Western and Southern Europe we organized pig farmers' juries in 3 countries representing these geographic differences: the Netherlands, Norway and Italy.
    A voice-of-consumer approach in development of new seafood product concepts
    Altintzoglou, T. ; Einarsdóttir, G. ; Valsdóttir, T. ; Schelvis, R. ; Skåra, T. ; Luten, J.B. - \ 2010
    Journal of Aquatic Food Product Technology 19 (2010)2. - ISSN 1049-8850 - p. 130 - 145.
    fish consumption - determinants - involvement - convenience - adulthood - barriers - quality - norway - age
    This article describes a consumer-based approach for development of new seafood product concepts among young adults in Norway and Iceland. The study aim was to gain insight into how young adults determine their acceptance of seafood and make potential product choices. Additional insights measured were confidence in seafood preparation and consumption choices when exposed to specific new seafood concepts. Based on consumer-reported values, three seafood product concepts were evaluated by 354 consumers in a web-based, conjoint experiment in Norway and Iceland. Consumers' evaluations showed a number of consumer preferences for specific seafood product concepts partly associated with and partly conflicting with their original values. Understanding consumer attitudes can help to explain these results. The results of this study will be used as a guide for the next step in developing seafood product concepts.
    Met burgers de boer op : Input voor een maatschappelijk debat over een gewaardeerde en duurzame veehouderij
    Boogaard, B.K. - \ 2010
    Wageningen : Wageningen University - 32
    melkveehouderij - duurzame veehouderij - dierlijke productie - samenleving - tradities - modernisering - attitudes - maatschappelijk draagvlak - nederland - noorwegen - dairy farming - sustainable animal husbandry - animal production - society - traditions - modernization - attitudes - public support - netherlands - norway
    Dit boekje behandelt de opmerkelijkste resultaten van het kwalitatieve deel van het promotieonderzoek over de beelden, wensen en zorgen van burgers over de melkveehouderij. Deze uitgave is gebaseerd op promotieonderzoek van Birgit K. Boogaard, getiteld "Sociaal-culturele duurzaamheid van de veehouderij", uitgevoerd bij de leerstoelgroepen Dierlijke Productiesystemen en Rurale Sociologie van Wageningen University.
    Diagnosis of the first cases of scrapie in Poland
    Polak, M.P. ; Larska, M. ; Langeveld, J.P.M. ; Buschmann, A. ; Groschup, M.H. ; Zmudzinski, J.F. - \ 2010
    The Veterinary Journal 186 (2010)1. - ISSN 1090-0233 - p. 47 - 52.
    bovine spongiform encephalopathy - atypical scrapie - prion protein - monoclonal-antibodies - prp genotypes - sheep - nor98 - discrimination - strains - norway
    This is the first report of cases of scrapie in Poland. The disease was an atypical phenotype, diagnosed in two aged sheep which were found dead. Brainstem samples from both animals were positive on the applied ELISA rapid test, while the confirmatory immunoblot indicated abnormal banding patterns of protease resistant prion protein (PrPres). The genotypes of these sheep were ALRQ/ALHQ and ALRQ/ALRR. The absence of premonitory clinical signs, the advanced age of the affected sheep, the higher concentration of PrPres in the cerebellum relative to the obex, the unusual banding profile of the prion protein and its relatively low resistance to proteolytic degradation confirmed the diagnosis of atypical scrapie (Nor98-like) in both cases
    Mosselkweek in Noorse fjorden
    Jansen, H.M. - \ 2010
    Aquacultuur 25 (2010)4. - ISSN 1382-2764 - p. 20 - 26.
