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 - 20 / 193

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Molen
Check title to add to marked list
Weather and crop dynamics in a complex terrain, the Gamo Highlands – Ethiopia : Towards a high-resolution and model-observation based approach
Minda, Thomas Torora - \ 2019
Wageningen University. Promotor(en): J. Vilà-Guerau de Arellano; P.C. Struik, co-promotor(en): M.K. van der Molen. - Wageningen : Wageningen University - ISBN 9789463950664 - 200
Nitrogen Deposition Maintains a Positive Effect on Terrestrial Carbon Sequestration in the 21st Century Despite Growing Phosphorus Limitation at Regional Scales
Fleischer, Katrin ; Dolman, A.J. ; Molen, Michiel K. van der; Rebel, Karin T. ; Erisman, Jan Willem ; Wassen, Martin J. ; Pak, Bernard ; Lu, Xingjie ; Rammig, Anja ; Wang, Ying Ping - \ 2019
Global Biogeochemical Cycles 33 (2019)6. - ISSN 0886-6236 - p. 810 - 824.
carbon sequestration - land carbon sink - nitrogen deposition - nitrogen fixation - phosphorus limitation - terrestrial ecosystems

Nitrogen (N) and phosphorus (P) are two dominant nutrients regulating the productivity of most terrestrial ecosystems. The growing imbalance of anthropogenic N and P inputs into the future is estimated to exacerbate P limitation on land and limit the land carbon (C) sink, so that we hypothesized that P limitation will increasingly reduce C sequestered per unit N deposited into the future. Using a global land surface model (CABLE), we simulated the effects of increased N deposition with and without P limitation on land C uptake and the fate of deposited N on land from 1901 to 2100. Contrary to our hypothesis, we found that N deposition continued to induce land C sequestration into the future, contributing to 15% of future C sequestration as opposed to 6% over the historical period. P limitation reduced the future land C uptake per unit N deposited only moderately at the global scale but P limitation increasingly caused N deposition to have net negative effects on the land C balance in the temperate zone. P limitation further increased the fraction of deposited N that is lost via leaching to aquatic ecosystems, globally from 38.5% over the historical period to 53% into the future, and up to 75% in tropical ecosystems. Our results suggest continued N demand for plant productivity but also indicate growing adverse N deposition effects in the future biosphere, not fully accounted for in global models, emphasizing the urgent need to elaborate on model representations of N and P dynamics.

Correction: Responses of canopy growth and yield of potato cultivars to weather dynamics in a complex topography: Belg farming seasons in the gamo highlands, Ethiopia
Minda, Thomas T. ; Molen, Michiel K. Van Der; Arellano, Jordi Vilà Guerau De; Chulda, Kanko C. ; Struik, Paul C. - \ 2019
Agronomy 9 (2019)5. - ISSN 2073-4395

In Minda et al. [1], an error was introduced. We propose the following amendment: Figure 9, in Section 3.2.4 (Days to Maturity and Yield), should be replaced by the following updated figure. (Figure Presented) The authors apologize for any inconvenience caused to the readers by these changes. The manuscript will be updated and the original will remain online on the article webpage, with a reference to this correction.

Global challenges, Dutch solutions? The shape of responsibility in Dutch science and technology policies
Molen, Franke van der; Ludwig, David ; Consoli, Luca ; Zwart, Hub - \ 2019
Journal of Responsible Innovation 6 (2019)3. - ISSN 2329-9460 - p. 340 - 345.
Responsible research and innovation - science and technology policy - the Netherlands

The Netherlands has a well-established tradition of gearing science and technology to economic interests as well as societal and ethical concerns. This article outlines how national dynamics in the Netherlands have not only contributed to the adoption of Responsible Research and Innovation (RRI) frameworks but also to a distinctly Dutch meaning and institutionalization of responsibility. It identifies three core features of the Dutch context that have shaped this meaning and institutionalization: 1) a strong focus on the societal and economic relevance of research and innovation, 2) a political culture that emphasizes inclusive deliberation and collaboration, and 3) a focus on integration and synergy with respect to RRI. The integration of RRI in a collaborative system of companies, government and universities is embraced as contributing to a global leadership of the Netherlands in response to grand challenges. However, this integrative approach also limits the potential of Dutch RRI to function as a disruptive concept that challenges the status of interactions between science, technology, and society.

