Viticulture in Oltenia Region (Romania) in the New Climatic Context

doi:10.21203/rs.3.rs-2202416/v1

Download PDF

Research Article

Viticulture in Oltenia Region (Romania) in the New Climatic Context

https://doi.org/10.21203/rs.3.rs-2202416/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 14 Jul, 2023

Read the published version in Theoretical and Applied Climatology →

You are reading this latest preprint version

As climate is one of the determining factors for grape production and quality, the viticultural potential of a region is greatly affected by climate changes, particularly temperature increase. Oltenia is one of the traditional Romanian winegrowing regions that is presently undergoing a progressive warming trend, which may require adaptation measures in the near future. The analysis is based on monthly values of temperature (mean, maximum and minimum), precipitation amount and sunshine duration from 10 meteorological stations located within the study area. The data cover the period 1961–2021, the modifications of the main climatic parameters and specific bioclimatic indices being analysed for the entire period and on two distinct sub-periods (1961–1990 and 1991–2021). The obtained results reveal an increase of the heliothermal resources in the region and a certain stability of the precipitation amounts during the last three decades. Thus, both Winkler and Huglin indices emphasize a northward shift of the area corresponding to quality red wines (about 60 km), which means also a shift of the quality white wines in areas considered without great potential so far. Trends detected in the climatic parameters and bioclimatic indices emphasize potential problems for viticulture in Oltenia, mainly in its southern and southwestern part, where climate suitability for quality wines is under pressure on the background of increasing temperature and reduced precipitation amounts during the growing season.

climate change

bioclimatic indices

viticulture

Oltenia

Romania

The development, yield and quality of grapevine (Vitis spp.) greatly, but not exclusively, depend on the climatic conditions (Fraga et al. 2013; Santos et al. 2010; Santos et al. 2020). Besides climate, other important natural factors that determine the quality of grapes are soil, respectively slope inclination and exposure. The clay, humus, gravel content of the soil influences the release of nutrients and water availability (Prado et al. 2007; Santos et al. 2020; Qi et al. 2019), while slope inclination and aspect conditions air drainage and exposure to solar radiation intensity and duration (Bois et al. 2008; Hunter et al. 2020; Irimia et al. 2014). For short time periods, grapevine is not irreversibly affected by temperatures of -15 to -20°C (Hidalgo 2002) or + 30 to + 35°C (Droulia and Charalampopoulos 2021; Greer and Weedon 2012) or by the fluctuation of the rainfall amount. However, even if grapevine is quite resilient to different climatic extremes, such as high and low temperatures, severe dryness, prolonged drought (Koufos et al. 2017; Malheiro et al. 2010), the quantity and quality of grapes is highly affected in such cases, as well as its capacity to cope with diseases and pests.

According to IPCC (2021), surface temperature over land increased with 1.59ºC (1.34 to 1.83°C) in the decade 2011–2020 compared to 1850–1900. In Europe, which manages to maintain its leading role in wine production, despite its noticeable decreasing share in world production over the last half century (FAO 2022), numerous studies confirmed the increase of the warming trend all over the continent (Jacob et al. 2018; Boé et al. 2020; Peña-Angulo et al. 2020; Spinoni et al. 2018a). Moreover, the frequency and intensity of hot temperature extremes are projected to continuously increase regardless the emission scenario, especially in the Mediterranean region (Spain, France and Italy – the largest grapevine production area), but also in Central and Eastern Europe, as well as drought and aridity (Coppola et al. 2021a, b; Kew et al. 2019; Manning et al. 2019; Russo et al. 2015; Spinoni et al. 2018b, 2020).

Grapevine can develop properly under certain specific and quite restrictive climatic conditions: the beginning of the growing cycle is set at a 10°C base temperature (Winkler et al. 1974), the range of the growing season average temperature is 13 to 21°C (Jones 2006, 2007; Malheiro et al. 2012), while quality grapes require precipitation amount between 250 and 390 mm during the growing season (Blanco-Ward et al. 2007). The thermal conditions, as the most significant limiting factor for high-quality productions, control grapevine phenology, as well as sugar accumulation, anthocyanin biosynthesis and content, metabolites content, volatile compounds, etc. (Greer et al. 2013; Molitor and Keller 2016; White et al. 2016). Thus, the projected temperature evolution (growing season temperature and heatwaves) will trigger an even greater heat stress, particularly in the south of the continent. In this context, any change of the current climatic conditions (mainly temperature and precipitation amount and distribution during the entire year and, especially, during the growing season) can determine important modifications of the suitable grapevine varieties presently cultivated in certain regions and even geographical displacements of the grapevine traditional growing areas (Cardell et al. 2019; Jones 2006, 2007; Moriondo 2013).

As Romania is one of the traditional viticultural countries in Europe, climate change and its potential impact on viticulture sector is of great importance. According to the report elaborated by The International Organisation of Vine and Wine (OIV 2022), in 2021, Romania had a vineyard surface of about 189,000 ha, holding the 10th place in the world (ca. 0.7% reduction compared to 2020) and an annual wine production of about 4.5 mhl, the 13th position in the world. Romania’s wine-growing area is structured in eight large wine-growing regions, which are included in the following European wine-growing zones: zone B (Transylvanian Plateau), zone C I (Moldavian Plateau, Crişana and Maramureş Hills) and zone C II (Muntenia – Buzău Hills, Dealu Mare; Oltenia – Severin and Drincea areas, the South wine region including sands and other favourable regions; Dobrogea and Danube Terraces) (Council Regulation (EC), 491/2009). Recent studies indicate a gradual increase of air temperature in Romania, especially during the warm half of the year, which coincides with the growing season of grapevine (Chitu et al. 2015; Dumitrescu et al. 2015; Ionita et al. 2013; Marin et al. 2014; Prăvălie 2014), no significant changes of the annual precipitation amount (Marin et al. 2014) and an upward trend of heatwaves (Croitoru et al. 2016, 2018) and drought, especially in the south of the country (Angearu et al. 2020). Even if the impact of climate change on viticulture sector was greatly analyzed worldwide, in Romania, studies are not that numerous (Bucur & Babeș 2016; Bucur et al. 2019; Irimia et al. 2013, 2014, 2017a, 2018a; Nistor et al. 2019).

The present study focusses on the south-western part of Romania, namely Oltenia Region, which is one of the most vulnerable regions in the country to climate change, as shown by the statistically significant increase of temperature, severe heatwaves, drought (mainly during summer) and aridity (Croitoru et al. 2016; Vlăduț and Onțel 2013; Vlăduț 2017; Vlăduț and Licurici 2020). It also has vast surfaces covered by sands and sandy soils, which impose certain restrictions in agricultural practices and make the region become even more vulnerable to the future projected changes of the main climatic parameters. Viticulture has been practiced in the region for centuries. According to the National Institute of Statistics (NIS 2022), in 2021, there were 28,981 ha cultivated with productive grapevine in Oltenia, 67.9% being hybrid grapevines. Hybrid varieties generally present a greater resistance to diseases, such as downy and powdery mildew, which are temperature-driven (Pugliese et al. 2011; Rienth et al. 2021; Salinari et al. 2006). In the context of the projected temperature increase, the hybrid varieties cultivated in the region may be the best solution for local viticulture. Even EU regulation modified (Regulation (EU) 2021/2117), allowing member states to employ resistant varieties in the production of wines with protected denominations of origin.

The goals of this research are: (1) to assess the suitability of climatic factors representatives for vineyards, based on multiannual mean values; (2) to determine potential changes in climate suitability for grapevine cultivation and the trends of the selected bioclimatic indices, based on observational series over 1961–2021.

2.1 Study area

The study area is located in the southwestern part of Romania and belongs to Oltenia region (43°40' N in the south and 45°35' N in the north and 22° E in the west and 24°53' E in the east). Oltenia has an extended surface covered by vineyards, within four of the five component counties. The most significant surfaces are located in its southern half, which corresponds to the Danube Floodplain and terraces and Oltenia Plain (the western sector of the Romanian Plain) and plateau area, namely the Getic Piedmont, from Mehedinți, Dolj, Olt and Vâlcea counties (Fig. 1). According to the National Institute of Statistics (NIS 2022), in 2021, the most extended surface cultivated with productive grapevine was registered in Dolj County, i.e. 10,051 ha (of which 6,602 ha hybrid grapevine), followed by Olt, Mehedinți and Vâlcea (with vineyards covering about 4,700 to 5,700 ha in each county). In the first two counties, there is a great share of hybrid grapevines (78.7%, respectively 65.5%), while in the case of Vâlcea, the percent is lower, i.e. 40.1%). Gorj County has the most reduced vineyard surface (3,230 ha), hybrid grapevines being exclusively cultivated there.

