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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Speckle pattern analysis of crumpled papers
Rad, Vahideh Farzam ; Ramírez-Miquet, Evelio E. ; Cabrera, Humberto ; Habibi, Mehdi ; Moradi, Ali Reza - \ 2019
Applied Optics 58 (2019)24. - ISSN 1559-128X - p. 6549 - 6554.

In this paper, we show that laser speckle analysis (LSA) can provide valuable information about the structure of crumpled thin sheets. Crumpling and folding of slender objects are present in several phenomena and in various ranges of size, e.g., paper compaction, cortical folding in brains, DNA packing in viral capsids, and flower buds, to name a few. The analysis of laser speckles, both numerical and graphical, is a source of information about the activity of biological or non-biological materials, and the development of digital electronics, which brought the ease of image processing, has opened new perspectives for a spectrum of LSA applications. LSA is applied on randomly crumpled and one-, two-, and three-times folded papers, and appreciable differences in LSA parameters are observed. The methodology can be applied for easy-to-implement quantitative assessment of similar phenomena and samples.

Author Correction: Diversity-dependent temporal divergence of ecosystem functioning in experimental ecosystems
Guerrero-Ramírez, Nathaly R. ; Craven, Dylan ; Reich, Peter B. ; Ewel, John J. ; Isbell, Forest ; Koricheva, Julia ; Parrotta, John A. ; Auge, Harald ; Erickson, Heather E. ; Forrester, David I. ; Hector, Andy ; Joshi, Jasmin ; Montagnini, Florencia ; Palmborg, Cecilia ; Piotto, Daniel ; Potvin, Catherine ; Roscher, Christiane ; Ruijven, Jasper van; Tilman, David ; Wilsey, Brian ; Eisenhauer, Nico - \ 2019
Nature Ecology & Evolution 3 (2019). - ISSN 2397-334X - p. 1365 - 1365.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Characterisation of the effect of day length, and associated differences in dietary intake, on the gut microbiota of Soay sheep
Thomas, Nadine A. ; Olvera-Ramírez, Andrea M. ; Abecia, Leticia ; Adam, Clare L. ; Edwards, Joan E. ; Cox, Georgina F. ; Findlay, Patricia A. ; Destables, Elodie ; Wood, Tracy A. ; McEwan, Neil R. - \ 2019
Archives of Microbiology 201 (2019)7. - ISSN 0302-8933 - p. 889 - 896.
Anaerobic fungi - Bacteria - Ciliated protozoa - Day length - Digestive tract - Soay sheep

Differences in the rumen bacterial community have been previously reported for Soay sheep housed under different day length conditions. This study extends this previous investigation to other organs of the digestive tract, as well as the analysis of ciliated protozoa and anaerobic fungi. The detectable concentrations of ciliated protozoa and anaerobic fungi decreased with increased day length in both the rumen and large colon, unlike those of bacteria where no effect was observed. Conversely, bacterial community composition was affected by day length in both the rumen and large colon, but the community composition of the detectable ciliated protozoa and anaerobic fungi was not affected. Day length-associated differences in the bacterial community composition extended to all of the organs examined, with the exception of the duodenum and the jejunum. It is proposed that differences in rumen fill and ruminal ‘by-pass’ nutrients together with endocrinological changes cause the observed effects of day length on the different gut microbial communities.

The problem of water use in rural areas of Southwestern Spain: A local perspective
Pulido, Manuel ; Barrena-González, Jesús ; Alfonso-Torreño, Alberto ; Robina-Ramírez, Rafael ; Keesstra, Saskia - \ 2019
Water 11 (2019)6. - ISSN 2073-4441
Drinking water - Irrigation - Leisure facilities - Local perception

