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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    Replication Data for: Effect of non-migrating bars on dune dynamics in a lowland river
    Ruijsscher, Timo de; Naqshband, Suleyman ; Hoitink, Ton - \ 2020
    Wageningen University & Research
    bars - bed level - discharge - dunes - longitudinal training dams - multibeam echosounding - roughness - Waal River - water level
    As dunes and larger scale bed forms such as bars coexist in rivers, the question arises whether dune dynamics are influenced by interaction with the underlying bed topography. The present study aims to establish the degree in which dune characteristics in two and three dimensions are influenced by an underlying topography dominated by non-migrating bars. As a case study, a 20 km stretch in the Waal River in the Netherlands is selected, which represents a sand-bed lowland river. At this location, longitudinal training dams (LTDs) have recently been constructed to ensure sufficient navigation depth during periods with low water levels, and to reduce flood risk. By using data covering two-year-long periods before and after LTD construction, the robustness of the results is investigated. Before LTD construction, dune characteristics show large variability both spatially and temporally, with dunes being longer, lower, less steep and having a lower lee side angle when they are located on bar tops. The correlation between dune characteristics and the underlying bed topography is disrupted by unsteady conditions for which the dunes are in a state of transition. The bar pattern causes tilting of dune crest lines, which may result from a transverse gradient in bed load sediment transport. As a result of LTD construction, the hydraulic and morphological conditions have changed significantly. Despite this, the main conclusions still hold, which strengthens the validity of the results.
    Dunes, above and beyond : The interactions between ecological and geomorphological processes during early dune development
    Puijenbroek, Marinka E.B. - \ 2017
    Wageningen University. Promotor(en): F. Berendse, co-promotor(en): J. Limpens. - Wageningen : Wageningen University - ISBN 9789463432146 - 183
    dunes - geomorphology - ecology - vegetation - duneland plants - beaches - duinen - geomorfologie - ecologie - vegetatie - duinplanten - stranden

    Coastal dunes occur along the sandy shores of most continents where they serve as coastal defence against flooding, provide areas for recreation, store drinking water and harbour unique biodiversity. Coastal dunes and the services they provide are threatened by climate-induced sea-level rise. This threat may be mitigated by the spontaneous formation of new dunes, for example in combination with mega-nourishments aimed at increasing beach width. Coastal dunes form by the interaction between vegetation, wind and wave action. Persistent dune development begins with the establishment of vegetation on the beach: the vegetation traps the wind-blown sand, forming an embryo dune. Over time an embryo dune can develop into a bigger foredune, increasing coastal safety. The formation and development of embryo dunes into foredunes depend on the vegetation establishment on the beach, dune growth over summer and dune erosion during winter. Although vegetation succession and geomorphological processes are each well described, the interaction between ecological and geomorphological processes during embryo dune development are not well known. The thesis aimed at further exploring these interactions, using a combination of experiments and high-resolution dune monitoring to study the mechanisms underlying early dune development and their implications for mega-nourishment design.

    To explore whether soil salinity, salt spray or storms determine the vegetation limit of dune building plant species on the beach, we performed a field transplantation experiment and a glasshouse experiment with two dune building grasses Ammophila arenaria and Elytrigia juncea. In the field growth of grasses transplanted into four vegetation zones from sea to dune was monitored for over a year and the response of these species to salt spray and soil salinity was tested in a glasshouse experiment. In the field, the vegetation zones were associated with differences in summer soil salinity: zones with both species present were significantly less saline than zones with only E. juncea or the zones without any vegetation. However, in our experiments the transplanted A. arenaria performed equal or better than E. juncea in all vegetation zones, suggesting soil salinity did not limit species performance at the studied site. Both species showed severe winter mortality. In the glasshouse experiment, A. arenaria biomass decreased linearly with soil salinity, presumably as a result of osmotic stress. Elytrigia juncea showed a nonlinear response to soil salinity with an optimum at 0.75% soil salinity and a decrease in biomass at higher salt concentrations. Our findings suggest that soil salinity stress either takes place in winter during storm inundation, or that development of vegetated dunes is less sensitive to soil salinity than hitherto expected.

    To understand the boundary conditions for embryo dune development over a longer time period we explored the effects of beach morphology, meteorological conditions and sand nourishment on early dune development using a 30 year time series of aerial photographs and beach profile monitoring data. We concluded that 1) beach morphology is highly influential in determining the potential for new dune development, with wide beaches enabling development of larger embryo dune fields, 2) sand nourishments stimulate early dune development by increasing beach width, and 3) weather conditions and non-interrupted sequences of years without high-intensity storms determine whether progressive dune development will take place.