Responses of Canopy Growth and Yield of Potato Cultivars to Weather Dynamics in a Complex Topography: Belg Farming Seasons in the Gamo Highlands, Ethiopia
Minda, Thomas T. ; Molen, Michiel K. Van Der; Vilà-Guerau de Arellano, Jordi ; Chulda, Kanko C. ; Struik, Paul C. - \ 2019
Agronomy 9 (2019)4. - ISSN 2073-4395 - 27 p.
Potato is an increasingly important crop in Ethiopia. The Gamo Highlands are one of the large potential potato producing regions in Ethiopia. The growing conditions are different from those in the temperate regions, where most of the agronomical expertise on potato has been developed. The influence of environmental conditions on the crop in the Gamo Highlands is poorly understood. We conducted field trials with eight potato cultivars in six locations and during two seasons. The canopy cover (CC) and plant height (PH) were measured with high temporal resolution and tuber yields were assessed as well. The experiments were conducted near our newly installed weather stations at different elevations. CC and PH were strongly correlated with temperature sum (Tsum). Tuber yields differed among elevations and cultivars. Nevertheless, these differences were poorly explained by environmental variables. We also found that no single cultivar performed best at all elevations. The number of branches was a predictor of yield, suggesting that radiation interception was limiting tuber growth. Tuber yield was optimal when the number of days to crop maturity was around 100–110 days. We conclude that Tsum is a predictor of crop growth, but environmental variables poorly explain yield variations, which calls for further investigation
A remote cis-regulatory region is required for nin expression in the pericycle to initiate nodule primordium formation in medicago truncatula
Liu, Jieyu ; Rutten, Luuk ; Limpens, Erik ; Molen, Tjitse Van Der; Velzen, Robin Van; Chen, Rujin ; Chen, Yuhui ; Geurts, Rene ; Kohlen, Wouter ; Kulikova, Olga ; Bisseling, Ton - \ 2019
The Plant Cell 31 (2019)1. - ISSN 1040-4651 - p. 68 - 83.

The legume-rhizobium symbiosis results in nitrogen-fixing root nodules, and their formation involves both intracellular infection initiated in the epidermis and nodule organogenesis initiated in inner root cell layers. NODULE INCEPTION (NIN) is a nodule-specific transcription factor essential for both processes. These NIN-regulated processes occur at different times and locations in the root, demonstrating a complex pattern of spatiotemporal regulation. We show that regulatory sequences sufficient for the epidermal infection process are located within a 5 kb region directly upstream of the NIN start codon in Medicago truncatula. Furthermore, we identify a remote upstream cis-regulatory region required for the expression of NIN in the pericycle, and we show that this region is essential for nodule organogenesis. This region contains putative cytokinin response elements and is conserved in eight more legume species. Both the cytokinin receptor 1, which is essential for nodule primordium formation, and the B-type response regulator RR1 are expressed in the pericycle in the susceptible zone of the uninoculated root. This, together with the identification of the cytokinin-responsive elements in the NIN promoter, strongly suggests that NIN expression is initially triggered by cytokinin signaling in the pericycle to initiate nodule primordium formation.