Water is a key strategic resource, particularly in Mediterranean climate-type areas with impermeable rocks and shallow soils like Southwestern Spain. The region of Extremadura is commonly known by its large surface occupied by big dams (30% of water dammed in Spain) although this theoretical abundance of water does not hide other problems of use. In this study, we have interviewed 132 people from the municipality of Arroyo de San Serván in order to know what the problems related to water use are, especially those that concern local people the most. Regarding the use of water at home, 90% of interviewees spend less than 60 EUR per month for water and their mean degree of satisfaction about the service is 3.7 out of 7. The reason for this low value can be the excessive content of calcium and bad taste according to 82.1%. Therefore, 64.2% of people do not usually drink water from the tap. Around two thirds of these local people usually buy water in the supermarket or drink filtered water. Concerning agricultural activities, local people gave great importance to irrigation as a source of employment (5.6/7) and inputs (4.5/7), although their satisfaction decreases about the current price of water for agriculture (0.02 EUR m-3). In addition, they are really worried about the overuse of fertilizers and herbicides (5.4/7) and they think about the necessity of taking measures to reduce these problems (6.1/7) as well as to reduce some management problems such as supply cuts. In the last few years, private (swimming pools) and public leisure facilities (swimming pool and spa) have been built in spite of not being considered important by local people (3.6-4.0/7). Nevertheless, about 60% of them consider these common facilities very positive in terms of employment, tourism attractions and entertainment for local people.

Latitudinal variation in soil nematode communities under climate warming-related range-expanding and native plants
Wilschut, Rutger A. ; Geisen, Stefan ; Martens, Henk ; Kostenko, Olga ; Hollander, Mattias de; Hooven, Freddy C. ten; Weser, Carolin ; Snoek, L.B. ; Bloem, Janneke ; Caković, Danka ; Čelik, Tatjana ; Koorem, Kadri ; Krigas, Nikos ; Manrubia, Marta ; Ramirez, Kelly S. ; Tsiafouli, Maria A. ; Vreš, Branko ; Putten, Wim H. van der - \ 2019
Global Change Biology 25 (2019)8. - ISSN 1354-1013 - p. 2714 - 2726.
Centaurea stoebe - enemy release hypothesis - plant-pathogenic nematodes - range expansion - range-expanding plant species - root-feeding nematodes

Current climate change has led to latitudinal and altitudinal range expansions of numerous species. During such range expansions, plant species are expected to experience changes in interactions with other organisms, especially with belowground biota that have a limited dispersal capacity. Nematodes form a key component of the belowground food web as they include bacterivores, fungivores, omnivores and root herbivores. However, their community composition under climate change-driven intracontinental range-expanding plants has been studied almost exclusively under controlled conditions, whereas little is known about actual patterns in the field. Here, we use novel molecular sequencing techniques combined with morphological quantification in order to examine nematode communities in the rhizospheres of four range-expanding and four congeneric native species along a 2,000 km latitudinal transect from South-Eastern to North-Western Europe. We tested the hypotheses that latitudinal shifts in nematode community composition are stronger in range-expanding plant species than in congeneric natives and that in their new range, range-expanding plant species accumulate fewest root-feeding nematodes. Our results show latitudinal variation in nematode community composition of both range expanders and native plant species, while operational taxonomic unit richness remained the same across ranges. Therefore, range-expanding plant species face different nematode communities at higher latitudes, but this is also the case for widespread native plant species. Only one of the four range-expanding plant species showed a stronger shift in nematode community composition than its congeneric native and accumulated fewer root-feeding nematodes in its new range. We conclude that variation in nematode community composition with increasing latitude occurs for both range-expanding and native plant species and that some range-expanding plant species may become released from root-feeding nematodes in the new range.

Range-expansion effects on the belowground plant microbiome
Ramirez, Kelly S. ; Snoek, L.B. ; Koorem, Kadri ; Geisen, Stefan ; Bloem, L.J. ; Hooven, Freddy ten; Kostenko, Olga ; Krigas, Nikos ; Manrubia, Marta ; Caković, Danka ; Raaij, Debbie van; Tsiafouli, Maria A. ; Vreš, Branko ; Čelik, Tatjana ; Weser, Carolin ; Wilschut, Rutger A. ; Putten, Wim H. van der - \ 2019
Nature Ecology & Evolution 3 (2019)4. - ISSN 2397-334X - p. 604 - 611.

