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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Food choice motives, attitude towards and intention to adopt personalised nutrition
Rankin, Audrey ; Bunting, Brendan P. ; Poínhos, Rui ; Lans, Ivo A. van der; Fischer, Arnout R.H. ; Kuznesof, Sharron ; Almeida, M.D.V. ; Markovina, Jerko ; Frewer, Lynn J. ; Stewart-Knox, Barbara J. - \ 2018
Public Health Nutrition (2018). - ISSN 1368-9800 - 11 p.
Attitudes - Food choice motives - Food Choices Questionnaire - Food4Me - Intention - Nutrigenomics - Personalised nutrition - Survey

Objective: The present study explored associations between food choice motives, attitudes towards and intention to adopt personalised nutrition, to inform communication strategies based on consumer priorities and concerns. Design/Setting: A survey was administered online which included the Food Choice Questionnaire (FCQ) and items assessing attitudes towards and intention to adopt personalised nutrition. Subjects: Nationally representative samples were recruited in nine EU countries (n 9381). Results: Structural equation modelling indicated that the food choice motives ‘weight control’, ‘mood’, ‘health’ and ‘ethical concern’ had a positive association and ‘price’ had a negative association with attitude towards, and intention to adopt, personalised nutrition. ‘Health’ was positively associated and ‘familiarity’ negatively associated with attitude towards personalised nutrition. The effects of ‘weight control’, ‘ethical concern’, ‘mood’ and ‘price’ on intention to adopt personalised nutrition were partially mediated by attitude. The effects of ‘health’ and ‘familiarity’ were fully mediated by attitude. ‘Sensory appeal’ was negatively and directly associated with intention to adopt personalised nutrition. Conclusions: Personalised nutrition providers may benefit from taking into consideration the importance of underlying determinants of food choice in potential users, particularly weight control, mood and price, when promoting services and in tailoring communications that are motivationally relevant.

Making personalised nutrition the easy choice : Creating policies to break down the barriers and reap the benefits
Stewart-Knox, B.J. ; Markovina, J. ; Rankin, A. ; Bunting, B.P. ; Kuznesof, S. ; Fischer, A.R.H. ; Lans, I.A. van der; Poínhos, R. ; Almeida, M.D.V. de; Panzone, L. ; Gibney, M. ; Frewer, L.J. - \ 2016
Food Policy 63 (2016). - ISSN 0306-9192 - p. 134 - 144.
Attitudes - Europe - Food4me - Nutrigenomics - Personalised nutrition - Survey

Personalised diets based on people's existing food choices, and/or phenotypic, and/or genetic information hold potential to improve public dietary-related health. The aim of this analysis, therefore, has been to examine the degree to which factors which determine uptake of personalised nutrition vary between EU countries to better target policies to encourage uptake, and optimise the health benefits of personalised nutrition technology. A questionnaire developed from previous qualitative research was used to survey nationally representative samples from 9 EU countries (N = 9381). Perceived barriers to the uptake of personalised nutrition comprised three factors (data protection; the eating context; and, societal acceptance). Trust in sources of information comprised four factors (commerce and media; practitioners; government; family and, friends). Benefits comprised a single factor. Analysis of Variance (ANOVA) was employed to compare differences in responses between the United Kingdom; Ireland; Portugal; Poland; Norway; the Netherlands; Germany; and, Spain. The results indicated that respondents in Greece, Poland, Ireland, Portugal and Spain, rated the benefits of personalised nutrition highest, suggesting a particular readiness in these countries to adopt personalised nutrition interventions. Greek participants were more likely to perceive the social context of eating as a barrier to adoption of personalised nutrition, implying a need for support in negotiating social situations while on a prescribed diet. Those in Spain, Germany, Portugal and Poland scored highest on perceived barriers related to data protection. Government was more trusted than commerce to deliver and provide information on personalised nutrition overall. This was particularly the case in Ireland, Portugal and Greece, indicating an imperative to build trust, particularly in the ability of commercial service providers to deliver personalised dietary regimes effectively in these countries. These findings, obtained from a nationally representative sample of EU citizens, imply that a parallel, integrated, public-private delivery system would capture the needs of most potential consumers.