    mosselteelt - schaal- en schelpdierenteelt - noorwegen - mossels - aquacultuur - mussel culture - shellfish culture - norway - mussels - aquaculture
    Schelpdiercultuur is een groeiende sector in Noorwegen, al kent de ontwikkeling ook belemmeringen zoals logistieke beperkingen, sluiting van de oogst door giftige algen, hiaten in de kennis over kweekmethoden, beperkte financiële middelen en een gering ontwikkelingen van de Sector. Zowel de sector als de gerelateerde onderzoeksactiviteiten staan in Noorwegen in de kinderschoenen. Het Institute of Marine (IMR) heeft daarom samenwerking gezocht met Nederlandse, Frans en Canadese onderzoeksinstituten. Deze landen kennen een lange historie en goed gestructureerd onderzoeksveld én hebben een grote schelpdiersector. De samenwerking met IMARES is één van de voorbeelden van deze samenwerkingsverbanden. Aad Smaal en Henrice Jansen zijn vanuit IMARES betrokken bij een project naar de draagkracht voor mosselkweek in Noorse fjorden. Henrice verblijft voor een periode van vier jaar in Noorwegen om promotieonderzoek uit te voeren naar de nutriëntendynamiek in mosselkwekerijen.
    Analyses of the impact of changes in atmospheric deposition and climate on forest growth in European monitoring plots: A stand growth approach
    Solberg, S. ; Dobbertin, M. ; Reinds, G.J. ; Andreassen, K. ; Lange, H. ; Garcia Fernandez, P. ; Hildingsson, A. ; Vries, W. de - \ 2009
    Forest Ecology and Management 258 (2009)8. - ISSN 0378-1127 - p. 1735 - 1750.
    nitrogen deposition - acid deposition - picea-abies - tree growth - carbon sequestration - soil acidification - density index - norway - spruce - responses
    During the last 15 years a number of studies have shown increasing forest growth in central Europe, rather than a decline as was expected due to negative effects of air pollution. We have here used data from intensive monitoring plots spread over Europe for a five year period in order to examine the influence of environmental factors on forest growth. Evaluations focussed on the influence of nitrogen, sulphur and acid deposition, temperatures, precipitation and on a drought index calculated as deviation from the long-term mean. The study included the main tree species Norway spruce, Scots pine, common beech as well as European and sessile oak and was based on data from 363 plots. As many other factors besides nitrogen and temperature influence tree growth, expected stem volume increments were modelled using site productivity, stand age and a stand density index. Relative volume increment was then calculated as actual increment in % of expected increment. The site productivity, assumed to be given by site conditions and past environmental conditions, was either taken from expert estimates or computed from site index curves from northern, central and southern Europe. The model explained between 18% and 39% of the variance with site productivity being positively related and age negatively related to actual increment. The various models and statistical approaches were fairly consistent, and indicated a fertilizing effect of nitrogen deposition, with slightly above one percent increase in volume increment per kg of nitrogen deposition per ha and year. This was most clear for spruce and pine, and most pronounced for plots having soil C/N ratios above 25. Also, we found a positive relationship between relative increment and summer temperature, i.e. May–August mean temperature deviation from the 1961–1990 means. The cause–effect relationship here is, however, less certain. Other influences were uncertain. Possibly, sulphur and acid deposition have effects on growth, but these effects are obscured by, and outweighed by the positive effect of nitrogen deposition, because of collinearity between these variables. Drought effects were uncertain also, and one reason for this might be large uncertainties in the precipitation data: precipitation measured on some 50% of the plots correlated poorly with the precipitation data obtained from Europe-wide databases. The major finding of this study was a positive relationship between higher than normal volume increment on one hand and nitrogen deposition on the other hand.
    Intradermal testing of horses with and without insect bite hypersensitivity in the Netherlands using an extract of native Culicoides species
    Sloet van Oldruitenborgh-Oosterbaan, M.M. ; Poppel, M. van; Raat, I.J. de; Boom, R. van den; Savelkoul, H.F.J. - \ 2009
    Veterinary Dermatology 20 (2009)5-6. - ISSN 0959-4493 - p. 607 - 614.