Plant range expansion is occurring at a rapid pace, largely in response to human-induced climate warming. Although the movement of plants along latitudinal and altitudinal gradients is well-documented, effects on belowground microbial communities remain largely unknown. Furthermore, for range expansion, not all plant species are equal: in a new range, the relatedness between range-expanding plant species and native flora can influence plant–microorganism interactions. Here we use a latitudinal gradient spanning 3,000 km across Europe to examine bacterial and fungal communities in the rhizosphere and surrounding soils of range-expanding plant species. We selected range-expanding plants with and without congeneric native species in the new range and, as a control, the congeneric native species, totalling 382 plant individuals collected across Europe. In general, the status of a plant as a range-expanding plant was a weak predictor of the composition of bacterial and fungal communities. However, microbial communities of range-expanding plant species became more similar to each other further from their original range. Range-expanding plants that were unrelated to the native community also experienced a decrease in the ratio of plant pathogens to symbionts, giving weak support to the enemy release hypothesis. Even at a continental scale, the effects of plant range expansion on the belowground microbiome are detectable, although changes to specific taxa remain difficult to decipher.

Phytochrome a protects tomato plants from injuries induced by continuous light
Velez-Ramirez, Aaron I. ; Vreugdenhil, Dick ; Millenaar, Frank F. ; Ieperen, Wim van - \ 2019
Frontiers in Plant Science 10 (2019). - ISSN 1664-462X
Continuous light - Far-red light - Photosynthesis down-regulation - Phytochrome - Solanum lycopersicum - Tomato

Plants perceive and transduce information about light quantity, quality, direction and photoperiod via several photoreceptors and use it to adjust their growth and development. A role for photoreceptors has been hypothesized in the injuries that tomato plants develop when exposed to continuous light as the light spectral distribution influences the injury severity. Up to now, however, only indirect clues suggested that phytochromes (PHY), red/far-red photoreceptors, are involved in the continuous-light-induced injuries in tomato. In this study, therefore, we exposed mutant and transgenic tomato plants lacking or over-expressing phytochromes to continuous light, with and without far-red light enrichment. The results show that PHYA over-expression confers complete tolerance to continuous light regardless the light spectrum. Under continuous light with low far-red content, PHYB1 and PHYB2 diminished and enhanced the injury, respectively, yet the effects were small. These results confirm that phytochrome signaling networks are involved in the induction of injury under continuous light. HIGHLIGHTS-PHYA over-expression confers tolerance to continuous light regardless the light spectrum.-In the absence of far-red light, PHYB1 slightly diminishes the continuous light-induced injury.-Continuous light down-regulates photosynthesis genes in sensitive tomato lines.

Assessment of browsed plants in a sub-tropical forest frontier by means of fuzzy inference
Dechnik-Vázquez, Yanus A. ; García-Barrios, Luis ; Ramírez-Marcial, Neptalí ; Noordwijk, Meine van; Alayón-Gamboa, Armando - \ 2019
Journal of Environmental Management 236 (2019). - ISSN 0301-4797 - p. 163 - 181.
Agroforestry - Browsing - Cattle - Fuzzy inference - Silvopastoral systems

Browsing of forest frontiers by cattle in sub-tropical landscapes is detrimental to ecosystem health, but essential to smallholder livelihoods. We described a silvopastoral landscape, searching for browsed plants to assess how much of the forest is actually used for this end, and also searching for potential new useful species for silvopastoral purposes. The first objective was accomplished through a floristic description, making observations of individuals with browsing marks. Information from interviews, bromatological analyses and vegetative propagation tests further complemented this information to achieve the second objective. We classified the results using Fuzzy Inference Systems (FISs). A great variety of nutritious browsed plants was found, distributed across various types of vegetation, growth habits and taxonomic groups: forest frontiers already are like silvopastoral systems. Various plants like Acalypha leptopoda, Montanoa tomentosa and Verbesina perymenioides are interesting prospects for further intensification of silvopastoral systems.

