Search results for "Landscape"
showing 10 items of 1561 documents
Landscape effects on crop pest biocontrol are modulated by local pesticide use
2019
International audience; Control of crop pests by their natural enemies provide a valuable but poorly quantified ecosystem service in farmland. Complex landscapes including semi-natural habitats are expected to favour natural enemies thereby enhancing natural pest biocontrol in crops. However, when considering a large number of situations, the response of natural biocontrol to landscape properties is globally inconsistent, a possible explanation being that local agricultural practices counteract landscape effects. Here, we report on survey conducted along a crossed gradient of pesticide use intensity and landscape simplification that analysed the interactive effects of landscape characterist…
Disentangling local agronomic practices from agricultural landscape effects on pest biological control
2019
International audience; The biological control of crop pests is a valuable service provided by various beneficial organisms that are naturally present in agricultural landscapes. Semi-natural habitats has long been recognized as essential to preserve beneficial insects, but proof of their efficiency to enhance biological control of pests remains non conclusive. Here, we examined the variability of landscape effect on biological pest control and the way local agronomic practices may modulate it. Biological pest control was monitored in 80 commercial fields (arable crops and orchards) during three consecutive years in four contrasting French agricultural landscapes distributed along a double …
Assessing habitat connectivity of the lesser horseshoe bat using graph theory to explain its distribution
2011
The lesser horseshoe bat, Rhinolophus hipposideros was formerly widespread and quite common in north-western Europe, but has undergone a dramatic decline from the 1960s. The main hypothesis for this decline is a change of habitat quality. Recent works have stressed the importance of good connection between roosts and foraging areas by tree lines and well-structured hedgerows. Thus, landscape connectivity is assumed to be a key-factor for population sustainability. The present study is based on a case study in Franche-Comté (France). Its purpose is to model the distribution of the lesser horseshoe bat and to characterize the functional connectivity of its habitat. Graph theory is used effici…
Intérêt d'aménagements paysagers pour la biodiversité : exemple d'ingénierie agroécologique sur le domaine expérimental d'Epoisses (Inra Dijon)
2013
The biodiversity conservation is one of the major agricultural issues of the XXIst century. The intensification of agriculture and the redesign of the agricultural landscape (grouping of fields, …) lead to huge decreases or damages of semi-naturals habitats, known to promote biodiversity at the farm and the landscape scale, and now recognised as “topographic surface equivalence” in France.In the experimental site of Epoisses (INRA of Dijon), a study to design the landscape elements in favour of the biodiversity has been initiated. Improving the management of existing habitats (woods, hedges, ditches, sown grass margin strips), establishing hedges, flower strips, redesigning the field organi…
Étude de la biologie d'une messicole en régression: le bleuet (Centaurea cyanus L.)
2011
Agroecosystems are currently experiencing high biodiversity loss, in particular among the plant species specifically adapted to this habitat. This decline results from cropping systems that have been intensified in Western Europe since the 1950s. The cornflower (Centaurea cyanus L.), considered as emblem of the flora associated with traditional cereals, appears as a species that may be at risk and should be monitored. Indeed, cornflower can serve as a host to predators of crop pests and is strongly attractive for the pollinators. This study examines the biological factors that could potentially cause the decline of this species: spatial distribution, potential for growth, population's genet…
Fragmentation des habitats et interactions hôtes-parasites
2021
Habitat fragmentation is one of the main threats to global biodiversity and despite an abundant literature on the impact of fragmentation on species abundance and diversity, the consequences of this global change in terms of ecological and evolutionary processes remain poorly understood. Beyond their direct contribution to biodiversity, as species-rich category of organisms, parasites could be involved in biodiversity change as key actors of ecological and evolutionary processes. The present work aims to understand the effect of forest fragmentation on host-parasite interactions. It is based on a large sampling carried out in the Lesser Antilles and in French Guiana, and allowing the obtent…
Avian biodiversity: impacts of pest management strategies and landscape in South-Eastern French apple orchards
2008
National audience; In French apple orchards, the predominant conventional management strategy has resulted insecticide resistance in major pests like codling moth and an increased frequency of environmentally harmful insecticide applications. Organic agriculture as well as IPM represent alternatives to this situation. Impacts on the avifauna of three different management strategies (organic, conventional and integrated) were studied during three years in 15 commercial apple orchards. These orchards were situated around Avignon and had similar contexts in terms of local and landscape features. Our results show that the avifauna differ significantly among the three management strategies with …
Arable weeds in agricultural landscapes: new paradigms and emerging challenges
2008
National audience
Temporal dynamics of soil bacterial communities at a landscape scale: dependence to soil properties and agricultural practices.
2019
International audience; Soil microbial communities play a major role in agricultural functions and are an efficient indicator to evaluate the impacts of agricultural practices on soils. Studies on wide scales ranging from landscape to countries demonstrated that soil microbial communities were heterogeneously distributed in space under the dependence of soil properties (e.g. pH, soil texture, Organic matter Content) and agricultural practices. However, temporal dynamics of soil microbial communities at a landscape scale still need to be documented in order to go further in evaluating the sustainability of agricultural practices. In this extensive monitoring study, we focused on landscape dy…