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 / 28

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Mariana
Check title to add to marked list
Archetypes of Climate Vulnerability : a Mixed-method Approach Applied in the Peruvian Andes
Vidal Merino, Mariana ; Sietz, Diana ; Jost, Francois ; Berger, Uta - \ 2018
Climate and Development (2018). - ISSN 1756-5529 - p. 1 - 17.
adaptive capacity - agro-ecological zones - Andean agriculture - pattern analysis - sustainable livelihoods
Farm household systems (FHSs) in the Andes handle climate-related hazards such as frost and droughts with risk-coping and risk-management strategies based on the adaptive capital available to them. Nevertheless, a higher frequency of climatic stressors observed during the last few decades is challenging their capacity to adapt at a pace fast enough to keep up with the changes in external conditions. This increases the demand on the scientific community from policy and decision makers to investigate climate impacts and propose viable adaptation pathways at the local and regional scales. Better understanding heterogeneity in climate vulnerability is an important step towards addressing this demand. We present here a mixed-method approach to assessing archetypes or patterns of climate vulnerability that combines qualitative tools from participatory rural assessment approaches and quantitative techniques including cluster analysis. We illustrate this by looking at a case study of the Central Andes of Peru. The operationalization of the methods revealed differential factors for climate vulnerability, allowing us to categorize FHS archetypes according to the differences in those underlying factors. The archetypes differed mainly according to farm area, agro-ecological zones, irrigation, off-farm employment and climate-related damages. The results suggest that the approach is useful for explaining vulnerability as a function of recurrent internal and external determinants of vulnerability and developing related adaptive strategies.
Species Distribution Modelling: Contrasting presence-only models with plot abundance data
Gomes, Vitor H.F. ; Ijff, Stéphanie D. ; Raes, Niels ; Amaral, Iêda Leão ; Salomão, Rafael P. ; Coelho, Luiz De Souza ; Matos, Francisca Dionízia De Almeida ; Castilho, Carolina V. ; Filho, Diogenes De Andrade Lima ; López, Dairon Cárdenas ; Guevara, Juan Ernesto ; Magnusson, William E. ; Phillips, Oliver L. ; Wittmann, Florian ; Carim, Marcelo De Jesus Veiga ; Martins, Maria Pires ; Irume, Mariana Victória ; Sabatier, Daniel ; Molino, Jean François ; Bánki, Olaf S. ; Guimarães, José Renan Da Silva ; Pitman, Nigel C.A. ; Piedade, Maria Teresa Fernandez ; Mendoza, Abel Monteagudo ; Luize, Bruno Garcia ; Venticinque, Eduardo Martins ; de Leão Novo, E.M.M. ; Vargas, Percy Núñez ; Silva, Thiago Sanna Freire ; Manzatto, Angelo Gilberto ; Terborgh, John ; Reis, Neidiane Farias Costa ; Montero, Juan Carlos ; Montero, Juan Carlos ; Casula, Katia Regina ; Marimon, Beatriz S. ; Marimon, Ben Hur ; Honorio Coronado, Euridice N. ; Feldpausch, Ted R. ; Duque, Alvaro ; Zartman, Charles Eugene ; Arboleda, Nicolás Castaño ; Killeen, Timothy J. ; Mostacedo, Bonifacio ; Vasquez, Rodolfo ; Schöngart, Jochen ; Assis, Rafael L. ; Medeiros, Marcelo Brilhante ; Simon, Marcelo Fragomeni ; Andrade, Ana ; Laurance, William F. ; Camargo, José Luís ; Demarchi, Layon O. ; Laurance, Susan G.W. ; Farias, Emanuelle De Sousa ; Nascimento, Henrique Eduardo Mendonça ; Revilla, Juan David Cardenas ; Quaresma, Adriano ; Costa, Flavia R.C. ; Vieira, Ima Célia Guimarães ; Cintra, Bruno Barçante Ladvocat ; Cintra, Bruno Barçante Ladvocat ; Castellanos, Hernán ; Brienen, Roel ; Stevenson, Pablo R. ; Feitosa, Yuri ; Duivenvoorden, Joost F. ; Aymard, Gerardo A.C. ; Mogollón, Hugo F. ; Targhetta, Natalia ; Comiskey, James A. ; Vicentini, Alberto ; Lopes, Aline ; Damasco, Gabriel ; Dávila, Nállarett ; García-Villacorta, Roosevelt ; Levis, Carolina ; Levis, Carolina ; Schietti, Juliana ; Souza, Priscila ; Emilio, Thaise ; Alonso, Alfonso ; Neill, David ; Dallmeier, Francisco ; Ferreira, Leandro Valle ; Araujo-Murakami, Alejandro ; Praia, Daniel ; Amaral, Dário Dantas Do; Carvalho, Fernanda Antunes ; Souza, Fernanda Coelho De - \ 2018
Scientific Reports 8 (2018)1. - ISSN 2045-2322
Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and MaxEnt predictions relates to a spatial abundance model, based on a large plot dataset for Amazonian tree species, using inverse distance weighting (IDW). We also propose a new pipeline to deal with inconsistencies in NHCs and to limit the area of occupancy of the species. We found a significant but weak positive relationship between the distribution of NHCs and IDW for 66% of the species. The relationship between SDMs and IDW was also significant but weakly positive for 95% of the species, and sensitivity for both analyses was high. Furthermore, the pipeline removed half of the NHCs records. Presence-only SDM applications should consider this limitation, especially for large biodiversity assessments projects, when they are automatically generated without subsequent checking. Our pipeline provides a conservative estimate of a species' area of occupancy, within an area slightly larger than its extent of occurrence, compatible to e.g. IUCN red list assessments.
Agriculture-driven deforestation in the tropics from 1990 to-2015: emissions, trends and uncertainties
Carter, Sarah ; Herold, Martin ; Avitabile, Valerio ; Bruin, Sytze de; Sy, Veronique de; Kooistra, Lammert ; Rufino, Mariana C. - \ 2018
Environmental Research Letters 13 (2018)1. - ISSN 1748-9326