Robust soil mapping at the farm scale with vis–NIR spectroscopy
Ramirez-Lopez, L. ; Wadoux, A.M.J.C. ; Franceschini, M.H.D. ; Terra, F.S. ; Marques, K.P.P. ; Sayão, V.M. ; Demattê, J.A.M. - \ 2019
European Journal of Soil Science 70 (2019)2. - ISSN 1351-0754 - p. 378 - 393.

Sustainable agriculture practices are often hampered by the prohibitive costs associated with the generation of fine-resolution soil maps. Recently, several papers have been published highlighting how visible and near infrared (vis–NIR) reflectance spectroscopy may offer an alternative to address this problem by increasing the density of soil sampling and by reducing the number of conventional laboratory analyses needed. However, for farm-scale soil mapping, previous studies rarely focused on sample optimization for the calibration of vis–NIR models or on robust modelling of the spatial variation of soil properties predicted by vis–NIR spectroscopy. In the present study, we used soil vis–NIR spectroscopy models optimized in terms of both number of calibration samples and accuracy for high-resolution robust farm-scale soil mapping and addressed some of the most common pitfalls identified in previous research. We collected 910 samples from 458 locations at two depths (A, 0–0.20 m; B, 0.80–1.0 m) in the state of São Paulo, Brazil. All soil samples were analysed by conventional methods and scanned in the vis–NIR spectral range. With the vis–NIR spectra only, we inferred statistically the optimal set size and the best samples with which to calibrate vis–NIR models. The calibrated vis–NIR models were validated and used to predict soil properties for the rest of the samples. The prediction error of the spectroscopic model was propagated through the spatial analysis, in which robust block kriging was used to predict particle-size fractions and exchangeable calcium content for each depth. The results indicated that statistical selection of the calibration samples based on vis–NIR spectra considerably decreased the need for conventional chemical analysis for a given level of mapping accuracy. The methods tested in this research were developed and implemented using open-source software. All codes and data are provided for reproducible research purposes. Highlights: Vis–NIR spectroscopy enables an increase in sampling density with little additional cost. Guided selection of vis–NIR calibration samples reduced the need for conventional soil analysis. Error of spectroscopic model prediction was propagated by spatial analysis. Maps from the vis–NIR augmented dataset were almost as accurate as those from conventional soil analysis.

Defining and applying the concept of Favourable Reference Values for species habitats under the EU Birds and Habitats Directives : examples of setting favourable reference values
Bijlsma, R.J. ; Agrillo, E. ; Attorre, F. ; Boitani, L. ; Brunner, A. ; Evans, P. ; Foppen, R. ; Gubbay, S. ; Janssen, J.A.M. ; Kleunen, A. van; Langhout, W. ; Pacifici, M. ; Ramirez, I. ; Rondinini, C. ; Roomen, M. van; Siepel, H. ; Swaaij, C.A.M. van; Winter, H.V. - \ 2019
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research report 2929) - 219
Defining and applying the concept of Favourable Reference Values for species habitats under the EU Birds and Habitats Directives : technical report
Bijlsma, R.J. ; Agrillo, E. ; Attorre, F. ; Boitani, L. ; Brunner, A. ; Evans, P. ; Foppen, R. ; Gubbay, S. ; Janssen, J.A.M. ; Kleunen, A. van; Langhout, W. ; Noordhuis, R. ; Pacifici, M. ; Ramirez, I. ; Rondinini, C. ; Roomen, M. van; Siepel, H. ; Winter, H.V. - \ 2019
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research report 2928) - 93
Recent insights on uncertainties present in integrated catchment water quality modelling
Tscheikner-Gratl, Franz ; Bellos, Vasilis ; Schellart, Alma ; Moreno-Rodenas, Antonio ; Muthusamy, Manoranjan ; Langeveld, Jeroen ; Clemens, Francois ; Benedetti, Lorenzo ; Rico-Ramirez, Miguel Angel ; Carvalho, Rita Fernandes de; Breuer, Lutz ; Shucksmith, James ; Heuvelink, Gerard B.M. ; Tait, Simon - \ 2019
Water Research 150 (2019). - ISSN 0043-1354 - p. 368 - 379.
Complexity management - Integrated catchment modelling - Sub-models of integrated modelling - Uncertainty - Water quality