    Dune development is the result of the interaction between vegetation development and sedimentation and erosion processes. To disentangle the effects of vegetation characteristics and that of dune size we monitored a natural dune field of 8 hectares for one year using an Unmanned Aerial Vehicle (UAV) with a camera. By constructing a digital surface model and a geometrical corrected image (an orthomosaic) for each flight campaign we calculated changes in dune volume over summer and winter and related these changes to vegetation, dune size and degree of shelter. The dune growth over summer was mainly determined by dune size, whereas dune growth over winter was determined by vegetation characteristics. Degree of shelter determined whether dune growth was limited by storm erosion (exposed dunes) or sand supply (sheltered dunes). These results suggest that vegetation characteristic may be particularly important for resisting storm erosion and speeding up recovery after erosion.

    Embryo dunes have been hypothesised to facilitate development of species rich green beach vegetation in the sheltered location between the embryo dunes and the primary foredunes. To test this hypothesis we explored the relative impacts of abiotic soil conditions as affected by the geomorphological setting on the species richness and species turn-over of green beach vegetation. To this end we characterised the geomorphology and measured abiotic conditions and species composition of green beach vegetation along transects from beach to foredune. We found that the geomorphological setting influenced plant species composition indirectly by affecting soil salinity and rate of sand burial. We found that plant species richness declined less at sheltered conditions, where there was a build-up of organic matter and no sand burial. Our results further suggest a non-linear relationship between embryo dune volume and number of green beach species: embryo dunes can be a source of shelter, thus stimulating green beach development, but can also compete for space, reducing green beach development. The net effect of embryo dunes most likely depends on the sediment budget of the beach and storm intensity.

    Mega-nourishments are single large sand nourishments that are applied locally, and are expected to exist for about 20 years, providing opportunities for the development of embryo dunes and rare pioneer plant communities (green beach vegetation). We explored this potential by comparing growth and development of dune building species on natural beaches with the results of plant transplantation and monitoring data of two mega-nourishments: the low-elevated Hondsbossche Duinen and the high-elevated Sandmotor. Our results suggest that establishment of dune building species on high-elevated mega-nourishment proceed slower than on natural beaches due to dispersal limitation. Once vegetation has established however, embryo dune development on high-elevated mega-nourishments may proceed faster than natural beaches due to low salinity and protection against storm erosion. Development of dune-building vegetation on the low-elevated mega-nourishment Hondsbossche Duinen showed the same rate and pattern as that on a natural beach. The potential for embryo dune development on mega-nourishments is far bigger than the potential for green beach development, since green beach vegetation develops under a narrower range of abiotic conditions. Such abiotic conditions can develop behind the shelter of embryo dunes or foredunes at low beach elevations.

    In conclusion this thesis shows that, 1) the potential of embryo dune development depends on a large beach width and low storm erosion which determines the vegetation limit. 2) Embryo dune growth over summer is mainly determined by existing dune volume and sand supply. 3) Heavy storms limit embryo dune development during winter, although dune erosion can be mitigated by vegetation composition. 4) On accreting beaches which continuously provide area for the development of new embryo dunes green beach vegetation can develop. 5) The design of a mega-nourishment determines the potential for the development of embryo dunes and green beach vegetation. Our findings provide insights in the interaction between ecological and geomorphological processes that determine embryo dune development. This knowledge can help to obtain better predictions of embryo dune development under the threat of sea-level rise.

    Ontwikkelen van een Remote Sensing monitoringssystematiek voor vegetatiestructuur : pilotstudie: detectie verruiging Grijze Duinen (H2130) voor het Natura 2000-gebied Meijendel-Berkheide
    Mücher, Sander ; Kramer, Henk ; Wijngaart, Raymond van der; Huiskes, Rik - \ 2017
    Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2838) - 45
    remote sensing - vegetatiemonitoring - duinen - nederland - remote sensing - vegetation monitoring - dunes - netherlands
    Ontwikkeling van de Zandmotor : samenvattende rapportage over de eerste vier jaar van het Monitoring- en Evaluatie Programma (MEP)
    Taal, M.D. ; Löffler, M.A.M. ; Vertegaal, C.T.M. ; Wijsman, J.W.M. ; Valk, L. van der; Tonnon, P.K. - \ 2016
    IJmuiden : IMARES Wageningen UR - 62
    zandsuppletie - kustbeheer - veiligheid - natuurontwikkeling - duinen - monitoring - sand suppletion - coastal management - safety - nature development - dunes - monitoring
    Dit rapport is als volgt opgebouwd: Hoofdstuk 2 behandelt de achtergrond van de Zandmotor. Hoofdstuk 3 bevat informatie over de betekenis van de Zandmotor voor kustveiligheid. In hoofdstuk 4 is te lezen wat de Zandmotor tot op heden betekent voor natuur en recreatie. Hoofdstuk 5 gaat in op het beheer van de Zandmotor. Ook de invloed van de Zandmotor op het bestaande duingebied Solleveld vormt hiervan een onderdeel. In hoofdstuk 6 staat de betekenis van de Zandmotor voor kennis en innovatie centraal.
    Modelling foredune dynamics in response to climate change
    Keijsers, J.G.S. - \ 2015
    Wageningen University. Promotor(en): Coen Ritsema, co-promotor(en): Michel Riksen; Alma de Groot. - Wageningen : Wageningen University - ISBN 9789462575844 - 186
    klimaatverandering - duinen - kustgebieden - vegetatie - sedimentatie - hoogwaterbeheersing - modelleren - nederland - climatic change - dunes - coastal areas - vegetation - sedimentation - flood control - modeling - netherlands

