Viticulture in Portugal: a Review of Recent Trends and Climate Change Projections
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Volume 51 > Number 2 > 2017 Viticulture in Portugal: A review of recent trends and climate change projections Helder Fraga 11* , Iñaki García de Cortázar Atauri 2, Aureliano C. Malheiro 1, José Moutinho-Pereira 1 and João A. Santos 1 1 Centre for the Research and Technology of Agro-Environmental and Biological Sciences, Universidade de Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal 2 French National Institute for Agricultural Research, INRA, US1116 AgroClim, F-84914 Avignon, France This article is published in cooperation with the ClimWine international conference held in Bordeaux 11-13 April 2016. Guest editor: Nathalie Ollat Abstract Aim: The winemaking sector in Portugal is of major socio-economic relevance, significantly contributing to the national exports and sustaining many wine-related activities, including oenotourism. Portuguese viticultural regions present a wide range of edaphoclimatic conditions with remarkable regional specificities, thus contributing to the individuality of their wines. Owing to the strong influence of climate and weather factors on grapevines, climate change may drive significant impacts on Portuguese viticulture. Methods and results: Climatic projections for the next decades in Portugal highlight an overall warming and drying trend of the grapevine growing season, potentially resulting in modifications in phenology, growth, development, yields and eventually wine characteristics and typicity. Furthermore, the current viticultural suitability of each region is projected to undergo significant changes, suggesting a reshaping of the optimal conditions for viticulture throughout the country. In order to sustain high quality levels and affordable yield regularity, cost-effective, appropriate and timely adaptation measures must be implemented by the sector. Conclusion: The most recent scientific studies covering the potential impacts of climate change on Portuguese viticulture are herein presented. Significance and impact of the study: Possible adaptation measures against these threats are also discussed, foreseeing their integration into decision support systems by stakeholders and decision-makers. Keywords: Vitis vinifera , viticulture, wine regions, Portugal, climate change Received : 10 July 2016; Accepted : 18 October 2016 DOI: 10.20870/oeno-one.2016.0.0.1621 OENO One , 2017, 51 , 2, 61-69 *Corresponding author : [email protected] - 61 - ©Université de Bordeaux (Bordeaux, France) Helder Fraga et al. Viticulture and winemaking in Portugal 2. The winemaking regions 1. Socio-economic context Portugal comprises a total of 14 wine regions (mainland Portugal, Azores and Madeira In Portugal, winemaking is historically one of the archipelagos) (Figure 1), which include 31 Protected most relevant socio-economic activities. In the Denominations of Origin. In the north, the Douro context of the overall agricultural sector (e.g. cereals, Demarcated Region, with almost 1.5 Mhl of total vegetables), this industry represents roughly 14% of wine production and 45,000 ha of vineyards, is the t l the total plan ted area and 6% of tsh e total productions oldest and one of the most important wine regions of (INE, 2016). With an average vineyard area of over the country. This region, famous for its Port wine, is 200 thousa nd h ectar es and a ye arly wine producgtiol n responsible for one fourth of all wine produced in of abo ut 6 million hect olitres ( IVV, 2013 ), th e Portugal (IVV, 2013), and its vineyard landscape is a o e national production has shown a slight decrease over also considered World Heritage by the UNESCO the past decade (-2%/yr), which can be mostly since 2001. In the northwest, the most maritime area of Portugal, the Minho wine region produces mostly at tributed to the g radual decrea se in vineyard area ( - th white wines, distinguishable for their typical 1% /yr). N onetheless, P ortu gal is cu rren tly th e 11 th freshness and slightly higher acidity. In the south, the wine pro duce r and the 10 exp orter in the worl d Alentejo wine region, with typical Mediterranean (OIV, 2013), wh ich is a r emarka ble out come takin g into account the size o f the countr y. Approx imatel y climates, has undergone remarkable growth rates over half of th e total annual wine productio n is currentl y the recent decades and is currently the leading region in terms of non-fortified wine production. In general, o ( being e xported. In ab solute ter ms, this cont ribu tes t o from the sparkling wines of the Beira-Atlântico the nati onal exp orts w ith o ver 700 mil lion €/y r, region to the fortified Madeira wine, many other which corresponds to nearly 2% of total national regions in Portugal present unique wines resulting exports. A major factor for this success is the wide from their specific terroirs . The wines of Portugal are recogniti on of Portug uese wines in foreign markets, thereby valuable national brands, increasingly jus t to mention the renowned Port wine. recognised worldwide. 