The Earth Observation Data for Habitat Monitoring (EODHaM) System
Lucas, R.M. ; Blonda, P. ; Bunting, P. ; Jones, G. ; Inglada, J. ; Arias-Maldonado, M. ; Kosmidou, V. ; Petrou, Z. ; Manakos, I. ; Adamo, M. ; Charnock, R. ; Tarantino, C. ; Mücher, C.A. ; Kramer, H. ; Jongman, R.H.G. ; Honrado, J. ; Mairota, P. - \ 2015
International Journal of applied Earth Observation and Geoinformation 37 (2015). - ISSN 0303-2434 - p. 17 - 28.
remotely-sensed data - categories ghc - file format - vegetation - satellite - classifications - biodiversity - reflectance - phenology - software
To support decisions relating to the use and conservation of protected areas and surrounds, the EU-funded BIOdiversity multi-SOurce monitoring System: from Space TO Species (BIO_SOS) project has developed the Earth Observation Data for HAbitat Monitoring (EODHaM) system for consistent mapping and monitoring of biodiversity. The EODHaM approach has adopted the Food and Agriculture Organization Land Cover Classification System (LCCS) taxonomy and translates mapped classes to General Habitat Categories (GHCs) from which Annex I habitats (EU Habitats Directive) can be defined. The EODHaM system uses a combination of pixel and object-based procedures. The 1st and 2nd stages use earth observation (EO) data alone with expert knowledge to generate classes according to the LCCS taxonomy (Levels 1 to 3 and beyond). The 3rd stage translates the final LCCS classes into GHCs from which Annex I habitat type maps are derived. An additional module quantifies changes in the LCCS classes and their components, indices derived from earth observation, object sizes and dimensions and the translated habitat maps (i.e., GHCs or Annex I). Examples are provided of the application of EODHaM system elements to protected sites and their surrounds in Italy, Wales (UK), the Netherlands, Greece, Portugal and India.
Multi-resolution time series imagery for forest disturbance and regrowth monitoring in Queensland, Australia
Schmidt, M. ; Lucas, R. ; Bunting, P. ; Verbesselt, J. ; Armston, J. - \ 2015
Remote Sensing of Environment 158 (2015). - ISSN 0034-4257 - p. 156 - 168.
reflectance fusion model - surface reflectance - aerial-photography - landsat data - vegetation - plus - phenology - framework - lidar
High spatio-temporal resolution optical remote sensing data provide unprecedented opportunities to monitor and detect forest disturbance and loss. To demonstrate this potential, a 12-year time series (2000 to 2011) with an 8-day interval of a 30 m spatial resolution data was generated by the use of the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) with Landsat sensor observations and Moderate Resolution Imaging Spectroradiometer (MODIS) data as input. The time series showed a close relationship over homogeneous forested and grassland sites, with r2 values of 0.99 between Landsat and the closest STARFM simulated data; and values of 0.84 and 0.94 between MODIS and STARFM. The time and magnitude of clearing and re-clearing events were estimated through a phenological breakpoint analysis, with 96.2% of the estimated breakpoints of the clearing event and 83.6% of the re-clearing event being within 40 days of the true clearing. The study highlights the benefits of using these moderate resolution data for quantifying and understanding land cover change in open forest environments.