2.2 Data. For the present study, there were used the following data: mean of daily mean temperature, mean of daily maximum and minimum temperature, monthly precipitation amounts and sunshine duration for the ten meteorological stations located within the analysed region (Fig. 1, Table 1). The data cover a period of 61 years (1961–2021), except for Slatina, which started its activity in 1977. Climatic data were provided by the National Meteorological Administration.

Table 1

Geographical coordinates of the considered meteorological stations
No.	Meteorological station	Altitude (m)	Latitude	Longitude
1.	Dr. Turnu-Severin	77	44°38`	22°38`
2.	Calafat	61	43°59`	22°57`
3.	Bechet	36	43°47`	23°57`
4.	Băileşti	57	44°01`	23°20`
5.	Craiova	192	44°19`	23°52`
6.	Caracal	106	44°06`	24°22`
7.	Slatina	172	44°26`	24°21`
8.	Bâcleş	313	44°29`	23°07`
9.	Târgu Logreşti	265	44°53`	23°42`
10.	Drăgăşani	280	44°40`	24°17`
Note: The meteorological stations are rendered from west to east, on landforms (the Danube Alluvial Plain, Oltenia Plain and the Getic Piedmont)

2.3 Methods

2.3.1 Bioclimatic indices

The assessment of the suitability of the climatic conditions for grapevine is based on the analysis of 12 bioclimatic indices (Table 2). The selected indices provide valuable information on the climatic potential of the region in terms of mean vegetative cycle of the grapevine and they are also linked to the quality of grapes and resulting viticultural products (sparkling wines, table wines, quality white and red wines).

The thermal potential of the region is assessed based on temperature (annual average temperature AAT, average temperature of the warmest month TWM, growing season average temperature GST). Temperature influences grapevine development during all the phenological stages and it also determines the accumulation of optimum levels of sugar and acid (Jones et al. 2005). Besides temperature, other climatic indices taken into account are sunshine duration (SD), growing season precipitation (GSP), which also determine both suitability of a region for a particular cultivar and the potential for obtaining quality wines (Blanco-Ward et al. 2007; Irimia 2012; Irimia et al. 2013). The length of the growing season (LGS) is important for late-ripening grapevine varieties and anthocyanin accumulation (Teodorescu et al. 1987; Irimia et al. 2014).

Besides the aforementioned simple indices, there were also used specific complex grapevine bioclimatic indices (based on two or more climatic parameters). Cool Night Index (CI) indicates the accumulation of secondary metabolites in grapes (polyphenols, aromas), which is important for wine colour and aromas (Tonietto and Carbonneau 2004). The Hydrothermic Index of Branas, Bernon and Levadoux (HyI) highlights the influence of temperature and precipitation on grape yield and wine quality as it reveals its potential exposure to diseases such as downy mildew (Blanco-Ward et al. 2007). Seleaninov hydrothermic coefficient (HTC) is used to assess the potential water availability in the soil indicating whether irrigation is required (Savić and Vukotić 2018).

As reference bioclimatic indices for viticulture, we applied Winkler index (WI) and Huglin heliothermal index (HI). WI refers to the heat accumulation during the growing season (April 1st - October 31st ) and it determines the completion of the phenological stages for grapevine (Malheiro et al. 2010). It uses the sum of the mean daily temperatures minus a base temperature of 10°C, which represents the active physiologically threshold of the vines to begin their growth cycle (Piña-Rey et al. 2020). HI offers a good correlation with the sugar content in berries (Briche et al. 2014).

Table 2

Bioclimatic indices, equations, suitability for different wine types and sources
Climatic parameter/index, abbreviation, units	Period	Suitability				Source
Climatic parameter/index, abbreviation, units	Period	Restrictive for grapevine	Sparkling wines	Quality white wines	Quality red wines	Source
Annual average temperature (AAT, °C)	January – December	< 8.5	8.5–9.3	9.4–10	˃10	Ţârdea and Dejeu 1994; Oşlobeanu et al. 1991
Average temperature of the warmest month (TWM, °C)	July	≤ 18	18.1–19	19.1–21	> 21	Ţârdea and Dejeu 1994; Oşlobeanu et al. 1991
Growing season average temperature (GST, °C)	April 1st to October 31th	< 13 > 21	13.1–15	15.1–17	17.1–21	Jones 2006; Jones 2007; Malheiro et al. 2012; Nesbitt et al. 2016
Growing season average temperature (GST, °C)	April 1st to October 31th	\(GST= \sum \frac{\left(Tmax-Tmin\right)}{2}\left(1\right)\) Too cool = < 13°C Cool = 13–15°C Intermediate = 15–17°C Warm = 17–19°C Hot = 19–21°C Very Hot = 21–24°C Too Hot = > 24°C
Sunshine duration (SD, hours)	April 1st to September 30th	< 1280	1280–1450	1451–1550	> 1550	Oşlobeanu et al. 1991; Irimia et al. 2013
Growing season precipitation (GSP mm)	April 1st to September 30th	< 250 > 390	250–390	250–390	250–390	Becker and Zimmermann 1984; Blanco-Ward et al. 2007
Sum of active temperatures (ΣAT, °C)	April 1st to September 30th	\(\sum AT=\left(Tavg-10\right)*Nd\) (2)				Branas et al. 1946; Oşlobeanu et al. 1991; Irimia et al. 2013
Sum of active temperatures (ΣAT, °C)	April 1st to September 30th	< 1045	1045–1200	1201–1400	> 1400
Length of the growing season (LGS, days) daily mean temperature ≥ 10°C	April to October	< 160	160–175	176–190	> 190	Jackson 2001; Malheiro et al. 2010; Irimia et al. 2013
Cool Night Index (CI, °C)	September	Very cool nights (CI + 2) ˂ 12°C Cool nights (CI + 1) 12–14°C Temperate nights (CI-1) 14–18°C Warm nights (CI-2) > 18°C				Tonietto 1999; Tonietto and Carbonneau 2004
Seleaninov hydrothermic coefficient (HTC, °C, mm)	April 1st to October 31th	\(HTC=\frac{\sum P}{\sum Tavg>10}*10\)(6) 0.8–1.4 < 0.8 (need for irrigation)				Selyaninov 1930; Savić and Vukotić 2018
Hydrothermic index of Branas, Bernon, and Levadoux (HyI, °C x mm)	April 1st to August 31st	\(HyI=\sum \left(Tavg*P\right)\)(3) > 5100 high risk 2500–5100 moderate risk < 2500 no risk				Branas et al. 1946; Köse 2014
Huglin Heliothermal Index (HI, °C)	April 1st to September 30th	\(HI= \sum _{April 1}^{Sept 30}\frac{\left[\left(Tavg-10\right)+(Tmax-10)\right]}{2}*d\)(4) Very Cool = ˂1500 (HI_− 3) Cool = 1500–1800 (HI_− 2) Temperate = 1800–2100 (HI_− 1) Temperate Warm = 2100–2400 (HI_+ 1) Warm = 2400–3000 (HI_+ 2) Very Warm = > 3000 (HI_+ 3)				Huglin 1978; Tonietto and Carbonneau 2004; Irimia et al. 2013
Winkler index (WI, °C)	April 1st to October 31th	\(WI= \sum \frac{(Tmax+Tmin)}{2}-10\)(5) Region Ia = 850–1111 Region Ib = 1111–1389 Region II = 1389–1667 Region III = 1667–1944 Region IV = 1944–2222 Region V = 2222–2700				Winkler et al. 1974 updated by Jones et al. 2010
Note: d – coefficient length of day (d) by latitude (1.03 for 42^◦01–44^◦00; 1.04 for 44^◦01–46^◦00); Nd – number of days in the growing season; P – monthly precipitation amount; SD = sunshine duration; Σta = sum of daily average temperatures > 10°C; Tavg – average air temperature; Tmax – maximum air temperature; Tmin – minimum air temperature; 10 – temperature base; 250 = minimum precipitation needed for unirrigated vine

2.3.2 Trend analysis

In order to emphasize long-term changes of the climatic conditions relevant for grapevine cultivation and their statistical significance, it was used the Mann-Kendall test (Mann 1945; Kendall 1975), which reveals increasing/decreasing monotonic trend in a data series for a given period, and the nonparametric Sen’s method, which renders the magnitude of the slope of a linear trend (Gilbert 1987). The data were processed in the Excel template MAKESENS, developed by the researchers of the Finnish Meteorological Institute (Salmi et al. 2002). The statistically significant trends are evaluated using the Z value - positive Z values stand for an increasing/upward trend, while negative Z values indicate a decreasing/downward trend. The significance levels (α) are 0.001, 0.01, 0.05, and 0.1.