    sweet itch - icelandic horses - british-columbia - summer eczema - challenge - ceratopogonidae - dermatitis - permethrin - diptera - norway
    Intradermal tests using a Culicoides nubeculosus extract have proven unreliable for diagnosis of equine insect bite hypersensitivity (IBH) in the Netherlands. The aim of this study was to evaluate the diagnostic value of an extract derived from the Dutch species C. obsoletus and C. pulicaris. Thirteen pairs of horses were tested, each pair consisting of one horse with IBH and the other a healthy control. Each horse was injected intradermally with 0.1 mL of three concentrations of Culicoides whole body extract (1 : 1000 w/v, 1 : 10,000 w/v and 1 : 25,000 w/v), histamine solution (0.01 mg/mL, positive control) and phosphate-buffered saline (negative control). Skin responses were evaluated after 30 min and at 1, 4 and 24 h. At all time points the absolute wheal diameter elicited by Culicoides extract 1 : 1000 w/v was significantly larger (P <0.01) in the IBH horses than in the control horses. Using the 1 : 10,000 w/v extract the difference was significant at 1, 4 and 24 h and using the 1 : 25,000 w/v extract only at 24 h. The relative wheal diameter was greater in IBH than in control horses at all concentrations and time points except at 0.5 h for the 1 : 10,000 w/v and 1 : 25,000 w/v concentrations. At the 1 : 1000 w/v concentration, the sensitivity and specificity was 92% using the relative wheal diameter. These results indicate that intradermal testing using 1 : 1000 w/v concentration Culicoides extracts relevant to the locality provides useful support for a clinical diagnosis of equine insect hypersensitivity
    The socio-cultural sustainability of animal farming : an inquiry into social perceptions of dairy farming in the Netherlands and Norway
    Boogaard, B.K. - \ 2009
    Wageningen University. Promotor(en): Akke van der Zijpp; Han Wiskerke, co-promotor(en): Simon Oosting; Bettina Bock. - [S.l. : S.n. - ISBN 9789085854470 - 207
    melkveehouderij - dierlijke productie - samenleving - cultuur - duurzaamheid (sustainability) - perceptie - attitudes - waarden - sociologie - nederland - noorwegen - dairy farming - animal production - society - culture - sustainability - perception - attitudes - values - sociology - netherlands - norway
    De afgelopen 50 jaar is de veehouderij in schaalgrootte toegenomen en geïntensiveerd. Tegelijkertijd zijn Westerse samenlevingen meer verstedelijkt en hebben minder mensen familieleden in de landbouw. Als gevolg daarvan hebben weinig burgers kennis van of directe ervaring met de landbouw. Duurzame ontwikkeling is een omstreden concept en wordt in veel gebieden bediscussieerd en op verschillende manieren gedefinieerd. Deze studie richt zich op burgerpercepties van de veehouderij om inzicht te krijgen in de sociaal-culturele aspecten van een duurzame veehouderij.
    Xeno-estrogenic compounds in precipitation
    Peters, R.J.B. ; Beeltje, H. ; Delft, R.J. - \ 2008
    Journal of Environmental Monitoring 10 (2008). - ISSN 1464-0325 - p. 760 - 769.
    neerslag - regen - oestrogenen - hormonen - verontreiniging - geurstoffen - hormoonverstoorders - precipitation - rain - oestrogens - hormones - pollution - odours - endocrine disruptors - polychlorinated-biphenyls - musk fragrances - german bight - great-lakes - air - urban - atmosphere - exposure - samples - norway
    The exposure to some chemicals can lead to hormone disrupting effects. Presently, much attention is focused on so-called xeno-estrogens, synthetic compounds that interact with hormone receptors causing a number of reactions that eventually lead to effects related to reproduction and development. The current study was initiated to investigate the presence of a number of such compounds in precipitation as a follow-up on a previous study in which pesticide concentrations in air and precipitation were determined. Rainwater samples were collected at about 50 locations in The Netherlands in a four week period. The samples were analysed for bisphenol-A, alkylphenols and alkylphenol ethoxylates, phthalates, flame retardants and synthetic musk compounds. The results clearly indicated the presence of these compounds in precipitation. The concentrations ranged from the low ng l-1 range for flame retardants to