The grapevine is a key crop for Mediterranean environments and is both sensitive to climate warming and air pollutants, of which ozone is the most damaging to crop yield and quality. Ambient ozone effects on the grapevine have been noticed since the late fifties but risk assessments are still impaired by the lack of information concerning differences in cultivar sensitivity, and adaptation capacity to environmental factors including drought conditions. This study develops a specific parametrization for autochthonous grape cultivars within a leaf-level stomatal flux model, the DO3SE model, coupled with a meteorological and atmospheric chemical transport modelling system, the WRF-CHIMERE, by using a renowned wine producing area, the Douro wine region of Portugal, as case study. The DO3SE model parametrization introduced in this study included phenology, photosynthetic active radiation, air temperature, air vapour pressure deficit, and leaf water potential as a proxy of soil water content. The modelling experiments, which included simulations with the current default Convention on Long-Range Transboundary Air Pollution DO3SE parametrization and with the proposed parametrization, covered a reference grapevine growing season (from April to September 2017), during which a measuring campaign was carried out. Simulation results show that the proposed parametrization succeeded to replicate the observed grapevine leaf-level stomatal flux gradient in the region. Both field and modified DO3SE model values indicate that considerable areas in the Douro wine region of Portugal can exceed critical phytotoxic ozone dose (POD) values, although with a lower and different spatial extent when compared to the default DO3SE parametrization for the grapevine. However, under irrigated conditions, the POD values increase, and the values are close to those obtained with the default parametrization. Overall, the research results indicate that air quality management, in particular the reduction of ozone levels in the ambient air, must also be considered to define sustainable grape and wine production strategies in the context of climate and wine production management change.
Tropospheric ozone (O3) can strongly damage vegetation. Grapevines (Vitis vinifera L.), in particular, have intermediate sensitivity to ozone. Wine production is an important economic activity, as well as a pillar to the cultural identity of several countries in the world. This study aims to evaluate the risk of Douro vineyards exposure to ozone, by estimating its concentration and deposition in the Demarcated Region of Douro in Portugal. Based on an assessment of the climatology of the area, the years 2003 to 2005 were selected among the hottest years of the recent past, and the chemical transport model CHIMERE was used to estimate the three-dimensional field of ozone and its dry deposition over the Douro region with 1 km2 of horizontal resolution. Model results were validated by comparison with measured data from the European air quality database (AirBase). The exposure indicator AOT40 (accumulated concentration of ozone above 40 ppb) was calculated and an exposure–response function was applied to determine the grapevine risk to ozone exposure. The target value for the protection of vegetation established by the Air Quality Framework Directive was exceeded on most of the Douro region, especially over the Baixo Corgo and Cima Corgo sub-regions. The results of the exposure–response functions suggest that the productivity loss can reach 27% and that the sugar content of the grapes could be reduced by 32%, but these values are affected by the inherent uncertainty of the used methodology.
The grapevine (Vitis vinifera L.) is a crop with great cultural, economic and ecological relevance for Mediterranean environments besides being the fruit crop with largest acreage and economic value at the global scale. Its exposure to high levels of tropospheric ozone (O3) can result in phytotoxic effects and thus it is important to comprehensively re-evaluate these effects as well as related processes. A review of the validity and limitations of the standards used for the protection of vegetation in relation to ambient O3, the state-of the-art knowledge on O3 phytotoxic effects on the grapevine and the available means to assess its impact are presented and discussed. It is concluded that wide regions in the world, mainly between latitudes 30° and 50° N, where the grapevine has been traditionally cultivated, are exposed to O3 concentrations that can affect both the yield and quality of the grape. Recently reported studies for global cultivars such as Cabernet Sauvignon or Merlot, along publicly available maps on O3 standards to protect vegetation at the European and global scale, indicate potential yield reductions in the range of 20–31% and the quality of the grape can also be affected by reductions of total polyphenols in the range of 15–23% for these areas. Although a tendency to reduce ambient O3 levels has been registered since 2000 in the western European Mediterranean basin, the flux of O3 into the grapevine leaves could still exceed critical levels with phenological advancement driven by the increase of temperatures or interaction between O3 and other climatic variables such as drought or high summer light intensities. Higher O3 exposures are reported in western United States of America and eastern China, with this last region maintaining an increasing tendency in summer ambient O3 levels. It is still necessary to adopt common experimental and monitoring protocols to establish grapevine-specific O3 relationships and critical levels, as there is not yet a coherent and shared database for detailed risk assessment for this crop.