2.3.3 Interpolation

As the climate variables required in the computation of bioclimatic indices relevant for grapevine are measured at meteorological stations, a georeferenced point data set comprising the ten stations in the study area, as well as eight support stations located in the nearest Romanian, Serbian, and Bulgarian areas was used in GIS environment. Effective determination of the spatial distribution of mean climate variables represents a necessary first step towards the development of stochastic models for more refined assessments of climate impact (Hutchinson 1995). Spatial interpolation was used in order to estimate the meteorological characteristics of the entire study area. Among the spatial interpolation techniques that we compared (IDW, Kriging, Natural Neighbor, Spline – with subtypes), the Spline regularized method, readily integrated in the ArcGIS Spatial analyst tools, proved to be well suited for the spatial attributes of our data set. Other studies also showed that among the methods that do not use elevation as ancillary information, regularized spline had minimum mean absolute error and root mean square error values in precipitation, minimum root mean square error in sunshine duration, and it did not have the highest error value for other climate parameters such as temperature or solar radiation (Apaydin et al. 2004).

3.1 Suitability of the climatic conditions for grapevine

The spatial distribution of the bioclimatic indices taken into considerations reveals certain differences within the analysed region, in spite of the fact it does not have an extended surface. Thus, all temperature-based indices clearly show a south-north decrease, the highest values corresponding to the area located in the immediate proximity of the Danube River, which has the lowest altitude (less than 100 m), and the most reduced to the northern extremity of Oltenia viticultural area, which is in the Getic Piedmont, while precipitation-based indices show a reverse pattern.

There is a 1.9ºC difference between the highest and the lowest AAT, 2.3ºC for TWM and 2.0ºC in case of GST (Fig. 2, Table 3), but, according to these indices, the entire area presents suitable conditions for producing quality red wines. This means that the region is within the limits of the optimum zone, which indicates the possibility of obtaining quality and well-balanced wines – consistent levels of sugar, acids and phenolics. GST values range between 18.9 and 16.9ºC, including the wine-growing areas from Oltenia in the warm climate-maturity grouping that is suitable for optimum maturity of the following international cultivars – Cabernet Franc, Merlot, Malbec, Viognier, Syrah, Cabernet Sauvignon, Grenache, Sangiovese, Zinfandel (Jones 2006). Besides these cultivars, the Romanian varieties Alutus, Băbească Neagră, Crâmpoşie selecţionată, Fetească Neagră, Negru de Drăgăşani also find suitable conditions, some varieties being specific to the analysed region (Alutus, Crâmpoşie selecţionată, Negru de Drăgăşani). CI indicates that most of the region is in the category cool nights (12–14°C) – almost the entire plain area and very cool nights (Tmin ˂ 12°C) – the piedmont and eastern part of the plain. However, the difference between the maximum and minimum values is not significant, namely 13.1°C at DT Severin (the western part) and 10.2°C at Tg. Logrești (the northern part). The minimum temperature registered at night during the ripening month (September in the Northern Hemisphere), correlated with high diurnal temperatures, is considered to be favourable for the synthesis of anthocyanins (Tonietto and Carbonneau 2004), which represent one of the major classes of phenolic compounds in red wines.

SD and AT, which emphasize the heliothermal potential of a region that also influences the accumulation of anthocyanins (Irimia et al. 2017b); they indicate a great suitability for high quality grapes, including red varieties. The cumulated SD for the growing season ranges between a maximum of 1634.3 hours in the central part of the plain area and a minimum of 1411.9 hours in the piedmont (one station). Generally, the values are between 1550 and 1590 hours, Oltenia displaying one of the highest sunshine durations in the country (Fig. 3a). With regard to AT, there is a greater difference than in case of the other indices, almost 400ºC (more than 1700ºC in the southwestern part of the region and 1356ºC, in the north, at Târgu Logreşti). In the northern part of the wine-growing area, the heliothermal potential is more reduced, about 1400ºC (Fig. 3b). Higher values, similar to the ones registered in the northern part of the plain, are registered at Drăgăşani, which in spite of a greater latitude and altitude compared to the southern plain area, displays a good topoclimate for grapevine.

Precipitation amounts represent another important climatic factor of influence, the suitability limits ranging between 250 and 390 mm during the growing season (April 1st and September 30th ). Lower amounts require irrigation, while higher amounts are not directly detrimental, but can enhance fungal diseases. However, the total amount of GSP just offers an initial image of the water availability in a region, as local rainfall frequency and timing are equally important for grapevine. While greater amounts during the early vegetative stage are beneficial for plants growth, the same amount during bloom represents a critical threat. Generally, GSP indicate a sufficient precipitation amount, the lowest values being registered in the southern and eastern extremities of the region – about 300 mm, and the highest in the north, up to 400 mm (Fig. 3c). As an average, the highest monthly amounts correspond to June, but May is also a rainy month (it is the month when bloom generally occurs). In case the precipitation amount is close to the average – about 60 mm in the plain area and 70–80 mm in the piedmont, pollination occurs normally. Rain also affects the quality of grapes during the ripening period if the amount is too high. In Oltenia, August and September are months with lower precipitation amounts, and thus, in a normal pluviometric year, the quality of grapes is not affected.

The suitability threshold in case of LGS (number of days with mean temperature ≥ 10°C) is set at 160 days. In the lower plain area, LGS exceeds 200 days on average (a maximum of 212 days at D.T. Severin in the south-west and a minimum of 200 days at Slatina in the north-east), which indicates a high favourability for grapevine cultivation. In the piedmont area, the average values also point out high favourability including red grape varieties, except for the northernmost station, Tg. Logrești, where the 187 days of LGS indicate suitability for white wines. Longer LGS means greater anthocyanin accumulation, which is a real mark for red cultivar recognition (a process that starts at veraison and continues throughout ripening).

HTC and HyI belong to the category of indices calculated based on temperature and precipitation values (Fig. 4). According to HTC, the average values for the growing season are above the 0.8 threshold. However, the monthly values indicate lower values in the second part of summer and even in September. Thus, July is below the 0.8 threshold in the south of the plain and the western part of the piedmont, while August is the most problematic month as the entire plain area displays low values indicating the need for irrigation. Dry conditions maintain even in September, especially in the proximity of the Danube. A moderate water deficit registered during the ripening phase is often associated with a greater wine quality, especially in case of red wines, due to the higher synthesis of anthocyanins and flavor compounds (Deluc et al. 2011; Savoi et al. 2016). On the other hand, when larger rainfall amounts are associated with high temperatures, downy mildew, which is caused by Plasmopara viticola, becomes a problem. According to HyI average values, the entire analysed region presents a high risk of downy mildew (HyI > 5100°C mm), the southwestern extremity (Calafat) being the only area that registers a moderate risk (5013.7°C mm).

Heat accumulation was assessed based on two largely used indices – HI and WI. It is considered that HI presents the highest correlation with sugar content, a key factor for producing high-quality wines (Huglin and Schneider 1998 apud Comte et al. 2022). Thus, the area along the Danube presents the highest values. Based on HI, the viticultural climate is warm (HI_+ 2), which means the potential of the region is greater than the heliothermal need of the cultivated grapevine varieties to ripen, but there is also a risk of thermal stress (Tonietto and Carbonneau 2004). Temperate warm viticultural climate (HI_+ 1) characterizes the entire plain area, as well as the eastern part of the piedmont, while westwards, in the same area, the climate is temperate (HI_− 1). Cabernet-Sauvignon, for example, which is a variety cultivated within the entire viticultural area of Oltenia, can reach maturity even in the temperate climate conditions. According to WI the entire plain area belongs to R III, displaying values between 1909.8°C (Calafat, the southwestern part) and 1705.7°C (Craiova, in the north), while the piedmont area is within the limits of R II climate region. In the first case, there are met favourable conditions for obtaining high production of good quality wines, while in the second, mid-season varieties are recommended in order to obtain quality wines (Fig. 5a, b).