3. The climate and the soils Overall, the wine regions in mainland Portugal r u present Mediterranean-like climatic conditions, with warm dry summers and mild wet autumns-winters. In the northern/coastal areas (i.e. Minho and Beira- Atlântico), the Atlantic influence is strong, resulting in relatively high precipitation totals (>1,000 mm). In general, temperatures are higher in the south (e.g. Alentejo) and lower in the north (e.g. Minho and Trás-os-Montes). In the inner areas, however, summertime low water availability critically limits grapevine development (inner Alentejo and Douro). o h Winter temperatures tend to be milder in the southern regions, such as in Lisboa and Algarve (January mean temperature of 10–12ºC), though late spring frost is common in some northern regions (e.g. Terras do Dão), which may lead to important damages in vineyards. Growing degree-day (GDD (Winkler, 1974); April–October, 1950–2000) climatologies over Portugal (Figure 2a) indicate that the northern regions d h typically show temperate climates, with cool areas at higher elevations and warm/temperate-warm areas at lower elevations, especially in the Douro region. Almost all of the southern part of the country shows a Figur e 1. Wine reg ions in mai nlan d P ortuga l. The warm climate, but with some inner areas already in A zores and Madeira archipelagos are not shown. OENO One , 2017, 51 , 2, 61-69 ©Universi té de Borde aux (B ordeaux, Fr ance) - 62 - g p r d e s e b d 0 the very-war m cl ass. R egard ing d ryness con ditions while sand and clay are less frequent (Fraga et al. , (Dryness Inde x ( Ton ietto and Ca rbon neau, 2004); 2014a). Wi th r espect to ph ysiograp hy, the most April–S epte mber, 1950–20 00), the Atla ntic in fluence mountainous areas are located in inner northern and is noticeable in the nor thern c oastal a rea s, w ith sub - central areas, no rthwards of the Ta gu s Riv er, whil e f humid or eve n hum id c limates (Figure 2b), w here as flatlands prevail i n coa stal and south ern areas . the rest of the cou ntry depic ts mod er ate dryness. 4. The v arietie s a nd practices There are tw o main s oil type s in Portu gal: ca mbisols g Portuguese vineyards preserve a large number of d in the centre-north and lithosols/luvisols in the south autochthonous and international varieties, with over (FAO, 2006 ). Th e most important excep tions are the 300 authoriz ed v arieties. Arago nez or Tin ta-R oriz Douro region i n th e no rth, wi th litho sols, a nd the (also known as Te mpra nill o, red) is t he most pl anted Peninsula-d e-S etubal and Tejo regi ons, w ith podsols. varie ty in P ortug al, followed by Tou riga- Franc a (red), Loam is the predominant soil texture in Portugal, Castelão (red), Fer não-Pires (w hite) a nd Touriga- Nacional (red). T hese varieties a re pres ent in nearly all region s. Othe r varieties are m ore region-sp ecific, such as Al varinho (wh ite) in Minho or B aga (red) in Beira-A tlânti co. A ll thes e varieties p resent un iqu e agrono mic a nd oenol ogical c haracte ristics th at n ultimately resu lt in dis tinct ive wines, either mon o- varietal or blended, though blended wines are more traditional, i ncludin g th e Port w ine. The cor don (unilateral or bilate ral) is th e m ost used training system, th ough pergol a ( in Mi nho) and gobel et (e.g. Trás-os- Mont es) can al so be fo und. Ph eno logic al timings (b udbu rst, flo wering, veraison and matur ation), although varietal-dependent, tend to occur earlier in the southern/warmest part of the country. Budburst occurs from March to April and flow ering in May–Jeu ne, while harvest is typically carried out from late August to early October. Climate change t 1. Climate c hange proje ctions Atmospheric co nditions a re one of the m ost importan t controllin g f acto rs for the gr owth a nd productiv ity of grapevin es (K)el ler, 2010). In fact, r grapevine ph ysio logy and berry com pos ition are highly in flu en ced by air tem pe ratures during the grow th c ycle (Keller , 2 010 ). Fu rth ermore, wi nter chillin g is also ve ry impor tant fo r bu d dorma ncy (Bates et al. , 2002; Fi eld et a l.