Responsible Research and Innovation in Practice
Molen, Franke van der; Consoli, Luca ; Ludwig, D.J. ; Macnaghten, Philip - \ 2018
Nijmegen : Radboud Universiteit - 25 p.
Referenties en maatlatten voor natuurlijke watertypen voor de Kaderrichtlijn Water 2021-2027
Altenburg, W. ; Arts, G. ; Baretta-Bekker, J.G. ; Berg, M.S. van den; Broek Broek, T. van den; Buskens, R. ; Bijkerk, R. ; Coops, H.C. ; Dam, H. van; Ee, G. van; Evers, C.H.M. ; Franken, R. ; Higler, B. ; Ietswaart, T. ; Jaarsma, N. ; Jong, D.J. de; Joosten, A.M.T. ; Klinge, M. ; Knoben, R.A.E. ; Kranenbarg, J. ; Loon, W.M.G.M. van; Noordhuis, R. ; Pot, R. ; Twisk, F. ; Verdonschot, P.F.M. ; Vlek, H. ; Backx, J.J.G.M. ; Beers, M. ; Buijse, A.D. ; Duursema, G. ; Fagel, M. ; Leeuw, J. de; Molen, J. van der; Nijboer, R.C. ; Postma, J. ; Vriese, T. ; Duijts, R. ; Hartholt, J.G. ; Jager, Z. ; Stikvoort, E.C. ; Walvoort, D. - \ 2018
Amersfoort : Stowa (Stowa rapport 2018-49) - ISBN 9789057738135 - 481
Observational characterization of the Synoptic and Mesoscale circulations in Relation to Crop Dynamics: Belg 2017 in the Gamo Highlands, Ethiopia
Minda, T.T. ; Molen, M.K. van der; Heusinkveld, B.G. ; Struik, P.C. ; Vilà-Guerau de Arellano, J. - \ 2018
Atmosphere 9 (2018)10. - ISSN 2073-4433 - 24 p.
The Gamo Highlands in Ethiopia are characterized by complex topography and lakes. These modulate the mesoscale and synoptic scale weather systems. In this study, we analyzed the temporal and spatial variations in weather as function of topography and season and their impact on potato crop growth. To determine how crop growth varies with elevation, we installed a network of six automatic weather stations along two transects. It covers a 30-km radius and 1800-m elevation difference. We conducted a potato field experiment near the weather stations. We used the weather observations as input for a crop model, GECROS. Data analysis showed large differences between weather in February and May. February is more dominated by mesoscale circulations. The averaged February diurnal patter shows a strong east to southeast lake breezes and, at night, weak localized flows driven by mountain density flows. In contrast, in May, the synoptic flow dominates, interacting with the mesoscale flows. The GECROS model satisfactorily predicted the elevational gradient in crop yield. Model sensitivity experiments showed that belg-averaged precipitation distribution gave the highest yield, followed by exchanging May weather observations with April.
Quantification and attribution of urban fossil fuel emissions through atmospheric measurements
Super, Ingrid - \ 2018
Wageningen University. Promotor(en): W. Peters, co-promotor(en): M.K. van der Molen; H.A.C. Denier van der Gon. - Wageningen : Wageningen University - ISBN 9789463434980 - 192
Increased water-use efficiency and reduced CO2 uptake by plants during droughts at a continental scale
Peters, W. ; Velde, I.R. van der; Schaik, Erik van; Miller, John B. ; Ciais, Philippe ; Duarte, Henrique F. ; Laan-Luijkx, I.T. van der; Molen, M.K. van der; Scholze, M. ; Schaefer, Kevin ; Vidale, Pier Luigi ; Verhoef, Anne ; Wårlind, D. ; Zhu, Dan ; Tans, Pieter P. ; Vaughn, Bruce ; White, James W.C. - \ 2018
Nature Geoscience 11 (2018). - ISSN 1752-0894 - p. 744 - 748.
Severe droughts in the Northern Hemisphere cause a widespread decline of agricultural yield, the reduction of forest carbon uptake, and increased CO2 growth rates in the atmosphere. Plants respond to droughts by partially closing their stomata to limit their evaporative water loss, at the expense of carbon uptake by photosynthesis. This trade-off maximizes their water-use efficiency (WUE), as measured for many individual plants under laboratory conditions and field experiments. Here we analyse the 13C/12C stable isotope ratio in atmospheric CO2 to provide new observational evidence of the impact of droughts on the WUE across areas of millions of square kilometres and spanning one decade of recent climate variability. We find strong and spatially coherent increases in WUE along with widespread reductions of net carbon uptake over the Northern Hemisphere during severe droughts that affected Europe, Russia and the United States in 2001–2011. The impact of those droughts on WUE and carbon uptake by vegetation is substantially larger than simulated by the land-surface schemes of six state-of-the-art climate models. This suggests that drought-induced carbon–climate feedbacks may be too small in these models and improvements to their vegetation dynamics using stable isotope observations can help to improve their drought response.
The combined effect of elevation and meteorology on potato crop dynamics : A 10-year study in the Gamo Highlands, Ethiopia
Minda, Thomas T. ; Molen, M.K. van der; Struik, Paul C. ; Combe, Marie ; Jiménez, Pedro A. ; Khan, Muhammad S. ; Arellano, Jordi Vilà Guerau de - \ 2018
Agricultural and Forest Meteorology 262 (2018). - ISSN 0168-1923 - p. 166 - 177.
Complex terrain - High-resolution agrometeorological model - Inter-annual variability

