Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    We have a manual that explains all the features 

    Records 1 - 17 / 17

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    Irrigation infrastructure and farm productivity in the Philippines: A stochastic Meta-Frontier analysis
    Bravo-Ureta, Boris E. ; Higgins, Daniel ; Arslan, Aslihan - \ 2020
    World Development 135 (2020). - ISSN 0305-750X
    Impact evaluation - Irrigation - Philippines - Productivity - Rice - Selectivity bias - Stochastic Production and Meta-Frontiers

    Irrigation is a lynchpin of rural development strategies and a key input to improving productivity and farm incomes, the key source of livelihood for the majority of the world's poor. Limited land and growing water scarcity mean that establishing systems to maximise the benefits from every drop is pivotal. In this paper, we analyse the impact of a canal irrigation project for smallholders in the Philippines, focusing on rice, one of the world's most water intensive crops. We contribute to two strands of literature by combining impact evaluation and efficiency analysis methods. Using a dataset for 714 treatment and 440 control farm parcels, we apply Propensity Score Matching and a selectivity-corrected Stochastic Production Frontier to handle biases from both observable and unobservable variables. We then analyse technical efficiency (TE) and frontier output using a shared Stochastic Meta-Frontier. We find that the project had a statistically significant impact on frontier output but not on TE, suggesting that improved irrigation technology increased beneficiaries' production potential, but it did not improve TE likely due to insufficient training and input access. Thus, beneficiaries were unable to take full advantage of their improved production potential, highlighting the need for suitable complementary support in future projects. Heterogeneity analysis reveals that the main beneficiaries were downstream parcels, smaller parcels, those located in the poorer project district, and farmers with lower education, all implying a pro-poor impact. Finally, we find that female-headed households benefitted less from the project, suggesting the need for additional support in future interventions.

    Global patterns and drivers of ecosystem functioning in rivers and riparian zones
    Tiegs, Scott D. ; Costello, David M. ; Isken, Mark W. ; Woodward, Guy ; McIntyre, Peter B. ; Gessner, Mark O. ; Chauvet, Eric ; Griffiths, Natalie A. ; Flecker, Alex S. ; Acuña, Vicenç ; Albariño, Ricardo ; Allen, Daniel C. ; Alonso, Cecilia ; Andino, Patricio ; Arango, Clay ; Aroviita, Jukka ; Barbosa, Marcus V.M. ; Barmuta, Leon A. ; Baxter, Colden V. ; Bell, Thomas D.C. ; Bellinger, Brent ; Boyero, Luz ; Brown, Lee E. ; Bruder, Andreas ; Bruesewitz, Denise A. ; Burdon, Francis J. ; Callisto, Marcos ; Canhoto, Cristina ; Capps, Krista A. ; Castillo, María M. ; Clapcott, Joanne ; Colas, Fanny ; Colón-Gaud, Checo ; Cornut, Julien ; Crespo-Pérez, Verónica ; Cross, Wyatt F. ; Culp, Joseph M. ; Danger, Michael ; Dangles, Olivier ; Eyto, Elvira De; Derry, Alison M. ; Villanueva, Veronica Díaz ; Douglas, Michael M. ; Elosegi, Arturo ; Encalada, Andrea C. ; Entrekin, Sally ; Espinosa, Rodrigo ; Ethaiya, Diana ; Ferreira, Verónica ; Ferriol, Carmen ; Flanagan, Kyla M. ; Fleituch, Tadeusz ; Follstad Shah, Jennifer J. ; Barbosa, André Frainer ; Friberg, Nikolai ; Frost, Paul C. ; Garcia, Erica A. ; Lago, Liliana García ; Soto, Pavel Ernesto García ; Ghate, Sudeep ; Giling, Darren P. ; Gilmer, Alan ; Gonçalves, José Francisco ; Gonzales, Rosario Karina ; Graça, Manuel A.S. ; Grace, Mike ; Grossart, Hans Peter ; Guérold, François ; Gulis, Vlad ; Hepp, Luiz U. ; Higgins, Scott ; Hishi, Takuo ; Huddart, Joseph ; Hudson, John ; Imberger, Samantha ; Iñiguez-Armijos, Carlos ; Iwata, Tomoya ; Janetski, David J. ; Jennings, Eleanor ; Kirkwood, Andrea E. ; Koning, Aaron A. ; Kosten, Sarian ; Kuehn, Kevin A. ; Laudon, Hjalmar ; Leavitt, Peter R. ; Lemes Da Silva, Aurea L. ; Leroux, Shawn J. ; LeRoy, Carri J. ; Lisi, Peter J. ; MacKenzie, Richard ; Marcarelli, Amy M. ; Masese, Frank O. ; McKie, Brendan G. ; Medeiros, Adriana Oliveira ; Meissner, Kristian ; Miliša, Marko ; Mishra, Shailendra ; Miyake, Yo ; Moerke, Ashley ; Mombrikotb, Shorok ; Mooney, Rob ; Moulton, Tim ; Muotka, Timo ; Negishi, Junjiro N. ; Neres-Lima, Vinicius ; Nieminen, Mika L. ; Nimptsch, Jorge ; Ondruch, Jakub ; Paavola, Riku ; Pardo, Isabel ; Patrick, Christopher J. ; Peeters, Edwin T.H.M. ; Pozo, Jesus ; Pringle, Catherine ; Prussian, Aaron ; Quenta, Estefania ; Quesada, Antonio ; Reid, Brian ; Richardson, John S. ; Rigosi, Anna ; Rincón, José ; Rîşnoveanu, Geta ; Robinson, Christopher T. ; Rodríguez-Gallego, Lorena ; Royer, Todd V. ; Rusak, James A. ; Santamans, Anna C. ; Selmeczy, Géza B. ; Simiyu, Gelas ; Skuja, Agnija ; Smykla, Jerzy ; Sridhar, Kandikere R. ; Sponseller, Ryan ; Stoler, Aaron ; Swan, Christopher M. ; Szlag, David ; Teixeira-De Mello, Franco ; Tonkin, Jonathan D. ; Uusheimo, Sari ; Veach, Allison M. ; Vilbaste, Sirje ; Vought, Lena B.M. ; Wang, Chiao Ping ; Webster, Jackson R. ; Wilson, Paul B. ; Woelfl, Stefan ; Xenopoulos, Marguerite A. ; Yates, Adam G. ; Yoshimura, Chihiro ; Yule, Catherine M. ; Zhang, Yixin X. ; Zwart, Jacob A. - \ 2019
    Science Advances 5 (2019)1. - ISSN 2375-2548 - p. 14966 - 14973.

    River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.

    Risk to the supply of ecosystem services across aquatic ecosystems
    Culhane, Fiona ; Teixeira, Heliana ; Nogueira, Antonio J.A. ; Borgwardt, Florian ; Trauner, Daniel ; Lillebø, Ana ; Piet, Gerjan ; Kuemmerlen, Mathias ; McDonald, Hugh ; O'Higgins, Tim ; Barbosa, Ana Luisa ; Wal, Jan Tjalling Van Der; Iglesias-Campos, Alejandro ; Arevalo-Torres, Juan ; Barbière, Julian ; Robinson, Leonie A. - \ 2019
    Science of the Total Environment 660 (2019). - ISSN 0048-9697 - p. 611 - 621.
    Sustainability - Biodiversity
    The capacity of ecosystems to supply ecosystem services is decreasing. Sustaining this supply requires an under- standing of the links between the impacts of pressures introduced by human activities and how this can lead to
    changes in the supply of services. Here, we apply a novel approach, assessing‘
    risk to ecosystem service supply’ (RESS), across a range of aquatic ecosystems in seven case studies. We link aggregate impact risk from human activities on ecosystem components, with a relative score of their potential to supply services. The greatest RESS is found where an ecosystem component with a high potential to supply services is subject to high impact risk. In this context, we explore variability in RESS across 99 types of aquatic ecosystem component from 11 realms, ranging from oceanic to wetlands. We explore some causes of variability in the RESS observed, including assessment area, Gross Domestic Product (GDP) and population density. We found that Lakes, Rivers, Inlets and
    Coastal realms had some of the highest RESS, though this was highly dependent on location. We found a positive relationship between impact risk and service supply potential, indicating the ecosystem components we rely on mostfor services, are also those most at risk. However, variability in this relationship indicates that protecting the supply of ecosystem services alone will not protect all parts of the ecosystem at high risk. Broad socio-economic factors explained some of the variability found in RESS. For example, RESS was positively associated with GDP and artificial and agricultural land use in most realms, highlighting the need to achieve balance between increasing GDP and sustaining ecosystem health and human wellbeing more broadly. This approach can be used for sustainablemanagement of ecosystemservice use, to highlight the ecosystemcomponents mostcriticalto supplying services, and those most at risk

    Linking biodiversity to ecosystem services supply: Patterns across aquatic ecosystems
    Teixeira, Heliana ; Lillebø, Ana I. ; Culhane, Fiona ; Robinson, Leonie ; Trauner, Daniel ; Borgwardt, Florian ; Kummerlen, Mathias ; Barbosa, Ana ; McDonald, Hugh ; Funk, Andrea ; O'Higgins, Tim ; Wal, Jan Tjalling Van Der; Piet, Gerjan ; Hein, Thomas ; Arévalo-Torres, Juan ; Iglesias-Campos, Alejandro ; Barbière, Julian ; Nogueira, António J.A. - \ 2019
    Science of the Total Environment 657 (2019). - ISSN 0048-9697 - p. 517 - 534.
