Climate-induced cyclical properties of regional wine production using a time-frequency approach in Douro and Minho Wine Regions

Mario Cunha,Christian Richter

doi:10.1051/ctv/20203501016

Abstract

The impact of climate on wine production (WP) temporal cycles in Douro (DR) and Vinhos Verdes (VVR) wine regions for a period of about 80 years, characterized by strong technological trend and climate variability, was modelled. The cyclical properties of WP, and which cycles are determined by spring temperature (ST) and soil water during summer (SW), were identified. It was achieved by applying a time-frequency approach, which is based on Kalman filter in the time domain. The time-varying autoregressive model can explain more than 67% (DR) and 95% (VVR) of the WP’ variability and the integration of the ST and mainly SW increase the models’ reliability. The results were then transferred into the frequency domain, and can show that WP in both regions is characterized by two cycles close to 5-6 and 2.5 years around the long run trend. The ST and SW showed great capacity to explain the cyclicality of WP in the studied regions being the coherence temporarily much more stable in VVR than in the DR, where a shift of the relative importance away from ST to SW can be recognized. This could be an indicator of lower impact of the foreseen hot and dry climate scenarios on WP in the regions with a maritime climate, such as the VVR, compared with hot and dry wine regions. Despite the marked differences in the two studied regions on ecological, viticulture practices and technological trend, the modelling approach based on time-frequency proved to be an efficient tool to infer the impact of climate on the dynamics of cyclical properties of regional WP, foreseeing its generalized use in other regions. This modelling approach can be an important tool for planning in the wine industry as well as for mitigation strategies facing the scenarios that combine technological progress and climate change.

Highlights

In Portugal grapevines are one of the most important perennial crops, growing in over 30 different denominations of origin, which support a reputed wine industry strongly linked to specific wine regions (Moriondo et al, 2013; IVV, 2018)
Wine production time-series in Douro and Vinhos Verde wine regions in the recent eighty years take the form of highly non-linear and non-stationary complex system, for which time-frequency is able to characterise the cyclical proprieties and the temporal variability of the relationship between climate and wine production (WP)
Despite the marked differences in the two studied regions on climate, soils, viticultural practices, as well as the period studied (DR: 1933-2013; Vinhos Verdes (VVR) 1936-2016), and temporal trend of the production, the cyclicality proprieties of the WP in both regions is very similar and could be predicted by this modelling approach. It provides the cyclical proprieties of WP, the long-run cycles or technological trend using low frequencies and the short cycles based on high frequencies, as well as what cycles in particular are explained by spring temperature (ST) and soil water (SW)

Summary

Introduction

In Portugal grapevines are one of the most important perennial crops, growing in over 30 different denominations of origin, which support a reputed wine industry strongly linked to specific wine regions (Moriondo et al, 2013; IVV, 2018). There is a strong demand of adequate study of time series of regional WP in order to improve the efficiency of vineyard and winery operations as well as to support commercial strategies and sectorial planning measures (Cunha et al, 2016). The National Governments and European Commission’s policy makers can use information from WP time series to implement regulator mechanisms provided under the Common Organization of Wine Market for moderating the impact of the inter-annual variability of WP in order to protect the denominations of origin (EU-CMO, 2019). Long-term analysis of WP would have a key importance, at the light of the recent global and regional climate change scenarios (Jones, 2012; Santos et al, 2013), in order to plan future mitigation actions for viticulture and wine industry (Hannah et al, 2013; Mosedale et al, 2016)

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