Limited data exists on emissions from agriculture-driven deforestation, and available data are typically uncertain. In this paper, we provide comparable estimates of emissions from both all deforestation and agriculture-driven deforestation, with uncertainties for 91 countries across the tropics between 1990 and 2015. Uncertainties associated with input datasets (activity data and emissions factors) were used to combine the datasets, where most certain datasets contribute the most. This method utilizes all the input data, while minimizing the uncertainty of the emissions estimate. The uncertainty of input datasets was influenced by the quality of the data, the sample size (for sample-based datasets), and the extent to which the timeframe of the data matches the period of interest. Area of deforestation, and the agriculture-driver factor (extent to which agriculture drives deforestation), were the most uncertain components of the emissions estimates, thus improvement in the uncertainties related to these estimates will provide the greatest reductions in uncertainties of emissions estimates. Over the period of the study, Latin America had the highest proportion of deforestation driven by agriculture (78%), and Africa had the lowest (62%). Latin America had the highest emissions from agriculture-driven deforestation, and these peaked at 974 ± 148 Mt CO2 yr−1 in 2000–2005. Africa saw a continuous increase in emissions between 1990 and 2015 (from 154 ± 21–412 ± 75 Mt CO2 yr−1), so mitigation initiatives could be prioritized there. Uncertainties for emissions from agriculture-driven deforestation are ± 62.4% (average over 1990–2015), and uncertainties were highest in Asia and lowest in Latin America. Uncertainty information is crucial for transparency when reporting, and gives credibility to related mitigation initiatives. We demonstrate that uncertainty data can also be useful when combining multiple open datasets, so we recommend new data providers to include this information.
A study of the origin of chloramphenicol isomers in honey
Yanovych, Dmytro ; Berendsen, Bjorn ; Zasadna, Zvenyslava ; Rydchuk, Mariana ; Czymai, Tobias - \ 2018
Drug Testing and Analysis 10 (2018)3. - ISSN 1942-7603 - p. 416 - 422.
Chiral LC-MS/MS - Chloramphenicol isomers - Dextramycin - Drug residues - Honey
Due to the unexpected detection of chloramphenicol isomer residues in honey, we have studied the hypothesis of unauthorized or unintended use of unregistered veterinary drug preparations. First, we have investigated honey samples in which a discrepancy was observed between the results of the immunological screening methods and the confirmatory liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. In all samples, previously identified to be contaminated with the banned antibiotic chloramphenicol according to LC-MS/MS only, the presence of dextramycin (SS-para isomer of chloramphenicol) was detected by chiral LC-MS/MS. The source of dextramycin in honey was investigated by studying the preparations utilized in apiaries from which the above non-compliant honey samples have been received. In all these preparations (beehive strips applied against the mite Varroa destructor) chloramphenicol was detected in the concentrations ranging from 33 to 34,400 μg kg-1. Chiral LC-MS/MS demonstrated the presence of chloramphenicol and dextramycin in different ratios, and it was concluded that these preparations can be the source of chloramphenicol and dextramycin residues in honey. These preparations were of foreign production and are not officially registered in accordance with current legislation.
AntiSMASH 4.0 - improvements in chemistry prediction and gene cluster boundary identification
Blin, Kai ; Wolf, Thomas ; Chevrette, Marc G. ; Lu, Xiaowen ; Schwalen, Christopher J. ; Kautsar, Satria A. ; Suarez Duran, Hernando G. ; Los Santos, Emmanuel L.C. De; Kim, Hyun Uk ; Nave, Mariana ; Dickschat, Jeroen S. ; Mitchell, Douglas A. ; Shelest, Ekaterina ; Breitling, Rainer ; Takano, Eriko ; Lee, Sang Yup ; Weber, Tilmann ; Medema, Marnix H. - \ 2017
Nucleic Acids Research 45 (2017)W1. - ISSN 0305-1048 - p. W36 - W41.
Many antibiotics, chemotherapeutics, crop protection agents and food preservatives originate from molecules produced by bacteria, fungi or plants. In recent years, genome mining methodologies have been widely adopted to identify and characterize the biosynthetic gene clusters encoding the production of such compounds. Since 2011, the â € antibiotics and secondary metabolite analysis shell - antiSMASH' has assisted researchers in efficiently performing this, both as a web server and a standalone tool. Here, we present the thoroughly updated antiSMASH version 4, which adds several novel features, including prediction of gene cluster boundaries using the ClusterFinder method or the newly integrated CASSIS algorithm, improved substrate specificity prediction for non-ribosomal peptide synthetase adenylation domains based on the new SANDPUMA algorithm, improved predictions for terpene and ribosomally synthesized and post-translationally modified peptides cluster products, reporting of sequence similarity to proteins encoded in experimentally characterized gene clusters on a per-protein basis and a domain-level alignment tool for comparative analysis of trans-AT polyketide synthase assembly line architectures. Additionally, several usability features have been updated and improved. Together, these improvements make antiSMASH up-to-date with the latest developments in natural product research and will further facilitate computational genome mining for the discovery of novel bioactive molecules.
Hydrogen Gas Recycling for Energy Efficient Ammonia Recovery in Electrochemical Systems
Kuntke, Philipp ; Rodríguez Arredondo, Mariana ; Widyakristi, Laksminarastri ; Heijne, Annemiek ter; Sleutels, Tom H.J.A. ; Hamelers, Hubertus V.M. ; Buisman, Cees J.N. - \ 2017
Environmental Science and Technology 51 (2017)5. - ISSN 0013-936X - p. 3110 - 3116.