This paper aims to stimulate discussion based on the experiences derived from the QUICS project (Quantifying Uncertainty in Integrated Catchment Studies). First it briefly discusses the current state of knowledge on uncertainties in sub-models of integrated catchment models and the existing frameworks for analysing uncertainty. Furthermore, it compares the relative approaches of both building and calibrating fully integrated models or linking separate sub-models. It also discusses the implications of model linkage on overall uncertainty and how to define an acceptable level of model complexity. This discussion includes, whether we should shift our attention from uncertainties due to linkage, when using linked models, to uncertainties in model structure by necessary simplification or by using more parameters. This discussion attempts to address the question as to whether there is an increase in uncertainty by linking these models or if a compensation effect could take place and that overall uncertainty in key water quality parameters actually decreases. Finally, challenges in the application of uncertainty analysis in integrated catchment water quality modelling, as encountered in this project, are discussed and recommendations for future research areas are highlighted.

Long-term effects of wild ungulates on the structure, composition and succession of temperate forests
Ramirez Chiriboga, J.I. ; Jansen, P.A. ; Ouden, J. den; Goudzwaard, L. ; Poorter, L. - \ 2019
Forest Ecology and Management 432 (2019). - ISSN 0378-1127 - p. 478 - 488.
Ungulates in temperate regions are increasing in range and abundance, leading to concerns that browsing and trampling reach levels that hamper tree recruitment and forest regeneration. However, studies that actually quantify the long-term effects of ungulates on forest succession are scarce. Here, we use a chronosequence of ungulate exclosures (fenced) and control (unfenced) plots to assess the long-term effects of ungulates on forest structure, diversity and litter depth in forests on poor sandy soils at the Veluwe, the Netherlands, which have moderate ungulate densities ( = 13.6 ungulates km−2). We surveyed the vegetation in 27 paired fenced and unfenced plots that ranged from 1 to 33 years old, and measured seven variables to characterize forest structure (stem density, canopy cover and understory vegetation cover), composition (Shannon diversity, species richness and conifer proportion) and leaf litter depth. We found on average that fencing compared to unfencing reduced understory vegetation cover (fenced = 64.3 ± 20.2%, unfenced = 80.3 ± 19.4%), increased canopy cover (fenced = 47.4 ± 30.1%, unfenced = 29.3 ± 21.1%), tree species richness (fenced = 4.5 ± 1.3 spp., unfenced = 2.7 ± 1.2 spp.), tree Shannon diversity (fenced = 1.1 ± 0.3 index, unfenced = 0.7 ± 0.3 index) and litter layer depth (fenced = 4.4 ± 1.4 cm, unfenced = 2.4 ± 1.1 cm). While fenced plots developed woody vegetation with palatable broadleaved species such as Betula pendula, Betula pubescens, Prunus serotina, and Quercus robur, unfenced plots were not associated with any particular tree species. Our results show that current ungulate densities in this system have pronounced long-term effects on forest structure, composition and litter depth, implying that ungulates can slow down natural succession of temperate forest, from light demanding to shade tolerant species, by keeping the system in an arrested state consisting of light demanding species.