several thousands of ng l-1 for the phthalates. Bisphenol-A was found in 30% of the samples in concentrations up to 130 ng l-1, while alkylphenols and alkylphenol ethoxylates were found in virtually all locations in concentrations up to 920 ng l-1 for the individual compounds. Phthalates were by far the most abundant xeno-estrogens in the precipitation samples and were found in every sample. Di-isodecyl phthalate was found in a surprisingly high concentration of almost 100000 ng l-1. Polybrominated flame retardants were found in the low ng l-1 range and generally in less than 20% of the samples. Noticeable was the finding of hexabromocyclododecane, a replacement for the polybrominted diphenyl ethers at one location in a concentration of almost 2000 ng l-1. Finally, as expected, synthetic musk compounds were detected in almost all samples. This is especially true for the polycyclic musks HHCB and AHTN. Nitro musks were found, but only on a few locations. Kriging techniques were used to calculate precipitation concentrations in between actual sampling locations to produce contour plots for a number of compounds. These plots clearly show located emission sources for a number of compounds such as bisphenol-A, nonylphenol ethoxylate, phthalates and AHTN. On the contrary, the results for HHCB and some phthalates indicated diffuse emission patterns, probably as the result of the use of consumer products containing these compounds
    Preliminary Water Assessment Reports of The Test Basins of The Watch Project
    Ludwig, F. ; Candel, M. ; Carrera, J. ; Fendekova, M. ; Haddeland, I. ; Horacek, S. ; Jodar, J. ; Koutroulis, A. ; Navorro, V. ; Tsanis, I. - \ 2008
    Wageningen : Watch (WATCH technical report / Water and Global Change no. X) - 19
    klimaatverandering - stroomgebieden - rivieren - watervoorraden - afvoer - waterbeheer - gevalsanalyse - noorwegen - spanje - tsjechië - griekenland - elbe - kreta - climatic change - watersheds - rivers - water resources - discharge - water management - case studies - norway - spain - czech republic - greece - river elbe - crete
    This report presents the initial plans of the case studies how they link to rest of the Watch project and on which water resources they will focus. This report will function as the basis for further discussions on how to improve the integration of the case studies within the project and to develop a more general protocol for each of the case studies. Currently 5 catchments are used within the Watch project, they differ in climatic and hydro-geological features and expected climate changes: the Glomma River basin (Eastern Norway), the upper Guadiana basin (Central Spanish Plateau), the Nitra River basin (central Slovakia), the Upper-Elbe basin (part of the Elbe River) and the island of Crete. Also the water resources issues vary over these cases. Agricultural (and domestic) water use is under pressure in the Mediterranean catchments probably aggravating with the expected increase in drought frequency under future climate. The Norwegian catchment provides hydropower services under threat of precipitation increase rather than decrease. The central European catchments are threatened mainly by increased variability, i.e. increased frequencies of extremes in a densely populated environment, and river flow may need additional buffers (reservoirs) to reduce floodrisk and store water for dry periods
    Biologische melkveehouderij in Noorwegen : kleinschalig met sterke koeien
    Noorduyn, L. ; Animal Sciences Group (ASG), - \ 2008
    Wageningen : Wageningen UR (BioKennis bericht : Zuivel & Rundvlees ) - 4
    biologische landbouw - melkveehouderij - agrarische bedrijfsvoering - noorwegen - organic farming - dairy farming - farm management - norway
    Noorwegen is een compleet ander land dan Nederland. Hoe is het om in zo’n land een biologisch melkveebedrijf te hebben? Waarin verschilt dat van een Nederlands bedrijf en kunnen Nederlandse boeren nog wat van hen leren? De themagroep Strategie van het Bedrijfsnetwerk Biologische Melkveehouderij organiseerde een tocht naar het belangrijkste veeteeltgebied van Noorwegen: het gebied rond Stavanger.
    Critical loads of sulphur and nitrogen for terrestrial ecosystems in Europe and Northern Asia influenced by different soil chemical criteria.
