Terroir 2014 banner
IVES 9 IVES Conference Series 9 International Terroir Conferences 9 Terroir 2014 9 Grape growing climates, climate variability 9 Thermal risk assessment for viticulture using monthly temperature data

Thermal risk assessment for viticulture using monthly temperature data

Abstract

Temperature extremes affect grapevine physiology, as well as grape quality and production. In most grape growing regions, frost or heat wave events are rare and as such conducting a risk analysis using robust statistics makes the use of long term daily data necessary. However, daily climate data suffers many constraints such as typically having a short-term history, with uneven spatial coverage worldwide, and their homogenization to account for changes in climate sensors or changes in site location are challenging. In contrast, monthly data sets offer a much more robust spatiotemporal coverage. Furthermore, data at monthly time steps is relevant for climate projection analyses over the 21st century.

Therefore, the current study evaluates the relevance of estimating thermal risks for viticulture using monthly data. Daily minimum (Tmin) and maximum (Tmax) temperature data were collected from 369 weather stations in Europe (European Climate Assessment & Dataset) and 1218 weather stations in the USA (United States Historical Climatology Network) for the period from 1972 to 2008. For the whole period and for each station, the average yearly number of winter freeze days (Tmin < -17°C), spring frost days (Tmin < -1°C), and heat stress days (Tmax > 35°C) were calculated. In addition, frequencies of years with at least one spring frost event, the date of the last spring frost event at 90% probability (i.e. the quantile 0.9) and frequencies of years with at least one winter freeze event were calculated.

These thermal risk indicators, analyzed on a daily time step, exhibited strong relationships with maximum and minimum monthly average temperatures during the 1972-2008 period. Winter freeze risk is strongly linked to January average monthly minimum temperature, while spring frost risk is related to April minimum monthly temperature. The average number of heat stress days is strongly correlated to July maximum temperature. Using WorldClim 5 arc-minute resolution climate grids, a winter frost risk map for the 1950-2000 period is proposed. The results suggest that grape growing region limits are strongly restrained by winter freeze risk hazards.

DOI:

Publication date: August 10, 2020

Issue: Terroir 2014

Type: Article

Authors

Benjamin BOIS (1), Marco MORIONDO (2) and Gregory V JONES (3)

(1) Centre de Recherches de Climatologie, UMR 6282 Biogéosciences CNRS Université de Bourgogne, 6 boulevard Gabriel, 21000 DIJON, France 
(2) CNR-IBIMET, via G. Caproni 8, 50145, Florence, Italy 
(3) Department of Environmental Studies, Southern Oregon University, 97520,101A Taylor Hall, Ashland, OR, U.S.A.

Keywords

Thermal risks, climate, viticulture, WFR, SFR, HST

Tags

IVES Conference Series | Terroir 2014

Citation

Related articles…

Legacy of land-cover changes on soil erosion and microbiology in Burgundian vineyards

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Second pruning as a strategy to delay maturation in cv. ‘Touriga nacional’ in the Portuguese Douro region

The advance in maturation of wine grapes is an important climate change risk related effect that could affect warm regions like Portuguese Douro Wine Region. Indeed, the climate analysis over the past years registered a decrease in the precipitation, significant higher average temperatures, and a more frequent occurrence of extreme weather events, including heat waves. In these conditions the length from anthesis until maturation is shortened and the uncoupling of technical and phenolic maturity results in berries with higher sugar concentration (and lower acidity), but lower anthocyanins, tannins, and total phenolic concentration, which produce unbalanced wines.
In this work, an innovative strategy of crop forcing, based on forcing vine regrowth after a second pruning of green shoots, was tested, aimed at delaying ripening until the temperature becomes lower and, therefore, preventing acidity loss and increasing anthocyanin-to-sugar ratio. The experiments were conducted in 2019 and 2020 in a commercial vineyard of ‘Touriga Nacional’ located in the Douro Region. Crop forcing was conducted 15 (CF1) to 30 (CF2) days after fruit set. Vines pruned with conventional methods were used as control (CF0). Results confirmed that fruit ripening was shifted from the hot season (August/September), until a cooler period (October through early-November). At harvest, grapevine berries from CF1 and CF2 presented lower pH and higher acidity, than control, with no significant differences in colour intensity and phenolic levels composition. Sugar content was lower in CF2-treated vines in both seasons. However, in CF-treated vines the number and size of clusters were significantly lower (up to 88% reduction) than in control plants. A metabolomics analysis of mature berries from CF-treated vines and control is underway. Crop forcing was indeed effective in producing a more balance berry composition but severely reduced grapevine yield,

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.