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 / 27

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Mathias
Check title to add to marked list
Plant Structure-Function Relationships and Woody Tissue Respiration: Upscaling to Forests from Laser-Derived Measurements
Meir, Patrick ; Shenkin, Alexander ; Disney, Mathias ; Rowland, Lucy ; Malhi, Yadvinder ; Herold, Martin ; Costa, Antonio C.L. da - \ 2018
In: Plant Respiration: Metabolic Fluxes and Carbon Balance / Tcherkez, G., Ghashghaie, J., Cham : Springer (Advances in Photosynthesis and Respiration ) - ISBN 9783319687018 - p. 89 - 105.
Land surface processes dominate the observed global signal of large inter-annual variability in the global carbon cycle , and this signal is itself dominated by responses of tropical forests to climatic variation and extremes. However, our understanding of the functioning of these forests is poorly constrained, not least in terms of the size and climate-sensitivity of gross ecosystem respiratory CO2 emission. Woody tissue CO2 effluxes contribute substantially to gross ecosystem CO2 emissions, thereby influencing the net ecosystem exchange of carbon. Our ability to estimate this component of the forest respiration budget has been limited by our technical capacity to measure vegetation size and structure in sufficient detail and at sufficient scale. The outcome has been to leave large uncertainties in land-surface model performance and prediction. A key challenge in estimating woody tissue CO2 efflux for the ecosystem has been the scaling of measurements made with chambers from the level of an organ to the stand. Appropriate scalars such as woody tissue mass, surface area and volume all require accurate structural information on both size and pattern. For individual trees, pattern is dominated by branching structure and this fundamentally determines how trees partition resources to address the trade-offs inherent in the simultaneous maintenance of structural integrity and metabolism. The detailed structural information needed to address this challenge has until recently been extremely scarce because of the difficulty of acquiring it, even for a single large tree. Recent developments in terrestrial light detection and ranging (LiDAR) technology have made possible a step change in our ability to quantify and describe tree form for continuous forest, for example describing hundreds of adjacent trees at the hectare scale. Connecting this new capability with tree physiology and fundamental theories of plant structure and metabolism offers to change the way we understand plant functional biology and its variation with environment, biogeography and phylogeny.
Defining tipping points for social-ecological systems scholarship - An interdisciplinary literature review
Milkoreit, Manjana ; Hodbod, Jennifer ; Baggio, Jacopo ; Benessaiah, Karina ; Calderón-Contreras, Rafael ; Donges, Jonathan F. ; Mathias, Jean Denis ; Rocha, Juan Carlos ; Schoon, Michael ; Werners, Saskia E. - \ 2018
Environmental Research Letters 13 (2018)3. - ISSN 1748-9318
non-linear change - social tipping points - social-ecological systems - tipping points
The term tipping point has experienced explosive popularity across multiple disciplines over the last decade. Research on social-ecological systems (SES) has contributed to the growth and diversity of the term's use. The diverse uses of the term obscure potential differences between tipping behavior in natural and social systems, and issues of causality across natural and social system components in SES. This paper aims to create the foundation for a discussion within the SES research community about the appropriate use of the term tipping point, especially the relatively novel term 'social tipping point.' We review existing literature on tipping points and similar concepts (e.g. regime shifts, critical transitions) across all spheres of science published between 1960 and 2016 with a special focus on a recent and still small body of work on social tipping points. We combine quantitative and qualitative analyses in a bibliometric approach, rooted in an expert elicitation process. We find that the term tipping point became popular after the year 2000 - long after the terms regime shift and critical transition - across all spheres of science. We identify 23 distinct features of tipping point definitions and their prevalence across disciplines, but find no clear taxonomy of discipline-specific definitions. Building on the most frequently used features, we propose definitions for tipping points in general and social tipping points in SES in particular.