Potato (Solanum tuberosum L.) is an important crop in the Gamo Highlands in Ethiopia. The region is characterised by a complex topography with large inter-annual weather variations, where potatoes grow in a range of altitudes between 1,600 and 3,200 m above sea level (a.s.l.). Traditional large-scale crop modelling studies only crudely represent the effect of complex topography, misrepresenting spatial variability in meteorology and potato growth in the region. Here, we investigate how weather influenced by topography affects crop growth. We used the Weather Research and Forecasting (WRF) model to simulate weather in relation to topography in coarse (54 km × 54 km) and fine (2 km × 2 km) resolution domains. The first has a resolution similar to those used by large-scale crop modelling studies that only crudely resolve the horizontal and vertical spatial effects of topography. The second realistically represents the most important topographical variations. The weather variables modelled in both the coarse and fine resolution domains are given as input to the GECROS model (Genotype-by-Environment interaction on CROp growth Simulator) to simulate the potato growth. We modelled potato growth from 2001 to 2010 and studied its inter-annual variability. This enabled us to determine for the first time in Ethiopia how variations in weather are linked to crop dynamics as a function of elevation at a fine resolution. We found that due to its finer representation of topography, weather and crop growth spatio-temporal variations were better represented in the fine than in the coarse resolution domain. The magnitude of crop growth variables such as Leaf Area Index (LAI) and Length of the Growing Season (LGS) obtained with weather from the coarse resolution domain were unrealistically low, hence unacceptable. Nevertheless, the resulting potato yields in the coarse resolution domain were comparable with the yields from the fine resolution domain. We explain this paradoxical finding in terms of a compensating effect, as the opposite effects of temperature and precipitation on yield compensated for each other along the major potato growing transect in the Gamo Highlands. These offsetting effects were also dependent on the correct estimations of the LGS, LAI. We conclude that a well-resolved representation of complex topography is crucial to realistically model meteorology and crop physiology in tropical mountainous areas.