    Coastal dunes are prominent features along many of the world’s sandy shorelines. They are valued for their contributions to flood protection, biodiversity, fresh water supply and recreation. The most seaward dune ridge or foredune is the most dynamic part, showing fluctuations in size and morphology in response to erosion by the sea and subsequent recovery by interactions between wind-blown sand and vegetation. Given their dependency on multiple natural processes, coastal dunes may be particularly sensitive to the effects of climate change, including sea-level rise (SLR) and changes in temperature and precipitation.

    To mitigate anticipated coastal erosion in the next decades, the Dutch sand nourishment regime will be intensified to raise the beach profile proportionally to the SLR. However, it is not clear how the added sand is distributed within the foredune system and whether this enables foredunes to keep up with sea-level rise. In addition, possibilities for dune re-mobilisation are investigated to enhance landward transport and biodiversity. However, effects of this intervention on foredune dynamics and the dune landscape are not entirely clear.

    This thesis has examined yearly to decadal scale foredune dynamics and the impacts of climate change and management options on these dynamics.

    Which factors control year-to-year variations in dune growth on the Dutch coast?

    Dunes depend on aeolian transport for sand supply. While measurements of aeolian transport show complex spatio-temporal variations, we find that the yearly sand supply to dunes along the Dutch coast is relatively constant, between 10-20 m3/m irrespective of the beach width (Chapter 2). This means that a wider beach does not necessarily provide more sand to dunes and beach width is not a limiting factor in sand supply to the dunes.

    In contrast to the sand input, the amount of sand lost during a storm surge does depend on the beach width. Wider beaches are able to dissipate more of the incoming wave energy and thus protect the dune better than narrow beaches. On a term of decades, this gives rise to steady dune growth on wider beaches and irregular, frequently interrupted growth on narrow ones.

    How do biogeomorphic interactions control foredune shape?

    The distribution of sand over the foredune, and therefore the morphological evolution, is strongly tied to vegetation patterns (Chapter 3). It was found that deposition patterns across foredunes show a characteristic distribution, starting with a sharp increase upon crossing the seaward vegetation limit, reaching a maximum between 5-20 m further landward and then gradually decreasing inland of the crest. The deposition pattern is further modified by the general vegetation pattern. On a timescale of years, there is no correlation between density of vegetation cover and the amount of accretion. However, by accounting for the gradual depletion of the sand load over the foredune, an empirical relationship can be defined between vegetation cover and its sand trapping efficiency. For fully covered surfaces, sand trapping efficiency is around 50%, indicating that sediment can pass densely covered foredunes.

    Although literature suggests a relation between the level of plant burial and plant growth, we found no evidence for enhanced vegetation growth in high-deposition zones. A gain in vegetation cover was found to occur for burial between 0 m/year and 1 m/year, which indicates that lower and upper tolerance limits of burial have not been exceeded. Other growth limiting factors are likely to be of similar importance, masking any possible dependency of vegetation growth on sand accretion.

    What are the effects of climate change on meso-scale evolution of coastal dunes?

    The results on yearly erosion/accretion and sedimentation patterns were implemented in a computer for dune evolution called DUBEVEG, developed in Wageningen (Chapter 4). Algorithms for aeolian transport and vegetation growth were taken from existing models and combined with a new module for wave action and dune erosion. The model was calibrated and validated against field measurements. The good agreement between observations and predictions indicates that the model successfully incorporates the suite of biogeomorphic and marine processes involved in dune building.