3.2 Changes in the main climatic parameters and bioclimatic indices between 1961 and 2021

Temperature, sunshine duration and precipitation amounts and distribution during the growing season are among the climatic factors that greatly condition grapevine. Consequently, any change of their values and regime triggers changes of grapevine phenology, grape productivity and wine quality. To better underline the importance of a changing climate for viticulture, the analysed period was split in two sub-periods (1961–1990 and 1991–2021).

On average, there is a + 1.0°C difference between the 1961–1990 and 1991–2021 periods in terms of AAT (Fig. 6a), 1.4°C in case of TWM and 0.96°C for GST (Fig. 6b), the increase being relatively uniformly distributed. However, the increase of TWM is 0.3°C higher than the average in the western part of the analysed region; there are also registered the highest GST values, almost 19°C, which means that in the near future the area will no longer have warm, but hot conditions. Thus, based on the projected temperature increase (+ 1.5°C for 2011–2040 and + 2.1°C for 2041–2070 for scenario RCP2.6, respectively + 1.7°C for 2011–2040 and + 3.8°C for 2041–2070 for scenario RCP8.5, according to Climate ADAPT), the region may exceed its optimum thermal conditions for the varieties currently grown here. On the other hand, warming also means a prolonged frost-free period, which for the moment is beneficial for wine quality. AT registered a + 204.8°C increase when comparing the two sub-periods rendering the same territorial distribution pattern within the region. Thus, for the period 1991–2021, only in the north-eastern extremity of the wine-growing region (Tg. Logrești), AT is below the 1400°C threshold (1393.9°C), which indicates favourability for obtaining quality red wines (Table 4, Fig. 6c). Consequently, we can assert that the thermal potential of the region significantly increased during the last two decades.

Precipitations are characterized by relatively constant amounts, higher GSP registered in the interval 1991–2021 being generally induced by some excessively rainy years, such as 2005 or 2014 (when the deviation compared to the average of the entire period reached and even exceeded 400 mm, especially in the north of the plain and the piedmont area). However, if taking into account temperature increase (AAT, TWM and, especially GST), the analysed region is subject to an intensified evapotranspiration, which means that the registered precipitation amounts may not be sufficient to support the proper development of grapevine and irrigation is recommended.

In terms of grapevine bioclimatic indices (WI and HI), the increase of their value is quite normal as they are both calculated based on temperature values. In case of WI, the greatest increase is characteristic to the southwestern plain area, as well as to the eastern part of the piedmont area. In case of five meteorological stations, this increase also corresponds to a shift of region. Thus, the southwestern plain area shifted from Region III to Region IV, while the northeastern plain area and the east of the piedmont shifted from Region II to Region III (Fig. 6d). With regard to HI, the shift in the class of viticultural climate is even more obvious than in the previous case. Accordingly, only the northeastern plain area remained classified as HI_+ 1, while the rest of the unit is presently HI_+ 2, and the piedmont shifted from HI_− 1 to HI_+ 1 (Fig. 6e). In case of viticultural climate HI_+ 2, there can emerge some risks of thermal stress, but all the varieties (including the late ones) can properly ripe (Tonietto and Carbonneau 2004).

3.3 Trends of the main climatic parameters and bioclimatic indices

Trends of all temperature-based indices (AAT, TWM, GST, AT, WI, HI) show significant changes within the entire analysed region, all being positive. The warming rates are not highly different between plain and piedmont in case of the first four indices, which suggests a uniform increase trend. However, heat accumulation is higher in the piedmont compared to the plain, as highlighted by both HI and WI, as T_max and T_min are part of the formula. Trends in HI for the plain unit are 5.33 units yr^− 1 ⁅325 units (61 year)⁻¹⁆, while in the piedmont they are 6.42 units yr^− 1 ⁅392 units (61 year)⁻¹⁆. In case of WI, trends are 5.21, respectively 7 units yr^− 1 ⁅318 units (61 year)⁻¹ in the first case and 426 units (61 year)⁻¹ in the second case⁆ (Fig. 7, Fig. 8).

Starting with 1990, HI values below 2100°C in the plain and below 1700°C in the piedmont became quite rare. In terms of WI, most of the values computed for the last two decades classify the climate as characteristic to Region III and IV in the plain area, while in the piedmont, they range between the limits of Region III. Besides these general upward values, there also emerge significant differences from year to year: 608.2°C in the plain area and 456.3°C in the piedmont area between 2012 (hot and dry) and 2014 (cold and rainy), which increase the impact of climatic variables on grapevine.

The significance of the increases of the aforementioned bioclimatic indices was evaluated for the entire analysed period using the nonparametric Mann-Kendall test. Thus, with some exceptions, all temperature-related parameters (AAT, TWM, GST, AT), as well as WI and HI registered highly significant positive trends (Fig. 9). Only the northern part of the piedmont area does not display statistically significant trends for GST and AT, while in case of AAT and TWM, the significance level is reduced (0.1 or 90%) compared to the region average (0.001 or 99%). GSP did not register any significant trend (either positive or negative), which is consistent with the results of other national or regional studies related to precipitations trends (Marin et al. 2014; Prăvălie 2014; Vlăduț and Onțel 2014).

The analysis of the spatial distribution and temporal evolution of the used bioclimatic indices emphasizes some changes that affect climate suitability for certain cultivars and wine production in Oltenia region as an effect of warming in particular. The determined trends in the used bioclimatic indices, correlated with future predicted temperatures, highlight the need for adaptation strategies. Oltenia region is undergoing an obvious temperature increase that will trigger modifications of the phenological stages and berry composition. If budburst, flowering, veraison occur earlier, consequently, harvesting will take place earlier. Besides a greater risk of thermal stress mainly induced by increased daily maximum temperatures, there will be registered modifications of the accumulation of organic acids, anthocyanins and flavonols (that are temperature-dependent), which condition the quality of grapes and wines. Possible consequences of these modifications refer to higher alcohol content due to higher sugar levels, low acidity, loss of the aromatic character, diminution of the deep red colour, etc. (Jones et al. 2005; Van Leeuwen et al. 2019).

In the region, there emerges mostly a latitudinal shift of climate suitability and less an altitudinal shift, situation explained by the reduced difference (about 200 m) between southern low areas and the northern piedmont area. This latitudinal shift is mainly the effect of temperature and sunshine duration changes and less of the precipitations amounts.

Average values of GST place the region under best thermal conditions (17–19ºC, warm) indicating its suitability for obtaining high quality wines. However, when analysing the data for the last decade (2012–2021), the 19ºC threshold was exceeded in the southwestern part of the region, where GST reached almost 20ºC placing the area under hot conditions and indicating the increase of the heat stress risk. In the years with low GSP, heat stress is also associated with water stress, while in years with high GSP, probability of pests and diseases increases (Santos et al. 2020). AT displays the same spatial and temporal distribution, the sums registered in the last 10 years revealing adequate conditions for obtaining high quality red wines even in the northern of the piedmont (Târgu Logrești).

HI pattern emphasizes a significant increase in the values of this index, particularly over the southern and central part of the plain area, where the viticultural climate changed from temperate warm to warm, as well as in the piedmont area, where climate became temperate warm. The same pattern is revealed by WI (in the southwestern part of the analysed region, Region III became Region IV, while in the east, Region II became Region III), indicating climate suitability for heat-tolerant or heat-stress-adapted cultivars.

This evolution pattern suggests that climate will become quite soon too warm for certain varieties presently cultivated in the region, particularly white varieties, such as Pinot Gris, Chardonnay, Rhine Riesling (HI: 1700–1800°C) or Italian Riesling, Cabernet Sauvignon (HI: 1900–2000°C). As already suggested for other viticultural areas, the introduction of new varieties should be part of the adaptation strategies. According to the present HI values, in the plain area, there are suitable conditions for Syrah, which is already cultivated, as well as Carignan, while Cabernet Sauvignon, Merlot and Cabernet Franc find proper conditions even in the piedmont area. Consequently, new climate conditions will lead to the reduction of the area suitable for white varieties and the increase of the area suitable for red wines due to its expansion northwards as a result of better heliothermal resources in the piedmont area, which is consistent with the results of different studies based on climate models (Fraga et al. 2013; Malheiro et al. 2010, 2012; Moriondo et al. 2013), as well as of studies for the Romanian territory (Irimia et al. 2017b, b).