    Global initiatives have been increasingly focusing on mainstreaming the values of biodiversity and ecosystem services into decision-making at all levels. Due to the accelerated rate at which biodiversity is declining and its consequences for the functioning of ecosystems and subsequently, the services they provide, there is need to develop comprehensive assessments of the services and the benefits nature delivers to society. Based on expertevaluation, we identified relevant flow linkages in the supply-side of the socio-ecological system, i.e. from biodiversity to ecosystem services supply for eight case studies across European aquatic ecosystems covering freshwater, transitional, coastal and marine waters realms. Biological mediated services were considered, as well as those reliant on purely physical aspects of the ecosystem, i.e. abiotic outputs, since both have implications for spatial planning, management and decision-making. Due to the multidimensional nature of ecosystems and their biodiversity, our approach used ecosystem components such as habitats and biota as proxies for biodiversity and as the focal point for linkage identification. Statistical analysis revealed the importance of considering mobile biota in the spatial assessment of habitats. Contrary to literature evidences so far, our results showed significantly different and complementary ecosystem services supply patterns across the continuum of aquatic realms. The implemented score of ecosystem services supply has a high potential for integrated aquatic ecosystem service supply assessments in the context of ecosystem-based management.
    Introducing the H2020 AQUACROSS project: Knowledge, Assessment, and Management for AQUAtic Biodiversity and Ecosystem Services aCROSS EU policies
    Lago, M. ; Boteler, B. ; Rouillard, J. ; Abhold, K. ; Jähnig, S.C. ; Iglesias-Campos, A. ; Delacámara, G. ; Piet, G.J. ; Hein, T. ; Nogueira, A.J.A. ; Lillebø, A.I. ; Strosser, P. ; Robinson, L.A. ; Wever, A. De; O'Higgins, T. ; Schlüter, M. ; Török, L. ; Reichert, P. ; Ham, C. Van; Villa, F. ; Hugh, Mcdonald - \ 2019
    Science of the Total Environment 652 (2019). - ISSN 0048-9697 - p. 320 - 329.
    Freshwater - Coastal - Marine ecosystems - Resilience - Social-ecological modelling - EU 2020 Biodiversity Strategy - Social learning - stakeholder engagement
    The AQUACROSS project was an unprecedented effort to unify policy concepts, knowledge, and management of freshwater, coastal, and marine ecosystems to support the cost-effective achievement of the targets set by the EU Biodiversity Strategy to 2020. AQUACROSS aimed to support EU efforts to enhance the resilience and stop the loss of biodiversity of aquatic ecosystems as well as to ensure the ongoing and future provision of aquatic ecosystem services. The project focused on advancing the knowledge base and application of Ecosystem-Based Management. Through elaboration of eight diverse case studies in freshwater and marine and estuarine aquatic ecosystem across Europe covering a range of environmental management problems including, eutrophication, sustainable fisheries as well as invasive alien species AQUACROSS demonstrated the application of a common framework to establish cost-effective measures and integrated Ecosystem-Based Management practices. AQUACROSS analysed the EU policy framework (i.e. goals, concepts, time frames) for aquatic ecosystems and built on knowledge stemming from different sources (i.e. WISE, BISE, Member State reporting within different policy processes, modelling) to develop innovative management tools, concepts, and business models (i.e. indicators, maps, ecosystem assessments, participatory approaches, mechanisms for promoting the delivery of ecosystem services) for aquatic ecosystems at various scales of space and time and relevant to different ecosystem types.
