Chardonnay wines climate plasticity: A worldwide geographical approach/Plasticite des vins issus de cepage

Chardonnay is the fifth most planted cultivar on Earth. This large spatial coverage suggests a strong flexibility of this wine grape variety to its environment, particularly when it comes to climate. To investigate the plasticity of Chardonnay for producing wine, we have built a geodatabase localizing the production areas (wine region, vineyard or plot, when possible) of 2029 wines awarded with either gold or bronze medals at the international wine competition ``Chardonnay du Monde'', from 2000 to 2015. Wines were produced by 982 different wineries, covering 231) world wine regions within 41 countries. The climate of each production region was depicted with the WorldClim. database. It consists of a set of high spatial resolution gridded (approximately 1 km) monthly rainfall accumulations and air temperature averaged on the 1950-2000 period. This data was updated to the 2000-2015 period by means of the delta method applied to the CRU TS 3.2 climate database at a lower resolution (0.5 degrees). Ten agroclimatic indices were calculated and analyzed. Grape growing climate of Chardonnay wine regions are extremely diverse. Their average growing season temperature (April to October for the northern hemisphere and October to April for the southern hemisphere) ranges from 15.2 to 21.7 degrees C (5% and 95% percentiles) for still Chardonnay wines, whereas it ranges from 14.7 to 20.3 degrees C for sparkling Chardonnay wines. Average growing season rainfall ranges from 106 to 630 nun with an average of 396 mm. This diversity indicates a considerable adaptation of Chardonnay for wine production. This plasticity probably offers an adaptive perspective to climate change, especially for cool climate regions such as Burgundy (the motherland of Chardonnay), where most of still and sparkling wines are produced with this variety.