Consequently, there is a strong need to develop adaptation strategies to the new climatic context in due time. As already mentioned in other studies, short-term and long-term adaptation strategies are equally important, depending on the site location and amplitude of change. Short-term strategies mainly refer to interventions at the level of the vineyard during the growing season (Santos et al. 2021), which can be very effective and less demanding from the financial point of view and can be implemented in the study region, as well. Among such measures, there can be mentioned:

Modifications of the vineyard design: reduction of the plantation density (Van Leeuwen et al. 2019), which determines lower water consumption; raw orientation that limits temperature increase and water stress (Hunter et al. 2016); shading systems that limit evapotranspiration and negative impact of high temperatures, but are less cost-efficient.
Canopy management practice: adequate pruning systems – semi-minimal pruning, which is used in Central Europe and influences the light interception and bunch sun exposure (Molitor et al. 2019); trimming shoots, which influences the ripening process and sugar accumulation (Valentini et al. 2019).
Soil management: tillage techniques or even no tillage (Bahar and Yasasin 2010), use of adequate cover cropping species (Unger and Vigil 1998) or mulches (Fraga and Santos 2018) that are essential for the reduction of water loss and potential erosion.
Irrigation: it is recommended to be used when rainfall is too low and does not meet grapevine water requirements, drip irrigation being considered as the most efficient especially in regions with water scarcity (Sauer et al. 2010).

Long-term adaptation strategies can be the solution to prevent drastic reduction in viticultural suitability (Santos et al. 2020). The suggested adaptations strategies are:

Changes of the training system: light interception and sun exposure of the bunch can be enhanced if a proper training system is adopted, delaying the maturation period (Molinor et al. 2019) and decreasing sugar accumulation; increase water use efficiency.
Plant material adapted to the selected site: heat-tolerant and drought-tolerant vine varieties are recommended in the region (varietal/clonal and rootstock selection may be taken into consideration).
Vineyard relocation: it is to be taken into account when deciding to set up a vineyard starting from the information emphasized by climatic models.

Shifting patterns in viticulture as a response to climate change is a reality noticed worldwide. If the previously predicted decline in suitability in many traditional wine-producing regions, especially in the Mediterranean one, has started to emerge, the climatic conditions registered in southern Romania, where the study region is located, are adequate for obtaining high quality wines. In fact, according to the calculated indices, suitability increased on the whole, but particularly in higher northern areas of the Getic Piedmont, which presently displays climatically suitable conditions for red table wine and quality red wines. Of course, besides the role of climate in grapevine development, there are other environmental factors to be considered in detailed suitability studies, such as soil (parent material, physical and chemical properties) and topography (slope aspect and elevation, which influence certain meteorological parameters, e.g. SD), availability of water resources for irrigations, etc.

However, the changes and trends detected in all the analysed climatic parameters and bioclimatic indices imply upcoming issues for viticulture in Oltenia, mainly in its southern and southwestern part, where climate suitability for high quality wines is under pressure on the background of increasing temperature and interannual variability of temperature and precipitation amounts, and greater frequency and intensity of extreme meteorological phenomena. Consequently, both winegrowers and policymakers should consider the new and future climatic conditions and develop the best adaptation strategies in order to reduce vulnerability and increase sustainability of winemaking sector.

Although they vary significantly, both geographically and varietally, the effects of climate change on viticulture trigger influences that are both environmental and socio-economic. Thus, it is important to analyse changing viticulture suitability firstly in relation to growers and decision makers, although other stakeholders, such as the consumers, the labour market or the scientific community are also relevant. Vintners must be aware of the changing environmental conditions in order to meet market demands and consumer expectations for specific products. Moreover, the economic investments associated with the adaptive management schemes and indeed innovations in the existing vineyards or the resource constraints associated with opening new ones must be carefully considered in this context. This is especially difficult without stakeholder cooperation (especially in the new potential viticultural areas), if farmers lack data and expertise about vine growing under new climate patterns, as well as financial resources for mitigation measures. As climate change impacts the region under study, understanding the risks and opportunities it presents is vital to maintaining a socio-ecologically sustainable viticulture system and future research should consider such challenges, focusing on how various stakeholders (from the local to the national or even international level) can work together to meet this aim.

Acknowledgments

The authors are grateful to the researchers at the Finnish Meteorological Institute, for making available the MAKESENS template for data processing. We express our cordial gratitude towards the National Meteorological Administration for providing the site-specific mean monthly climatic data used for the present analysis.

Statements and Declarations

Funding

The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Competing Interests

The authors have no relevant financial or non-financial interests to disclose.

Author Contributions

All authors contributed to the study conception and design. Data collection was performed by CDB, analysis was conducted by AȘV and the graphical material was achieved by ML. The first draft of the manuscript was written by AȘV and all authors commented on previous versions of the manuscript. All authors reviewed and approved the final manuscript.

Data Availability

The raw datasets that support the findings are not publicly available due to proprietary nature. The data generated during the study and analysed are included in this article. The spatial support for the processing and representation of the analysed climate data was derived from public resources. Supplementary data are available from the corresponding author on reasonable request.