Recycling of hydrogen gas (H2) produced at the cathode to the anode in an electrochemical system allows for energy efficient TAN (Total Ammonia Nitrogen) recovery. Using a H2 recycling electrochemical system (HRES) we achieved high TAN transport rates at low energy input. At a current density of 20 A m-2, TAN removal rate from the influent was 151 gN m-2 d-1 at an energy demand of 26.1 kJ gN -1. The maximum TAN transport rate of 335 gN m-2 d-1 was achieved at a current density of 50 A m-2 and an energy demand of 56.3 kJ gN -1. High TAN removal efficiency (73-82%) and recovery (60-73%) were reached in all experiments. Therefore, our HRES is a promising alternative for electrochemical and bioelectrochemical TAN recovery. Advantages are the lower energy input and lower risk of chloride oxidation compared to electrochemical technologies and high rates and independence of organic matter compared to bioelectrochemical systems. (Chemical Equation Presented).

Load ratio determines the ammonia recovery and energy input of an electrochemical system
Rodríguez Arredondo, Mariana ; Kuntke, Philipp ; Heijne, Annemiek Ter; Hamelers, Hubertus V.M. ; Buisman, Cees J.N. - \ 2017
Water Research 111 (2017). - ISSN 0043-1354 - p. 330 - 337.
Complete removal and recovery of total ammonia nitrogen (TAN) from wastewaters in (bio)electrochemical systems has proven to be a challenge. The system performance depends on several factors, such as current density, TAN loading rate and pH. The interdependence among these factors is not well understood yet: insight is needed to achieve maximum ammonium recovery at minimal energy input. The aim of this study was to investigate the influence of current density and TAN loading rate on the recovery efficiency and energy input of an electrochemical cell (EC). We therefore defined the load ratio, which is the ratio between the applied current and the TAN loading rate. The system consisted of an EC coupled to a membrane unit for the recovery of ammonia. Synthetic wastewater, with TAN concentration similar to urine, was used to develop a simple model to predict the system performance based on the load ratio, and urine was later used to evaluate TAN transport in a more complex wastewater. High fluxes (up to 433 gN m−2 d−1) and recovery efficiencies (up to 100%) were obtained. The simple model presented here is also suited to predict the performance of similar systems for TAN recovery, and can be used to optimize their operation.
Reducing emissions from agriculture to meet the 2 °C target
Wollenberg, Eva ; Richards, Meryl ; Smith, Pete ; Havlík, Petr ; Obersteiner, Michael ; Tubiello, Francesco N. ; Herold, Martin ; Gerber, Pierre ; Carter, Sarah ; Reisinger, Andrew ; Vuuren, Detlef P. van; Dickie, Amy ; Neufeldt, Henry ; Sander, Björn O. ; Wassmann, Reiner ; Sommer, Rolf ; Amonette, James E. ; Falcucci, Alessandra ; Herrero, Mario ; Opio, Carolyn ; Roman-cuesta, Rosa Maria ; Stehfest, Elke ; Westhoek, Henk ; Ortiz-Monasterio, Ivan ; Sapkota, Tek ; Rufino, Mariana C. ; Thornton, Philip K. ; Verchot, Louis V. ; West, Paul C. ; Soussana, Jean-François ; Baedeker, Tobias ; Sadler, Marc ; Vermeulen, Sonja ; Campbell, Bruce M. - \ 2016
Global Change Biology 22 (2016)12. - ISSN 1354-1013 - p. 3859 - 3864.
More than 100 countries pledged to reduce agricultural greenhouse gas (GHG) emissions in the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change. Yet technical information about how much mitigation is needed in the sector vs. how much is feasible remains poor. We identify a preliminary global target for reducing emissions from agriculture of ~1 GtCO2e yr−1 by 2030 to limit warming in 2100 to 2 °C above pre-industrial levels. Yet plausible agricultural development pathways with mitigation cobenefits deliver only 21–40% of needed mitigation. The target indicates that more transformative technical and policy options will be needed, such as methane inhibitors and finance for new practices. A more comprehensive target for the 2 °C limit should be developed to include soil carbon and agriculture-related mitigation options. Excluding agricultural emissions from mitigation targets and plans will increase the cost of mitigation in other sectors or reduce the feasibility of meeting the 2 °C limit.
Rhizobacteria and plant symbiosis in heavy metal uptake and its implications for soil bioremediation
Sobariu, Dana Luminita ; Fertu, Daniela Ionela Tudorache ; Diaconu, Mariana ; Pavel, Lucian Vasile ; Hlihor, Raluca Maria ; Drăgoi, Elena Niculina ; Curteanu, Silvia ; Lenz, Markus ; Corvini, Philippe François Xavier ; Gavrilescu, Maria - \ 2016
New Biotechnology 39 (2016). - ISSN 1871-6784 - p. 125 - 134.
Azotobacter sp. - Cadmium - Chromium - Lepidium sativum - Rhizobacteria - Tolerance