    Model simulations show that the evolution of a dune strongly depends on the sequence of storms and quiet periods. During quiet periods, dunes are able to build seaward at several metres per year as vegetation colonises the area near the dune foot, leading to dune accretion. Following the dune-foot position through time, we find an irregular pattern of seaward advance and regression. However, the average of a large number of runs with varying storm sequences reveals a clear trend. For a given wave climate and beach profile, we find that the model predicts a certain seaward limit to which the foredunes may build, or equilibrium position at which erosion and accretion are balanced. If the momentary position of the dune foot is seaward of this limit, seaward movement can be rapid. If, in contrast, the momentary position is at or seaward of the limit, periods of minor seaward growth are followed by periods of landward retreat, resulting in an oscillation around the equilibrium.

    Climate scenarios, consisting of SLR and a gradual change in vegetation growth, were developed to examine climate-change effects on dune dynamics. Sea-level rise largely determines the direction of dune evolution by forcing the dune-foot landwards. The rate of rising controls whether dunes are able to preserve their height or sand volume while migrating landwards. The effect of changing vegetation growth rates, resulting from climate change, is most manifest in dune response to large disturbances. If vegetation is removed halfway into the simulation, vegetation growth rate determines whether a foredune will re-vegetate and re-stabilise: a value below the threshold will preclude complete recovery and the dune remains bare.

    What management options are available to mitigate climate-change effects on coastal dune evolution?

    Sand nourishments are effective to mitigate the effect of SLR on coastal dunes. Model results show that by raising the beach proportionally to SLR, dunes are able to preserve their dunefoot position, height and volume. sHowever, the associated landward retreat is often not feasible.

    A reduction in vegetation cover, related to either (1) artificial remobilisation, (2) dunefoot erosion or (3) climate change promotes landwards transport and therefore contributes to the long-term preservation of a wider dune zone. If vegetation growth is reduced as a consequence of increasing summer drought, re-mobilisation becomes more effective, with high rates of landwards transport persisting for several decades.

    On the long term, it is recommended to use a combination of sand nourishments and remobilisation efforts to preserve the coastline, promote landwards transport and make benefit of a dune’s natural self-regenerating capacity. Under the precondition that safety requirements are met, these natural processes enable long-term preservation of flood protection, biodiversity and dynamic landscapes.