EFO-LCI : A New Life Cycle Inventory Database of Forestry Operations in Europe
Cardellini, Giuseppe ; Valada, Tatiana ; Cornillier, Claire ; Vial, Estelle ; Dragoi, Marian ; Goudiaby, Venceslas ; Mues, Volker ; Lasserre, Bruno ; Gruchala, Arkadiusz ; Rørstad, Per Kristian ; Neumann, Mathias ; Svoboda, Miroslav ; Sirgmets, Risto ; Näsärö, Olli Pekka ; Mohren, Frits ; Achten, Wouter M.J. ; Vranken, Liesbet ; Muys, Bart - \ 2018
Environmental Management 61 (2018)6. - ISSN 0364-152X - p. 1031 - 1047.
Forest management - Forest Unit - Life cycle assessment - Silviculture - Wood
Life cycle assessment (LCA) has become a common methodology to analyze environmental impacts of forestry systems. Although LCA has been widely applied to forestry since the 90s, the LCAs are still often based on generic Life Cycle Inventory (LCI). With the purpose of improving LCA practices in the forestry sector, we developed a European Life Cycle Inventory of Forestry Operations (EFO-LCI) and analyzed the available information to check if within the European forestry sector national differences really exist. We classified the European forests on the basis of “Forest Units” (combinations of tree species and silvicultural practices). For each Forest Unit, we constructed the LCI of their forest management practices on the basis of a questionnaire filled out by national silvicultural experts. We analyzed the data reported to evaluate how they vary over Europe and how they affect LCA results and made freely available the inventory data collected for future use. The study shows important variability in rotation length, type of regeneration, amount and assortments of wood products harvested, and machinery used due to the differences in management practices. The existing variability on these activities sensibly affect LCA results of forestry practices and raw wood production. Although it is practically unfeasible to collect site-specific data for all the LCAs involving forest-based products, the use of less generic LCI data of forestry practice is desirable to improve the reliability of the studies. With the release of EFO-LCI we made a step toward the construction of regionalized LCI for the European forestry sector.
From diversity to justice – Unraveling pluralistic rationalities in urban design
Hartmann, Thomas ; Jehling, Mathias - \ 2018
Cities (2018). - ISSN 0264-2751
Cultural Theory - Economic goods - Grid and group - Justice - Leipzig - Urban space
For Jane Jacobs, the city is a fundamental unit of diversity; she develops her ideas in the city around this key axiom. Diversity provides an ethical orientation and thus defines what a just city should achieve. For Jacobs, justice is represented by peoples’ inherent right to ‘make cities’. According to Jacobs, cities become just places by their ability to facilitate the spontaneous dynamics among social fabrics and urban spaces to generate the beauty and value of cities. This contribution picks up this claim for diversity and develops a theoretical lens to explore how diversity is incorporated in urban design. We use a theory on pluralism—Cultural Theory—to analyse forms of managing urban space in different types of goods. This is applied to analyse four idealistic urban spaces in the city of Leipzig.
New perspectives on the ecology of tree structure and tree communities through terrestrial laser scanning
Malhi, Yadvinder ; Jackson, Tobias ; Bentley, Lisa Patrick ; Lau, Alvaro ; Shenkin, Alexander ; Herold, Martin ; Calders, Kim ; Bartholomeus, Harm ; Disney, Mathias I. - \ 2018
Interface Focus 8 (2018)2. - ISSN 2042-8898
Branching - Metabolic scaling theory - Terrestrial laser scanning - Tree architecture - Tree surface area - Wind speed
Terrestrial laser scanning (TLS) opens up the possibility of describing the three-dimensional structures of trees in natural environments with unprecedented detail and accuracy. It is already being extensively applied to describe how ecosystem biomass and structure vary between sites, but can also facilitate major advances in developing and testing mechanistic theories of tree form and forest structure, thereby enabling us to understand why trees and forests have the biomass and three-dimensional structure they do. Here we focus on the ecological challenges and benefits of understanding tree form, and highlight some advances related to capturing and describing tree shape that are becoming possible with the advent of TLS. We present examples of ongoing work that applies, or could potentially apply, new TLS measurements to better understand the constraints on optimization of tree form. Theories of resource distribution networks, such as metabolic scaling theory, can be tested and further refined. TLS can also provide new approaches to the scaling of woody surface area and crown area, and thereby better quantify the metabolism of trees. Finally, we demonstrate how we can develop a more mechanistic understanding of the effects of avoidance of wind risk on tree form and maximum size. Over the next few years, TLS promises to deliver both major empirical and conceptual advances in the quantitative understanding of trees and tree-dominated ecosystems, leading to advances in understanding the ecology of why trees and ecosystems look and grow the way they do.