Small Fish and Food Security : Towards innovative integration of small fish in African food systems to improve nutrition
Kolding, Jeppe ; Overa, Ragnhild ; Kjellevold, Marian ; Zwieten, P.A.M. van; Pucher, Johannes ; Yaro, Joseph ; Njiru, James ; Taabu-Munyaho, Anthony - \ 2018
In: WSFC 3rd world small-scale fisheries congress, Chiang Mai, Thailand, October 22-26, 2018. - - p. 57 - 57.
Study on the approaches to management for data-poor stocks in mixed fisheries : DRuMFISH : final report - Study
Poos, J.J. ; Oliveira, José De; Ulrich, C. ; Brunel, T.P.A. ; Plet-Hansen, Kristian ; Mildenberger, Tobias ; Nielsen, J.R. ; Kokkalis, A. ; Minto, Coilín ; Pawlowski, Lionel ; Robert, Marianne ; Macher, Claire ; Merzereaud, Mathieu ; Garcia, Dorleta ; Ibaibarriaga, L. ; Bertignac, Michel ; Vermard, Youen ; Fischer, Simon ; Carpi, Piera ; Walker, Nicola ; Earl, Timothy ; Davie, Sarah ; Haslob, Holger ; Kempf, A. ; Taylor, Marc ; Martin, Paloma ; Maynou, Francesc ; Recasens, Laura ; Ramirez, John Gabriel ; Lleonart, Jordi ; Garriga, Mariona ; Tserpes, George ; Sgardeli, Viki ; Coro, Gianpolo ; Scarcella, Giuseppe ; Angelini, Silvia - \ 2018
EU - ISBN 9789292024062 - 84 p.
This is the final report of the European Commission funded research project "DRuMFISH" (service contract n° EASME/EMFF/2014/l.3.2.4/ SI2.721116). The main aim of the project was to develop models and strategies for providing advice for mixed fisheries that account for: (i) fishing mortality ranges consistent with MSY, (ii) all fish caught being landed, and (iii) significant components of the marine fish ecosystem lacking key biological information. In order to meet this aim, DRuMFISH delivered a review of assessment approaches for data-poor stocks, extended mixed fisheries simulation frameworks to include data-poor stocks. The assessment approaches and simulation frameworks were implemented in 7 case studies. These case studies were mixed fisheries in the Baltic Sea, the North Sea, the Celtic Sea, the Bay of Biscay, the Western Mediterranean, the Adriatic Sea, and the Aegean Sea. Within the case studies, 35 data-poor stock assessments were done. These assessments provided exploitation status of data-poor stocks. Different harvest control rules were subsequently tested for their expected yields and stock biomasses from the mixed fisheries in the simulation frameworks. Now that data-poor stocks can be incorporated with in the mixed fisheries simulation frameworks, the design of new management plans can account for data-poor stocks in mixed fisheries.
Opportunities for soil sustainability in Europe
Putten, W.H. van der; Ramirez, Kelly S. ; Poesen, Jean ; Winding, A. ; Lemanceau, Philippe ; Lisa, Lenka ; Simek, Miloslaw ; Moora, M. ; Setala, Heikki ; Zaitsev, A. ; Economou-Eliopoulos, Maria ; Hornung, E. ; Wall, David ; Angelis, P. de; Lipiec, Jerzy ; Briones, M.J.I. ; Hedlund, Katarina ; Heijden, M. ; Six, Johan ; Bardgett, Richard D. ; Powlson, D. ; Goulding, K. ; Norton, Michael - \ 2018
- 48 p.
Reduction in nutritional quality and growing area suitability of common bean under climate change induced drought stress in Africa
Hummel, Marijke ; Hallahan, Brendan F. ; Brychkova, Galina ; Ramirez-Villegas, Julian ; Guwela, Veronica ; Chataika, Bartholomew ; Curley, Edna ; McKeown, Peter C. ; Morrison, Liam ; Talsma, Elise F. ; Beebe, Steve ; Jarvis, Andy ; Chirwa, Rowland ; Spillane, Charles - \ 2018
Scientific Reports 8 (2018)1. - ISSN 2045-2322 - 11 p.