    Reinds, G.J. ; Posch, M. ; Vries, W. de; Slootweg, J. ; Hettelingh, J.P. - \ 2008
    Water Air and Soil Pollution 193 (2008)1-4. - ISSN 0049-6979 - p. 269 - 287.
    reduction agreements - deposition - forest - acidification - uncertainty - netherlands - simulation - vegetation - acidity - norway
    A critical load data base was developed for Europe and Northern Asia using the latest data bases on soils, vegetation, climate and forest growth. Critical loads for acidity and nutrient nitrogen for terrestrial ecosystems were computed with the Simple Mass Balance model. The resulting critical loads are in accordance with critical loads from previous global empirical studies, but have a much higher spatial resolution. Critical loads of acidity are sensitive to both the chemical criterion and the critical limit chosen. Therefore a sensitivity analysis of critical loads was performed by employing different chemical criteria. A critical limit based on an acid neutralizing capacity (ANC) of zero resulted in critical loads that protect ecosystems against toxic concentrations of aluminium and unfavourable Al/Bc ratios, suggesting that ANC could be an alternative to the commonly used Al/Bc ratio. Critical loads of nutrient nitrogen are sensitive to the specified critical nitrate concentration, especially in areas with a high precipitation surplus. If limits of 3¿6 mg N l¿1 are used for Western Europe instead of the widely used 0.2 mg N l¿1, critical loads double on average. In low precipitation areas, the increase is less than 50%. The strong dependence on precipitation surplus is a consequence of the simple modelling approach. Future models should explore other nitrogen parameters (such as nitrogen availability) instead of leaching as the factor influencing vegetation changes in terrestrial ecosystems.
    How trust in institutions and organizations builds general consumer confidence in the safety of food: A decomposition of effects
    Jonge, J. de; Trijp, J.C.M. van; Lans, I.A. van der; Renes, R.J. ; Frewer, L.J. - \ 2008
    Appetite 51 (2008)2. - ISSN 0195-6663 - p. 311 - 317.
    risk-management - determinants - information - communication - knowledge - attitudes - norway - europe - choice
    This paper investigates the relationship between general consumer confidence in the safety of food and consumer trust in institutions and organizations. More specifically, using a decompositional regression analysis approach, the extent to which the strength of the relationship between trust and general confidence is dependent upon a particular food chain actor (for example, food manufacturers) is assessed. In addition, the impact of specific subdimensions of trust, such as openness, on consumer confidence are analyzed, as well as interaction effects of actors and subdimensions of trust. The results confirm previous findings, which indicate that a higher level of trust is associated with a higher level of confidence. However, the results from the current study extend on previous findings by disentangling the effects that determine the strength of this relationship into specific components associated with the different actors, the different trust dimensions, and specific combinations of actors and trust dimensions. The results show that trust in food manufacturers influences general confidence more than trust in other food chain actors, and that care is the most important trust dimension. However, the contribution of a particular trust dimension in enhancing general confidence is actor-specific, suggesting that different actors should focus on different trust dimensions when the purpose is to enhance consumer confidence in food safety. Implications for the development of communication strategies that are designed to regain or maintain consumer confidence in the safety of food are discussed.
    Praktijkervaringen met zwart- en grijswatersystemen in Noorwegen en Duitsland
    Mels, A.R. ; Telkamp, P. ; Koetse, E. ; Braadbaart, O.D. - \ 2007
    H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 40 (2007)10. - ISSN 0166-8439 - p. 51 - 54.
    nieuwe sanitatie - afvalwaterbehandeling - huishoudens - verzamelen - proefprojecten - afvalwater - urine - duitsland - noorwegen - new sanitation - waste water treatment - households - collection - pilot projects - waste water - urine - germany - norway
    De laatste jaren bestaat wereldwijd steeds meer aandacht voor de ontwikkeling van nieuwe sanitatiesystemen die gebaseerd zijn op gescheiden inzameling van geconcentreerde en minder geconcentreerde afvalwaterstromen uit het huishouden. Ook in Nederland vindt het nodige onderzoek plaats en zijn recentelijk enkele projecten gerealiseerd. Wageningen Universiteit verzamelt systematisch de praktijkervaringen uit verschillende EU-landen en vergelijkt deze om de kennis op dit vlak verder te ontwikkelen. Dit artikel presenteert het resultaat van onderzoek naar vier praktijksystemen met vacuüminzameling en grijswaterzuivering in Noorwegen en Duitsland
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