    Exploring variability in environmental impact risk from human activities across aquatic ecosystems
    Borgwardt, Florian ; Robinson, Leonie ; Trauner, Daniel ; Teixeira, Heliana ; Nogueira, Antonio J.A. ; Lillebø, Ana I. ; Piet, Gerjan ; Kuemmerlen, Mathias ; O'Higgins, Tim ; McDonald, Hugh ; Arevalo-Torres, Juan ; Barbosa, Ana Luisa ; Iglesias-Campos, Alejandro ; Hein, Thomas ; Culhane, Fiona - \ 2019
    Science of the Total Environment 652 (2019). - ISSN 0048-9697 - p. 1396 - 1408.
    Aquatic ecosystem - Freshwater - Marine - Coastal - Biodiversity - Drivers
    Aquatic ecosystems are under severe pressure. Human activities introduce an array of pressures that impact ecosystems and their components. In this study we focus on the aquatic domains of fresh, coastal and marine waters, including rivers, lakes and riparian habitats to transitional, coastal as well as shelf and oceanic habitats. In an environmental risk assessment approach, we identified impact chains that link 45 human activities through 31 pressures to 82 ecosystem components. In this linkage framework >22,000 activity-pressure-ecosystem component interactions were found across seven European case studies. We identified the environmental impact risk posed by each impact chain by first categorically weighting the interactions according to five criteria: spatial extent, dispersal potential, frequency of interaction, persistence of pressure and severity of the interaction, where extent, dispersal, frequency and persistence account for the exposure to risk (spatial and temporal), and the severity accounts for the consequence of the risk. After assigning a numerical score to each risk criterion, we came up with an overall environmental impact risk score for each impact chain. This risk score was analysed in terms of (1) the activities and pressures that introduce the greatest risk to European aquatic domains, and (2) the aquatic ecosystem components and realms that are at greatest risk from human activities. Activities related to energy production were relevant across the aquatic domains. Fishing was highly relevant in marine and environmental engineering in fresh waters. Chemical and physical pressures introduced the greatest risk to the aquatic realms. Ecosystem components that can be seen as ecotones between different ecosystems had high impact risk. We show how this information can be used in informing management on trade-offs in freshwater, coastal and marine resource use and aid decision-making
    Impact of thiamine metabolites and spent medium from Chlorella sorokiniana on metabolism in the green algae Auxenochlorella prototheciodes
    Higgins, Brendan T. ; Wang, Qichen ; Du, Sandon ; Hennebelle, Marie ; Taha, Ameer Y. ; Fiehn, Oliver ; VanderGheynst, Jean S. - \ 2018
    Algal Research 33 (2018). - ISSN 2211-9264 - p. 197 - 208.
    Metabolism - Microalgae - Substrate utilization - Symbiosis - Thiamine

    Auxenochlorella protothecoides is a known thiamine auxotroph but our past work has shown that it can synthesize thiamine if provided with the precursor molecule 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP). Partial thiamine auxotrophy is common in microalgae with important ramifications for global phytoplankton productivity as well as engineering applications of algae. While thiamine deficiency can greatly depress algae growth and lipid content, the detailed metabolic impacts of thiamine deficiency are not well understood. We used metabolomics to study the response to thiamine-limited and replete conditions in mixotrophic A. protothecoides. We also investigated the impacts of exogenous HMP addition and the use of spent medium from another green algae, C. sorokiniana, as a source of thiamine metabolites. This is the first study, to our knowledge, that addresses metabolic impacts of thiamine deficiency and alleviation in green microalgae. Thiamine deficient cultures exhibited accumulation of pyruvate and α-ketoglutarate, indicating bottlenecks at the pyruvate dehydrogenase (PDH) and oxoglutarate dehydrogenase (OGDH) complexes. Both PDH and OGDH require thiamine pyrophosphate (TPP) as a cofactor. Transketolase also requires TPP but we only observed build-up of ribose-5-phosphate when glucose was supplied as a substrate. As expected, thiamine and HMP addition could alleviate these metabolic bottlenecks while greatly increasing algal growth, neutral lipid and starch content. Spent medium from C. sorokiniana only appeared to partially alleviate thiamine deficiency and resulted in build-up of isocitrate and glycolate, metabolites that appeared relatively unaffected by the presence or absence of thiamine. Interestingly, longer culture time of C. sorokiniana when preparing the spent medium led to much higher availability of thiamine metabolites. Thus, under the right conditions, it may be possible to co-culture mutually beneficial algae species and/or recycle spent cultivation medium to overcome auxotrophy in algae.