    Vegetation and sedimentation on coastal foredunes
    Keijsers, J.G.S. ; Groot, A.V. de; Riksen, M.J.P.M. - \ 2015
    Geomorphology 228 (2015). - ISSN 0169-555X - p. 723 - 734.
    prince-edward-island - sand transport - ammophila-breviligulata - dutch coast - air-flow - dunes - wind - dynamics - geomorphology - morphology
    On a timescale of years to decades, vegetated foredunes may show various modes of morphological development. Vegetation is one of the factors that determine the sedimentation pattern and thus morphology on the foredune. In turn, the vegetation pattern may be controlled by the sedimentation pattern. Although these effects have been quantified for short timescales, there is relatively little information on the interaction between vegetation and sedimentation for timescales of over a year. For the island of Ameland, the Netherlands, elevation measurements and aerial photographs between 2002 and 2012 were used to derive changes in elevation and vegetation patterns on a year-to-year basis. This was done for a range of stable to accreting foredunes. Sedimentation increases from the beach to a maximum halfway up the seaward slope of the foredune, and then decreases again when going landward. This trend is further modified by the vegetation's spatial pattern. On a timescale of years, there is no correlation between the density of vegetation cover and the amount of accretion. However, by accounting for the gradual depletion of the sand load over the foredune, a relationship can be defined between vegetation cover and its trapping efficiency. Foredune vegetation spreads mainly by lateral expansion of existing patches. No strong effect was found of the sedimentation balance on the expansion of vegetation. It is suggested that other growth-limiting factors are of similar importance, masking any possible dependency of vegetation growth on sand accretion.
    Het oude continent : beschouwingen over de natuur in Europa
    Schaminee, J.H.J. ; Janssen, J.A.M. - \ 2014
    Zeist : KNNV uitgeverij (Vegetatiekundige Monografieën 6) - ISBN 9789050115148 - 184
    natuur - landschap - vegetatie - flora - biodiversiteit - graslanden - duinen - moerassen - zoetwaterecologie - europa - fritillaria meleagris - nature - landscape - vegetation - flora - biodiversity - grasslands - dunes - marshes - freshwater ecology - europe - fritillaria meleagris
    Een verzameling essays over de grote verscheidenheid aan natuur in Europa: wildernis, natuurlijke en oude cultuurlandschappen. Hoe staat het met de bescherming van deze uiteenlopende natuurtypen? Van de Europese laaglandrivieren en hun begeleidende hooilanden tot kalkmoerassen in de bergen: tal van bijzondere landschappen en hun verhalen komen aan bod. flora, fauna, biodiversiteit, natuurbeheer, halfnatuurlijke graslanden, plantengemeenschappen, vegetatiekunde, ecologie, duinen, kalkmoerassen, wateren, bevloeiingssystemen, wildernis, natuur in Europa
    Soft engineering vs. a dynamic approach in coastal dune management: a case study on the North Sea barrier island of Ameland, the Netherlands
    Jong, B. de; Keijsers, J.G.S. ; Riksen, M.J.P.M. ; Krol, J. ; Slim, P.A. - \ 2014
    Journal of Coastal Research 30 (2014)4. - ISSN 0749-0208 - p. 670 - 684.
    hoogwaterbeheersing - kustbeheer - duinen - eolische processen - geologische sedimentatie - nederlandse waddeneilanden - flood control - coastal management - dunes - aeolian processes - geological sedimentation - dutch wadden islands - dutch coast - beach - foredunes - erosion - storms
    Dunes act as flood defences in coastal zones, protecting low-lying interior lands from flooding. To ensure coastal safety, insight is needed on how dunes develop under different types of management. The current study focuses on two types of coastal dune management: (1) a “soft engineering” approach, in which sand fences are placed on the seaward side of foredunes, and (2) “dynamic coastal management,” with minimal or no dune maintenance. The effects of these management styles on dune formation are examined for two adjacent coastal sections of the North Sea barrier island of Ameland, The Netherlands, where dynamic coastal management was introduced in 1995 and 1999, respectively.
    Dunes act as flood defenses in coastal zones, protecting low-lying interior lands from flooding. To ensure coastal safety, insight is needed on how dunes develop under different types of management. The current study focuses on two types of coastal dune management: (1) a "soft engineering" approach, in which sand fences are placed on the seaward side of foredunes, and (2) "dynamic coastal management," with minimal or no dune maintenance. The effects of these management styles on dune formation are examined for two adjacent coastal sections of the North Sea barrier island of Ameland, The Netherlands, where dynamic coastal management was introduced in 1995 and 1999, respectively. For each section, we analyzed cross-shore profile data from 1980 until 2010, deriving dune foot position, crest position, crest height, and foredune volume for each year and analyzing the situation before and after the change in management. We further assessed the effect of the management regime on dune vegetation. Other factors that could influence dune development were also taken into account, such as beach width and shape, water levels, wave heights, and nourishments. Results show that implementation of dynamic coastal management did not directly affect the volume of the foredune. Growth was occasionally interrupted, coinciding with high-water events. In periods between erosive storms, dune growth rates did not show a significant difference between management types (p = 0.09 and 0.32 for sections 1 and 2, respectively). The main effect of the change was on vegetation development. Dynamic coastal management, therefore, did not reduce coastal safety.