Ozone is the most damaging phytotoxic air pollutant to crop yield quantity and quality. This study presents the validation of a simulation with the WRF-CHIMERE modelling system in order to assess the risk of phytotoxicity by tropospheric ozone for an important and characteristic Mediterranean crop, i.e. the grapevine. The study region was the Douro wine region in Portugal, which is characterized by a rugged relief and a Mediterranean climate. The simulation covered a reference grapevine growing season in the Northern Hemisphere (from April to September 2017), during which a particular measuring campaign was also carried out. The validation of the meteorological simulations on a daily and hourly time resolution was performed based on data from three weather stations, namely on temperature, global solar radiation, relative humidity, wind speed and direction values. The ozone phytotoxicity was assessed with data from two measuring stations. A specific grapevine growth parameter based on monitored phenological observations was introduced for ozone stomatal uptake assessment. Concerning meteorology, validation statistics were acceptable and within the range of what has been found in other regional climate modelling simulations. Ground-level ozone-based values were calculated for a better assessment of the phytotoxic risk, in particular cumulative standards for vegetation protection. Stomatal flux estimates were within the range of those measured for the local cultivars in the field campaign when there was not severe water stress limitation. Both field and statistically adjusted model values indicate that considerable areas in the Demarcated Douro Region of Portugal can exceed the critical exposure values for vegetation according to current European legislation standards. Moreover, measured and simulated results indicate an ozone impact on grapevine yield and quality in the target region because the exposure- and flux-based indices exceed the criteria based on current open-top-chamber experimental knowledge.
Tropospheric ozone (O3) can damage vegetation, affecting productivity and quality of the crops. Vines, in particular, have an intermediate sensitivity to ozone. Moreover, an increase of ozone levels is foreseen under climate change scenarios. The Douro Demarcated Region is one of the most productive wine areas in Portugal; thus studying the ozone deposition over this region and assessing its potential effects is a nowadays concern. This work aims to evaluate the risk of Douro vineyards exposure to ozone in present and future climates. The chemical transport model CHIMERE, with a spatial resolution of 1 km2, fed by meteorological data from the WRF model, was applied for the years 2003–2005 (present climate), for 2049 and 2064 (mid-term future) and for 2096 and 2097 (long-term future). The assessment of the potential damage in terms of productivity and quality was done through the analysis of ozone deposition and the application of concentration-response functions. The exposure indicator AOT40 (accumulated concentration of ozone above 40 ppb) for the period established in the Air Quality Framework Directive 2008/50/CE was also estimated. The model results show, for present and future climate, that the AOT40 levels in the entire Douro region are above the target value for the protection of vegetation. The results of the exposure-response functions suggest that the tropospheric ozone levels in the future, in the region, would influence the quality and productivity of the wine.
Climate change is of major relevance to wine production as most of the wine-growing regions of the world are located within relatively narrow latitudinal bands with average growing-season temperatures (GSTs) limited to 13-21 degrees C. This study focuses on the incidence of climate variables and indices that are relevant both for climate change assessment and for grape production, with emphasis on grapevine bioclimatic indices and extreme events (e.g., cold waves, storms, heatwaves). Dynamical downscaling of European Reanalysis-Interim and Max Planck Institute Earth System low-resolution global simulations forced with a Representative Concentration Pathway 8.5 (RCP8.5) greenhouse gas emission scenario was performed with the Weather Research and Forecast (WRF) model to a regional scale including the Douro Valley of Portugal for recent-past (1986-2005) and future periods (2046-2065, 2081-2100). The number, duration and intensity of events were superimposed over critical phenological phases estimated by using a specific local grapevine varietal phenological model in order to assess their positive or negative implications for wine production in the region. An assessment of the relevance of climate parameters and indices and their progression in recent-past and future climate scenarios with regard to the potential impact on wine production was performed. Results indicate a positive relation between higher growing-season heat accumulations and greater vintage yields. A moderate incidence of very hot days (daily maximum temperature above 35 degrees C) and drought from pre-veraison phenological conditions have a positive association with vintage ratings. However, the mid- and long-term WRF-MPI RCP8.5 future climate scenarios reveal shifts to warmer and drier conditions, with the mean GST not remaining within range for quality wine production in the long-term future climate scenario. These results indicate potential impacts that suggest a range of strategies to maintain wine production and quality in the region.
In this work, bioclimatic parameters and indices relevant to the grapevine are estimated for the years 2000 (recent-pat), 2049 (medium-term future) and 2097 (long-term future), based on very high resolution (1 km × 1 km) MPI-WRF RCP8.5 climate simulations. The selected parameters and indices are the mean temperature during the grapevine growing season period (April to October, Tgs), the cumulative rainfall during the grapevine growing season period (Pgs), the Winkler index (WI), the Huglin heliothermic index (HI), the night cold index (CI) and the dryness index (DI). In general, a significant increase in mean temperature during the grapevine growing season period is observed, together with a significant decrease in precipitation. The recent-past WI is associated with the production of high-quality wines; the higher values predicted for the future represent intensive production of wines of intermediate quality. The HI shows the passage of a grapevine growing region considered as temperate-warm to a warm category of higher helio-thermicity. The recent-past CI indicates very cool conditions (associated with quality wines), while in the future there is a tendency for temperate or warmer nights. Finally, DI indicates an increase in water stress considered already high under the recent-past climate conditions. These results point to an increased climatic stress on the Douro region wine production and increased vulnerability of its vine varieties, providing evidence to support strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.
