Ecophysiological modelling of Burgundy wine terroirs–effect of climate and soil on plant water stress and fruit composition

Abstract

Burgundy terroirs are famous worldwide but have never been described from an ecophysiological point of view. To better understand plant-environment relations in these terroirs 8 grapevine plots were monitored during two vintages (2011-2013), on Corton Hill, Burgundy, France. Grapevine water status was monitored weekly by surveying water potential, and, at the end of the season, using δ¹³C analysis of grape juice. Plots were distributed along a calcareous topolithosequence. Geopedology and soil profiles of the site were described. During the three years of monitoring, grapevines experienced great variation in water status, which ranged from low to substantial water deficit. In addition, significant differences were observed in grapevine water status according to variations in the physical characteristics of the terroir (slope, gravel content and texture). Relationships of plant water stress with climatic data of easy access (temperature and rainfall) were also described and predictive models were developed. The use of δ¹³C in Burgundy was also evaluated. A significant correlation was found between δ¹³C and minimum predawn leaf water potential recorded between veraison and maturity. When compared to cultivars and pedoclimatic situations from other studies it is observable that while the slope of the relations between δ¹³C and leaf water potential stays similar absolute values changes. Chardonnay in Burgundy shows lower values of δ¹³C than Cabernet-Sauvignon in Bordeaux and Syrah in Languedoc. Finally, the relations of grapevine water status and grape composition at maturity was evaluated, a light to moderate water stress seems suitable to a good balance between sugars and acids also for Burgundy Chardonnay.