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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Surviving in a Marine Desert: The Sponge Loop Retains Resources Within Coral Reefs
Goeij, J.M. de; Oevelen, D. van; Vermeij, M.J.A. ; Osinga, R. ; Middelburg, J.J. ; Goeij, A.F.P.M. de; Admiraal, W. - \ 2013
Science 342 (2013)6154. - ISSN 0036-8075 - p. 108 - 110.
organic-carbon doc - halisarca-caerulea - phase-shifts - red-sea - populations - community - removal - productivity - biodiversity - microbes
Ever since Darwin’s early descriptions of coral reefs, scientists have debated how one of the world’s most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is transferred to higher trophic levels. Here we show that sponges make DOM available to fauna by rapidly expelling filter cells as detritus that is subsequently consumed by reef fauna. This “sponge loop” was confirmed in aquarium and in situ food web experiments, using 13C- and 15N-enriched DOM. The DOM-sponge-fauna pathway explains why biological hot spots such as coral reefs persist in oligotrophic seas-the reef’s paradox-and has implications for reef ecosystem functioning and conservation strategies
Soil and freshwater and marine sediment food webs: their structure and function
Krumins, J.A. ; Oevelen, D. van; Bezemer, T.M. ; Deyn, G.B. de; Hol, W.H.G. ; Donk, E. van; Boer, W. de; Ruiter, P.C. de; Middelburg, J.J. ; Monroy, F. ; Soetaert, K. ; Thébault, E. ; Koppel, J. van de; Veen, J.A. van; Viketoft, M. ; Putten, W.H. van der - \ 2013
Bioscience 63 (2013)1. - ISSN 0006-3568 - p. 35 - 42.
global carbon-cycle - terrestrial ecosystems - real ecosystems - climate-change - biodiversity - stability - communities - limitation - patterns - sequestration
The food webs of terrestrial soils and of freshwater and marine sediments depend on adjacent aboveground or pelagic ecosystems for organic matter input that provides nutrients and energy. There are important similarities in the flow of organic matter through these food webs and how this flow feeds back to primary production. In both soils and sediments, trophic interactions occur in a cycle in which consumers stimulate nutrient cycling such that mineralized resources are made available to the primary producers. However, aquatic sediments and terrestrial soils differ greatly in the connectivity between the production and the consumption of organic matter. Terrestrial soils and shallow aquatic sediments can receive organic matter within hours of photosynthesis when roots leak carbon, whereas deep oceanic sediments receive organic matter possibly months after carbon assimilation by phytoplankton. This comparison has implications for the capacity of soils and sediments to affect the global carbon balance.
Schakel voor mens en dier, Natuurbrug Zanderij Crailoo
Grift, E.A. van der; Oevelen, E. van - \ 2008
Nieuwe Wildernis 43 (2008)29. - ISSN 1383-2115 - 1 p.
Estimating surface soil moisture with the scanning low frequency microwave radiometer (SLFMR) during the Southern Great Plains 1997 (SGP97) hydrology experiment
Uitdewilligen, D.C.A. ; Kustas, W.P. ; Oevelen, P.J. van - \ 2003
Physics and Chemistry of the Earth 28 (2003)(B). - ISSN 1474-7065 - p. 41 - 51.
dielectric behavior - vegetation indexes - wet soil - emission - variability - temperature - radiation - models
The scanning low frequency microwave radiometer (SLFMR) was used to map surface soil moisture (0-5 cm depth) during the Southern Great Plains 1997 (SGP97) hydrology experiment. On June 29, July 2, and July 3. surface soil moisture maps with a pixel resolution of 200 m were obtained using a soil moisture retrieval algorithm, developed for L-band (1.4 GHz frequency, 21 cm wavelength) passive microwave data. In comparison with the 800 m resolution data from the electronically scanned thinned array radiometer (ESTAR), the higher resolution SLFMR data required a more site specific calibration. After calibration root mean square difference (RMSD) between model and observed surface soil moisture observations were on the order of 5%, Although the higher pixel resolution generally provided brightness temperatures of individual fields, it is also meant the greater spatial variability in land cover properties (primarily vegetation cover) were affecting the microwave observations and had to be accounted for in the soil moisture algorithm. Parameters in the soil moisture algorithm required local recalibration, particularly for the heavily vegetated fields, in order to account for vegetation effects on the microwave brightness temperatures. Thus having microwave data at resolutions that differentiate field boundaries with sharp contrasts in vegetation cover amounts will likely require greater variation in parameter values (and more uncertainty) be assigned to the soil moisture algorithm than at coarser resolutions. This result indicates that parameter values in the soil moisture algorithm may be resolution dependent under certain land cover conditions. particularly at resolutions that discriminate field boundaries. (C) 2003 Elsevier Science Ltd. All rights reserved.
