Climate trends and variability in the Chilean viticultural production zones during 1985–2015

Abstract

Chile is characterised by offering high-quality wine and table grapes and its renowned viticultural valleys. Chile has been considered vulnerable to climate change, bringing a major concern to the national wine sector. This research aimed to analyse the climate trends and variability of Chilean viticulture from 1985 to 2015, evaluating meteorological, bioclimatic and risk indices at forty-seven weather stations. Meteorological data indicated that the warmest zone was Atacama, while the coldest was Aysén. The rainiest region was Austral, while the driest was Arica and Parinacota. Growing-season indices (GST, GDD and HI) showed that Central Valley was warmer than Arica and Parinacota, whereas the latter presented a higher sum of spring temperatures (SONMean and SONMax). Atacama presented the highest risk for T > 30 °C, whereas Central and South Valleys for T > 35 °C. The highest frost risk was in Aysén, while the lowest was in Arica and Parinacota. Tmin decreased by 0.33 ºC, while Tmax increased by 0.83 ºC. None of the trends for precipitation (PP) were statistically significant. GST, GDD, HI, BEDD, SONMean and SONMax increased by 0.58 ºC, 118.29 heat units, 140.57 heat units, 79.72 heat units, 8.42 heat units and 45.17 heat units, respectively, while CI decreased by 0.19 ºC. Some stations with negative trends for CI also coincided with the highest Tmax. Locations in Coquimbo and Aconcagua valleys changed from intermediate to warm climates. Locations from Coquimbo and Central valleys changed from warm to hot climates. Quilaco changed from a cool to a warm climate, while Osorno changed from without classification to a cool climate. PCA analysis reported that meteorological variables were related to the distance of the site to the Pacific Ocean. This information is important for the national industry and may allow producers to define mitigation strategies for climate change.