61 research outputs found
Multidimensional Performance of Farming Approaches
Fil: Garibaldi, Lucas Alejandro. Universidad Nacional de RĂo Negro. Sede Andina; Argentina.Fil: Gemmill Herren, Barbara. World Agroforestry Centre; Kenya.Fil: DâAnnolfo, Raffaele. UniversitĂ Cattolica del Sacro Cuore; Italia.Fil: Graeub, Benjamin E. Biovision Foundation for Ecological Development y Ricolab; Suiza.Fil: Cunningham, Saul A. Australian National University; Australia.Fil: Breeze, Thomas D. University of Reading; UK.Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas (CONICET); Argentina.The letter by Mehrabi et al. [1] provides interesting insights regarding the scientific framework and attitudes needed to support farming approaches for greater biodiversity, livelihoods, and food security. In general, we do not see a dichotomy between our point of view [2] and that put forward by Mehrabi et al. [1]. We share their view that the different farming systems we have described do not form distinct, non-overlapping categories. We do not seek to promote a binary choice between conventional and alternative farming
The 10 Elements of Agroecology:Enabling transitions towards sustainable agriculture and food systems through visual narratives
The magnitude and urgency of the challenges facing agriculture and food systems demand profound modifications in different aspects of human activity to achieve real transformative change and sustainability. Recognizing that the inherent complexity of achieving sustainability is commonly seen as a deterrent to decision-making, the Food and Agriculture Organization of the United Nations (FAO) has approved the 10 Elements of Agroecology as an analytical framework to support the design of differentiated paths for agriculture and food systems transformation, hence facilitating improved decision-making by policymakers, practitioners and other stakeholders in differing contexts at a range of levels on a number of scales. Biodiversity, consumers, education and governance are identified as promising entry points to build a structured process using visual narratives that rely on the 10 Elements of Agroecology to graphically dissect prospective social-ecological transition trajectories. We illustrate such applications with examples from agroforestry worldwide, public food procurement in Brazil and the United States of America, and agroecology education vis-Ă -vis secure access to land in Senegal. Nexus approaches are used to highlight and examine salient interactions among different sectors and entry points, and to develop visual narratives describing plausible theories of transformative change towards sustainable agriculture and food systems
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Policies for ecological intensification of crop production
Ecological intensification aims to increase crop productivity by enhancing biodiversity and associated ecosystem services, while minimizing the use of synthetic inputs and cropland expansion. Policies to promote ecological intensification have emerged in different countries, but they are still scarce and vary widely across regions. Here, we propose ten policy targets that governments can follow for ecological intensification
Do riparian forest fragments provide ecosystem services or disservices in surrounding oil palm plantations?
Agricultural expansion across tropical regions is causing declines in biodiversity and altering ecological processes. However, in some tropical agricultural systems, conserving natural habitat can simultaneously protect threatened species and support important ecosystem services. Oil palm cultivation is expanding rapidly throughout the tropics but the extent to which non-crop habitat supports biodiversity and ecosystem services in these landscapes is poorly documented. We investigated whether riparian forest fragments (riparian reserves) provide a pest control service or increase pest activity (disservice) within oil palm dominated landscapes in Sabah, Malaysian Borneo. We assessed the activity of potential predators of pest herbivores using plasticine caterpillar mimics and quantified herbivory rates on oil palm fronds in areas with and without riparian reserves. We also manipulated the shape and colour of the mimics to assess the extent to which artificial pest mimics reflect a predatory response. The presence of riparian reserves increased the attack rate on mimics by arthropods, but not by birds. Our methodological study suggested attacks on artificial pest mimics provide a better indication of predatory activity for birds than for arthropod predators. Herbivory rates were also not significantly affected by the presence of a riparian reserve, but we found some evidence that herbivory rates may decrease as the size of riparian reserves increases. Overall, we conclude that riparian forest fragments of 30 â 50 m width on each side of the river are unlikely to provide a pest control service. Nevertheless, our results provide evidence that these riparian buffer strips do not increase the density of defoliating pests, which should reassure managers concerned about possible negative consequences of preserving riparian buffers
Eco-agri-food systems: today's realities and tomorrow's challenges
Provides an overview of the diversity of agriculture and food systems, each with different contributions to global food security, impacts on the natural resource base and ways of working through food system supply chains. We describe âeco-agri-food systemsâ and further identify their many manifestations through a review of typologies. We identify challenges ahead with existing systems due to prevailing economic and political pressures resulting in patterns of invisible flows and impacts across global food systems. We describe pathways to ensure sustainability by securing the benefits from working with, rather than against, natural systems and ecosystem processes and the challenges for farmers, communities and societies to reorient food value chains and build resilience in eco-agri-food systemsFil: Pengue, Walter Alberto. Universidad Nacional de General Sarmiento; Argentina. Universidad de Buenos Aires; ArgentinaFil: Gemmill Herren, Barbara. World Agroforestry Centre; KeniaFil: BalĂĄzs, BĂĄlint. Environmental Social Science Research Group; HungrĂaFil: Ortega, Enrique. Universidade Estadual de Campinas; BrasilFil: Acevedo, Francisca. National Commission for the Knowledge and Use of Biodiversity,; MĂ©xicoFil: Diaz, Daniel N,. Instituto Nacional de TecnologĂa Agropecuaria; ArgentinaFil: DĂaz de Astarloa, Diego. Universidad Nacional de General Sarmiento; ArgentinaFil: Fernandez, Rosa. Instituto Nacional de TecnologĂa Agropecuaria; ArgentinaFil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte. Instituto de Investigaciones En Recursos Naturales, AgroecologĂa y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones En Recursos Naturales, AgroecologĂa y Desarrollo Rural; ArgentinaFil: Giampietro, Mario. Universidad de Barcelona; EspañaFil: Goldberg, Andrea. Instituto Nacional de TecnologĂa Agropecuaria; ArgentinaFil: Khosla, Ashok. Development Alternatives; IndiaFil: Westhoek, Henk. PBL Netherlands Environmental Assessment Agency. Water, Agriculture and Food; PaĂses Bajo