Certain species of plants can benefit from synergistic effects with plant growth-promoting rhizobacteria (PGPR) that improve plant growth and metal accumulation, mitigating toxic effects on plants and increasing their tolerance to heavy metals. The application of PGPR as biofertilizers and atmospheric nitrogen fixators contributes considerably to the intensification of the phytoremediation process. In this paper, we have built a system consisting of rhizospheric . Azotobacter microbial populations and . Lepidium sativum plants, growing in solutions containing heavy metals in various concentrations. We examined the ability of the organisms to grow in symbiosis so as to stimulate the plant growth and enhance its tolerance to Cr(VI) and Cd(II), to ultimately provide a reliable phytoremediation system. The study was developed at the laboratory level and, at this stage, does not assess the inherent interactions under real conditions occurring in contaminated fields with autochthonous microflora and under different pedoclimatic conditions and environmental stresses. . Azotobacter sp. bacteria could indeed stimulate the average germination efficiency of . Lepidium sativum by almost 7%, average root length by 22%, average stem length by 34% and dry biomass by 53%. The growth of . L. sativum has been affected to a greater extent in Cd(II) solutions due its higher toxicity compared to that of Cr(VI). The reduced tolerance index (TI, %) indicated that plant growth in symbiosis with PGPR was however affected by heavy metal toxicity, while the tolerance of the plant to heavy metals was enhanced in the bacteria-plant system.A methodology based on artificial neural networks (ANNs) and differential evolution (DE), specifically a neuro-evolutionary approach, was applied to model germination rates, dry biomass and root/stem length and proving the robustness of the experimental data. The errors associated with all four variables are small and the correlation coefficients higher than 0.98, which indicate that the selected models can efficiently predict the experimental data.

