Bioclimatic zoning of Argentinean Malbec grape production

Abstract

Winegrape production is largely controlled by climate conditions. Identifying how climate conditions impact on vine allows for identifying the suitability of a specific variety for a given region. Given the relevance of the Malbec wine production in Argentina, this study is devoted to derive a Unique Combined Index (UCI) for assessing the suitability of Malbec grape production (MGP) in Argentina. The index, considered as a zoning tool, takes into account suitability and also quantifying the degree of suitability. Monthly mean temperature and precipitation data from a set of stations over the main winemaking regions of Argentina together with MGP data over Mendoza for the period 1993-2014 were used. First, the co-variability between a set of bioclimatic indices and MGP was explored in order to identify the climatic variables that more strongly impact on the year-to-year variability of MGP. The Growing Season Temperature (GST), the Cool Night Index (CN), the Thermal Amplitude (GSTA) and the Growing Season Precipitation (GSP) were found to be the bioclimatic indices significantly correlated with MGP. This analysis allowed also identifying the ranges of each climatic variable corresponding to upper, normal and lower than normal MGP, allowing for defining categories for each of them. Then, the individual categorized indices were combined into the UCI. Finally, the UCI index was evaluated in terms of its spatial behavior, which demonstrated its utility as zoning tool and motivates its use to evaluate the future impact of climate change on the production of Malbec in Argentina.