The Impact of Three-Dimensional Effects on the Simulation of Turbulence Kinetic Energy in a Major Alpine Valley
Goger, Brigitta ; Rotach, Mathias W. ; Gohm, Alexander ; Fuhrer, Oliver ; Stiperski, Ivana ; Holtslag, A.A.M. - \ 2018
Boundary-Layer Meteorology 168 (2018)1. - ISSN 0006-8314 - p. 1 - 27.
The correct simulation of the atmospheric boundary layer (ABL) is crucial for reliable weather forecasts in truly complex terrain. However, common assumptions for model parametrizations are only valid for horizontally homogeneous and flat terrain. Here, we evaluate the turbulence parametrization of the numerical weather prediction model COSMO with a horizontal grid spacing of Δx=1.1km
for the Inn Valley, Austria. The long-term, high-resolution turbulence measurements of the i-Box measurement sites provide a useful data pool of the ABL structure in the valley and on slopes. We focus on days and nights when ABL processes dominate and a thermally-driven circulation is present. Simulations are performed for case studies with both a one-dimensional turbulence parametrization, which only considers the vertical turbulent exchange, and a hybrid turbulence parametrization, also including horizontal shear production and advection in the budget of turbulence kinetic energy (TKE). We find a general underestimation of TKE by the model with the one-dimensional turbulence parametrization. In the simulations with the hybrid turbulence parametrization, the modelled TKE has a more realistic structure, especially in situations when the TKE production is dominated by shear related to the afternoon up-valley flow, and during nights, when a stable ABL is present. The model performance also improves for stations on the slopes. An estimation of the horizontal shear production from the observation network suggests that three-dimensional effects are a relevant part of TKE production in the valley.
Estimation of above-ground biomass of large tropical trees with terrestrial LiDAR
Gonzalez De Tanago, Jose ; Lau, Alvaro ; Bartholomeus, Harm ; Herold, Martin ; Avitabile, Valerio ; Raumonen, Pasi ; Martius, Christopher ; Goodman, Rosa C. ; Disney, Mathias ; Manuri, Solichin ; Burt, Andrew ; Calders, Kim - \ 2018
Methods in Ecology and Evolution 9 (2018)2. - ISSN 2041-210X - p. 223 - 234.
1. Tropical forest biomass is a crucial component of global carbon emission estimations. However, calibration and validation of such estimates require accurate and effective methods to estimate in situ above-ground biomass (AGB). Present methods rely on allometric models that are highly uncertain for large tropical trees. Terrestrial laser scanning (TLS) tree modelling has demonstrated to be more accurate than these models to infer forest AGB. Nevertheless, applying TLS methods on tropical large trees is still challenging. We propose a method to estimate AGB of large tropical trees by three-dimensional (3D) tree modelling of TLS point clouds. 2. Twenty-nine plots were scanned with a TLS in three study sites (Peru, Indonesia and Guyana). We identified the largest tree per plot (mean diameter at breast height of 73.5 cm), extracted its point cloud and calculated its volume by 3D modelling its structure using quantitative structure models (QSM) and converted to AGB using species-specific wood density. We also estimated AGB using pantropical and local allometric models. To assess the accuracy of our and allometric methods, we harvest the trees and took destructive measurements. 3. AGB estimates by the TLS–QSM method showed the best agreement in comparison to destructive harvest measurements (28.37% coefficient of variation of root mean square error [CV-RMSE] and concordance correlation coefficient [CCC] of 0.95), outperforming the pantropical allometric models tested (35.6%–54.95% CV-RMSE and CCC of 0.89–0.73). TLS–QSM showed also the lowest bias (overall underestimation of 3.7%) and stability across tree size range, contrasting with the allometric models that showed a systematic bias (overall underestimation ranging 15.2%–35.7%) increasing linearly with tree size. The TLS–QSM method also provided accurate tree wood volume estimates (CV RMSE of 23.7%) with no systematic bias regardless the tree structural characteristics. 4. Our TLS–QSM method accounts for individual tree biophysical structure more effectively than allometric models, providing more accurate and less biased AGB estimates for large tropical trees, independently of their morphology. This non-destructive method can be further used for testing and calibrating new allometric models, reducing the current under-representation of large trees in and enhancing present and past estimates of forest biomass and carbon emissions from tropical forests.