Multi-gas and multi-source comparisons of six land use emission datasets and AFOLU estimates in the Fifth Assessment Report, for the tropics for 2000–2005
Roman-Cuesta, Rosa Maria ; Herold, Martin ; Rufino, Mariana C. ; Rosenstock, Todd S. ; Houghton, Richard A. ; Rossi, Simone ; Butterbach-Bahl, Klaus ; Ogle, Stephen ; Poulter, Benjamin ; Verchot, Louis ; Martius, Christopher ; Bruin, Sytze de - \ 2016
Biogeosciences 13 (2016)20. - ISSN 1726-4170 - p. 5799 - 5819.
The Agriculture, Forestry and Other Land Use (AFOLU) sector contributes with ca. 20–25 % of global anthropogenic emissions (2010), making it a key component of any climate change mitigation strategy. AFOLU estimates, however, remain highly uncertain, jeopardizing the mitigation effectiveness of this sector. Comparisons of global AFOLU emissions have shown divergences of up to 25 %, urging for improved understanding of the reasons behind these differences. Here we compare a variety of AFOLU emission datasets and estimates given in the Fifth Assessment Report for the tropics (2000–2005) to identify plausible explanations for the differences in (i) aggregated gross AFOLU emissions, and (ii) disaggregated emissions by sources and gases (CO2, CH4, N2O). We also aim to (iii) identify countries with low agreement among AFOLU datasets to navigate research efforts. The datasets are FAOSTAT (Food and Agriculture Organization of the United Nations, Statistics Division), EDGAR (Emissions Database for Global Atmospheric Research), the newly developed AFOLU “Hotspots”, “Houghton”, “Baccini”, and EPA (US Environmental Protection Agency) datasets. Aggregated gross emissions were similar for all databases for the AFOLU sector: 8.2 (5.5–12.2), 8.4, and 8.0 Pg CO2 eq. yr−1 (for Hotspots, FAOSTAT, and EDGAR respectively), forests reached 6.0 (3.8–10), 5.9, 5.9, and 5.4 Pg CO2 eq. yr−1 (Hotspots, FAOSTAT, EDGAR, and Houghton), and agricultural sectors were with 1.9 (1.5–2.5), 2.5, 2.1, and 2.0 Pg CO2 eq. yr−1 (Hotspots, FAOSTAT, EDGAR, and EPA). However, this agreement was lost when disaggregating the emissions by sources, continents, and gases, particularly for the forest sector, with fire leading the differences. Agricultural emissions were more homogeneous, especially from livestock, while those from croplands were the most diverse. CO2 showed the largest differences among the datasets. Cropland soils and enteric fermentation led to the smaller N2O and CH4 differences. Disagreements are explained by differences in conceptual frameworks (carbon-only vs. multi-gas assessments, definitions, land use vs. land cover, etc.), in methods (tiers, scales, compliance with Intergovernmental Panel on Climate Change (IPCC) guidelines, legacies, etc.) and in assumptions (carbon neutrality of certain emissions, instantaneous emissions release, etc.) which call for more complete and transparent documentation for all the available datasets. An enhanced dialogue between the carbon (CO2) and the AFOLU (multi-gas) communities is needed to reduce discrepancies of land use estimates.
Limited coalescence and Ostwald ripening in emulsions stabilized by hydrophobin HFBII and milk proteins
Dimitrova, Lydia M. ; Boneva, Mariana P. ; Danov, Krassimir D. ; Kralchevsky, Peter A. ; Basheva, Elka S. ; Marinova, Krastanka G. ; Petkov, Jordan T. ; Stoyanov, Simeon D. - \ 2016
Colloids and Surfaces. A: Physicochemical and Engineering Aspects 509 (2016). - ISSN 0927-7757 - p. 521 - 538.
Drop size distribution - Emulsification - Emulsion stability - HFBII hydrophobin - Ostwald ripening

Hydrophobins are proteins isolated from filamentous fungi, which are excellent foam stabilizers, unlike most of the proteins. In the present study, we demonstrate that hydrophobin HFBII can also serve as excellent emulsion stabilizer. The HFBII adsorption layers at the oil/water interface solidify similarly to those at the air/water interface. The thinning of aqueous films sandwiched between two oil phases ends with the formation of a 6 nm thick protein bilayer, just as in the case of foam films, which results in strong adhesive interactions between the emulsion drops. The drop-size distribution in hydrophobin stabilized oil-in-water emulsions is investigated at various protein concentrations and oil volume fractions. The data analysis indicates that the emulsification occurs in the Kolmogorov regime or in the regime of limited coalescence, depending on the experimental conditions. The emulsions with HFBII are very stable – no changes in the drop-size distributions are observed after storage for 50 days. However, these emulsions are unstable upon stirring, when they are subjected to the action of shear stresses. This instability can be removed by covering the drops with a second adsorption layer from a conventional protein, like β-lactoglobulin. The HFBII surface layer is able to suppress the Ostwald ripening in the case when the disperse phase is oil that exhibits a pronounced solubility in water. Hence, the hydrophobin can be used to stabilize microcapsules of fragrances, flavors, colors or preservatives due to its dense adsorption layers that block the transfer of oil molecules.

