La richesse de la flore comme levier pour maintenir la biodiversité dans le vignoble ?

Abstract

The intensification of crop management have led to an impoverishment of the biological diversity, resulting in the loss of ecosystem services. In viticulture, flora could play an interesting role because it can compensate the negative impacts of vine monoculture. The flora biodiversity favours fauna biodiversity, sustaining especially the presence of pollinating insects in the grapevine inter row sown with grass or legumes and area around grapevine plots. These aspects have been poorly studied until now. A grapevine experiment set in Alsace at INRA Colmar in the frame of the DEPHY-EXPE PEPSVI project was used to address these questions. Between 2014 and 2016, floristic survey was carried out on 4 sites, within an area of 500 m2 within each plot. On those sites, different grapevine systems based on integrated, biological, or biodynamic production were tested. The “presence/absence” method implemented to characterize flora composition and richness on the grapevine row, the inter-row sown with grass, and the tilled inter-row. Results showed that Asteraceae, Fabaceae and Poaceae were the most represented flora families. Asteraceae and Fabaceae may provide pollination ecosystem services if they are well managed and allowed to flower. Moreover, Fabaceae family increases soil fertility by symbiotic fixation. The role of environmental factors, i.e., semi-natural area like hedge or forest edge close to vineyard, and anthropic factors, i.e., soil cover management, were also characterized and shown as impacted on flora composition and richness under grapevine rows and between inter- rows. Flora characterization will continue in 2017 and 2018 to validate the present results and to assess the evolution of flora composition and richness in different climatic conditions.