Role of microwave remote sensing for soil erosion studies using inversion process modelling : a precursor attempt in the Lesser Himalyas
Saran, S. ; Roy, P.S. ; Sterk, G. ; Oevelen, P.J. van - \ 2002
In: Abstracts of the ISPRS Commission VII Symposium on Resource and Environmental Monitoring : VII Symposium on Resource and Environmental Monitoring, Hyderabad, India, 2002. - Hyderabad, India : NRSA, 2002 - p. 57 - 57.
Role of microwave remote sensing for soil erosion studies using inversion process modelling : a precursor attempt in the Lesser Himalyas
Saran, S. ; Roy, P.S. ; Kumar, S. ; Sterk, G. ; Oevelen, P.J. van - \ 2002
In: ISPRS Commission VII Symposium : Resource and Environmental Monitoring, Hyderabad, India, 2002 / R.R. Navalgund, S.R. Nayak, R. Sudarshana, R. Nagaraja and S. Ravindran. - Hyderabad, India : National Remote Sensing Agency (NRSA), 2002 - p. 741 - 745.
Erosion processes modelling at catchment scales using remote sensing in northern India Himalayas
Oevelen, P.J. van; Sterk, G. - \ 2002
In: Abstracts of the ISPRS Commission VII Symposium on Resource and Environmental Monitoring : Symposium on Resource and Environmental Monitoring, Hyderabad, India, 2002 - p. 54 - 54.
Erosion processes modelling using microwave remote sensing at a catchment scale
Oevelen, P.J. van; Sterk, G. - \ 2001
In: Proceedings of the International Symposium : Soil Research for the 21ste Century, Hawai, USA - p. 623 - 625.
Estimation of areal soil water content through microwave remote sensing
Oevelen, P.J. van - \ 2000
Agricultural University. Promotor(en): R.A. Feddes; D.H. Hoekman. - S.l. : s.n. - ISBN 9789058083210 - 228
bodemwater - schatting - meting - bodemtextuur - oppervlakteruwheid - remote sensing - soil water - estimation - measurement - soil texture - surface roughness
<p>In this thesis the use of microwave remote sensing to estimate soil water content is investigated. A general framework is described which is applicable to both passive and active microwave remote sensing of soil water content. The various steps necessary to estimate areal soil water content are discussed through literature review, laboratory experimental results and results of extensive field experimental work. Even with the large amount of field data being available, no experiment provided all the necessary data to illustrate the framework completely for both passive and active techniques.</p><p>The framework developed is intended to be independent of the models used. In this way insight is gained in the dominating factors and problems associated with the use of remote sensing and not with specific models. Throughout the thesis both passive and active techniques are used and compared.</p><p>The passive techniques, mainly L-band and C-band, show better results that are more easily obtained at the cost of a relatively low spatial resolution. The standard error in the remotely sensed soil moisture estimates (&lt; 5%) even in the presence of low to moderate vegetation cover is often lower than that of the ground truth measurements. The launch of a space-borne L-band radiometer will make this technique useful for mesoscale and global scale hydrological and meteorological modeling.</p><p>The active techniques are severely tampered by vegetation and surface roughness effects making soil water content estimation more cumbersome. Despite these drawbacks this technique is complimentary to the passive technique because of the higher attainable spatial resolutions and the possible use of longer wave lengths (P-band). The latter enables estimation of soil water content under vegetation cover and over larger depths, about 30 cm for P-band, compared to for example about 5-10 cm depth for L-band. The standard error of soil moisture estimates in absence of vegetation is in general around 5%.</p><p>In this thesis the effects of vegetation have been excluded in the analysis. To operationalise remotely sensed soil moisture estimation it will be necessary to develop methods that can estimate soil water content when vegetation is present. Especially for active and space-borne passive techniques.</p><p>Direct comparison between a passive L-band radiometer and an active C-band radar showed consistent results over stationary heterogeneous areas, i.e. low vegetation cover and relatively homogeneous surface roughness characteristics.</p><p>The estimation of soil water content needs to be done from the perspective of the objective. This means that in the case of hydrological and meteorological modeling <em>assimilation of direct remotely sensed measurements such as brightness temperatures or backscattering coefficients can yield better results, e.g. better forecast, than incorporation of the remotely sensed soil water content</em> . This depends strongly on the land surface parameterization and in particular the definition of soil water content in the models used.</p>
Microwave radiometry for atmospheric research and monitoring : 1. Retrieval, analysis and assimilation methods; 2. Assessment of methods : COST 712 workshop : microwave radiometry for atmospheric research &monitoring : retrieval, analysis & assimilation methods : assessment of methods, Noordwijk
Oevelen, P.J. van; Eymard, L. ; English, S. - \ 1999
Unknown Publisher (ESA-WPP 139) - 161 p.