    De Zandmotor - Gepassioneerde Wetenschap
    Baptist, M.J. - \ 2014
    kustbeheer - zandsuppletie - natuurontwikkeling - openluchtrecreatie - duinen - kustgebieden - waterbouwkunde - zuid-holland - coastal management - sand suppletion - nature development - outdoor recreation - dunes - coastal areas - hydraulic engineering
    De Zandmotor is een groot pilotproject voor natuurlijke kustbescherming, waarmee tegelijk ruimte voor natuur en recreatie ontststaat. Onderzoekers van verschillende universiteiten volgen de ontwikkelingen op de voet. De Zandmotor ontwikkelt zich zoals verwacht; de kust wordt versterkt,voor kitesurfers is de Zandmotor één van de beste plekken in Nederland en de natuur ontwikkelt zich op verschillende fronten. In deze korte documentaire zie je hoe dat werkt. Selecteer HD bij instellingen voor optimale weergave)
    Developing an interactive Tool for evaluating sand nourishment strategies along the Holland coast in perspective of benthos, fish nursery and dune quality
    Baptist, M.J. ; Wolfshaar, K.E. van de; Huisman, B.J.A. ; Groot, A.V. de; Boer, W. de; Ye, Q. - \ 2012
    Den Burg : IMARES (Rapport / IMARES Wageningen UR C083/12) - 38
    kustbeheer - zandsuppletie - versterking - duinen - nadelige gevolgen - geologische sedimentatie - vissen - aquatische ecologie - noordzee - coastal management - sand suppletion - reinforcement - dunes - adverse effects - geological sedimentation - fishes - aquatic ecology - north sea
    Sand nourishments can affect the coastal ecosystem in various ways. Direct effects are the burial of benthic species under a layer of sand. In the direct vicinity, suffocation of benthos can occur due to the settling of a plume of suspended sediment particles. A plume of fine particles may also increase turbidity and thereby affect primary production and the foraging success of filter-feeding benthos and fish. Indirect effects are habitat change, such as altered morphology and sedimentology. It was tested by investigating whether it is possible to optimise nourishment configuration, location and timing, to: - minimise the impact on benthos, - increase nursery area and/or quality, and - enhance dune quality.
    TO-rapportage Monitoring en Evaluatie pilot Zandmotor
    Tonnon, P.K. ; Baptist, M.J. - \ 2011
    Den Burg : IMARES (Rapport / IMARES C016/11) - 198
    geomorfologie - duinen - kustgebieden - versterking - bescherming - ecologie - vogels - zandsuppletie - geomorphology - dunes - coastal areas - reinforcement - protection - ecology - birds - sand suppletion
    Met het concept van de Zandmotor, een megasuppletie voor de kust waarmee de kustveiligheid voor de lange termijn wordt gecombineerd met de realisatie van ruimte voor natuur en recreatie, is nog geen ervaring opgedaan. Ten behoeve van uitbestedingen van monitoringpakketten is het monitoringplan in het Uitvoeringsprogramma thematisch geordend op basis van expertisegebieden. De volgende thema’s worden onderscheiden: - Meteo- en hydrodynamiek - Strand en Vooroever, morfologie en sedimentsamenstelling - Strand en Vooroever, ecologie - Natuur/duinen, geomorfologie en ecologie
    Reducing the impact of wave attack: dunes as natural buffers
    Stroosnijder, L. - \ 2010
    Kennis voor Klimaat
    duinen - kustbeheer - klimaatadaptatie - sediment - nederland - dunes - coastal management - climate adaptation - sediment - netherlands
    Coastal dune systems, with their self-regenerating capacity after storm erosion, represent natural defense zones against flooding of the hinterland. Condition: the total dune volume exceeds a certain minimum value related to the safety standard. As such, coastal dune systems represent natural buffers to climate change. To maintain the functions of the dune system at a certain level under conditions of sea level rise, the dunes require an input of sand proportional to the rate of sea level rise. Focus of the research is on the problem of how sediment supply and dune management may be optimized under conditions of climate change in order to sustainably preserve the safety function of the dunes in harmony with other functions of the system. The aim of this project is to derive a model of dune development and apply it together with other models and expert judgment, to develop and evaluate a set of potential dune management strategies, aimed at improvement of the climate buffer function of dunes. This text is an extract of the full project proposal.
    Historisch cultuurlandschap in Nederland; Vijf bijdragen
    Baas, H. ; Braaksma, P.J. ; Keunen, L.J. ; Lachaert, P.J. ; Marrewijk, D. van; Renes, H. ; Spek, T. ; Weijschede, T.J. - \ 2010
    Utrecht : Uitgeverij Matrijs - ISBN 9789053454145 - 96
    cultuurlandschap - historische geografie - nederland - duinen - noord-brabant - zuid-holland - zeeland - zandgronden - cultural landscape - historical geography - netherlands - dunes - noord-brabant - zuid-holland - zeeland - sandy soils
    In 2006 werd het Netwerk Historisch Cultuurlandschap (NHC) opgericht. Dit netwerk heeft als doel het onderlinge contact, het overleg en de samenwerking tussen al deze onderzoekers, beleidsmakers, belangenorganisaties en liefhebbers op het gebied van het Nederlandse cultuurlandschap te versterken. Deze bundel is een initiatief van het NHC en bevat bijdragen die een overzicht bieden en het onderzoek van de laatste jaren samenvatten.