Angearu CV, Ontel I, Boldeanu G, Mihailescu D, Nertan A, Craciunescu V, Catana S, Irimescu A (2020) Multi-Temporal Analysis and Trends of the Drought Based on MODIS Data in Agricultural Areas, Romania. Remote Sens. 12, 3940. https://doi.org/10.3390/rs12233940
Apaydin H, Sonmez FK, Yildirim YE (2004) Spatial Interpolation Techniques for Climate Data in the GAP Region in Turkey, Climate Research 28:31–40. https://doi.org/10.3354/cr028031
Bahar E, Yasasin AS (2010) The yield and berry quality under different soil tillage and clusters thinning treatments in grape (Vitis vinifera L.) cv. Cabernet-Sauvignon. Afr. J. Agric. Res. 5:2986–2993
Blanco-Ward D, Queijeiro JMG, Jones GV (2007) Spatial climate variability and viticulture in the Miño River Valley of Spain. Vitis 46:63 – 70. https://doi.org/10.5073/vitis.2007.46.63-70
Becker N, Zimmermann H (1984) Influence de divers apports d’eau sur des vignes en pots, sur la maturation des sarments, le développement des baies et la qualité du vin. Bull. OIV 57(641/642): 584–596
Boé J, Somot S, Corre L, Nabat P (2020) Large differences in summer climate change over Europe as projected by global and regional climate models: Causes and consequences. Climate Dynamics 54(5–6):2981–3002. https://doi.org/10.1007/s00382-020-05153-1
Bois B, Wald L, Pieri P, van Leeuwen C, Commagnac L, Chery P, Christen M, Gaudillère JP, Saur E (2008) Estimating spatial and temporal variations in solar radiation within Bordeaux winegrowing region using remotely sensed data. OENO One 42(1):15–25. https://doi.org/10.20870/oeno-one.2008.42.1.829
Branas J, Bernon G, Levadoux L (1946) Élements de Viticulture Générale. Imp. Déhan, Bordeaux
Briche E, Beltrando G, Somot S, Quenol H (2014) Critical analysis of simulated daily temperature data from the ARPEGE-climate model: application to climate change in the Champagne wine-producing region. Climatic Change 123:241–254. https://doi.org/10.1007/s10584-013-1044-5
Bucur MG, Babeș AC (2016) Research on Trends in Extreme Weather Conditions and their Effects on Grapevine in Romanian Viticulture. Bulletin UASMV Horticulture 73:126–134. DOI: 10.15835/buasvmcn-hort:12190
Bucur GM, Cojocaru GA. Antoce AO (2019) The climate change influences and trends on the grapevine growing in Southern Romania: A long-term study. BIO Web Conf. 15:01008. DOI: https://doi.org/10.1051/bioconf/20191501008
Cardell MF, Amengual A, Romero R (2019) Future effects of climate change on the suitability of wine grape production across Europe. Reg Environ Change 19:299–2310. https://doi.org/10.1007/s10113-019-01502-x
Chitu E, Giosanu D, Mateescu E (2015) The Variability of Seasonal and Annual Extreme Temperature Trends of the Latest Three Decades in Romania. Agriculture and Agricultural Science Procedia 6:429–437. https://doi.org/10.1016/j.aaspro.2015.08.113
Climate ADAPT, Daily Mean Temperature - Monthly Statistics, 2011–2099, https://climate-adapt.eea.europa.eu/metadata/indicators/daily-mean-temperature-monthly-mean-2011-2099#details, accessed August 19, 2022
Comte V, Schneider L, Calanca P, Reberez M (2022). Effects of climate change on bioclimatic indices in vineyards along Lake Neuchatel, Switzerland. Theor Appl Climatol 147:423–436. https://doi.org/10.1007/s00704-021-03836-1
Copernicus Land Monitoring Service (2022), CORINE Land Cover 2018 and 2012 Data, available at https://land.copernicus.eu/pan-european/corine-land-cover, accessed July 1, 2022
Coppola E, Nogherotto R, Ciarlo’ JM, Giorgi F, Meijgaard EV, Kadygrov N, Iles C, Corre L et al. (2021a) Assessment of the European climate projections as simulated by the large EURO-CORDEX regional and global climate model ensemble.<bvertical-align:super;> </bvertical-align:super;>J. Geophys. Res.: Atmos. 126(4). https://doi.org/10.1029/2019jd032356
Coppola E, Raffaele F, Giorgi F et al. (2021b) Climate hazard indices projections based on CORDEX-CORE, CMIP5 and CMIP6 ensemble. Clim Dyn 57:1293–1383. https://doi.org/10.1007/s00382-021-05640-z
Council Regulation (EC) No 491/2009 of 25 May 2009 amending Regulation (EC) No 1234/2007 establishing a common organisation of agricultural markets and on specific provisions for certain agricultural products (Single CMO Regulation), available at https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32009R0491&from=EN
Croitoru AE, Piticar A, Ciupertea AF, Rosca CF (2016) Changes in heat waves indices in Romania over the period 1961–2015. Global and Planetary Change 146:109–121. https://doi.org/10.1016/j.gloplacha.2016.08.016
Croitoru AE, Piticar A, Sfica L, Harpa GV, Rosca CF, Tudose T, Horvath C, Minea I, Ciupertea FA, Scripca AS (2018) Extreme Temperature and Precipitation Events in Romania. Romanian Academy Press, Bucharest
Deluc L, Decendit A, Papastamoulis Y, Merillon J, Cushman J, Cramer G (2011) Water deficit increases stilbene metabolism in Cabernet-Sauvignon berries. J Agric Food Chem 59:289–297. https://doi.org/10.1021/jf1024888
Droulia F, Charalampopoulos I (2021) Future Climate Change Impacts on European Viticulture: A Review on Recent Scientific Advances. Atmosphere 12(4):495. https://doi.org/10.3390/atmos12040495
Dumitrescu A, Bojariu R, Birsan MV, Marin L, Manea A (2015) Recent climatic changes in Romania from observational data (1961–2013). Theor Appl Climatol 122:111–119. https://doi.org/10.1007/s00704-014-1290-0
FAO (2022) FAOSTAT Database, available online at https://www.fao.org/faostat/en/#data/QCL, accessed August 20, 2022
Fraga H, Malheiro AC, Moutinho-Pereira J. et al. (2013) Future scenarios for viticultural zoning in Europe: ensemble projections and uncertainties. Int J Biometeorol 57:909–925. https://doi.org/10.1007/s00484-012-0617-8
Fraga H, Santos JA (2018) Vineyard mulching as a climate change adaptation measure: future simulations for Alentejo, Portugal. Agric. Syst. 164:107–115. doi:10.1016/j.agsy.2018.04.006
Geo-spațial (2007), Shuttle Radar Topography Mission (SRTM90) reprojected in Stereo70, available at http://geo-spatial.org/vechi/download/datele-srtm90-reproiectate-in-stereo70, accessed July 1, 2022
Geo-spațial (2022), Romania: general vector datasets, available at http://geo-spatial.org/vechi/download/romania-seturi-vectoriale, accessed July 1, 2022
Gilbert RO (1987) Statistical methods for environmental pollution monitoring. Van Nostrand Reinhold, New York
Greer DH, Weedon MM (2012) Modelling photosynthetic responses to temperature of grapevine (Vitis vinifera cv. Semillon) leaves on vines grown in a hot climate. Plant Cell Environ 35:1050–1064. DOI: 10.1111/j.1365-3040.2011.02471.x
Greer DH, Weedon MM (2013) The impact of high temperatures on Vitis vinifera cv. Semi lion grapevine performance and berry ripening. Front. Plant Sci. 4. https://doi.org/10.3389/fpls.2013.00491
Hidalgo L (2002) Tratado de viticultura general. Ediciones Mundi-Prensa, Madrid
Huglin P (1978) Nouveau mode d’évaluation des possibilites héliothermiques d’un milieu viticole. Comptes Rendus de l'Académie d'Agriculture de France, Académie d'agriculture de France 64:1117–1126. ⟨hal-02732734⟩
Huglin P, Schneider C (1998) Biologie et écologie de la vigne. 2nd edition edn. TecDoc, Paris
Hunter JJ, Volschenk CG, Zorer R (2016) Vineyard row orientation of Vitis vinifera L. cv. Shiraz/101 – 14 Mgt: climatic profiles and vine physiological status. Agric. For. Meteorol. 228–229:104–119. doi: 10.1016/j.agrformet.2016.06.013
Hunter JK, Tarricone L, Volschenk C, Giacalone C, Melo MS, Zorer R (2020) Grapevine physiological response to row orientation-induced spatial radiation and microclimate changes. OENO One 54(2):411–433. https://doi.org/10.20870/oeno-one.2020.54.2.3100
Hutchinson MF (1995) Interpolating Mean Rainfall Using Thin Plate Smoothing Splines, International Journal of Geographic Information Systems 9(4):385–403 https://doi.org/10.1080/02693799508902045
Ionita M, Rimbu N, Chelcea S, Patrut S (2013) Multidecadal variability of summer temperature over Romania and its relation with Atlantic Multidecadal Oscillation. Theor Appl Climatol 113(1–2):305–315. DOI: 10.1007/s00704-012-0786-8
IPCC (2021). Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte V, Zhai P, Pirani A, Connors SL, Péan C, Berger S, Caud N, Chen Y, Goldfarb L, Gomis MI, Huang M, Leitzell K, Lonnoy E, Matthews JBR, Maycock TK, Waterfield T, Yelekçi O, Yu R, Zhou B (eds.)]. In Press
Irimia LM (2012) Biologia, Ecologia şi Fiziologia Viţei de Vie. Ed. Ion Ionescu de la Brad, Iaşi
Irimia LM, Patriche CV, Quenol H (2013) Viticultural zoning: A comparative study regarding the accuracy of different approaches in vineyards climate suitability assessment. Cercetări Agronomice in Moldova 46(3):95–106
Irimia LM, Patriche CV, Quénol H (2014) Analysis of viticultural potential and delineation of homogeneous viticultural zones in a temperate climate region of Romania. OENO One 48(3):145–167. https://doi.org/10.20870/oeno-one.2014.48.3.1576
Irimia LM, Patriche CV, Roșca B (2017a) Changes in oenoclimate aptitude index characterizing climate suitability of Romanian wine growing regions. Applied Ecology and Environmental Research 15:755–767. DOI: http://dx.doi.org/10.15666/aeer/1504_755767
Irimia LM, Patriche CV, Roşca B, Cotea VV (2017b) Modifications in climate suitability for wine production of Romanian wine regions as a result of climate change. BIO Web of Conferences 9:01026. https://doi.org/10.1051/bioconf/20170901026
Irimia L, Patriche CV, Quenol H, Sfâcă L, Foss C (2018a) Shifts in climate suitability for wine production as a result of climate change in a temperate climate wine region of Romania. Theor Appl Climatol 131:1069–1081 doi:10.1007/s00704-017-2033-9
Irimia LM, Patriche CV, Roșca B (2018b) Climate change impact on climate suitability for wine production in Romania. Theor Appl Climatol 133:1–14. https://doi.org/10.1007/s00704-017-2156-z
Jackson D (2001) Climate: monographs in cool climate viticulture–2. Daphne Brasell Associates, Wellington
Jacob D, Kotova L, Teichmann C et al (2018) Climate impacts in Europe under + 1.5°C global warming. Earth’s Future 6:264–285. <background-color:#CFBFB1;uvertical-align:super; >https://doi.org/10.1002/2017EF000710 </background-color:#CFBFB1;uvertical-align:super;>
Jones GV, White MA, Cooper OR, Storchmann K (2005) Climate Change and Global Wine Quality. Climatic Change 73(3):319–343. https://doi.org/10.1007/s10584-005-4704-2
Jones GV (2006) Climate and Terroir: Impacts of Climate Variability and Change on Wine. In: Fine Wine and Terroir – The Geoscience Perspective. Macqueen RW, Meinert LD (eds) Geoscience Canada Reprint Series Number 9; Geological Association of Canada; St. John’s, Newfoundland: 247 p.
Jones GV (2007) Climate Change and the global wine industry. Proceedings from the 13th Australian Wine Industry Technical Conference, Adelaide, Australia https://www.linfield.edu/assets/files/Wine-Studies/GregJones/AWITC%20GJones.pdf
Jones GV, Duff AA, Hall A, Myers JW (2010) Spatial analysis of climate in winegrape growing regions in the western United States. American Journal of Enology and Viticulture 61(3):313–326. https://www.ajevonline.org/content/61/3/313.full
Kendall MG (1975) Rank Correlation Methods. 4th edition, Charles Griffin, London
Kew SF, Philip SY, van Oldenborgh GJ, van der Schrier G, Otto FEL, Vautard R (2019) The Exceptional Summer Heat Wave in Southern Europe 2017, Bull Amer Meteor Soc 100(1):S49-S53. Retrieved Feb 18, 2022, from https://journals.ametsoc.org/view/journals/bams/100/1/bams-d-18-0109.1.xml. https://doi.org/10.1175/BAMS-D-18-0109.1