Radar backscatter inversion techniques for estimation of surface soil moisture : EFEDA-Spain and HAPEX-Sahel case studies
Oevelen, P.J. ; Hoekman, D.H. - \ 1999
IEEE Transactions on Geoscience and Remote Sensing 37 (1999). - ISSN 0196-2892 - p. 113 - 123.
Ground-based investigation of soil moisture variability within remote sensing footprints during the Southern Great Plains 1997 (SGP97) Hydrology Experiment
Famiglietti, J.S. ; Devereaux, J.A. ; Laymon, C.A. ; Tsegaye, T. ; Houser, P.R. ; Jackson, T.J. ; Graham, S.T. ; Rodell, M. ; Oevelen, P.J. van - \ 1999
Water Resources Research 35 (1999)6. - ISSN 0043-1397 - p. 1839 - 1851.
Surface soil moisture content is highly variable in both space and time. While remote sensing provides an effective methodology for mapping surface moisture content over large areas, it averages within-pixel variability thereby masking the underlying heterogeneity observed at the land surface. This variability must be better understood in order to rigorously evaluate sensor performance and to enhance the utility of the larger-scale remotely sensed averages by quantifying the underlying variability that remote sensing cannot record explicitly. In support of the Southern Great Plains 1997 (SGP97) Hydrology Experiment (a surface soil moisture mapping mission conducted between June 18 and July 17, 1997, in central Oklahoma) an investigation was conducted to characterize soil moisture variability within remote sensing footprints (approximately 0.64 km2) with more certainty than would be afforded with conventional gravimetric moisture content sampling. Nearly every day during the experiment period, portable impedance probes were used to intensively monitor volumetric moisture content in the 0- to 6-cm surface soil layer at six footprint-sized fields scattered over the SGP97 study area. A minimum of 49 daily moisture content measurements were made on most fields. Higher-resolution grid and transect data were also collected periodically. In total, more than 11,000 impedance probe measurements of volumetric moisture content were made at the six sites by over 35 SGP97 participants. The wide spatial distribution of the sites, combined with the intensive, near-daily monitoring, provided a unique opportunity (relative to previous smaller-scale and shorter-duration soil moisture studies) to characterize variations in surface moisture content over a range of wetness conditions. In this paper the range and temporal dynamics of the variability in moisture content within each of the six fields are described, as are general relationships between the variability and footprint-mean moisture content. Results indicate that distinct differences in mean moisture content between the six sites are consistent with variations in soil type, vegetation cover, and rainfall gradients. Within fields the standard deviation, coefficient of variation, skewness, and kurtosis increased with decreasing moisture content; the distribution of surface moisture content evolved from negatively skewed/nonnormal under very wet conditions, to normal in the midrange of mean moisture content, to positively skewed/nonnormal under dry conditions; and agricultural practices of row tilling and terracing were shown to exert a major control on observed moisture content variations. Results presented here can be utilized to better evaluate sensor performance, to extrapolate estimates of subgrid-scale variations in moisture content across the entire SGP97 region, and in the parameterization of soil moisture dynamics in hydrological and land surface models. | Surface soil moisture content is highly variable in both space and time. While remote sensing provides an effective methodology for mapping surface moisture content over large areas, it averages within-pixel variability thereby masking the underlying heterogeneity observed at the land surface. This variability must be better understood in order to rigorously evaluate sensor performance and to enhance the utility of the larger-scale remotely sensed averages by quantifying the underlying variability that remote sensing cannot record explicitly. In support of the Southern Great Plains 1997 (SGP97) Hydrology Experiment (a surface soil moisture mapping mission conducted between June 18 and July 17, 1997, in central Oklahoma) an investigation was conducted to characterize