Hotspots of gross emissions from the land use sector: patterns, uncertainties, and leading emission sources for the period 2000–2005 in the tropics
Roman-cuesta, Rosa Maria ; Rufino, Mariana C. ; Herold, Martin ; Butterbach-bahl, Klaus ; Rosenstock, Todd S. ; Herrero, Mario ; Ogle, Stephen ; Li, Changsheng ; Poulter, Benjamin ; Verchot, Louis ; Martius, Christopher ; Stuiver, John ; Bruin, Sytze De - \ 2016
Biogeosciences 13 (2016)14. - ISSN 1726-4170 - p. 4253 - 4269.
According to the latest report of the Intergovernmental Panel on Climate Change (IPCC), emissions must be cut by 41–72 % below 2010 levels by 2050 for a likely chance of containing the global mean temperature increase to 2 °C. The AFOLU sector (Agriculture, Forestry and Other Land Use) contributes roughly a quarter ( ∼  10–12 Pg CO2e yr−1) of the net anthropogenic GHG emissions mainly from deforestation, fire, wood harvesting, and agricultural emissions including croplands, paddy rice, and livestock. In spite of the importance of this sector, it is unclear where the regions with hotspots of AFOLU emissions are and how uncertain these emissions are. Here we present a novel, spatially comparable dataset containing annual mean estimates of gross AFOLU emissions (CO2, CH4, N2O), associated uncertainties, and leading emission sources, in a spatially disaggregated manner (0.5°) for the tropics for the period 2000–2005. Our data highlight the following: (i) the existence of AFOLU emissions hotspots on all continents, with particular importance of evergreen rainforest deforestation in Central and South America, fire in dry forests in Africa, and both peatland emissions and agriculture in Asia; (ii) a predominant contribution of forests and CO2 to the total AFOLU emissions (69 %) and to their uncertainties (98 %); (iii) higher gross fluxes from forests, which coincide with higher uncertainties, making agricultural hotspots appealing for effective mitigation action; and (iv) a lower contribution of non-CO2 agricultural emissions to the total gross emissions (ca. 25 %), with livestock (15.5 %) and rice (7 %) leading the emissions. Gross AFOLU tropical emissions of 8.0 (5.5–12.2) were in the range of other databases (8.4 and 8.0 Pg CO2e yr−1 in FAOSTAT and the Emissions Database for Global Atmospheric Research (EDGAR) respectively), but we offer a spatially detailed benchmark for monitoring progress in reducing emissions from the land sector in the tropics. The location of the AFOLU hotspots of emissions and data on their associated uncertainties will assist national policy makers, investors, and other decision-makers who seek to understand the mitigation potential of the AFOLU sector.
High primary production contrasts with intense carbon emission in a eutrophic tropical reservoir
Almeida, Rafael M. ; Nóbrega, Gabriel N. ; Junger, Pedro C. ; Figueiredo, Aline V. ; Andrade, Anízio S. ; Moura, Caroline G.B. de; Tonetta, Denise ; Oliveira, Ernandes S. ; Araújo, Fabiana ; Rust, Felipe ; Piñeiro-Guerra, Juan M. ; Mendonça, Jurandir R. ; Medeiros, Leonardo R. ; Pinheiro, Lorena ; Miranda, Marcela ; Costa, Mariana R.A. ; Melo, Michaela L. ; Nobre, Regina L.G. ; Benevides, Thiago ; Roland, Fábio ; Klein, Jeroen de; Barros, Nathan O. ; Mendonça, Raquel ; Becker, Vanessa ; Huszar, Vera L.M. ; Kosten, Sarian - \ 2016
Frontiers in Microbiology 7 (2016)MAY. - ISSN 1664-302X
Caatinga - Carbon dioxide - Methane - Net ecosystem production - Organic carbon burial - Semiarid

Recent studies from temperate lakes indicate that eutrophic systems tend to emit less carbon dioxide (CO2) and bury more organic carbon (OC) than oligotrophic ones, rendering them CO2 sinks in some cases. However, the scarcity of data from tropical systems is critical for a complete understanding of the interplay between eutrophication and aquatic carbon (C) fluxes in warm waters. We test the hypothesis that a warm eutrophic system is a source of both CO2 and CH4 to the atmosphere, and that atmospheric emissions are larger than the burial of OC in sediments. This hypothesis was based on the following assumptions: (i) OC mineralization rates are high in warm water systems, so that water column CO2 production overrides the high C uptake by primary producers, and (ii) increasing trophic status creates favorable conditions for CH4 production. We measured water-air and sediment-water CO2 fluxes, CH4 diffusion, ebullition and oxidation, net ecosystem production (NEP) and sediment OC burial during the dry season in a eutrophic reservoir in the semiarid northeastern Brazil. The reservoir was stratified during daytime and mixed during nighttime. In spite of the high rates of primary production (4858 ± 934 mg C m-2 d-1), net heterotrophy was prevalent due to high ecosystem respiration (5209 ± 992 mg C m-2 d-1). Consequently, the reservoir was a source of atmospheric CO2 (518 ± 182 mg C m-2 d-1). In addition, the reservoir was a source of ebullitive (17 ± 10 mg C m-2 d-1) and diffusive CH4 (11 ± 6 mg C m-2 d-1). OC sedimentation was high (1162 mg C m-2 d-1), but our results suggest that the majority of it is mineralized to CO2 (722 ± 182 mg C m-2 d-1) rather than buried as OC (440 mg C m-2 d-1). Although temporally resolved data would render our findings more conclusive, our results suggest that despite being a primary production and OC burial hotspot, the tropical eutrophic system studied here was a stronger CO2 and CH4 source than a C sink, mainly because of high rates of OC mineralization in the water column and sediments.