Köse B (2014) Phenology and Ripening of Vitis vinifera L. and Vitis labrusca L. varieties in the Maritime Climate of Samsun in Turkey’s Black Sea Region. S. Afr. J. Enol. Vitic. 35(1): 90–102. DOI: https://doi.org/10.21548/35-1-988
Koufos G, Mavromatis T, Koundouras S, Jones GV (2017) Response of viticulture-related climatic indices and zoning to historical and future climate conditions in Greece. Int. J. Climatol. 38:2097–2111, DOI: 10.1002/joc.5320
Malheiro AC, Santos JA, Fraga H, Pinto JG (2010) Climate change scenarios applied to viticultural zoning in Europe. Clim. Res. 43:163–177. DOI: 10.3354/cr00918
Malheiro AC, Santos JA, Pinto JG, Jones GV (2012) European Viticulture Geography in a changing climate. Bull. de l’OIV 85:971–972
Mann HB (1945) Non-parametric tests against trend. Econometrica 13:163–171
Manning C, Widmann M, Bevacqua E, van Loon A, Maraun D, Vrac M (2019). Increased probability of compound long-duration dry and hot events in Europe during summer (1950–2013). Environ. Res. Lett. 14 094006. https://doi.org/10.1088/1748-9326/ab23bf
Marin L, Birsan MV, Bojariu R, Dumitrescu A, Micu DM, Manea A (2014). An overview of annual climatic changes in Romania: trends in air temperature, precipitation, sunshine hours, cloud cover, relative humidity and wind speed during the 1961–2013 period. Carpathian Journal of Earth and Environmental Sciences 9(4):253–258. http://www.cjees.ro/viewTopic.php?topicId=489
Molitor D, Keller M (2016) Yield of Müller-Thurgau and Riesling grapevines is altered by meteorological conditions in the current and the previous growing seasons. OENO One 50:245–258. https://doi.org/10.20870/oeno-one.2016.50.4.1071
Molitor D, Schultz M, Mannes R, Pallez-Barthel M, Hoffmann L, Beyer M (2019) Semi-minimal pruned hedge: A potential climate change adaptation strategy in viticulture. Agronomy 9(4):173. https://doi.org/10.3390/agronomy9040173
Moriondo M, Jones GV, Bois B et al. (2013) Projected shifts of wine regions in response to climate change. Clim Change 119(3):825–839. https://doi.org/10.1007/s10584-013-0739-y
Natural Earth (2022), International free vector dataset, available at https://www.naturalearthdata.com/downloads/, accessed July 1, 2022
Nesbitt A, Kemp B, Steele C, Lovett A, Dorling S (2016) Impact of recent climate change and weather variability on the viability of UK viticulture – combining weather and climate records with producers’ perspectives. Aust J Grape Wine Res 22:324–335. https://doi.org/10.1111/ajgw.12215
NIS (2022) TEMPO Online Database available at http://statistici.insse.ro:8077/tempo-online/#/pages/tables/insse-table, accessed 20 August, 2022
Nistor E, Dobrei AG, Dobrei A, Camen D (2019) Growing season climate variability and its influence on Sauvignon blanc and Pinot gris berries and wine quality: study case in Romania (2005–2015). South African Journal for Enology and Viticulture.39(2):196–207. https://doi.org/10.21548/39-2-2730
OIV (2022) State of the World Vine and Wine Sector 2021, available on line at https://www.oiv.int/public/medias/8778/eng-state-of-the-world-vine-and-wine-sector-april-2022-v6.pdf, accessed August 20, 2022
Oşlobeanu M, Macici M, Georgescu M, Stoian V (1991) Zonarea soiurilor de viţă de vie în România. Ed. Ceres, Bucureşti (in Romanian)
Peña-Angulo D, Reig-Gracia F, Domínguez-Castro F, Revuelto J, Aguilar E, van der Schrier G, Vicente-Serrano SM (2020) ECTACI: European climatology and trend atlas of climate indices (1979–2017). Journal of Geophysical Research: Atmospheres 125(16). https://doi.org/10.1029/2020JD032798
Piña-Rey A, González-Fernández E, Fernández-González M, Lorenzo MN, Rodríguez-Rajo FJ (2020) Climate Change Impacts Assessment on Wine-Growing Bioclimatic Transition Areas. Agriculture 10(12):605. https://doi.org/10.3390/agriculture10120605
Prado RA, Yuste-Rojas M, Sort X, Lacueva CA, Torres M, Lamuela-Raventós RM (2007) Effect of soil type on wines produced from Vitis vinifera L. Cv. Grenache in commercial vineyards. J Agric Food Chem 55:779–786. https://doi.org/10.1021/jf062446q
Prăvălie R (2014) Analysis of temperature, precipitation and potential evapotranspiration trends in southern Oltenia in the context of climate change. Geographia Technica 9(2):68–84. https://technicalgeography.org/pdf/2_2014/08_pravalie.pdf
Pugliese M, Gullino ML, Garibaldi A (2011) Effect of climate change on infection of grapevine by downy and powdery mildew under controlled environment. Commun Agric Appl Biol Sci. 76(4):579–582. PMID: 22702176
Regulation (EU) 2021/2117 of the European Parliament and of the Council of 2 December 2021 amending Regulations (EU) No 1308/2013 establishing a common organisation of the markets in agricultural products, (EU) No 1151/2012 on quality schemes for agricultural products and foodstuffs, (EU) No 251/2014 on the definition, description, presentation, labelling and the protection of geographical indications of aromatised wine products and (EU) No 228/2013 laying down specific measures for agriculture in the outermost regions of the Union, available at https://eur-lex.europa.eu/eli/reg/2021/2117/oj, accessed February 22, 2022
Rienth M, Vigneron N, Walker RP, Castellarin SD, Sweetman C, Burbidge CA, Bonghi C, Famiani F, Darriet P (2021) Modifications of Grapevine Berry Composition Induced by Main Viral and Fungal Pathogens in a Climate Change Scenario. Front Plant Sci 12:717223. doi: 10.3389/fpls.2021.717223
Russo S, Sillmann J, Fischer EM (2015). Top ten European heatwaves since 1950 and their occurrence in the coming decades. Environ Res Lett 10(12):124003. https://doi.org/10.1088/1748-9326/10/12/124003
Qi Y, Wang R, Qin Q, Sun Q. (2019) Soil affected the variations in grape and wine properties along the eastern foot of Helan Mountain, China. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 69:6, 494–502. https://doi.org/10.1080/09064710.2019.1611914
Salinari F, Giosué S, Tubiello FN, Rettori A, Rossi A, Spanna F, Rosenzweig C, Gullino ML (2006) Downy mildew (Plasmopara viticola) epidemics on grapevine under climate change. Glob Change Biol 12:1299–1307. https://doi.org/10.1111/j.1365-2486.2006.01175.x
Salmi T, Määttä A, Anttila P, Ruoho-Airola T, Ammell T (2002) Detecting trends of annual values of atmospheric pollutants by the Mann-Kendall test and Sen’s slope estimates – the Excel template application MAKESENS. Publications of Air Quality No. 31, Report code FMI-AQ-31
Santos JA, Malheiro AC, Karremann MK, Pinto JG (2010) Statistical modelling of grapevine yield in the Port Wine region under present and future climate conditions. Int J Biometeorol 55:119–131. https://doi.org/10.1007/s00484-010-0318-0
Santos JA, Fraga H, Malheiro AC, Moutinho-Pereira J, Dinis LT., Correia C, Moriondo M, Leolini L, Dibari C, Costafreda-Aumedes S et al. (2020) A Review of the Potential Climate Change Impacts and Adaptation Options for European Viticulture. Appl. Sci. 10(9):3092. https://doi.org/10.3390/app10093092
Santos JA, Chenyao Y, Fraga H, Malheiro AC, Moutinho-Pereira J, Dinis LT, Correia C, Moriondo M et al. (2021) Short-term adaptation of European viticulture to climate change: an overview from the H2020 Clim4Vitis action. Technical Reviews, vine and wine, DOI: 10.20870/IVES-TR.2021.4637
Sauer T, Havlík P, Schneider UA, Schmid E, Kindermann G, Obersteiner M (2010) Agriculture and resource availability in a changing world: The role of irrigation. Water Resour Res 46:6, https://doi.org/10.1029/2009WR007729
Savić S, Vukotić M (2018) Viticulture Zoning in Montenegro. Bull. UASVM Hortic. 75(1):73–86. DOI:10.15835/buasmvcn-hort:003917
Savoi S, Wong DCJ, Arapitsas P, Miculan M, Bucchetti B, Peterlunger E, Fait A, Mattivi F, Castellarin SD (2016) Transcriptome and metabolite profiling reveals that prolonged drought modulates the phenylpropanoid and terpenoid pathway in white grapes (Vitis vinifera L.). BMC Plant Biology 16:67–67. https://doi.org/10.1186/s12870-016-0760-1
Selyaninov GT (1930) Methods of agricultural climatology (in Russian), Agricultural Meteorology, No. 22 L.
Spinoni J, Vogt JV, Barbosa P, Dosio A, Mccormick N, Bigano A, Fussel HM (2018a) Changes of heating and cooling degree-days in Europe from 1981 to 2100. Int J Climatol, 38(Suppl. 1): e191–e208. https://doi.org/10.1002/joc.5362
Spinoni J, Vogt JV, Naumann G, Barbosa P, Dosio A (2018b) Will drought events become more frequent and severe in Europe? Int J Climatol 38(4):1718–1736. https://doi.org/10.1002/joc.5291
Spinoni J, Barbosa P, Bucchignani E, Cassano J. Cavazos T, Christensen JH, Christensen OB et al. (2020) Future Global Meteorological Drought Hot Spots: A Study Based on CORDEX Data. Journal of Climate 33(9):3635–3661. Retrieved Feb 18, 2022, from https://journals.ametsoc.org/view/journals/clim/33/9/jcli-d-19-0084.1.xml https://doi.org/10.1175/JCLI-D-19-0084.1
Ţârdea C, Dejeu L (1994). Viticultura. Ed. Didactică şi Pedagogică, Bucureşti (in Romanian)
Teodorescu Ş, Popa AI, Sandu G (1987) Oenoclimatul României. Ed. Ştiinţifică şi Enciclopedică, Bucureşti (in Romanian)
Tonietto J (1999) Les macroclimats viticoles mondiaux et l’influence du mésoclimat sur la typicité de la Syrah et du Muscat de Hambourg dans le sud de la France: méthodologie de caractérisation. PhD dissertation, Ecole Nationale Supérieure Agronomique, Montpellier
Tonietto J, Carbonneau A (2004) A multicriteria climatic classification system for grape-growing regions worldwide. Agricultural and Forest Meteorology 124/1–2:81–97. https://doi.org/10.1016/j.agrformet.2003.06.001
Unger PW, Vigil MF (1998) Cover crop effects on soil water relationships. J Soil Water Conserv 53:200–207. https://www.jswconline.org/content/53/3/200
Valentini G, Allegro G, Pastore C, Colucci E, Filippetti I (2019) Post-veraison trimming slow down sugar accumulation without modifying phenolic ripening in sangiovese vines: post-veraison trimming of sangiovese vines. J. Sci. Food Agric. 99:1358–1365. doi: 10.1002/jsfa.9311
Van Leeuwen C, Destrac-Irvine A, Dubernet M, Duchêne E, Gowdy M, Marguerit E, Pieri P, Parker A, De Rességuier L, Ollat N (2019) An update on the impact of climate change in viticulture and potential adaptations. Agronomy. 9:514. doi: 10.3390/agronomy9090514
Vlăduț A, Onțel I (2013). Summer air temperature variability and trends within Oltenia Plain. Journal of the Geographical Institute "Jovan Cvijic" SASA 63(3):371–381. DOI: 10.2298/IJGI1303371V
Vlăduț A, Onțel I (2014) Analysis of precipitation characteristics and trends for the Getic Piedmont and Subcarpathians, Oltenia region, Romania. Forum Geografic – Studii şi cercetări de geografie şi protecţia mediului XIII (2):147–152. doi:10.5775/fg.2067-4635.2014.036.d
Vlăduţ A (2017) Analysis of the Mean of Daily Maximum Temperature within the Romanian Plain (1961–2015). Forum geografic– Studii şi cercetări de geografie şi protecţia mediului XVI(1):37–48. doi:10.5775/fg.2017.040.i
Vlăduţ A, Licurici M (2020) Aridity conditions within the region of Oltenia (Romania) from 1961 to 2015. Theor Appl Climatol 140:589–602. https://doi.org/10.1007/s00704-020-03107-5
White MA, Diffenbaugh NS, Jones GV, Pal JS, Giorgi F (2006) Extreme heat reduces and shifts United States premium wine production in the 21st century. Proc. Natl. Acad. Sci. USA 103:11217–11222. https://doi.org/10.1073/pnas.0603230103
Winkler AJ, Cook JA, Kliewer WM, Lider LA (1974) General Viticulture. 4th Edition, University of California Press, Berkley