Psychological Determinants of Consumer Acceptance of Personalised Nutrition in 9 European Countries
Poinhos, R. ; Lans, I.A. van der; Rankin, A. ; Fischer, A.R.H. ; Bunting, B. ; Kuznesof, S. ; Stewart-Knox, B. ; Frewer, L.J. - \ 2014
PLoS One 9 (2014)10. - ISSN 1932-6203 - 13 p.
protection motivation theory - food-related hazards - self-efficacy - planned behavior - cardiovascular-disease - health behavior - predictive-validity - perceived control - attitude-change - fear appeals
Objective To develop a model of the psychological factors which predict people’s intention to adopt personalised nutrition. Potential determinants of adoption included perceived risk and benefit, perceived self-efficacy, internal locus of control and health commitment. Methods A questionnaire, developed from exploratory study data and the existing theoretical literature, and including validated psychological scales was administered to N = 9381 participants from 9 European countries (Germany, Greece, Ireland, Poland, Portugal, Spain, the Netherlands, the UK, and Norway). Results Structural equation modelling indicated that the greater participants’ perceived benefits to be associated with personalised nutrition, the more positive their attitudes were towards personalised nutrition, and the greater their intention to adopt it. Higher levels of nutrition self-efficacy were related to more positive attitudes towards, and a greater expressed intention to adopt, personalised nutrition. Other constructs positively impacting attitudes towards personalised nutrition included more positive perceptions of the efficacy of regulatory control to protect consumers (e.g. in relation to personal data protection), higher self-reported internal health locus of control, and health commitment. Although higher perceived risk had a negative relationship with attitude and an inverse relationship with perceived benefit, its effects on attitude and intention to adopt personalised nutrition was less influential than perceived benefit. The model was stable across the different European countries, suggesting that psychological factors determining adoption of personalised nutrition have generic applicability across different European countries. Conclusion The results suggest that transparent provision of information about potential benefits, and protection of consumers’ personal data is important for adoption, delivery of public health benefits, and commercialisation of personalised nutrition.
Management of Water and Agroecosystems in Landscapes for Sustainable Food Security
Boelee, E. ; Scherr, S.J. ; Pert, P. ; Barron, J. ; Finlayson, M. ; Descheemaeker, K.K.E. ; Milder, J.C. ; Fleiner, R. ; Nguyen-Khoa, S. ; Barchiesi, S. ; Bunting, S.W. ; Tharme, R. ; Khaka, E. ; Coates, D. ; Solowey, E.M. ; Lloyd, G.J. ; Molden, D. ; Cook, S. - \ 2013
In: Managing water and agroecosystems for food security / Boelee, E., CABI - ISBN 9781780640884 - p. 156 - 170.
Mangrove, resilient shrimp production and macro-economic sustainability
Bosma, R.H. ; Sidik, A.S. ; Bunting, S.W. - \ 2013
Increasing Water Productivity in Agriculture
Descheemaeker, K.K.E. ; Bunting, S.W. ; Bindraban, P.S. ; Muthuri, C. ; Molden, D. ; Beveridge, M. ; Brakel, M. van; Herrero, M. ; Clement, F. ; Boelee, E. ; Jarvis, D. - \ 2013
In: Managing water and agroecosystems for food security CABI - ISBN 9781780640884 - p. 104 - 123.
Bioeconomic Modeling Of Shrimp Aquaculture Strategies For The Mahakam Delta, Indonesia
Bunting, S.W. ; Bosma, R.H. ; Zwieten, P.A.M. van; Sidik, A.S. - \ 2013
Aquaculture Economics & Management 17 (2013)1. - ISSN 1365-7305 - p. 51 - 70.
mangrove forestry farms - southern vietnam - mixed shrimp - ecology - limitations - systems
Bioeconomic modeling was used to evaluate traditional and extensive shrimp production in the Mahakam Delta and impacts of adopting Better Management Practices (BMP) for semi-intensive and integrated mangrove-shrimp culture. Modeling outcomes indicate that traditional production is not financially viable, failing to generate a positive 10-year Internal Rate of Return (IRR). Such practices persist in the Mahakam Delta as capital costs have been depreciated against past financial returns, input costs are negligible, risks are minimal, opportunity costs are low and options to intensify production have been retained by producers. Returns from BMP-guided semi-intensive culture (20% IRR) are marginally higher compared to extensive culture but entail a 10-fold increase in operating costs and greater risks. Integrated mangrove-shrimp production gives a reasonable IRR (53%) but costs remain high, management demanding and risks uncertain. Risk adverse operators with short-term leases may favor traditional and extensive practices. Sustainable intensification, allied to social capital development and rehabilitation of mangrove ecosystem services and environmental flows, is needed to reconcile multiple demands.