Erratum to: Western US high June 2015 temperatures and their relation to global warming and soil moisture
Philip, Sjoukje Y. ; Kew, Sarah F. ; Hauser, Mathias ; Guillod, Benoit P. ; Teuling, Adriaan J. ; Whan, Kirien ; Uhe, Peter ; Oldenborgh, Geert Jan Van - \ 2018
Climate Dynamics 50 (2018)7-8. - ISSN 0930-7575 - p. 2603 - 2604.
Western US high June 2015 temperatures and their relation to global warming and soil moisture
Philip, Sjoukje Y. ; Kew, Sarah F. ; Hauser, Mathias ; Guillod, Benoit P. ; Teuling, Adriaan J. ; Whan, Kirien ; Uhe, Peter ; Oldenborgh, Geert Jan van - \ 2018
Climate Dynamics 50 (2018)7-8. - ISSN 0930-7575 - p. 2587 - 2601.
$$\\pi$$π-metric - Global warming - Land attribution - Soil moisture - Surface–atmosphere coupling - Temperature extremes - US West Coast states - VAC-metric

The Western US states Washington (WA), Oregon (OR) and California (CA) experienced extremely high temperatures in June 2015. The temperature anomalies were so extreme that they cannot be explained with global warming alone. We investigate the hypothesis that soil moisture played an important role as well. We use a land surface model and a large ensemble from the weather@home modelling effort to investigate the coupling between soil moisture and temperature in a warming world. Both models show that May was anomalously dry, satisfying a prerequisite for the extreme heat wave, and they indicate that WA and OR are in a wet-to-dry transitional soil moisture regime. We use two different land surface–atmosphere coupling metrics to show that there was strong coupling between temperature, latent heat flux and the effect of soil moisture deficits on the energy balance in June 2015 in WA and OR. June temperature anomalies conditioned on wet/dry conditions show that both the mean and extreme temperatures become hotter for dry soils, especially in WA and OR. Fitting a Gaussian model to temperatures using soil moisture as a covariate shows that the June 2015 temperature values fit well in the extrapolated empirical temperature/drought lines. The high temperature anomalies in WA and OR are thus to be expected, given the dry soil moisture conditions and that those regions are in the transition from a wet to a dry regime. CA is already in the dry regime and therefore the necessity of taking soil moisture into account is of lower importance.

Above-ground biomass assessment of tropical trees with Terrestrial LiDAR and 3D architecture models
Lau Sarmiento, A.I. ; Gonzalez de Tanago Meñaca, J. ; Bartholomeus, H.M. ; Herold, M. ; Avitabile, V. ; Raumonen, Pasi ; Martius, Christopher ; Goodman, R.C. ; Disney, Mathias ; Manuri, Solichin ; Burt, Andrew ; Calders, Kim - \ 2017
In: SilviLaser 2017 Program. - Blacksburg : Virginia Tech - p. 123 - 124.
