Characterisation of the vertical temperature gradient in the canopy reveals increased trunk height to be a potential adaptation to climate change

Abstract

Given the important role of temperature in vine development and grape composition, climate change has already impacted wine production. Adaptation strategies are needed in order to sustain the production of wines and maintain their typicity. Several levers of adaptation are possible, including the use of more heat and drought tolerant plant material, relocating the vineyard and adaptations in the cellar. The training system is also a potential lever for adaptation that is relatively easy to implement. Taking that avenue, a study of the vertical thermal gradient in the vine canopy was carried out in order to determine whether trunk height could be an adaptation strategy for manipulating micro-climate in the bunch zone. Temperature was measured at four different heights from the soil (30, 60, 90 and 120 cm) in two adjacent vineyard parcels. One parcel was managed with cover crop and the other by tilling the soil. The results of this study show that increased trunk height is not likely to significantly delay ripeness, but it could minimise the potential damages of both frost and heat wave events. Type of parcel management was found to have an effect: close to the ground, the cover crop parcel generally had lower minimum temperatures and higher maximum temperatures in comparison to the tilled parcel, exposing the vines to an increased risk of both frost and heat wave damage. When investigating the factors driving the vertical thermal gradient, soil moisture and weather type were found to have an impact. Some of these factors, like mean temperature and soil moisture, may exacerbate the vertical temperature gradient of maximum temperature in a climate change context and increase the risk of damages due to extreme temperatures.

Climate Change Affects Choice and Management of Training Systems in the Grapevine

“…It might represent a future trend when the training system must be chosen. Another study [109] investigated whether trunk height could be a viable option for manipulating microclimate in the fruiting area and measured air T at 30, 60, 90, and 120 cm above ground in two parcels, one cover-cropped and the other tilled. Close to the ground (30 and 60 cm heights), the cover crop parcel generally had lower minimum temperatures and higher maximum temperatures in comparison to the tilled parcel, exposing the vine to an increased risk of both frost and heat wave damage.…”

The role of soil temperature in mediterranean vineyards in a climate change context

“…air temperature, solar radiation and wind) (Baver, 1965;Evett, 2000) influence soil heat and water fluxes and ultimately ST variables (thermal conductivity, thermal regime, maximum and minimum temperatures) (Brady and Weil, 2017). On the other hand, anthropological conditions, including agricultural soil management strategies (Table 1), can modify heat and water fluxes between soil, plant and atmosphere influencing ST variation (Neilsen et al, 1986;Resseǵuier et al, 2023).…”