Land cover and habitat classification from Earth Observation data: a new approach from BIO_SOS
Lucas, R. ; Jones, G. ; Bunting, P. ; Kosmidou, V. ; Petrou, Z. ; Inglada, J. ; Blonda, P. ; Adamo, M. ; Mücher, C.A. ; Arvor, D. - \ 2013
In: Proceedings of GI Forum 2013 ‘Creating the GISociety’, Symposium Ecosystem and Biodiversity Monitoring – Best practice in Europe and Globally - 2-5 July 2013, Salzburg, Austria. - - p. 520 - 523.
A new approach to the land cover and habitat classification in support of biodiversity monitoring
Lucas, R. ; Bunting, P. ; Jones, G. ; Kosmidou, V. ; Inglada, J. ; Blonda, P. ; Adamo, M. ; Tarantino, C. ; Mücher, C.A. - \ 2013
Modelling the financial feasibility of sustainably managed shrimp culture agro-ecosystems in Mahakam delta, Indonesia
Bosma, R.H. ; Bunting, S.W. - \ 2012
Modelling the financial feasibility of transforming the extensive shrimp of the Mahakam delta, Indonesia, in sustainable aquaculture ecosystems
Bosma, R.H. ; Bunting, S.W. - \ 2012
In: Global Aquaculture: Securing our future. Prague 1-5 september, AQUA-2012. - - p. 279 - 279.
In 2006, mangrove forests covered less than 10% of the 1100 km2 Mahakam delta which was virgin until 1930. This regression was mainly due to their transformation to shrimp ponds. Pond size varied between 3 and 30 ha but the effective pond size was much smaller than the area between the dikes as only the soil needed to make the dikes was excavated while the central plateau was left intact. Shrimp production is extensive, but production of 200 to 300 kg/ha in the first year gradually declined on average to 50 kg/ha/yr as only one crop in four is successful. Due to declining productivity as a result of deteriorating quality of bottom and water, and outbreaks of disease such as white spot virus, the area covered by ponds gradually decreased. Most pond farmers, caretakers and workers have little alternative employment opportunities. Improving the shrimp production is important to provide farmers with sustainable livelihoods and maintain biodiversity elsewhere (Bush et al. 2010, Ecology and Society, 15(2),15). In the Philippines where mangrove cutting was prohibited since 1982 (Primavera, 1997 Aquac Res 28,815-827), farmers developed the so-called green-water technology (GW). Tendencia et al (2011, Aquaculture 311(1-4),87-93) showed that the presence of mangrove in the water source is a disease preventing factor. In Mahakam delta the Fisheries Services tested a farming system associating mangrove and extensive shrimp ponds. To test whether a production system integrating both shrimp culture using GW and mangrove forestry is a financially feasible alternative for the extensive system in the Mahakam delta we applied economic modelling. The baselines used were farms using GW in the Philippines (Bosma et al. AFAF 2011) and the extensive system in the Mahakam (Bunting et al. 2012, Aquac Manag & Econ), both in 2009. Without accounting for livelihood contributions from collecting in close to 8 ha mangrove, nor its cultural services, the associated mangrove GW aquaculture system more than doubled farmers income compared to the extensive system (Table). Compared to the extensive system the associated mangrove GW shrimp farming delivered 20 times more shrimp, thus dramatically increasing the contribution to the national economy without accounting its ecosystems services, e.g. fish breeding and nursing grounds. Disclaimer: Preparation of this paper was supported by the EC INCO-DEV MANGROVE project with funds from by the European Communitys Sixth Framework Programme [Contract: INCO-CT-2005-003697] and by the RESCOPAR project funded by the INREF program of Wageningen University This publication reflects the authors views and the European Community is not liable for any use that may be made of the information contained herein.