Tea and coffee consumption in relation to DNA methylation in four European cohorts
Ek, Weronica E. ; Tobi, Elmar W. ; Ahsan, Muhammad ; Lampa, Erik ; Ponzi, Erica ; Kyrtopoulos, Soterios A. ; Georgiadis, Panagiotis ; Lumey, L.H. ; Heijmans, Bastiaan T. ; Botsivali, Maria ; Bergdahl, Ingvar A. ; Karlsson, Torgny ; Rask-Andersen, Mathias ; Palli, Domenico ; Ingelsson, Erik ; Hedman, Åsa K. ; Nilsson, Lena Maria ; Vineis, Paolo ; Lind, Lars ; Flanagan, James M. ; Johansson, Åsa - \ 2017
Human Molecular Genetics 26 (2017)16. - ISSN 0964-6906 - p. 3221 - 3231.

Lifestyle factors, such as food choices and exposure to chemicals, can alter DNAmethylation and lead to changes in gene activity. Two such exposures with pharmacologically active components are coffee and tea consumption. Both coffee and tea have been suggested to play an important role inmodulating disease-risk in humans by suppressing tumour progression, decreasing inflammation and influencing estrogenmetabolism. Thesemechanismsmay bemediated by changes in DNA methylation. To investigate if DNAmethylation in blood is associated with coffee and tea consumption, we performed a genome-wide DNAmethylation study for coffee and tea consumption in four European cohorts (N=3,096). DNAmethylation wasmeasured fromwhole blood at 421,695 CpG sites distributed throughout the genome and analysed inmen and women both separately and together in each cohort. Meta-analyses of the results and additional regional-level analyses were performed. After adjusting formultiple testing, themeta-analysis revealed that two individual CpG-sites,mapping to DNAJC16 and TTC17, were differentiallymethylated in relation to tea consumption in women. No individual sites were associated withmen or with the sex-combined analysis for tea or coffee. The regional analysis revealed that 28 regions were differentiallymethylated in relation to tea consumption in women. These regions contained genes known to interact with estradiolmetabolismand cancer. No significant regions were found in the sex-combined andmale-only analysis for either tea or coffee consumption.

Data acquisition considerations for Terrestrial Laser Scanning of forest plots
Wilkes, Phil ; Lau Sarmiento, Alvaro ; Disney, Mathias ; Calders, Kim ; Burt, Andrew ; Gonzalez De Tanago Meñaca, J. ; Bartholomeus, Harm ; Brede, Benjamin ; Herold, Martin - \ 2017
Remote Sensing of Environment 196 (2017). - ISSN 0034-4257 - p. 140 - 153.
The poor constraint of forest Above Ground Biomass (AGB) is responsible, in part, for large uncertainties in modelling future climate scenarios. Terrestrial Laser Scanning (TLS) can be used to derive unbiased and non-destructive estimates of tree structure and volume and can, therefore, be used to address key uncertainties in forest AGB estimates. Here we review our experience of TLS sampling strategies from 27 campaigns conducted over the past 5 years, across tropical and temperate forest plots, where data was captured with a RIEGL VZ-400 laser scanner. The focus is on strategies to derive Geometrical Modelling metrics (e.g. tree volume) over forest plots (≥1 ha) which require the accurate co-registration of 10s to 100s of individual point clouds. We recommend a 10 m × 10 m sampling grid as an approach to produce a point cloud with a uniform point distribution, that can resolve higher order branches (down to a few cm in diameter) towards the top of 30+ m canopies and can be captured in a timely fashion i.e. ∼3–6 days per ha. A data acquisition protocol, such as presented here, would facilitate data interoperability and inter-comparison of metrics between instruments/groups, from plot to plot and over time.
Evaluation of the Range Accuracy and the Radiometric Calibration of Multiple Terrestrial Laser Scanning Instruments for Data Interoperability
Calders, Kim ; Disney, Mathias I. ; Armston, John ; Burt, Andrew ; Brede, Benjamin ; Origo, Niall ; Muir, Jasmine ; Nightingale, Joanne - \ 2017
IEEE Transactions on Geoscience and Remote Sensing 55 (2017)5. - ISSN 0196-2892 - p. 2716 - 2724.