soil moisture variability within remote sensing footprints (approximately 0.64 km2) with more certainty than would be afforded with conventional gravimetric moisture content sampling. Nearly every day during the experiment period, portable impedance probes were used to intensively monitor volumetric moisture content in the 0- to 6-cm surface soil layer at six footprint-sized fields scattered over the SGP97 study area. A minimum of 49 daily moisture content measurements were made on most fields. Higher-resolution grid and transect data were also collected periodically. In total, more than 11,000 impedance probe measurements of volumetric moisture content were made at the six sites by over 35 SGP97 participants. The wide spatial distribution of the sites, combined with the intensive, near-daily monitoring, provided a unique opportunity (relative to previous smaller-scale and shorter-duration soil moisture studies) to characterize variations in surface moisture content over a range of wetness conditions. In this paper the range and temporal dynamics of the variability in moisture content within each of the six fields are described, as are general relationships between the variability and footprint-mean moisture content. Results indicate that distinct differences in mean moisture content between the six sites are consistent with variations in soil type, vegetation cover, and rainfall gradients. Within fields the standard deviation, coefficient of variation, skewness, and kurtosis increased with decreasing moisture content; the distribution of surface moisture content evolved from negatively skewed/nonnormal under very wet conditions, to normal in the midrange of mean moisture content, to positively skewed/nonnormal under dry conditions; and agricultural practices of row tilling and terracing were shown to exert a major control on observed moisture content variations. Results presented here can be utilized to better evaluate sensor performance, to extrapolate estimates of subgrid-scale variations in moisture content across the entire SGP97 region, and in the parameterization of soil moisture dynamics in hydrological and land surface models.
RESMEDES Spain 1996: ground data collection and analysis report.
Oevelen, P.J. van; Vissers, M.A.M. ; Woodhouse, I.H. - \ 1998
Wageningen : Landbouwuniversiteit Wageningen (Rapport / Landbouwuniversiteit Wageningen, Afdeling Waterhuishouding 77) - 69
bodemwater - planten - habitats - milieu - remote sensing - toepassingen - spanje - soil water - plants - environment - applications - spain
Soil moisture variability: a comparison between detailed field measurements and remote sensing measurement techniques.
Oevelen, P.J. van - \ 1998
Hydrological Sciences Journal 43 (1998). - ISSN 0262-6667 - p. 511 - 520.
Error estimation of landsurface parameters retrieved from remote sensing.
Oevelen, P.J. van; Hoekman, D.H. ; Feddes, R.A. - \ 1998
In: Climate and hydrology at mesoscale: the contribution of future sensor systems / Roerink, G.J., Menenti, M., - p. 98 - 107.
Soil water content.
Oevelen, P.J. van; Hoekman, D.H. ; Feddes, R.A. ; Kavvas, M.L. - \ 1998
In: Climate and hydrology at mesoscale: the contribution of future sensor systems / Roerink, G.J., Menenti, M., - p. 68 - 72.
Backscatter modelling in the NOPEX area : Boreal Forests and Agricultural Fields
Woodhouse, I.H. ; Oevelen, P.J. van; Hoekman, D.H. - \ 1997
In: Proceedings of the EMAC Final Workshop - p. 133 - 140.
Passive and active microwave remote sensing of soil moisture
Oevelen, P.J. van; Menenti, M. ; Woodhouse, I. ; Feddes, R.A. ; Bastiaanssen, W. ; Hoekman, D.H. ; Kavvas, M. - \ 1997
In: Planning Workshop for Southern Great Plains'97 Experiment, Beltsville, Maryland, USA, 26-28 August 1997. - [S.l.] : [s.n.], 1997 - p. 225 03:C1 - 225 03:C1.
FOREST-DYNAMO: Forest Environmental Dynamics Monitoring by Microwave Remote Sensing.
Griend, A.A. van der; Ruiter, J. de; Woodhouse, I.H. ; Oevelen, P.J. van; Hoekman, D.H. ; Paloscia, S. ; Pampaloni, P. ; Sogaard, H. ; Kerr, Y. - \ 1997
Unknown Publisher - 177 p.
Airborne microwave radiometty on a semi-arid area during HAPEX-Sahel.
Chanzy, A. ; Schmugge, T.J. ; Calvet, J.C. ; Kerr, Y. ; Oevelen, P. van; Grosjean, O. ; Wang, J.R. - \ 1997
Journal of Hydrology 188-189 (1997). - ISSN 0022-1694 - p. 285 - 309.
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