DIVERSIT’HAIES

Combining hedgerows and organic farming at different spatial scales, a lever for conserving plant diversity and managing weeds in bocage landscapes ?  DIVERSIT’HAIES

2020-2022 Coordinateur : UMR BAGAP Contact BAGAP : Audrey Alignier Thèmes de recherche BAGAP : Biodiversity conservation Mots clés : hedgerow, weed, organic farming, landscape, functional approach

Research

Agri-environmental transition desired under recent agri-environmental policies tends to lead agricultural systems towards more environmentally friendly practices. At the local scale, studies showed that the extension of agricultural practices, in particular the abandonment of synthetic inputs in organic farming (OF), promotes the diversity and abundance of weeds. In addition, semi-natural elements directly adjacent to cultivated areas, such as hedgerows, are generally perceived as sources of weeds increasing the diversity and abundance of uncultivated flora around the crop fields. At the landscape scale, the extension of agricultural practices is rarely considered. The general objective of the DIVERSIT'HAIES project is to assess the relative effect of the presence of hedgerows and the extensification of agricultural practices (organic vs. conventional farming, OF vs. OC) at different spatial scales on weeds, in order to optimize the trade-off between biodiversity conservation and weed management.

The project is structured into 2 parts. The first aims to evaluate the effect of hedgerows combined with organic farming, at the local scale (i.e. presence vs. absence of hedgerows bordering crop fields, crop field in OC vs. OF) and at the landscape scale (i.e. density of the hedgerow network and percentage of fields in OF) on the diversity (taxonomic and functional) and abundance of plant communities within crop fields and within hedgerows. The second part consists in implementing a new experimental protocol to measure the flux of seeds from the hedgerows towards the crop fields and vice versa, in order to compare the strength of the “source” vs. “barrier” effects of the hedgerows on weeds.

Expected results

The results of the DIVERSIT’HAIES project will help to fill a knowledge gap on the effect of hedgerows combined with organic farming on weeds, which plays a fundamental role in the functioning of agroecosystems. They will make it possible to identify the best option(s) to limit the abundance of weeds while promoting plant diversity (taxonomic but also functional), in order to optimize the agroecological potential of bocage landscapes, with a view to sustainable agriculture.

BAGAP staff involved

• Audrey Alignier: ecology
• Stéphanie Aviron: ecology
• Sébastien Boinot: ecology

Partners

• CNRS – Université de Rennes 1 UMR ECOBIO

Funding

• Fondation de France