Terrestrial laser scanning (TLS) data provide 3-D measurements of vegetation structure and have the potential to support the calibration and validation of satellite and airborne sensors. The increasing range of different commercial and scientific TLS instruments holds challenges for data and instrument interoperability. Using data from various TLS sources will be critical to upscale study areas or compare data. In this paper, we provide a general framework to compare the interoperability of TLS instruments. We compare three TLS instruments that are the same make and model, the RIEGL VZ-400. We compare the range accuracy and evaluate the manufacturer's radiometric calibration for the uncalibrated return intensities. Our results show that the range accuracy between instruments is comparable and within the manufacturer's specifications. This means that the spatial XYZ data of different instruments can be combined into a single data set. Our findings demonstrate that radiometric calibration is instrument specific and needs to be carried out for each instrument individually before including reflectance information in TLS analysis. We show that the residuals between the calibrated reflectance panels and the apparent reflectance measured by the instrument are greatest for highest reflectance panels (residuals ranging from 0.058 to 0.312).
Data from: Creating a regional MODIS satellite-driven net primary production dataset for european forests
Neumann, Mathias ; Moreno, Adam ; Thurnher, Christopher ; Mues, Volker ; Härkönen, Sanna ; Mura, Matteo ; Bouriaud, Olivier ; Lang, Mait ; Cardellini, Giuseppe ; Thivolle-Cazat, Alain ; Bronisz, Karol ; Merganic, Jan ; Alberdi, Iciar ; Astrup, Rasmus ; Mohren, G.M.J. ; Zhao, Maosheng ; Hasenauer, Hubert - \ 2016
Creating a regional MODIS satellite-driven net primary production dataset for european forests
Neumann, Mathias ; Moreno, Adam ; Thurnher, Christopher ; Mues, Volker ; Härkönen, Sanna ; Mura, Matteo ; Bouriaud, Olivier ; Lang, Mait ; Cardellini, Giuseppe ; Thivolle-Cazat, Alain ; Bronisz, Karol ; Merganic, Jan ; Alberdi, Iciar ; Astrup, Rasmus ; Mohren, Frits ; Zhao, Maosheng ; Hasenauer, Hubert - \ 2016
Remote Sensing 8 (2016)7. - ISSN 2072-4292 - 18 p.
Bioeconomy - Biomass - Carbon - Climate - Downscaling - Forest inventory - Increment - MOD17 - NFI - NPP

Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm provides valuable information for monitoring NPP at 1-km resolution. Since coarse-resolution global climate data are used, the global dataset may contain uncertainties for Europe. We used a 1-km daily gridded European climate data set with the MOD17 algorithm to create the regional NPP dataset MODIS EURO. For evaluation of this new dataset, we compare MODIS EURO with terrestrial driven NPP from analyzing and harmonizing forest inventory data (NFI) from 196,434 plots in 12 European countries as well as the global MODIS NPP dataset for the years 2000 to 2012. Comparing these three NPP datasets, we found that the global MODIS NPP dataset differs from NFI NPP by 26%, while MODIS EURO only differs by 7%. MODIS EURO also agrees with NFI NPP across scales (from continental, regional to country) and gradients (elevation, location, tree age, dominant species, etc.). The agreement is particularly good for elevation, dominant species or tree height. This suggests that using improved climate data allows the MOD17 algorithm to provide realistic NPP estimates for Europe. Local discrepancies between MODIS EURO and NFI NPP can be related to differences in stand density due to forest management and the national carbon estimation methods. With this study, we provide a consistent, temporally continuous and spatially explicit productivity dataset for the years 2000 to 2012 on a 1-km resolution, which can be used to assess climate change impacts on ecosystems or the potential biomass supply of the European forests for an increasing bio-based economy. MODIS EURO data are made freely available at