Financial Feasibility of Green-water Shrimp Farming Associated with Mangrove Compared to Extensive Shrimp Culture in the Mahakam Delta, Indonesia
Bosma, R.H. ; Tendencia, E.A. ; Bunting, S.W. - \ 2012
Asian Fisheries Science 25 (2012)3. - ISSN 0116-6514 - p. 258 - 269.
This paper presents a post-hoc assessment of the introduction of intensive shrimp farming strategies, with and without green-water (GW) technology, in the Mahakam Delta where extensive systems (ES) dominate. The study also assesses the potential of integrated mangrove GW shrimp production (MGW). The method section describes the systems considered, the cost-benefit analysis applied and the assumptions for different scenarios. The data for the GW and non-GW systems were based on a survey in the Philippines. Assessing cultured shrimp yields from the total farm area showed that production from non-GW was 10% higher than from GW farms. Compared to these two systems, the MGW system produces about 20% of the total shrimp, but provides complementary livelihood options and ecosystem services. Per unit area covered, MGW system produces 20 times more shrimp than ES, while income for farmers doubles and opportunities for livelihoods enhancement associated with the mangrove area increase. Low operating costs make the ES interesting for resource poor farmers, but risks to producers and societal cost are underrated. Transferring from ES to MGW system will increase the contribution to the national economy whilst maintaining ecosystem services, that would otherwise be lost, were intensive culture systems to predominate.
From marginal to resilient aquaculture based livelihoods in coastal mangrove zones
Bosma, R.H. ; Tendencia Alapide, E. ; Bunting, S.W. - \ 2011
ncreasing welfare pushes the global demand for luxury food such as shrimp. This growing demand has to be reconciled with concerns for the environment. In many countries mangrove forest is still threatened by short term benefits from timber and unsustainable practices of shrimp farming. Financial returns of semi-intensive shrimp culture systems in former mangrove forests are often short lived. Following declines in productivity as a result of deteriorating quality of bottom and water, and outbreaks of shrimp disease such as white spot virus, farmers e.g. in free access mangrove forests of East-Kalimantan reverted to extensive systems. Contrastingly farmers in the Philippines intensified and developed the so-called green-water (GW) technology. Using mangrove to filter the effluent water, such systems contribute to sustainable livelihoods in resilient aquatic ecosystems. In East-Kalimantan, mangroves recover in areas where shrimp production collapsed, but in search for a livelihood people turn to other virgin natural resources. Can we prevent the cycle of destruction and collapse by reorganising the sector and create resilient livelihoods? Though the GW system spreads rapidly over the Philippines it’s dissemination to e.g. Indonesia requires convincing financial data. Using bio-economic modelling we explore potential constraints hindering uptake of apparently more sustainable strategies, to generate information for policy makers. After presenting financial data of GW and non-GW farms in the Philippines, we model development options of extensive farms in East-Kalimantan.We discuss the outcomes of the financial assessment, and the implications for options of sustainable mangrove-shrimp agro-ecosystems management.