Numerical simulation of explosive volcanic eruptions from the conduit flow to global atmospheric scales
Volcanic eruptions are unsteady multiphase phenomena, which encompass many inter-related processes across the
whole range of scales from molecular and microscopic to macroscopic, synoptic and global. We provide an
overview of recent advances in numerical modelling of volcanic effects, from conduit and eruption column processes
to those on the Earth s climate. Conduit flow models examine ascent dynamics and multiphase processes like
fragmentation, chemical reactions and mass transfer below the Earth surface. Other models simulate atmospheric
dispersal of the erupted gas-particle mixture, focusing on rapid processes occurring in the jet, the lower convective
regions, and pyroclastic density currents. The ascending eruption column and intrusive gravity current generated
by it, as well as sedimentation and ash dispersal from those flows in the immediate environment of the volcano are
examined with modular and generic models. These apply simplifications to the equations describing the system depending
on the specific focus of scrutiny. The atmospheric dispersion of volcanic clouds is simulated by ash tracking
models. These are inadequate for the first hours of spreading in many cases but focus on long-range prediction
of ash location to prevent hazardous aircraft - ash encounters. The climate impact is investigated with global models.
All processes and effects of explosive eruptions cannot be simulated by a single model, due to the complexity
and hugely contrasting spatial and temporal scales involved. There is now the opportunity to establish a closer integration
between different models and to develop the first comprehensive description of explosive eruptions and
of their effects on the ground, in the atmosphere, and on the global climate
Aspects determining the risk of pesticides to wild bees: risk profiles for focal crops on three continents
In order to conduct a proper risk assessment of pesticides to bees, information is needed in three areas: the toxicity of the pesticide;the probability of bee exposure to that pesticide; andthe population dynamics of the bee species in question.Information was collected on such factors affecting pesticide risk to (primarily wild) bees in several crops in Brazil, Kenya and The Netherlands. These data were used to construct ârisk profilesâ of pesticide use for bees in the studied cropping systems. Data gaps were identified and potential risks of pesticides to bees were compared between the crops. Initially, risk profiling aims to better identify gaps in our present knowledge. In the longer term, the established risk profiles may provide structured inputs into risk assessment models for wild and managed bees, and lead to recommendations for specific risk mitigation measures. Keywords: pesticide, exposure, risk, wild bees, risk profil
Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?
Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong ânumericalâ effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative âidentityâ effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.info:eu-repo/semantics/publishedVersio
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A global-scale expert assessment of drivers and risks associated with pollinator decline.
Pollinator decline has attracted global attention and substantial efforts are underway to respond through national pollinator strategies and action plans. These policy responses require clarity on what is driving pollinator decline and what risks it generates for society in different parts of the world. Using a formal expert elicitation process, we evaluated the relative regional and global importance of eight drivers of pollinator decline and ten consequent risks to human well-being. Our results indicate that global policy responses should focus on reducing pressure from changes in land cover and configuration, land management and pesticides, as these were considered very important drivers in most regions. We quantify how the importance of drivers and risks from pollinator decline, differ among regions. For example, losing access to managed pollinators was considered a serious risk only for people in North America, whereas yield instability in pollinator-dependent crops was classed as a serious or high risk in four regions but only a moderate risk in Europe and North America. Overall, perceived risks were substantially higher in the Global South. Despite extensive research on pollinator decline, our analysis reveals considerable scientific uncertainty about what this means for human society.University of Readingâs Building Outstanding Impact Support Programm
Non-bee insects are important contributors to global crop pollination
Wild andmanaged bees arewell documented as effective pollinators of global crops of economic importance. However, the contributions by pollinators other than bees have been little explored despite their potential to contribute to crop production and stability in the face of environmental change. Non-bee pollinators include flies, beetles, moths, butterflies, wasps, ants, birds, and bats, among others. Here we focus on non-bee insects and synthesize 39 field studies from five continents that directly measured the crop pollination services provided by non-bees, honey bees, and other bees to compare the relative contributions of these taxa. Non-bees performed 25-50% of the total number of flower visits. Although non-bees were less effective pollinators than bees per flower visit, they made more visits; thus these two factors compensated for each other, resulting in pollination services rendered by non-bees that were similar to those provided by bees. In the subset of studies that measured fruit set, fruit set increased with non-bee insect visits independently of bee visitation rates, indicating that non-bee insects provide a unique benefit that is not provided by bees. We also show that non-bee insects are not as reliant as bees on the presence of remnant natural or seminatural habitat in the surrounding landscape. These results strongly suggest that non-bee insect pollinators play a significant role in global crop production and respond differently than bees to landscape structure, probably making their crop pollination services more robust to changes in land use. Non-bee insects provide a valuable service and provide potential insurance against bee population declines.Peer Reviewe
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