Relationships between Cabernet Sauvignon phenology and climate in two Spanish viticultural regions: observations and predicted future changes

Abstract

AbstractThe aim of the current research is to analyse potential changes in the phenology of Cabernet Sauvignon under future climate change scenarios. The study compares results from two areas with different climatic conditions in Spain: Ribera del Duero and Penedès. Phenology data for budbreak (BB), bloom (BL), veraison (V) and maturity (M) were analysed for the period 2004–2015 in Ribera del Duero and for 1996–2012 in Penedès. Thermal requirements to initiate the growing cycle and to reach each phenological event were evaluated. Simulated data of changes in climate from eight models provided by Agencia Estatal de Meteorología (AEMET) of Spain, and for two Representative Concentration Pathways (RCP) (greenhouse gas concentration trajectories) – RCP4.5 and RCP8.5 by 2030, 2050 and 2070 were used. Differences of approximately 6 days for BL and about 12 days, on average, for V existed between the two areas. Based on the predicted changes of temperature and the accumulated degree days needed to reach each stage, future changes in phenology were modelled. The results indicate potentially greater changes in the warmer region (Penedès), particularly for the later growth stages, which is in agreement with greater temperature increases in Penedès. The advance of BB, BL, V and M by 2070 could be up to 5, 11, 17 and 24 days, respectively, under the RCP4.5 emission trajectory, and up to 50% higher in some stages under the RCP8.5 emission trajectory.