Climate change impacts on food security will involve negative impacts on crop yields, and potentially on the nutritional quality of staple crops. Common bean is the most important grain legume staple crop for human diets and nutrition worldwide. We demonstrate by crop modeling that the majority of current common bean growing areas in southeastern Africa will become unsuitable for bean cultivation by the year 2050. We further demonstrate reductions in yields of available common bean varieties in a field trial that is a climate analogue site for future predicted drought conditions. Little is known regarding the impact of climate change induced abiotic stresses on the nutritional quality of common beans. Our analysis of nutritional and antinutritional compounds reveals that iron levels in common bean grains are reduced under future climate-scenario relevant drought stress conditions. In contrast, the levels of protein, zinc, lead and phytic acid increase in the beans under such drought stress conditions. This indicates that under climate-change induced drought scenarios, future bean servings by 2050 will likely have lower nutritional quality, posing challenges for ongoing climate-proofing of bean production for yields, nutritional quality, human health, and food security.

A framework for priority-setting in climate smart agriculture research
Thornton, Philip K. ; Whitbread, Anthony ; Baedeker, Tobias ; Cairns, Jill ; Claessens, Lieven ; Baethgen, Walter ; Bunn, Christian ; Friedmann, Michael ; Giller, Ken E. ; Herrero, Mario ; Howden, Mark ; Kilcline, Kevin ; Nangia, Vinay ; Ramirez-Villegas, Julian ; Kumar, Shalander ; West, Paul C. ; Keating, Brian - \ 2018
Agricultural Systems 167 (2018). - ISSN 0308-521X - p. 161 - 175.
Adaptation - Agriculture - Climate change - Mitigation - Research

Climate-smart agriculture (CSA) is widely promoted as an approach for reorienting agricultural development under the realities of climate change. Prioritising research-for-development activities is crucial, given the need to utilise scarce resources as effectively as possible. However, no framework exists for assessing and comparing different CSA research investments. Several aspects make it challenging to prioritise CSA research, including its multi-dimensional nature (productivity, adaptation and mitigation), the uncertainty surrounding many climate impacts, and the scale and temporal dependencies that may affect the benefits and costs of CSA adoption. Here we propose a framework for prioritising agricultural research investments across scales and review different approaches to setting priorities among agricultural research projects. Many priority-setting case studies address the short- to medium-term and at relatively local scales. We suggest that a mix of actions that span spatial and temporal time scales is needed to be adaptive to a changing climate, address immediate problems and create enabling conditions for enduring change.

Monitoreo climático: herramienta al servicio de la caficultura Colombiana
Sarmiento, Ninibeth ; Ramírez, Carolina ; Jaramillo, Álvaro ; Restrepo, Alexander ; García López, Juan Carlos ; Wolters, W. ; Miguel Ayala, L. - \ 2018
Bogota : APC Columbia - ISBN 9789588490298 - 110
Symmetry-reversals in chiral active matter
Workamp, Marcel ; Ramirez, Gustavo ; Daniels, Karen E. ; Dijksman, Joshua A. - \ 2018
Soft Matter 14 (2018)27. - ISSN 1744-683X - p. 5572 - 5580.

We perform experiments on an active granular material composed of individually-driven, spinning disks confined within a circular arena. Small bumps at the outer edges of the disks provide a variable amount of interparticle coupling in the form of geometric friction. The disks each spin counter-clockwise, but undergo a transition in their collective circulation around the center of the arena, from a clockwise orbit to a counter-clockwise orbit, as a function of packing fraction φ. We identify that, unlike for vibrated granular gases, the particles' velocity distributions are Gaussian over a large range of φ. By fitting the speed distribution to a Maxwell-Boltzmann distribution, we identify a temperature-like parameter which is a universal function of φ; this parameter is also equal to the mean translational energy of the particles. We quantify the collective circulation via its solid-body-like rotation rate, and find that this is a universal function centered around a critical packing fraction. In addition, the ratio of orbital kinetic energy to spin kinetic energy is also a universal function for non-zero geometric friction. These findings highlight the important role of both the type of driving and the interparticle interactions (here, geometric friction) in controlling the collective behavior of active granular systems.

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