    Growing the future: High-tech farmers are using LED lights in ways that seem to border on science fiction
    Marcelis, Leo - \ 2018
    A workshop on 'Dietary Sweetness-Is It an Issue?'
    Wittekind, Anna ; Higgins, Kelly ; McGale, Lauren ; Schwartz, Camille ; Stamataki, Nikoleta S. ; Beauchamp, Gary K. ; Bonnema, Angela ; Dussort, Pierre ; Gibson, Sigrid ; Graaf, Cees de; Halford, Jason C.G. ; Marsaux, Cyril F.M. ; Mattes, Richard D. ; McLaughlin, John ; Mela, David J. ; Nicklaus, Sophie ; Rogers, Peter J. ; Macdonald, Ian A. - \ 2018
    International Journal of Obesity 42 (2018)4. - ISSN 0307-0565 - p. 934 - 938.
    This report summarises a workshop convened by ILSI Europe on 3 and 4 April 2017 to discuss the issue of dietary sweetness. The objectives were to understand the roles of sweetness in the diet, establish whether exposure to sweetness affects diet quality and energy intake, and consider whether sweetness per se affects health. Although there may be evidence for tracking of intake of some sweet components of the diet through childhood, evidence for tracking of whole diet sweetness, or through other stages of maturity are lacking. The evidence to date does not support adverse effects of sweetness on diet quality or energy intake, except where sweet food choices increase intake of free sugars. There is some evidence for improvements in diet quality and reduced energy intake where sweetness without calories replaces sweetness with calories. There is a need to understand the physiological and metabolic relevance of sweet taste receptors on the tongue, in the gut and elsewhere in the body, as well as possible differentiation in the effects of sustained consumption of individual sweeteners. Despite a plethora of studies, there is no consistent evidence for an association of sweetness sensitivity/preference with obesity or type 2 diabetes. A multifaceted integrated approach, characterising nutritive and sensory aspects of the whole diet or dietary patterns, may be more valuable in providing contextual insight. The outcomes of the workshop could be used as a scientific basis to inform the expert community and create more useful dialogue among health care professionals.
    Cinco años de experiencia con Drosophila suzukii en Holanda
    Helsen, H.H.M. - \ 2018
    Polyfluorinated substances in abiotic standard reference materials
    Reiner, J.L. ; Blaine, A.C. ; Higgins, C.P. ; Kwadijk, C.J.A.F. - \ 2015
    Analytical and Bioanalytical Chemistry 407 (2015)11. - ISSN 1618-2642 - p. 2975 - 2983.
    alkyl acid concentrations - perfluorinated compounds - temporal trends - perfluorooctane sulfonate - spatial trends - human plasma - house-dust - perfluorochemicals - contaminants - china
    The National Institute of Standards and Technology (NIST) has a wide range of Standard Reference Materials (SRMs) which have values assigned for legacy organic pollutants and toxic elements. Existing SRMs serve as homogenous materials that can be used for method development, method validation, and measurement for contaminants that are now of concern. NIST and multiple groups have been measuring the mass fraction of a group of emerging contaminants, polyfluorinated substances (PFASs), in a variety of SRMs. Here we report levels determined in an interlaboratory comparison of up to 23 PFASs determined in five SRMs: sediment (SRMs 1941b and 1944), house dust (SRM 2585), soil (SRM 2586), and sludge (SRM 2781). Measurements presented show an array of PFASs, with perfluorooctane sulfonate being the most frequently detected. SRMs 1941b, 1944, and 2586 had relatively low concentrations of most PFASs measured while 23 PFASs were at detectable levels in SRM 2585 and most of the PFASs measured were at detectable levels in SRM 2781. The measurements made in this study were used to add values to the Certificates of Analysis for SRMs 2585 and 2781.