Ecosystems for water and food security
Boelee, E. ; Atapattu, S. ; Barron, J. ; Bindraban, P. ; Bunting, S.W. ; Coates, D. ; Descheemaeker, K.K.E. ; Eriyagama, N. ; Finlayson, M. ; Gordon, L. - \ 2011
Colombo : UNEP (Job Number: DEPI/1392/NA ) - ISBN 9789280731705 - 194
ecosysteemdiensten - voedselzekerheid - waterzekerheid - ecosystem services - food security - water security
Mangrove ecosystem and the related community livelihoods
Bosma, R.H. ; Jumnongsong, S. ; Dulyapurk, V. ; Sidik, S.A. ; Dao, P.T.A. ; Tuan, L.X. ; Zwieten, P.A.M. van; Bunting, S.W. - \ 2010
Bridging gaps in fragmented marshland : applying landscape ecology for bird conservation
Foppen, R.F.B. - \ 2001
University. Promotor(en): Paul Opdam. - S.l. : S.n. - ISBN 9789058084897 - 168
vogels - terrestrische ecosystemen - fragmentatie - verspreiding - populaties - moerassen - wetlands - nederland - landschapsecologie - moerasvogels - natuur - versnippering - birds - terrestrial ecosystems - fragmentation - dispersal - populations - marshes - netherlands
<p>An important part of the natural values in The Netherlands is based on the fact that the country has a unique geographical position in temperate lowland Europe at the mouth of the rivers Rhine and Meuse. This creates a number of interesting gradient situations e.g. between saltwater and freshwater systems, between eutrophic and oligotrophic systems, and between tidal, streaming and stagnant waters. This position offers excellent conditions for a wide variety of wetland systems: river and clay marshlands with open water and macrophyte vegetation like reedlands, peat marshland with bogs, fens and mires, as well as estuaries with saltmarshes. This marshland diversity resulted in a very diverse avifauna with many species occurring in high densities. The diversity and quantity of these wetland ecosystems, however, is severely threatened and consequently the number and the distribution of typical marshland bird species decreased (Den Boer 2000). Acidification, euthrophication and desiccation, cultivation and unfavourable management practices all contributed to a decline of total area and an increasing degree of fragmentation of the remaining habitat for marshland birds (Figure 1.1). The Dutch Nature Policy Plan, published in 1990 (NPP 1990), mentioned fragmentation as one of the most important threats to biodiversity. A nation-wide ecological network of nature areas was proposed as the solution for this problem. It is vital for the success of this strategy that the implementation is underpinned by ecological knowledge of the underlying processes in this network system.</p><p> The process of habitat fragmentation leads to landscapes with dispersed small populations within an inhospitable matrix. Small populations are likely to go extinct by stochastic demographic fluctuations. Consequently, the viability of these small populations depends on the likelihood that they will be recolonised by individuals from elsewhere. Crucial is whether the distances most individuals are likely to cover between years, as a result of the dispersal process, are large enough compared to the interpatch distances within a landscape. A set of subpopulations (or metapopulation), may be viable, even when all subpopulations are small in size under the condition that local extinction and recolonisation rates are balanced.</p><p> Fragmentation can lead to a conservation problem, which asks for spatial solutions. In a multifunctional society, like The Netherlands, finding and implementing effective solutions are part of a spatial planning process. The way from problem definition to the actual implementation of a plan can be regarded as a cyclic planning process (Figure 1.2) with successive phases on problem detection, exploring solutions, development of landscape scenarios, designing an actual plan and plan evaluation. Often, ecological knowledge is poorly used in such planning processes. It is probably due to the fact that the knowledge is not tailored for the different phases of the planning cycle. This asks for generalisations, from case studies to a variety of landscapes. It also asks for aggregation of knowledge on single species to knowledge on multispecies level.</p><p> It is a challenge for landscape ecology to develop and support such an approach and link ecology and spatial planning and, to my opinion, knowledge systems should play a major role (Figure 1.3).</p><p>This thesis is an attempt to elaborate this landscape ecological line of thought for the problem of fragmented marshland and conservation of bird species. It tries to bridge two 'gaps'. Firstly, the gap (in literal sense) between remaining pieces of marshland. What is an effective spatial strategy for the persistence of marshland birds in The Netherlands? How should we 'bridge' the gaps between our remaining habitats? The second gap is metaphorical and refers to the transfer of ecological knowledge gathered in case studies and at the species level into tools and instruments for application in nature management and policy. In conclusion, the central questions of this thesis are: (1) under what spatial conditions do marshland birds demonstrate negative effects of fragmentation and (2) how to utilise ecological knowledge for practical tools in conservation?