Migration and Self-Protection Against Climate Change : A Case Study of Samburu County, Kenya
Ng'ang'a, Stanley ; Bulte, Erwin H. ; Giller, Ken E. ; McIntire, John M. ; Rufino, Mariana C. - \ 2016
World Development (2016). - ISSN 0305-750X - p. 55 - 68.
Adaptation - Climate change - Insurance - Migration - Remittance

Climate change will affect the livelihoods of pastoralists in arid and semi-arid lands. Using data on agro-pastoral households from northern Kenya, we explore whether migration of household members enhances adoption of agricultural innovations that aim to provide protection against weather shocks. Specifically, we seek to test whether migration and adaptation are complementary mechanisms to protect the household against adverse shocks, or whether they are substitutes. Do remittances relax capital constraints and facilitate the uptake of adaptive measures, or do they render adaptation superfluous? Our data provide suggestive evidence that remittances from migrant household members may relax capital constraints, and that remittances are an important mechanism linking migration to adoption, enabling the uptake of new technologies that involve change in activities or high costs. Specifically, migrant households adopt more adaptive measures (promoting self-protection), and we document some support for the hypothesis that this is especially the case for high-cost adaptations such as the purchasing of drought tolerant livestock. These findings suggest that migration and local innovation are complementary rather than substitutive mechanisms of self-protection for pastoral households in the semi-arid lands of northern Kenya. Households who have at least one member who has migrated are able to overcome barriers to employ high-cost agricultural innovations-through using remittances received-thus enhancing their self-protection against climate change related shocks.

Livestock wealth and social capital as insurance against climate risk : A case study of Samburu County in Kenya
Ng'ang'a, Stanley ; Bulte, Erwin H. ; Giller, Ken E. ; Ndiwa, Nicholas N. ; Kifugo, Shem C. ; McIntire, John M. ; Herrero, Mario ; Rufino, Mariana C. - \ 2016
Agricultural Systems 146 (2016). - ISSN 0308-521X - p. 44 - 54.
Climate - Cognitive capital - Insurance - Risks - Social capital - Structural capital

We use data from 500 households in Samburu County (Kenya) to explore how natural environment and market accessibility affect coping and adaptation strategies of pastoralists. In particular, we ask whether households accumulate livestock wealth and invest in structural and cognitive social capital to protect themselves against climate risks. We find weak evidence that households accumulate livestock wealth in response to living in a drier environment, and no evidence that households invest in either structural or cognitive social capital as insurance against climate risks. However, coping strategies vary across social groups. For example, while rainfall does not robustly affect cognitive social capital (trust)-we find that the "poor" and "financially-integrated" households (i.e., those who have relatively good access to credit and capacity to save money) show greater mutual trust in drier environments. The results from this study can be used for priority setting by policy makers and development agencies for programs aimed at safeguarding household livelihoods in arid and semi-arid lands (ASALs).

Effects of geographical origin, varietal and farming system on the chemical composition and functional properties of purple grape juices : A review
Granato, Daniel ; Magalhães Carrapeiro, Mariana de; Fogliano, Vincenzo ; Ruth, Saskia M. van - \ 2016
Trends in Food Science and Technology 52 (2016). - ISSN 0924-2244 - p. 31 - 48.
Antioxidant activity - Bioactivity - Biodynamic farming - Organic viticulture - Phenolic compounds - Vitis labrusca - Vitis vinifera

Background: Grape juice is a beverage derived from Vitis sp genus, mainly V. labrusca, V. vinifera and V. rotundifolia species, in which sales have increased steeply because of the alleged beneficial health effects it exerts when consumed regularly. However, the isolated and interlinked impacts of geographical origin, varietal, and farming system on the juice's chemical composition and functional properties still are not fully comprehended. Scope and approach: This paper aims to assess how the producing region, variety, and farming system of grapes (conventional, organic, and biodynamic) affect the quantitative and qualitatively the chemical composition and the functionality (in vitro, in vivo) of juices. Key findings and conclusions: Data have shown that the effects of botanical and geographical origins of purple grapes on the chemical composition (especially phenolic compounds) and functional properties of juices are remarkable. On the other hand, organic and biodynamic grape juices have very similar composition and functional properties in vitro, while organic and conventional are somewhat different. This evidence is in line with in vivo animal studies and human trials on healthy individuals have shown: differences in functional properties, especially antioxidant effects, between organic and conventional grape juices are negligible from the nutritional and biochemical perspectives.

Adaptation of agriculture to climate change in semi-arid Borena, Ethiopia
Ng'ang'a, Stanley ; Wijk, Mark T. van; Rufino, Mariana C. ; Giller, Ken E. - \ 2016
Regional Environmental Change 16 (2016)8. - ISSN 1436-3798 - p. 2317 - 2330.
Adaptation - Adaptive capacity - Adoption - Agro-pastoralists - Borena - Institutions

Livestock production is very risky due to climate variability in semi-arid Sub-Saharan Africa. Using data collected from 400 households in the Borena zone of the Oromia Region, we explored what drives adoption of agricultural practices that can decrease the vulnerability of agro-pastoralists to climate change. Households with more adaptive capacity adopted a larger number of practices. The households’ adaptive capacity was stronger when the quality of local institutions was high. However, adaptive capacity had less explanatory power in explaining adoption of adaptation options than household socio-economic characteristics, suggesting that aggregating information into one indicator of adaptive capacity for site-specific studies may not help to explain the adoption behaviour of households. Strong local institutions lead to changes in key household-level characteristics (like membership to community groups, years lived in a village, access to credit, financial savings and crop income) which positively affect adoption of agricultural practices. In addition, better local institutions were also positively related to adoption of livestock-related adaptation practices. Poor access to a tarmac road was positively related to intensification and diversification of crop production, whereas it was negatively related to the intensification of livestock production, an important activity for generating cash in the region. Our findings suggest that better local institutions lead to changes in household characteristics, which positively affect adoption of adaptation practices, suggesting that policies should aim to strengthen local institutions.

