484 research outputs found
Network properties data and code used in "Ecological plasticity governs ecosystem services in multilayer networks".
No full textCode and network properties data used in the analyses presented in "Ecological plasticity governs ecosystem services in multilayer networks". Further information can be requested of the author David A. Bohan ([email protected])
Atlanta’s Desegregation Era Social Studies Curriculum: An Examination of Georgia History Textbooks
No full textAuthor accepted manuscript version of a chapter published in:
Bohan, C. H. & Randolph, P. (2012). Desegregation era social studies curriculum: An examination of Georgia History textbooks. Chapter seven in C. Woyshner and C. H. Bohan (Eds.) Histories of social studies and race, 1890–2000. (pp. 135−158). New York: Palgrave MacMillan.</p
Ballooning dispersal in arthropod taxa: conditions at take-off
No full textWe have solved a long-standing and seemingly paradoxical set of questions that relate to the conditions which govern spider ballooning. We show that observations of spider ballooning excursions are best explained by meteorological conditions which maximize dispersal. Dispersal is predicted to be most effective in terms of distance when the stability of the atmosphere is non-ideally convective and is less effective during purely convective or neutrally stable conditions. Ballooners are most likely to travel a few hundred metres, but dispersal distances of several hundred kilometres are possible
[Archives de la parole]. , [Travaux de la campagne] : patois de Bohan ; [Le travail des bois] : patois de Bohan / [Ferdinand Brunot], collecteur ; [Charles Bruneau], collecteur, transcr. ; [Antonin David, 50 ans, bûcheron], voix
No full text[Traditions. France. Ardennes]dialecte wallonEnregistrement : (Belgique) Bohan, 05-07-1912Appartient à l’ensemble documentaire : ChArdenn
Disentangling the Pathways and Effects of Ecosystem Service Co-Production
No full textResearch on ecosystem services has become a dominant field within environmental management, framing the way in which human–nature relationships are understood and managed. Although ecosystem services are usually defined as ‘the benefits that humans receive from nature’, our work shows that most services are actually co-produced by a mixture of natural capital and various forms of social, human, financial and technological capital. Here, we review how ecosystem services are co-produced, and then we assess how this affects the quantity, quality, trade-offs, resilience and the equity of the distribution of ecosystem services. Then we discuss the implications of co-production for sustainability. Finally, we present some challenges for an adequate consideration of co-production within the assessment of ecosystem services
Conceptualizing pathways to sustainable agricultural intensification
No full textThere is widespread consensus among scientists, policy makers, and practitioners that agriculture should become more sustainable, while maintaining the ability to meet future food demand. However, there are still many diverging views on what sustainable intensification means, and how to get there. In this article, we present a conceptual framework to navigate agricultural intensification pathways. The conceptual framework aligns three research themes central to improving the sustainability of agriculture: (1) What are the social, economic, and environmental trade-offs of alternative agricultural intensification options? (2) How do land managers decide on intensification strategies, and how can the adoption of sustainable practices be made more attractive? (3) How do socio-political, technological, and environmental mega-trends and other drivers of change affect sustainable intensification measures and agricultural landscapes? The framework presented here goes beyond earlier frameworks by considering multiple dimensions of intensity and sustainability, drawing from both natural and social science theories. Also, it operates across spatial and temporal scales, and is outcome-focused while explicitly considering the linkages between decision making processes and sustainability outcomes. We argue that given these novelties the conceptual framework can serve as a blueprint to assess pathways towards sustainable agricultural intensification
Reducing reliance on herbicides with farmland biodiversity
No full textInternational audienceSome beetles prey on seeds from weeds. Promoting good environmental conditions for these beetles may be a way to reduce the use of herbicides. The natural world is highly competitive. Space, light, nutrients, and water and are all up for grabs as plants, insects and other organisms compete with each other to get as much of the good things for themselves as they can. Weeds and agricultural crops are no exception, with weeds reducing crop yields. To fight back, farmers try and give their crops the edge over weeds, often by using herbicides. The use of herbicides might be reduced with help from the insect world. A group of scientists aims to find out if this is so in a new European project involving researchers from five different research institutions in France, Austria, Sweden, Czech Republic and the Netherlands. They will explore whether a high biodiversity of insect weed seed predators can provide reliable natural weed control. The three-year research project, entitled BioAWARE, has a total budget of '1,147,602 and has been granted '858,967 through the C-IPM second call. Our hypothesis is that enhancing the diversity of insect weed seed predators, using in-field and landscape management, will result in a higher and more reliable weed seed predation, and reduce the need for herbicide use, says the coordinator of the new project, Dr David Bohan from Institut Nationale de la Recherche Agronomique (INRA) in France. Beetles may help keep weeds at bay. On the ground level, the clean-up crew of shiny beetles, belonging to the Carabidae family, actively searches for weed seeds, eating those they find and ultimately reducing weed numbers. This creates more favourable and less competitive conditions for crop plants to grow. The question is whether farmers can promote this helpful carabid army so that their clean-up operation can reduce the need for herbicides. Finding the answer to this question will be the first step of the research project. - We will identify and promote management options that can support a high diversity of weed seed predators for reliable weed control. We will consider all weed seed predator groups, where information is available, but will only do new experiments on insects, in particular carabid beetles, says Dr Michael Traugott of the University of Innsbruck. The researchers will then investigate how management of the field and the surrounding landscape can support the beneficial weed seed predators and examine if weed seed predation can be used as a tool in the integrated pest management (IPM) toolbox to replace or reduce the use of herbicides. Farmer awareness and approval of ecological manipulations in crop management is crucial to the implementation of IPM, so the researchers will also investigate how farmers take on the idea of using weed seed predators as an IPM tool and how can they be encouraged to do so. - We will evaluate farmer attitudes to natural weed regulation from ecological, social and economic viewpoints. We will also work with farmers, advisors and researchers directly to develop, demonstrate and evaluate practical solutions that can contribute to the spread of IPM in Europe, says Dr Maia David of INRA/AgroParisTech
Prey choice by carabid beetles feeding on an earthworm community analysed using species- and lineage-specific PCR primers
No full textThe carabid beetle Pterostichus melanarius is a major natural enemy of pests, such as aphids and slugs in agricultural systems. Earthworms are a dominant non-pest component of the diet of P. melanarius which help sustain the beetles during periods when the pest population is low or absent. In this study we wanted to test whether this predator exercises prey choice among different earthworm species or ecological groups. High levels of genetic diversity within morphological species of earthworm necessitated the development of primers that were specific not just to species but lineages and sub-lineages within species as well. Gut samples from beetles were analysed using multiplex-PCR and fluorescent-labelled primers. Calibratory feeding trials were undertaken to calculate median detection times for prey DNA following ingestion. Extensive testing demonstrated that the primers were species-specific, that detection periods were negatively related to amplicon size and that meal size had a highly significant effect on detection periods. Monte Carlo simulations showed that, in general, worms were being predated in proportion to their densities in the field with little evidence of prey choice, other than probable avoidance of the larger, deep-living species. There was no evidence that epigeic species were being taken preferentially in comparison with endogeic species. There was also no evidence that defensive secretions by Allolobophora chlorotica reduced predation pressure on this species by P. melanarius. We concluded that any management system that increases earthworm densities generally, regardless of component species, is likely to be optimal for increasing numbers of this beneficial beetle predator
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