</p><p> In Chapter 2 distribution data of six typical marshland passerines occurring in heavily fragmented landscapes in Gelderland and Sealand Flanders are analysed. Some of the species are common, like the reed warbler and the reed bunting (occurring in &gt;50% of the habitat patches), others are scarce or rare (sedge warbler, great reed warbler, penduline tit and bluethroat). After correcting for patch size and quality, in most cases occurrence is significantly explained by patch connectivity, a measure for the spatial configuration of the patch. The response of species to fragmentation is variable, but the analyses confirm that in many landscapes in The Netherlands habitat fragmentation negatively influences occurrence of bird populations. By linking the fraction of occupied patches to ecologically scaled landscape indices (ESLI) a diagnostic tool was set up. The ESLI 'average patch carrying capacity' is a good estimator of the fraction of occupied patches and that the 50% occupation threshold (assumed to be a viability threshold according to Vos et al. 2001) will be reached at an average patch carrying capacity of 2-5 territories. This diagnostic instrument is practical and quickly applicable because no field data are required, the essential information concerning carrying capacity can be collected from literature.</p><p> Spatially explicit population models, mathematical models simulating population dynamics of a species with subdivided populations, are useful research tools to explore and understand the behaviour of populations in a fragmented landscape. These models require lots of information for parameterisation of the essential parameters, the most important source are field data. Particularly quantitative data on the dispersal and emigration rates are essential, though collecting these data is time-consuming and difficult. In Chapter 3 the results of a field study on the great reed warbler are presented. The study area consisted of reed beds along lakes, total length around 15 kilometres. During 1994-2000 over 1100 individuals were colour banded and more than 250 individuals were resighted in one or more following years. By analysing records of marked individuals, survival, dispersal and emigration rates were quantified. Most individuals show displacements within the study area. Survival is estimated by analysing the capture-recapture data using the program MARK and depends on age, sex and year. Emigration rates are estimated by dividing the study area in six equal parts and analysing the differences in local survival between the parts and various combinations. The resulting function describes the relation between the emigration rate and the size of an area. The demographic data and the quantification of dispersal are subsequently used for the parameterisation of a metapopulation model. This model is decribed and used in the following chapters.</p><p> Chapter 4 demonstrates the influence of large environmental impacts on the dynamics of a metapopulation. In the last decades a number of passerines wintering in the Sahel zone suffers from the droughts. The sedge warbler is one of those species. After drought years (like in the mid-seventies and eighties) the population shows a decline of more than 50%. After these collapses the population recovers, but not in all marshlands. An analysis of the population trends in a large number of marshlands in The Netherlands indicated that populations in large marshlands recovered quickly, but that small and relatively isolated populations, like in the eastern and southern parts of the country, did not recover at all. Exercises with a metapopulation model support the hypothesis that this lack of resilience is due to fragmentation effects. Populations of fragmented areas are particularly vulnerable for catastrophic events, probably because certain thresholds for population viability are linked with population size.</p><p> Chapter 5 elaborates on the role of low quality habitats (sinks) in a metapopulation. Persistence of sink populations depends on nearby source populations. However, do sink areas also contribute to the persistence of source areas? In a riverine landscape in the province of Gelderland a number of large marshlands are located close to each other, these constitute source areas for the reed warbler. In a radius of 20-30 kilometres around these marshlands hundreds of small marshlands occur in a landscape dominated by agriculture. A field study demonstrated that in many of these small reed elements reed warblers occur. A regression analysis shows that the habitat quality of these habitat patches is poor and that they most likely are to be considered sink areas. Furthermore, spatial parameters are very important in explaining the probability of occurrence, the abundance and also extinction and recolonisation rates of the habitat patches. In isolated patches the probability of occurrence is low, densities are low, the probability of extinction is high and recolonisation probabilities are low. Thus reed warbler populations in these small elements show metapopulation dynamics. Using a spatially explicit population model proves that sink areas do contribute to the stability and persistence of source areas. A recovery after a population decline is much faster in source areas embedded in a network with sink patches than in source areas with no sinks around. This influence however, depends on the spatial conditions. For reed warblers mainly the sink areas within 2-5 kilometres of a source patch are of importance, and the total number of individuals supported by the sinks should be at least 25% of the source population size.