Climate change impacts on thermal growing conditions of Portuguese grapevine varieties

Abstract

Heat accumulation conditions of a collection of 44 grapevine cultivars currently grown in Portugal are assessed at very high spatial resolution (~1 km) and for 1981–2015. A Growing Degree Hours – GDH (February–October) index is used for this purpose. Three clusters of grapevine cultivars are identified, assembling varieties with close heat accumulation requirements (early, intermediate and late ripening). These clusters provide more physiologically consistent information when compared to previous studies, as non-linear plant-temperature relationships are herein taken into account. For the future climates in Portugal, ensemble mean projections under two anthropogenic-driven scenarios (RCP4.5 and RCP8.5, 2041–2070), from four EURO-CORDEX simulations, reveal a widespread increase of GDH, but with spatial heterogeneities. The spatial variability throughout Portugal is projected to decrease in GDH, with strongest increases in the coolest regions of the northeast. The typical heat accumulation conditions of each cluster are projected to gradually shift north-eastwards and to higher-elevation areas. An unprecedented level of detail for a large collection of grapevine varieties in Portugal is provided, which may promote a better planning of climate change adaptation measures in Portuguese viticulture.

The role of grapevine leaf morphoanatomical traits in determining capacity for coping with abiotic stresses: a review

“…A better understanding of climate change will assist in vineyard adaptation in order to guarantee fruitful future harvests. Grapevine thermal requirements are increasingly demonstrating that climate change is contributing to the review of the distribution of cultivars as well as the displacement of some due to an inadequate capacity to cope with seasonal temperature changes; also highlighting the importance of cultivar-dependent analyses (Santos et al, 2018). Historically, the grapevine has been considered as a drought tolerant species (Schultz, 2003;Schultz and Stoll, 2010), which is well adapted to the Mediterranean climate and has the ability to alter growth and physiology in order to store current reserves, and to control future demand for resources (Schultz, 2003).…”