New approaches to the ecological risk assessment of multiple stressors
Brink, Paul J. Van Den; Choung, Catherine Bo ; Landis, Wayne ; Mayer-Pinto, Mariana ; Pettigrove, Vincent ; Scanes, Peter ; Smith, Rachael ; Stauber, Jenny - \ 2016
Marine and Freshwater Research 67 (2016)4. - ISSN 1323-1650 - p. 429 - 439.
adaptive management - anthropogenic stress - aquatic ecosystems.

So as to assess how emerging science and new tools can be applied to study multiple stressors at a large (ecosystem) scale and to facilitate greater integration of approaches among different scientific disciplines, a workshop was organised on 10-12 September 2014 at the Sydney Institute of Marine Sciences, Sydney, Australia. The present paper discusses the limitations of the current risk-assessment approaches and how multiple stressors at large scales can be better evaluated in ecological risk assessments to inform the development of more efficient and preventive management policies based on adaptive management in the future. A future risk-assessment paradigm that overcomes these limitations is presented. This paradigm includes cultural and ecological protection goals, the development of ecological scenarios, the establishment of the relevant interactions among species, potential sources of stressors, their interactions and the development of cause-effect models. It is envisaged that this will be achievable through a greater integration of approaches among different scientific disciplines and through the application of new and emerging tools such as 'big data', ecological modelling and the incorporation of ecosystem service endpoints.

Identifying groundwater recharge pathways in the Moscow sub-basin
Candel, J.H.J. ; Brooks, E.S. ; Verhoeff, Eric ; Dobre, Mariana ; Sanchez-Murillo, Ricardo ; Grader, Jr., George W. ; Dijksma, R. - \ 2016
Continual groundwater decline over the last 80 years in the Moscow-Pullman basin is motivating communities to explore a wide range of strategies ranging from reservoir development to direct injection to aquifers to ensure a sustainable regional water supply. Historic pumping records indicate the shallow Wanapum aquifer in the Moscow region does receive recharge however it is less certain that the deeper Grand Ronde aquifer is receiving any significant recharge. Moreover there is not a clear consensus in the region of the location of the major aquifer recharge flow paths. In this study we used both distributed hydrologic modeling based on detailed soil mapping and stable isotope tracers to explore and evaluate potential groundwater recharge pathways in the Moscow sub-basin. Modelling results indicate that subsurface water flow off the forested granitics in eastern margin of the sub-basin is likely a significant source of recharge. Biweekly water samples taken from 22 wells and 2 springs and high frequency streamflow and precipitation samples collected over a two year period throughout the Moscow sub-basin were analyzed for stable isotopes of hydrogen and oxygen. Frequency analysis of these stable isotope data suggest the some wells are receiving recharge. Furthermore many of these wells exist on the eastern margin of the sub-basin lending further support to the hypothesis that this region should be considered to be a critical ground recharge zone.
Scaling point/plot measurements of greenhouse gas fluxes, balances and intensities to whole-farms and landscapes
Rosenstock, T.S. ; Rufino, Mariana ; Chirinda, N. ; Bussel, L.G.J. van; Reidsma, P. ; Butterbach-Bahl, K. - \ 2015
In: Methods for Measuring Greenhouse Gas Balances and Evaluating Mitigation Options in Smallholder Agriculture / Rosenstock, T.S., Rufino, M.C., Butterbach-Bahl, K., Wollenberg, E., Richards, M., Springer - ISBN 9783319297927 - p. 175 - 188.
Measurements of nutrient stocks and greenhouse gas (GHG) fluxes are typically collected at very local scales (<1 to 30 m2) and then extrapolated to estimate impacts at larger spatial extents (farms, landscapes, or even countries). Translating point measurements to higher levels of aggregation is called scaling. Scaling fundamentally involves conversion of data through integration or interpolation and/or simplifying or nesting models. Model and data manipulation techniques to scale estimates are referred to as scaling methods. In this chapter, we first discuss the necessity and underlying premise of scaling and scaling methods. Almost all cases of agricultural GHG emissions and carbon (C) stock change research relies on disaggregated data, either spatially or by farming activity, as a fundamental input of scaling. Therefore, we then assess the utility of using empirical and process-based models with disaggregated data, specifically concentrating on the opportunities and challenges for their application to diverse smallholder farming systems in tropical regions. We describe key advancements needed to improve the confidence in results from these scaling methods in the future.
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.