Un exemple de valorisation d’une étude de terroir au sein d’une unité coopérative de production à Saint Hilaire d’Ozilhan (Gard) dans les cotes du Rhône

Le territoire de Suzette se développe sur un grand coteau viticole et boisé situé au cœur du site naturel des Dentelles de Montmirail (40km au nord d’Avignon). Ce site est à la fois l’un des pôles d’attraction touristique du département et le lieu d’une production viticole renommée (Gigondas, Vacqueyras, Beaumes de Venise, … ). Cet ensemble remarquable de terrasses viticoles et de crêtes rocheuses et boisées, forme un des paysages emblématiques du Vaucluse. La commune est actuellement soumise à une importante pression foncière due à une forte demande résidentielle. Le paysage du coteau forme et possède de ce fait un patrimoine culturel de valeur et une image de marque importante pour la production viticole locale.

Climate change is having a profound effect on viticulture by altering the conditions under which vines grow, leading to increased water stress and earlier harvests, which in turn affect the quality and character of wines [1].

Global climate change affects regional climates and hold implications for wine growing regions worldwide. Although winegrowers are constantly adapting to internal and external factors, it seems relevant to develop tools, which will allow them to better define actual and future agro-climatic potentials. Within this context, we develop a modelling approach, able to simulate the impact of environmental conditions and constraints on vine behaviour and to highlight potential adaptation strategies according to different climate change scenarios. Our modeling approach, named SEVE (Simulating Environmental impacts on Viticultural Ecosystems), provides a generic modeling framework for simulating grapevine growth and berry ripening under different conditions and constraints (slope, aspect, soil type, climate variability…) as well as production strategies and adaptation rules according to climate change scenarios. Each activity is represented by an autonomous agent able to react and adapt its reaction to the variability of environmental constraints. Using this model, we have recently analyzed the evolution of vineyards’ exposure to climatic risks (frost, pathogen risk, heat wave) and the adaptation strategies potentially implemented by the winegrowers. This approach, implemented for two climate change scenarios, has been initiated in France on traditional (Loire Valley) and emerging (Brittany) vineyards. The objective is to identify the time horizons of adaptations and new opportunities in these two regions. Carried out in collaboration with wine growers, this approach aims to better understand the variability of climate change impacts at local scale in the medium and long term.

Rotundone is the main aroma compound responsible for peppery notes in red wine. This positive and very potent molecule has an odor threshold of 8 ng/L in water and 16 ng/L in red wine. It has been detected in several grape varieties with some of the highest concentrations recorded in Syrah, Duras, Tardif and Noiret, an interspecific hybrid grown in the North-East of the USA. If several winemaking practices have been identified to lower rotundone in wine, up to date, no enological solution has proved its efficiency to maximize it. This means that efforts to produce high rotundone wines must be undertaken in vineyards. This work provides practical ways that can be used by winegrowers to modulate rotundone levels in their wines.

The Valpolicella hilly area, north of Verona, is highly vocated for viticulture but its vineyards are sometimes characterized by very different soil and microclimate conditions which can greatly affect their oenological potential.