Statistical modelling of grapevine phenology in Portuguese wine regions: observed trends and climate change projections

Abstract

SUMMARYPhenological models are considered key tools for the short-term planning of viticultural activities and long-term impact assessment of climate change. In the present study, statistical phenological models were developed for budburst (BUD), flowering (FLO) and veraison (VER) of 16 grapevine varieties (autochthonous and international) from the Portuguese wine-making regions of Douro, Lisbon and Vinhos Verdes. For model calibration, monthly averages of daily minimum (Tmin), maximum (Tmax) and mean (Tmean) temperatures were selected as potential regressors by a stepwise methodology. Significant predictors included Tmin in January–February–March for BUD, Tmax in March–April for FLO, and Tmin, Tmax and Tmean in March–July for VER. Developed models showed a high degree of accuracy after validation, representing 0·71 of total variance for BUD, 0·83 for FLO and 0·78 for VER. Model errors were in most cases < 5 days, outperforming classic growing degree-day models, including models based on optimized temperature thresholds for each variety. Applied to the future scenarios RCP4·5/8·5, projections indicate earlier phenophase onset and shorter interphases for all varieties. These changes may bring significant challenges to the Portuguese wine-making sector, highlighting the need for suitable adaptation/mitigation strategies, to ensure its future sustainability.

Modelling climate change impacts on viticultural yield, phenology and stress conditions in Europe

“…Smaller changes are expected for other regions in western/central Europe, such as northern France and Germany. These outcomes are in general agreement with previous studies projecting future advances in grapevine phenological timings throughout Europe (García De Cortázar‐Atauri et al ., ; Donatelli et al ., ), Germany (Neumann & Matzarakis, ), France (Duchene et al ., ; Cuccia et al ., ), Italy (Caffarra & Eccel, ) and Portugal (Fraga et al ., 2016b). Nonetheless, the phenology submodel used in STICS does not take into account very high temperature effect (Wang and Engel model), which may result in biases in very hot regions (Cuccia et al ., ).…”

Viticulture in Portugal: A review of recent trends and climate change projections

“…As temperatures are a major driver of the grapevine development stages (Parker et al, 2013), significant warmings are expected to lead to earlier onsets (Bock et al, 2011;Chuine et al, 2004;Dalla Marta et al, 2010;Daux et al, 2011;Jones et al, 2005a;Molitor et al, 2014;Sadras and Petrie, 2011;Webb et al, 2011). Recent studies for Portugal isolated future projections for the phenological stages of 16 native varieties under RCP4.5 and 8.5 (Fraga et al, 2015;Fraga et al, 2016c;Malheiro et al, 2013). The results hint at earlier onsets of 2-5 days for budburst and flowering, and of 7-15 days for veraison until 2070, depending on the selected future scenario and variety.…”

Simulations of quantitative shift in bio-climatic indices in the viticultural areas of Trentino (Italian Alps) by an open source R package

“…Moriondo et al (2011) suggested possible negative effects of temperature increase on wine quality in the Mediterranean area (particularly Italy). The recorded advance in phenological timing (Caffarra and Eccel, 2011;Tomasi et al, 2011;Fraga et al, 2015) is a clear warning against a change in the match between a variety and its longlived growing context, questioning the subsistence of the balance between the ripening process and the meteorological conditions occurring in the relevant period (Mullins et al, 1992). The action of meteorological drivers on physiological development may also affect yield (Bindi et al, 1996;Duchêne and Schneider, 2005;Webb et al, 2008), due to an expected higher, unsatisfied water demand in summer, and to a shorter ripening period.…”