Table 3 and 4 are available in the Supplementary Files section.

No competing interests reported.

Table34.docx

Download PDF

Journal Publication

published 14 Jul, 2023

Read the published version in Theoretical and Applied Climatology →

Editorial decision: Major revision
26 Feb, 2023
Reviews received at journal
04 Nov, 2022
Reviewers agreed at journal
29 Oct, 2022
Reviewers agreed at journal
27 Oct, 2022
Reviewers invited by journal
27 Oct, 2022
Editor assigned by journal
25 Oct, 2022
Submission checks completed at journal
25 Oct, 2022
First submitted to journal
25 Oct, 2022

You are reading this latest preprint version

Viticulture in Oltenia Region (Romania) in the New Climatic Context

Status:

Journal Publication

Version 1

Abstract

Figures

1. Introduction

2. Study Area, Data And Methods

2.1 Study area

2.3 Methods

2.3.1 Bioclimatic indices

2.3.2 Trend analysis

2.3.3 Interpolation

3. Results

3.1 Suitability of the climatic conditions for grapevine

3.2 Changes in the main climatic parameters and bioclimatic indices between 1961 and 2021

3.3 Trends of the main climatic parameters and bioclimatic indices

4. Discussions

5. Conclusions

Declarations

References

Tables 3-4

Additional Declarations

Supplementary Files

Status:

Journal Publication

Version 1