    TRY - a global database of plant traits
    Kattge, J. ; Diaz, S. ; Lavorel, S. ; Prentices, I.C. ; Leadley, P. ; Bönisch, G. ; Garnier, E. ; Westobys, M. ; Reich, P.B. ; Wrights, I.J. ; Cornelissen, C. ; Violle, C. ; Harisson, S.P. ; Bodegom, P.M. van; Reichstein, M. ; Enquist, B.J. ; Soudzilovskaia, N.A. ; Ackerly, D.D. ; Anand, M. ; Atkin, O. ; Bahn, M. ; Baker, T.R. ; Baldochi, D. ; Bekker, R. ; Blanco, C.C. ; Blonders, B. ; Bond, W.J. ; Bradstock, R. ; Bunker, D.E. ; Casanoves, F. ; Cavender-Bares, J. ; Chambers, J.Q. ; Chapin III, F.S. ; Chave, J. ; Coomes, D. ; Cornwell, W.K. ; Craine, J.M. ; Dobrin, B.H. ; Duarte, L. ; Durka, W. ; Elser, J. ; Esser, G. ; Estiarte, M. ; Fagan, W.F. ; Fang, J. ; Fernadez-Mendez, F. ; Fidelis, A. ; Finegan, B. ; Flores, O. ; Ford, H. ; Frank, D. ; Freschet, T. ; Fyllas, N.M. ; Gallagher, R.V. ; Green, W.A. ; Gutierrez, A.G. ; Hickler, T. ; Higgins, S.I. ; Hodgson, J.G. ; Jalili, A. ; Jansen, S. ; Joly, C.A. ; Kerkhoff, A.J. ; Kirkup, D. ; Kitajima, K. ; Kleyer, M. ; Klotz, S. ; Knops, J.M.H. ; Kramer, K. ; Kühn, I. ; Kurokawa, H. ; Laughlin, D. ; Lee, T.D. ; Leishman, M. ; Lens, F. ; Lewis, S.L. ; Lloyd, J. ; Llusia, J. ; Louault, F. ; Ma, S. ; Mahecha, M.D. ; Manning, P. ; Massad, T. ; Medlyn, B.E. ; Messier, J. ; Moles, A.T. ; Müller, S.C. ; Nadrowski, K. ; Naeem, S. ; Niinemets, Ü. ; Nöllert, S. ; Nüske, A. ; Ogaya, R. ; Oleksyn, J. ; Onipchenko, V.G. ; Onoda, Y. ; Ordonez Barragan, J.C. ; Ozinga, W.A. ; Poorter, L. - \ 2011
    Global Change Biology 17 (2011)9. - ISSN 1354-1013 - p. 2905 - 2935.
    relative growth-rate - tropical rain-forest - hawaiian metrosideros-polymorpha - litter decomposition rates - leaf economics spectrum - old-field succession - sub-arctic flora - functional traits - wide-range - terrestrial biosphere
    Plant traits – the morphological, anatomical, physiological, biochemical and phenological characteristics of plants and their organs – determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services and provide a link from species richness to ecosystem functional diversity. Trait data thus represent the raw material for a wide range of research from evolutionary biology, community and functional ecology to biogeography. Here we present the global database initiative named TRY, which has united a wide range of the plant trait research community worldwide and gained an unprecedented buy-in of trait data: so far 93 trait databases have been contributed. The data repository currently contains almost three million trait entries for 69 000 out of the world's 300 000 plant species, with a focus on 52 groups of traits characterizing the vegetative and regeneration stages of the plant life cycle, including growth, dispersal, establishment and persistence. A first data analysis shows that most plant traits are approximately log-normally distributed, with widely differing ranges of variation across traits. Most trait variation is between species (interspecific), but significant intraspecific variation is also documented, up to 40% of the overall variation. Plant functional types (PFTs), as commonly used in vegetation models, capture a substantial fraction of the observed variation – but for several traits most variation occurs within PFTs, up to 75% of the overall variation. In the context of vegetation models these traits would better be represented by state variables rather than fixed parameter values. The improved availability of plant trait data in the unified global database is expected to support a paradigm shift from species to trait-based ecology, offer new opportunities for synthetic plant trait research and enable a more realistic and empirically grounded representation of terrestrial vegetation in Earth system models.