    Aardkastanje, onopvallend en te weinig om te eten
    Spruijt, T. - \ 2010
    Nature Today 2010 (2010)05-07.
    bunium bulbocastanum - apiaceae - wilde planten - karakteristieken - identificatie - duinen - noord-holland - bunium bulbocastanum - apiaceae - wild plants - characteristics - identification - dunes - noord-holland
    Hij staat vanaf half juni volop in bloei, maar wordt door weinigen gezien. Hoewel een zoektocht op Google anders doet vermoeden, wordt hij niet meer gegeten. De Aardkastanje is daarvoor te onopvallend en te zeldzaam in Nederland. Toch is het een bijzondere schermbloem.
    Monitoringsonderzoek recreatie duingebied Meijendel - deel XX; Analyse van het recreatieverkeer en het recreatiebezoek in de periode maart 2007 - februari 2008
    Webster, M.J. ; Beunen, R. ; Jaarsma, C.F. - \ 2008
    Wageningen : WUR, Leerstoelgroep Landgebruiksplanning (Nota / Vakgroep Ruimtelijke Planvorming nr. 106) - ISBN 9789085854814 - 102
    recreatie - bezoeken - verkeer - monitoring - duinen - openluchtrecreatie - tellen - nederland - zuid-holland - recreation - visits - traffic - monitoring - dunes - outdoor recreation - counting - netherlands - zuid-holland
    Ten behoeve van het Duinwaterbedrijf Zuid-Holland voert Wageningen UR een meerjarig momitoringsonderzoek uit naar het recreatief gebruik van het duingebied Meijendel. Doel van het onderzoek is het verkrijgen van inzicht in aard en omvang van het gebruik van dit gebied en hiermee samenhangende variabelen. Daartoe worden vanaf maart 1992 veldwaarnemingen verricht in het gebied. Dit is deel 20 in het kader van Monitoringsonderzoek recreatie duingebied Meijendel
    Responses of root-feeding nematodes (Helicotylenchus spp.) to local and non-local populations of the host plant Ammophila arenaria
    Schreck Reis, C. ; Freitas, H. ; Putten, W.H. van der - \ 2008
    Applied Soil Ecology 39 (2008)3. - ISSN 0929-1393 - p. 245 - 253.
    parasitic nematodes - l. link - mycorrhizal fungi - soil organisms - grass - degeneration - communities - vegetation - feedback - dunes
    The root-feeding nematode community of wild plants may vary throughout their natural range. Little is known about how the variation of wild plants along their range affects their relationship with root-feeding nematodes. In the present study, we examined local and non-local combinations of host plants and root-feeding nematodes to test the hypothesis that nematode reproduction is favoured by local hosts. In two indoor experiments, we exposed populations of the wild dune grass Ammophila arenaria from northern and southern European coastal sand dunes to plant parasitic nematode species (Helicotylenchus spp.) from those same geographical origins. First, we used the southern nematode species to determine whether the effect of a local versus a non-local host may depend on nematode density. Then, in a cross-inoculation experiment we investigated how both nematode species performed with their local, as compared to the non-local hosts. In both experiments, plant biomass and ontogenetic characteristics were not significantly different between the northern and southern populations. The applied nematode densities did not have a negative impact on plant performance. This allowed us to consider the response of the two different nematode species and their host plants without co-varying differences in plant responses. Reproduction of the nematode species differed according to host origin, but contrary to what we expected, nematode species did not perform better on their local hosts. Helicotylenchus n. sp., the southern species originating from Portugal, performed better on the non-local than on the local host. Male to female ratios were significantly different between the two nematode populations and were lowest in Helicotylenchus pseudorobustus from The Netherlands. Female and juveniles percentages were also quite distinct, with more females in the nematode species from The Netherlands and more juveniles in the nematode species from Portugal. We concluded that ectoparasitic root-feeding nematodes Helicotylenchus spp. do not necessarily perform best on their local host population of the foredune grass A. arenaria. Our results imply that the natural distribution of Helicotylenchus spp. along the European coast is determined by other factors than host populations. These other factors that could be abiotic, e.g. water availability, or biotic, e.g. local natural enemies adapted to Helicotylenchus spp. Introducing plant genotypes from other parts of the natural range will, therefore, not necessarily lead to reduced abundance of semi-endo or ectoparasitic root-feeding nematodes
    Comparison of Michigan and Dutch Podzolized
    Buurman, P. ; Jongmans, A.G. ; Nierop, K.G.J. - \ 2008
    Soil Science Society of America Journal 72 (2008)5. - ISSN 0361-5995 - p. 1344 - 1356.
    lake-michigan - vegetation succession - incipient podzols - forest soil - c-13 nmr - gc-ms - horizons - fractions - dunes - sand