Data from: "African savanna-forest boundary dynamics: a 20-year study"
Cuni-sanchez, Aida ; White, Lee J.T. ; Calders, K. ; Jeffery, Kathryn J. ; Abernethy, Katharine ; Burt, Andrew ; Disney, Mathias ; Gilpin, Martin ; Gomez-dans, Jose L. ; Lewis, Simon L. - \ 2016
Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of forest-savanna boundary change over time. Using long-term inventory plots we quantify changes in above-ground biomass (AGB), vegetation structure and biodiversity over 20 years for five vegetation types (savanna, colonising forest or F1, successional monodominant forest or F2, Marantaceae forest or F3 and mixed forest or F4) along a savanna-forest transition of central Gabon, all occurring on similar soils. Additionally, we use novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences across the transition. Overall, F1 and F2 forests increased in AGB, mainly as a result of adding stems (recruitment in F1) or increased Basal Area (F2). Some plots of F3 and F4 increased in AGB while some decreased. Changes in biodiversity and species’ dominance were small. After 20 years no plot could be classified as having moved to the next stage in the succession. TLS vertical plant profiles showed very distinctive differences amongst the vegetation types. We highlight two relevant points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store important quantities of Carbon. Decades long-term monitoring is likely to be required to assess the speed of transition between vegetation types, ideally with TLS, as this provides more objective forest classifications than inventory monitoring.
3D Measurements of Tropical Forest Structure for BIOMASS, Morphology and Calibration and Validation of Satellite Observations
Disney, Mathias ; Burt, Andrew ; Calders, K. ; Raumonen, P. ; Herold, M. ; Lewis, P. ; Lewis, S. ; Boni Vicari, M. ; Rowland, L. ; Meir, P. ; Mitchard, Edward - \ 2016
Modeled dietary impact of pizza reformulations in US children and adolescents
Masset, Gabriel ; Mathias, Kevin C. ; Vlassopoulos, Antonis ; Molenberg, Famke ; Lehmann, Undine ; Gibney, Mike ; Drewnowski, Adam - \ 2016
PLoS One 11 (2016)10. - ISSN 1932-6203 - 13 p.

Background and Objective Approximately 20% of US children and adolescents consume pizza on any given day; and pizza intake is associated with higher intakes of energy, sodium, and saturated fat. The reformulation of pizza products has yet to be evaluated as a viable option to improve diets of the US youth. This study modeled the effect on nutrient intakes of two potential pizza reformulation strategies based on the standards established by the Nestlé Nutritional Profiling System (NNPS). Methods Dietary intakes were retrieved from the first 24hr-recall of the National Health and Nutrition Examination Survey (NHANES) 2011-12, for 2655 participants aged 4-19 years. The composition of pizzas in the NHANES food database (n = 69) were compared against the NNPS standards for energy, total fat, saturated fat, sodium, added sugars, and protein. In a reformulation scenario, the nutrient content of pizzas was adjusted to the NNPS standards if these were not met. In a substitution scenario, pizzas that did not meet the standards were replaced by the closest pizza, based on nutrient content, that met all of the NNPS standards. Results Pizzas consistent with all the NNPS standards (29% of all pizzas) were significantly lower in energy, saturated fat and sodium than pizzas that were not. Among pizza consumers, modeled intakes in the reformulation and substitution scenarios were lower in energy (-14 and -45kcal, respectively), saturated fat (-1.2 and -2.7g), and sodium (-143 and -153mg) compared to baseline. Conclusions Potential industry wide reformulation of a single food category or intra-category food substitutions may positively impact dietary intakes of US children and adolescents. Further promotion and support of these complimentary strategies may facilitate the adoption and implementation of reformulation standards.