    Conservation of biodiversity in sacred natural sites in Asia and Africa : A review of the scientific literature
    Dudley, Nigel ; Bhagwat, Shonil ; Higgins-Zogib, Liza ; Lassen, Barbara ; Verschuuren, Bas ; Wild, Robert - \ 2010
    In: Sacred Natural Sites / Verschuuren, Bas, Wild, Robert, McNeely, Jeffrey, Oviedo, Gonzalo, Taylor and Francis - ISBN 9781849711661 - p. 19 - 32.
    Sacred natural sites are frequently better protected than many officially protected areas, but an overall understanding of their role in conservation strategies is lacking. Over the last few years, scientists have assembled quantitative data from sacred natural sites, comparing their biodiversity values with those of the surrounding officially protected areas and other management approaches such as forest reserves. This chapter draws on information from over a hundred studies throughout Africa and Asia, which provides concrete evidence that many sacred natural sites have great importance to biodiversity conservation, in addition to their spiritual value to one or more faith groups. Sacred natural sites appear to be extremely common in some countries, although much remains to be learned about their global extent, as research reported in the scientific literature tends to be focused on a few countries. Sacred natural sites are often the only remaining patches of natural or semi-natural habitat in cultural landscapes (see Figure 2.1) and can contain rich biodiversity, sometimes exceeding nearby protected areas and

    forest reserves. Sacred natural sites are sometimes heavily modified or even planted; a proportion of these may nonetheless retain a rich complement of biodiversity at local level. Sacred natural sites are often recognized and used by local communities for their secular values, including medicinal plants, non timber forest products and other ecosystem services such as tourism or watershed protection. However, a number of problems have been identified threatening the role of sacred natural sites in long term conservation strategies. They are often too small to support a full complement of expected species and many sites are suffering from increased anthropogenic pressure, in some cases exceeding the capacity of the ecosystem to maintain its integrity. Unfortunately, many sacred natural sites are now degrading or have already disappeared in recent years. The pattern of loss has not been quantified but it is recognized to be increasing. Integration of sacred natural sites into conservation strategies can be complicated but provides an important way of preserving these unique places and the biological and cultural values they represent. Where appropriate from social and conservation perspectives, the conservation of sacred natural sites should be included in national conservation plans.
    Understanding tree-grass coexistence and impacts of disturbances and resource variability in savannas
    Langevelde, F. van; Tomlinson, K.W. ; Barbosa, E.R. ; Bie, S. de; Prins, H.H.T. ; Higgins, S.I. - \ 2010
    In: Ecosystem function in savannas Boca Raton, USA : CRC Press - ISBN 9781439804704 - p. 257 - 271.
    Determinants of woody cover in African savannas
    Sankaran, M. ; Hanan, N.P. ; Scholes, R.J. ; Ratnam, J. ; Augustine, D.J. ; Cade, B.S. ; Gignoux, J. ; Higgins, S.I. ; Roux, X. Le; Ludwig, F. ; Ardo, J. ; Banyikwa, F. ; Bronn, A. ; Bicini, G. ; Caylor, K.K. ; Coughenour, M.B. ; Diouf, A. ; Ekaya, W. ; Feral, C.J. ; February, E.C. ; Frost, P.G.H. ; Hiernaux, P. ; Hrabar, H. ; Metzger, K.L. ; Prins, H.H.T. ; Ringrose, S. ; Sea, W. ; Tews, J. ; Worden, J. ; Zambatis, N. - \ 2005
    Nature 438 (2005)7069. - ISSN 0028-0836 - p. 846 - 849.
    tree-grass coexistence - quantile regression - fire - vegetation - mechanisms - stability - systems
    Savannas are globally important ecosystems of great significance to human economies. In these biomes, which are characterized by the co-dominance of trees and grasses, woody cover is a chief determinant of ecosystem properties 1-3. The availability of resources (water, nutrients) and disturbance regimes (fire, herbivory) are thought to be important in regulating woody cover1,2,4,5, but perceptions differ on which of these are the primary drivers of savanna structure. Here we show, using data from 854 sites across Africa, that maximum woody cover in savannas receiving a mean annual precipitation (MAP) of less than ~650 mm is constrained by, and increases linearly with, MAP. These arid and semi-arid savannas may be considered 'stable' systems in which water constrains woody cover and permits grasses to coexist, while fire, herbivory and soil properties interact to reduce woody cover below the MAP-controlled upper bound. Above a MAP of ~650 mm, savannas are 'unstable' systems in which MAP is sufficient for woody canopy closure, and disturbances (fire, herbivory) are required for the coexistence of trees and grass. These results provide insights into the nature of African savannas and suggest that future changes in precipitation 6 may considerably affect their distribution and dynamics.