Wat je moet weten over luchtkwaliteit in je huis. Wat adem je in?
Molen, Michiel van der - \ 2018
Operatie schone lucht
Molen, Michiel van der - \ 2018
The CarbonTracker Data Assimilation System for CO2 and δ13C (CTDAS-C13 v1.0) : Retrieving information on land-atmosphere exchange processes
Velde, Ivar R. Van Der; Miller, John B. ; Molen, Michiel K. Van Der; Tans, Pieter P. ; Vaughn, Bruce H. ; White, James W.C. ; Schaefer, Kevin ; Peters, Wouter - \ 2018
Geoscientific Model Development 11 (2018)1. - ISSN 1991-959X - p. 283 - 304.
To improve our understanding of the global carbon balance and its representation in terrestrial biosphere models, we present here a first dual-species application of the CarbonTracker Data Assimilation System (CTDAS). The system's modular design allows for assimilating multiple atmospheric trace gases simultaneously to infer exchange fluxes at the Earth surface. In the prototype discussed here, we interpret signals recorded in observed carbon dioxide (CO2) along with observed ratios of its stable isotopologues 13CO2/12CO2 (δ13C). The latter is in particular a valuable tracer to untangle CO2 exchange from land and oceans. Potentially, it can also be used as a proxy for continent-wide drought stress in plants, largely because the ratio of 13CO2 and 12CO2 molecules removed from the atmosphere by plants is dependent on moisture conditions. The dual-species CTDAS system varies the net exchange fluxes of both 13CO2 and CO2 in ocean and terrestrial biosphere models to create an ensemble of 13CO2 and CO2 fluxes that propagates through an atmospheric transport model. Based on differences between observed and simulated 13CO2 and CO2 mole fractions (and thus δ13C) our Bayesian minimization approach solves for weekly adjustments to both net fluxes and isotopic terrestrial discrimination that minimizes the difference between observed and estimated mole fractions. With this system, we are able to estimate changes in terrestrial δ13C exchange on seasonal and continental scales in the Northern Hemisphere where the observational network is most dense. Our results indicate a decrease in stomatal conductance on a continent-wide scale during a severe drought. These changes could only be detected after applying combined atmospheric CO2 and δ13C constraints as done in this work. The additional constraints on surface CO2 exchange from δ13C observations neither affected the estimated carbon fluxes nor compromised our ability to match observed CO2 variations. The prototype presented here can be of great benefit not only to study the global carbon balance but also to potentially function as a data-driven diagnostic to assess multiple leaf-level exchange parameterizations in carbon-climate models that influence the CO2, water, isotope, and energy balance.
Scepsis over proef om stadslucht te zuiveren
Molen, Michiel van der - \ 2017
Moet Oosterhout fijnstofvangers aanschaffen?
Molen, Michiel van der - \ 2017
Towards a Healthy Urban Route Planner for cyclists and pedestrians in Amsterdam
Steeneveld, G.J. ; Vreugdenhil, L.C. ; Molen, M.K. van der; Ligtenberg, A. - \ 2017
EMS annual meeting abstracts 14 (2017). - ISSN 1812-7053 - 1 p.
Cities are hotspots of air pollution and heat stress, resulting in nuisance, health risks, cost of medication, reduced labour productivity and sick leave for citizens. Yet the air pollution and heat stress are spatially and temporally unevenly distributed over the city, depending on pollutant emissions, street design and atmospheric turbulent mixing and radiation. This spatiotemporal variation allows pedestrians and bikers to choose alternative routes to minimize their exposure, if the distribution is known. In this project, we develop a route planner for bicyclists and pedestrians for Amsterdam (NL), that proposes routes and departure times based on model simulations of weather and air quality.We use the WRF-Chem atmosphere and air quality model at unprecedented grid spacing of 100-m (Ronda et al, 2015), with an underlying urban canopy model and NOx and PM10 emissions. The emissions by traffic are calculated based on observed traffic intensities and emission factors. An urban land use map will characterize urban density and street configuration to estimate urban heat storage (Attema et al, 2015). WRF-Chem runs will be issued daily for a lead time of 48 hours, resulting in forecast maps of temperature and pollutant concentrations that will be uniquely expressed in a metric that combines both treats The hourly fields of this metric are provided to the route planner based on the open source routing library pgRouting to identify more healthy routes on the route network of Amsterdam. The objectives of the healthy urban route planner are to raise awareness of heat and air quality issues in Amsterdam, to provide an innovative adaptation tool for citizens and tourists, to locate the most important bottlenecks in (the exposure to) air pollution and heat stress, and ultimately to test the readiness of the travellers to use the information and adapt the route.
Development of a Healthy Urban Route Planner for cyclists and pedestrians in Amsterdam
Steeneveld, G.J. ; Vreugdenhil, L.C. ; Molen, M.K. van der; Ligtenberg, A. - \ 2017
In: Societal Geo-innovation. Selected Papers of the 20th AGILE Conference on Geographic Information Science. - Cham : Springer - 3 p.
Cities are hotspots of air pollution and heat stress, resulting in nuisance, health risks, medication costs, reduced labour productivity and sick leave for citizens. Yet the air pollution and heat stress are spatially and temporally unevenly distributed over the city, depending on pollutant emissions, street design and atmospheric turbulent mixing and radiation. If accurately forecasted, this spatiotemporal variation offers pedestrians and bikers alternative routes to minimize their exposure. We develop a route planner for bicyclists and pedestrians for Amsterdam (NL), that proposes routes based on model simulations of weather and air quality. We use the WRF-Chem atmosphere and air quality model at unprecedented grid spacing of 100-m (Ronda et al, 2015), with an underlying urban canopy model and NOx and PM10 emissions. The traffic emissions are based on observed traffic intensities and emission factors. WRF-Chem runs will be issued daily for a lead time of 48 hours, resulting in forecast maps of temperature and pollutant concentrations that will be uniquely expressed in a metric that combines both threats. The route planner that we build, using the open source routing library pgRouting and the OpenStreetMap network.
Development of a Healthy Urban Route Planner for cyclists and pedestrians in Amsterdam
Steeneveld, G.J. ; Vreugdenhil, L.C. ; Molen, M.K. van der; Ligtenberg, A. - \ 2017
Check title to add to marked list
<< previous | next >>

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.