Potential and limitations of inferring ecosystem photosynthetic capacity from leaf functional traits
Musavi, Talie ; Migliavacca, Mirco ; Weg, Martine Janet van de; Kattge, Jens ; Wohlfahrt, Georg ; Bodegom, Peter M. van; Reichstein, Markus ; Bahn, Michael ; Carrara, Arnaud ; Domingues, Tomas F. ; Gavazzi, Michael ; Gianelle, Damiano ; Gimeno, Cristina ; Granier, André ; Gruening, Carsten ; Havránková, Kateřina ; Herbst, Mathias ; Hrynkiw, Charmaine ; Kalhori, Aram ; Kaminski, Thomas ; Klumpp, Katja ; Kolari, Pasi ; Longdoz, Bernard ; Minerbi, Stefano ; Montagnani, Leonardo ; Moors, Eddy ; Oechel, Walter C. ; Reich, Peter B. ; Rohatyn, Shani ; Rossi, Alessandra ; Rotenberg, Eyal ; Varlagin, Andrej ; Wilkinson, Matthew ; Wirth, Christian ; Mahecha, Miguel D. - \ 2016
Ecology and Evolution 6 (2016)20. - ISSN 2045-7758 - p. 7352 - 7366.
FLUXNET - Ecosystem functional property - Eddy covariance - Interannual variability - Photosynthetic capacity - Plant traits - Spatiotemporal variability - TRY database

The aim of this study was to systematically analyze the potential and limitations of using plant functional trait observations from global databases versus in situ data to improve our understanding of vegetation impacts on ecosystem functional properties (EFPs). Using ecosystem photosynthetic capacity as an example, we first provide an objective approach to derive robust EFP estimates from gross primary productivity (GPP) obtained from eddy covariance flux measurements. Second, we investigate the impact of synchronizing EFPs and plant functional traits in time and space to evaluate their relationships, and the extent to which we can benefit from global plant trait databases to explain the variability of ecosystem photosynthetic capacity. Finally, we identify a set of plant functional traits controlling ecosystem photosynthetic capacity at selected sites. Suitable estimates of the ecosystem photosynthetic capacity can be derived from light response curve of GPP responding to radiation (photosynthetically active radiation or absorbed photosynthetically active radiation). Although the effect of climate is minimized in these calculations, the estimates indicate substantial interannual variation of the photosynthetic capacity, even after removing site-years with confounding factors like disturbance such as fire events. The relationships between foliar nitrogen concentration and ecosystem photosynthetic capacity are tighter when both of the measurements are synchronized in space and time. When using multiple plant traits simultaneously as predictors for ecosystem photosynthetic capacity variation, the combination of leaf carbon to nitrogen ratio with leaf phosphorus content explains the variance of ecosystem photosynthetic capacity best (adjusted R2 = 0.55). Overall, this study provides an objective approach to identify links between leaf level traits and canopy level processes and highlights the relevance of the dynamic nature of ecosystems. Synchronizing measurements of eddy covariance fluxes and plant traits in time and space is shown to be highly relevant to better understand the importance of intra- and interspecific trait variation on ecosystem functioning.

Efficient Reconstruction of Predictive Consensus Metabolic Network Models
Heck, Ruben G.A. van; Ganter, Mathias ; Martins dos Santos, Vitor A.P. ; Stelling, Joerg - \ 2016
PLoS Computational Biology 12 (2016)8. - ISSN 1553-734X

Understanding cellular function requires accurate, comprehensive representations of metabolism. Genome-scale, constraint-based metabolic models (GSMs) provide such representations, but their usability is often hampered by inconsistencies at various levels, in particular for concurrent models. COMMGEN, our tool for COnsensus Metabolic Model GENeration, automatically identifies inconsistencies between concurrent models and semi-automatically resolves them, thereby contributing to consolidate knowledge of metabolic function. Tests of COMMGEN for four organisms showed that automatically generated consensus models were predictive and that they substantially increased coherence of knowledge representation. COMMGEN ought to be particularly useful for complex scenarios in which manual curation does not scale, such as for eukaryotic organisms, microbial communities, and host-pathogen interactions.

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.