Climate change is of major relevance to wine production as most of the wine-growing regions of the world, in particular the Douro region, are located within relatively narrow latitudinal bands with average growing season temperatures limited to 13-21oC. This study focuses on the temporal variability of three grapevine bioclimatic indices, which are commonly used as part of the Geoviticulture Multicriteria Climatic Classification System (MCC) to classify the climate of wine producing regions worldwide. Dynamical downscaling of MPI-ESM-LR global data forced with RCP8.5 climatic scenario is performed with the Weather Research and Forecast (WRF) model to a regional scale including the Douro valley of Portugal for recent-past (19862005) and future periods (2046-2065; 2081-2100). Results indicate significant shifts towards warmer and dryer conditions during the growing season and higher night temperatures during the grape ripening period. An assessment on the statistical significance of the differences between the recent-past and the future scenarios and the potential impact on wine production in the study area is performed. These results will provide evidence for future strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way. Keywords— climate change, grapevine bioclimatic indices, wine production, Douro valley
Climate change is of major relevance to wine production as most of the wine-growing regions of the world, in particular the Douro region, are located within relatively narrow latitudinal bands with average growing season temperatures limited to 13–21°C. This study focuses on the incidence of climate variables and indices that are relevant both for climate change detection and for grape production with particular emphasis on extreme events (e.g. cold waves, storms, heat waves). Dynamical downscaling of MPI-ESM-LR global data forced with RCP8.5 climatic scenario is performed with the Weather Research and Forecast (WRF) model to a regional scale including the Douro valley of Portugal for recent-past (1986–2005) and future periods (2046–2065; 2081–2100). The number, duration and intensity of events are superimposed over critical phenological phases of the vine (dormancy, bud burst, flowering, véraison, and maturity) in order to assess their positive or negative implications on wine production in the region. An assessment on the statistical significance of climatic indices, their differences between the recent-past and the future scenarios and the potential impact on wine production is performed. Preliminary results indicate increased climatic stress on the Douro region wine production and increased vulnerability of its vine varieties. These results will provide evidence for future strategies aimed to preserve the high-quality wines in the region and their typicality in a sustainable way.
Total and extractable (5 extractants) Cu concentrations were determined in thirteen acid vineyards soils. Mean total copper concentration was 259 mg kg(-1) and most of the soil samples (87%) were above the upper limit allowed by the European Union for this element in soils. The largest Cu fraction was found to be that bound to soil organic matter, which accounted for 49% of the total Cu. None of the Cu fractions showed significant differences with depth. Nevertheless, bioavailable Cu (extracted in Na(2)-EDTA) was found to show a strong correlation with Cu bound to soil organic matter, which may indicate that Na(2)-EDTA is able to extract part of the organically bound Cu, resulting in an overestimation of bioavailable Cu. However, practices associated to soil use change and management affecting the stability of Cu organic complexes could induce an increase in bioavailable Cu levels in these soils.
Understanding spatial variations in climates that are crucial for crop suitability form the basis of zonation studies in viticulture. This research applies principal components analysis and cluster analysis to 39 climate stations in the Galician region of northwest Spain to examine the applicability for zonation in the region and produce a better understanding of the spatial climate structure in Galicia. Roughly 90 % of the spatial variation in climate types is explained by three main components, which are defined by precipitation, temperature, and frost risk variations across the region. The climate variables or indices most important for the Galician region include the three main indices (Huglin index, Dryness index, and Cool night index) used within the Multicriteria Climatic Classification System (Geoviticulture MCC System). The results provide evidence that the Geoviticulture MCC System, which was developed at the global scale, has tremendous applicability at the mesoscale. The identification of six climate types of the Geoviticulture MCC System, which are used quite extensively for wine growing in the region, depicts the great spatial diversity of viticultural potential found within the relatively small area of Galicia.
Arsenic fractionation has been studied in nine vineyard soils from a wine-producing area in Galicia (NW Spain) characterized by an unusually high As content. Total As concentrations are 7 to 10 times higher the maximum values allowed by the legislation, reaching maximum value of 200 mg kg(-1). The study of As fractionation revealed that those fractions showing strong correlations to crystalline Fe and Al hydrous oxides (r>0.69, p<0.01 and r>0.71, p<0.01 respectively) represented, on average, higher than the 80% of total As. The low levels of mobile and potentially toxic As fractions (<4% of total As) suggest that its toxicity is partially minimized in these soils, although the modifications induced by soil management could promote an increase of As availability.
The assessment of flash flood potential of wadi (dry river) systems in arid lands is often difficult because of the lack of sufficiently long rainfall and discharge records of the infrequent and spatially variable rainfall events. Characterization of active wadi systems by remote sensing may offer an alternative solution. A methodology is presented to characterize the channel infill of wadi systems based on the soil composition, and the geomorphic and geologic properties of drainage basins. Spectral mixture modeling is performed on a Landsat TM image to identify the source material (endmembers) and source upland area of the alluvial infill. Endmembers are determined by two methods: (1) identifying pure image pixels, and (2) using spectral libraries representing main rock units of the drainage basin. Both methods are evaluated in terms of their ability to establish the relative contribution of upland source rocks to the overall alluvium composition in the lowland. The identification of wadi systems that are presently most active (high stream-power values) and efficient in transporting sediments to the basin outlet may enable identification of areas prone to flash floods.