    Morphological, molecular, and differential-host characterization of Meloidogyne floridensis n. sp (Nematoda : Meloidogynidae), a root-knot nematode parasitizing peach in Florida
    Handoo, Z.A. ; Nyczepir, A.P. ; Esmenjaud, D. ; Beek, J.G. van; Castagnone-Sereno, P. ; Carta, L.K. ; Skantar, A.M. ; Higgins, J.A. - \ 2004
    Journal of Nematology 36 (2004)1. - ISSN 0022-300X - p. 20 - 35.
    myrobalan plum - enzyme phenotypes - perineal patterns - prunus-cerasifera - resistance - heteroderidae - rootstock - identification - polymorphism - javanica - descriptions - host range - hosts - morphology - morphotaxonomy - new species - parthenogenesis - peaches - plant pests - Meloidogyne - Meloidogyne arenaria - Meloidogyne chitwoodi - Meloidogyne fallax - Meloidogyne floridensis - Meloidogyne graminicola - Meloidogyne hapla - Meloidogyne incognita - Meloidogyne javanica - Prunus persica - Florida - Meloidogynidae - invertebrates - animals - eukaryotes - Prunus - Rosaceae - Rosales - dicotyledons - angiosperms - Spermatophyta - plants - Gulf States of USA - Southern States of USA - APEC countries - Developed Countries - North America - America - OECD Countries - South Atlantic States of USA - Southeastern States of USA - animal anatomy - nucleotide sequences - plant parasitic nematodes - nematoda - host parasite relationships - random amplified polymorphic DNA - taxonomy - USA - beschrijvingen - gastheerreeks - gastheren (dieren, mensen, planten) - morfologie - morfotaxonomie - nieuwe soorten - parthenogenese - perziken - plantenplagen - Meloidogyne - Meloidogyne arenaria - Meloidogyne chitwoodi - Meloidogyne fallax - Meloidogyne floridensis - Meloidogyne graminicola - Meloidogyne hapla - Meloidogyne incognita - Meloidogyne javanica - Prunus persica - Florida - Meloidogynidae - ongewervelde dieren - dieren - eukaryoten - Prunus - Rosaceae - Rosales - tweezaadlobbigen - bedektzadigen - Spermatophyta - planten - golfstaten van de VS - zuidelijke staten van de VS - APEC-landen - ontwikkelde landen - Noord-Amerika - Amerika - OESO-landen - zuid-Atlantische staten van de VS - zuidoostelijke staten van de VS - dieranatomie - nucleotidenvolgordes - plantenparasitaire nematoden - Nematoda - gastheer parasiet relaties - random amplified polymorphic DNA - taxonomie - VS
    A root-knot nematode, Meloidogyne floridensis n. sp., is described and illustrated from peach originally collected from Gainesville, Florida. This new species resembles M. incognita, M. christiei, M. graminicola, and M. hispanica, but with LM and SEM observations it differs from these species either by the body length, shape of head, tail and tail terminus of second-stage juveniles, body length and shape of spicules in males, and its distinctive female perineal pattern. This pattern has a high to narrowly rounded arch with coarsely broken and network-like striae in and around anal area, faint lateral lines interrupting transverse striae, a sunken vulva and anus, and large distinct phasmids. Molecular data from ribosomal IGS illustrate that M. floridensis n. sp. is different from the mitotic species M. arenaria, M. incognita, and M. javanica. Data from RAPDs confirm it and suggest that this new species lies in an intermediate phylogenetic position between the previous species and the meiotic species M. hapla, M. fallax, and M. chitwoodi. Differential host tests based on annual crops and on Prunus accessions are reported.
    Use of race and cultivar-specific elicitors from intercellular fluids for characterizing races of Cladosporium fulvum and resistant tomato cultivars
    Higgins, V.J. ; Wit, P.J.G.M. de - \ 1985
    Phytopathology 75 (1985). - ISSN 0031-949X - p. 695 - 699.
    Check title to add to marked list

    Show 20 50 100 records per page

     
    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.