</p><p> In Chapter 6 I analyse distribution data of the bittern in The Netherlands. The bittern is a scarce breeding bird, occurring in less than 50% of all suitable reed dominated marshlands. The species is rare in the eastern, north-eastern and southern parts of the country, although suitable habitat patches occur. A regression model is used to predict probability of occurrence of the bittern in a patch given the size, abiotic (soil) conditions of the marshland and the connectivity. The results indicate that low probability of occurrence of the bittern in certain regions can be explained by unfavourable spatial conditions. The predictions per habitat patch are subsequently used as a calibration set for a simple expert model, SCAN, based on connectivity. The model uses a connectivity value for grid cells of 250x250 meters as an indicator of spatial conditions. The SCAN output gives satisfactory results and correlates well with the regression model predictions. It is considered a useful instrument for problem detection, although the challenge is to find generic rules to translate the model output into probability of occurrence or persistence measures. </p><p> In Chapters 2-6 a number of methods is introduced for the analysis of species occurrence and persistence in fragmented landscapes: developing landscape indices (Chapter 2), metapopulation models (Chapter 4 and 5) and regression models (Chapter 2 and 6). Can we develop an instrument that integrates the various methods and is applicable on landscape rather than on species level? In Chapter 7 a rule-based system is described that combines the merits of all previously mentioned methods. Central issue is the key-patch approach. A key patch is defined as a habitat patch within a habitat network of such a size that the probability of extinction of the local population is less than 5% in 100 years. It is the basis of a persistent metapopulation. The predictive models resulting from the various regression analyses are used to indicate key population standards for a number of species. With help of metapopulation models for two ecoprofiles, a marshland passerine 'reed warbler' and a marshland heron 'bittern' these key population standards are extrapolated to landscape configurations. Literature data on various species groups are used to test the validity of the standards. Three standards are proposed, for long-lived large vertebrates (example: bittern, otter): 20 individuals, for middle-long lived, medium sized vertebrates (example: great reed warbler): 40 individuals and for short-lived, small vertebrates (reed warbler, voles): 100 individuals. These standards are implemented in a GIS and rule-based system, called LARCH, and this is considered a useful evaluation tool for spatial scenarios and plans. </p><p>In Chapter 8 I conclude that the occurrence and persistence of marshland bird species in The Netherlands is negatively influenced by the current degree of habitat fragmentation. I also discuss the value of the presented instruments and tools for application in the different phases of the planning cycle.</p><p>What spatial strategy is effective to bridge the gaps between isolated marshlands? The results of this thesis indicate that the primary option is to enlarge existing marshlands, creating at least five key populations for most of the marshland birds. This requires extension of the size of most existing marshlands by nature restoration, aiming at totals of 5000-10 000 ha. Next, a marshland 'backbone' should be created with restoration of medium-sized marshlands along several axes. By this way marshland bird populations in the periphery are better 'connected' with the core areas and will show a higher, regional, persistence. It will also enhance the probability of occurrence and saturation in existing marshland areas and thus is a cost-effective measure.</p>
Black-faced Bunting Emberiza spodocephala on Taliabu Island, Sula Island group; the first record for Indonesia.
Stones, A.J. ; Bean, N.A.J. ; Balen, S. van - \ 1997
Kukila 9 (1997). - ISSN 0216-9223 - p. 56 - 57.
Quantitative land evaluation for agro-ecological characterization.
Keulen, H. van; Berkhout, J.A.A. ; Diepen, C.A. van; Heemst, H.D.J. van; Janssen, B.H. ; Rappoldt, C. ; Wolf, J. - \ 1987
In: Agricultural environments : characterization, classification and mapping : proceedings of the Rome workshop on agro-ecological characterization, classification and mapping, 14 - 18 April 1986 / Bunting, A.H., - p. 185 - 197.
grondvermogen - landevaluatie - modellen - onderzoek - bodemgeschiktheid - agro-ecologie - land capability - land evaluation - models - research - soil suitability - agroecology
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