    Soil organic matter in a chronosequence of Michigan soils (Spodic Udipsamments and precursors) was studied in thin section and by pyrolysis-gas chromatography/mass spectrometry (GC/MS). The Michigan soils were compared with a well-drained Dutch Typic Haplorthod that was studied with the same methods. Both techniques indicate that most B-horizon organic matter in the Michigan sequence is root- and char-derived and not due to illuviation. Microbial matter contributes significantly to B-horizon chemistry. Although charcoal is common in A horizons, it hardly contributes to soil organic matter (SOM) chemistry in this horizon, while it constitutes a significant part of B-horizon C. This suggests that silt-size particulate charcoal is transported downward. Nitrogen-containing pyrolysis fragments are abundant, which, together with significant amounts of aromatic components, points to contribution of proteins. The Michigan soils are far less rich in alkyl C than the Dutch counterpart. This suggests a much lower residual accumulation of recalcitrant compounds in the former, probably due to a larger contribution of root litter and a more efficient decomposition. Faster decomposition (shorter mean residence time) in the Michigan soils is also suggested by the low accumulation of SOM in the B horizon. Thus we can conclude that in the Michigan soils, dissolved organic matter contributes significantly to transport of Al and Fe, but essentially without illuviation of organic matter in the B. In the Dutch Spodosol, on the other hand, both transport of dissolved organic C to the B horizon and accumulation of SOM through decomposition of roots play important roles. Pyrolysis-GC/MS is a powerful tool in deciphering organic-matter-related aspects of soil genesis. The formation of many soils is organic matter driven, and this aspect is still poorly understood.
    Diversity of ground beetles (Coleoptera: Carabidae) and spiders (Araneae) in roadside verges with grey hair-grass
    Noordijk, J. ; Schaffers, A.P. ; Sykora, K.V. - \ 2008
    European Journal of Entomology 105 (2008)2. - ISSN 1210-5759 - p. 257 - 265.
    dispersal corridors - habitats - impact - netherlands - movements - fragments - abundance - survival - faunas - dunes
    Roadside verges in densely populated areas are often a significant addition to the total semi-natural area and as such may contribute to the conservation of biodiversity. Furthermore, they can enhance the ecological cohesion of a region, especially when the existing nature reserves are small and/or highly fragmented. We investigated the occurrence of ground beetles and spiders in six highway verges with grey hair-grass vegetation in the Veluwe region, The Netherlands. Total species number in the verges was similar to the values found in nearby nature reserves with comparable vegetation, but the ground beetles tended to be more abundant in the reserves. Many stenotopic species were present in the verges, confirming the significant conservation value of this habitat. However, compared with the nature reserves, there were fewer species of stenotopic ground beetles and the stenotopic spiders were less abundant in the verges. From our knowledge of the biology and ecology of the species captured it seems likely that this is attributable to differences in "habitat quality". In the verges, species preferring bare sand are scarcer, and the weighted mean body length of ground beetles is shorter than in nature reserves. This suggests that the sward in the road verges is too dense and the suitable vegetation too patchy to sustain some of the stenotopic species. Habitat analyses support this contention: Compared with the nature reserves, the verges had proportionally less bare sand, more herb and tree cover and the vegetation patches were smaller. The strategy suggested to promote stenotopic species entails removing encroaching trees and shrubs from the verges in order to expand the nutrient-poor zone and (re-)create pioneer conditions. Subsequent management should aim at further improving the road verges as extensions of nutrient-poor habitat.
    Thema 2. Ecologisch geoptimaliseerde kustverdediging. Zachte kustverdediging en dynamisch kustbeheer
    Riksen, Michel - \ 2008
    geomorphology - dunes - protective structures - reinforcement - sand suppletion - sand dune stabilization - climatic change - wind erosion - netherlands - sea level
    Interacties tussen plantparasitaire nematoden en hun natuurlijke vijanden in buitenduinen
    Piskiewicz, A.M. - \ 2008
    Gewasbescherming 39 (2008)2. - ISSN 0166-6495 - p. 67 - 69.
    ammophila arenaria - duinen - tylenchorhynchus - plantenparasitaire nematoden - natuurlijke vijanden - gastheer parasiet relaties - verdedigingsmechanismen - microbiële flora - ecosystemen - duingebieden - ammophila arenaria - dunes - tylenchorhynchus - plant parasitic nematodes - natural enemies - host parasite relationships - defence mechanisms - microbial flora - ecosystems - duneland
    De resultaten van de experimenten van dit promotieonderzoek samen met de beschikbare gegevens van het EcoTrain-project over nematodenonderdrukking in buitenduinen laat zien dat de regulatie van nematoden veel complexer is dan tevoren werd verondersteld. Het regulatiemechanisme hangt niet alleen af van het voedseltype, maar ook van de soort nematode. De conclusie is dat vaak meer dan één factorbetrokken is bij de succesvolle onderdrukking van nematoden. Hoewel nematodenpopulaties succesvol onderdrukt kunnen worden in natuurlijke ecosystemen, is nematode-onderdrukking in de landbouw niet altijd succesvol. De resultaten van het EcoTrain-project doen sterk vermoeden dat een scala aan controlemechanismen nodig zou kunnen zijn voor nematode-onderdrukking in de landbouw en in andere productiesystemen
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