Background & Summary

The Protected Designation of Origin (PDO) label is a European Union (EU) quality scheme that protects products made within closely defined areas, under specific physical and biological conditions and using strictly defined production practices1,2. In the overall list of products that are registered and protected by the EU, wine plays a major role and includes the largest share of recognized PDO (65%)3. The 1177 European wine PDO comprise 21 countries and a broad range of wine products, including still, sparkling, and liquor wine. As such, PDO viticulture and winemaking represent a key socioeconomic activity4, for instance, in 2018 more than 81 million hl of PDO wine were produced, with an export business value of around 9 billion €5.

The quality scheme for PDO wines was set up to protect the unique characteristics of specific wine products and to promote their high quality6. It includes strict regulations regarding cultivation and production processes together with the definition of the area where the grapes must be cultivated. For example, a PDO regulation may require that wines are exclusively produced from traditional vine cultivars of a region, or that they are aged for a certain amount of time in wooden barrels. To be labelled as a PDO product, a wine needs to be formally recognized by the European commission, which requires applicants to establish a direct link between the quality attributes of the product and its geographical origin7. In this process, the producers need to elaborate a detailed documentation that specifies the production requirements of each wine product, i.e., the product specification, and summarize it in a stand-alone report, the so-called single document. Once a wine product is recognized and registered as a PDO, the product specification along with the single document can only be amended after presenting specific reasons why the changes are required8. The documents produced during the application and all eventual amendments are published online in the official EU indication register eAmbrosia, that represents the legal repository of all the geographical indications for agri-food production, wine and spirits registered and protected in the EU9,10.

Because of the strong relation between PDO wines and the specific conditions and production practices defined during the application process, these products are highly vulnerable to any changes in the climatic, environmental, or economic conditions in the production area1,11. For example, warmer climate conditions are already affecting the growing suitability of several cultivars, posing significant challenges to many labelled wine products from PDO regions12,13,14,15,16. Moreover, the introduction of alien pest species from other wine growing areas is endangering the health of vines, requiring vineyard managers to use new agricultural practices for pest control17,18,19. Economic and social preferences, on the other hand, are pushing for a more sustainable management of vineyards encouraging many European winegrowers to adopt new production practices, such as organic viticulture20,21,22. All these factors are impacting wine PDO throughout Europe and are often in conflict with the regulations defined in the application documents. For instance, to maintain their quality standards, PDO areas may need to use new production practices that are different from those specified in the regulatory documents. For this reason, there is a need to thoroughly plan and develop specific adaptation strategies that consider the local conditions and legal regulations of single PDO1,23. However, such strategies require knowledge about the legal specifications that characterize each PDO, which is currently only available in the regulatory documents of each wine PDO and not as a harmonized dataset.

Here, we present the first geospatial inventory of regulatory information for all 1177 PDO areas across Europe (as of 04.11.2021). We collected, standardized and spatialized a set of regulatory information from the EU indications register eAmbrosia and aggregated it in a harmonized dataset. This information is intended to be a fundamental support to inform research and decision making in the field of viticulture. For instance, crop modellers can use the information to model possible scenarios of climate impacts and adaptation in wine PDO areas. Agronomists can suggest new wine growing strategies by comparing information about different PDO, and decision makers can plan possible actions to improve high quality grapevine production.

Methods

Extraction and standardization of the information from the legal documents was carried out during the period March 2021 – November 2021 using the EU geographical indication register eAmbrosia as a source3. The last time we checked for any changes to the legal documents of the PDO regions was on 04.11.2021; PDO areas or amendments that were published after this date are therefore not included in the present dataset. We focused on all PDO recognized in the EU and the United Kingdom. The two main steps of the process were: (1) the spatialization of the wine PDO cultivation areas and (2) the selection and standardization of regulatory information for each PDO (Fig. 1). Team members were fluent in Italian, French, German, Spanish, Portuguese, and English. The knowledge of these languages was helpful, because in most cases the regulatory documents are provided in the language of the country where the PDO is located and 80% of European wine PDO are located in Italy, France, Germany, Austria, Spain and Portugal. In case the team was not fluent in the language of a document, we had to use Regulation (EU) No 1308/201310 and the commission implementing regulation (EU) 2019/3324 and 349. These documents specify the rules for PDO regulation in the EU and the guidelines to write the application as PDO for wine products, respectively, and are translated in all the EU languages. We used them to find relevant keywords in the different EU languages that we were not fluent with and then used these keywords to find the relevant information in the regulatory documents. This was necessary for part or all of the PDOs located in Bulgaria, Belgium, Croatia, Cyprus, Czech Republic, Greece, Hungary, Romania, Slovakia and Slovenia. If any of the official documents were not available in the eAmbrosia register, we searched on dedicated websites for each country or contacted the related governmental institution to obtain the missing information.

Fig. 1
figure 1

Conceptual diagram of the methodology and data formats used to build the inventory. (1) Spatialization: mapping of the municipalities included in the wine PDOs, creation of a .gpkg spatial dataset. (2) Regulatory information: extraction and harmonization of selected regulatory information, creation of two different .csv datasets one with a focus on the PDO level and the other with a focus on the categories of wine products in each PDO.

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STEP 1: spatialization of PDO cultivation areas

In the vast majority of legal documents, the PDO area was defined by including a list of municipalities where the cultivation of grapes for the PDO wines is allowed. For this reason, we georeferenced the wine PDO areas using the administrative boundaries at the municipal scale provided by the EuroRegionalMap dataset (© EuroGeographics 202225) as the minimum mapping unit. For each PDO, we copied the municipality names from the legal document one-by-one, manually extracted the corresponding boundaries in the geographic dataset, merged all the single municipalities and finally exported the PDO boundary as a single shapefile. For countries where the EuroRegionalMap did not include information on the municipality boundaries, we used administrative boundaries from other repositories26,27. This was necessary for Bulgaria, Hungary, Slovenia, Romania, Denmark, United Kingdom and Greece. In some cases, the documentation provided a detailed outline of the boundaries of the PDO area but did not include any reference to the municipality, typically only indicating specific landscape features such as roads and rivers. In these cases, we manually selected the relevant municipalities using satellite images from various sources (e.g., Esri28, Google Earth29) as a reference. Once we obtained the municipal polygons that together constitute the total PDO cultivation area, we dissolved them first to have a single polygon per PDO and then merged each single PDO together to build a unified spatial dataset (Fig. 2). The steps to spatialize the PDO areas were carried out using the QGIS30, ArcGIS31 and R32 software.

Fig. 2
figure 2

Overview of the area covered by the 1177 PDO included in the inventory. Non-European countries are represented by the striped pattern, we included United Kingdom as it was part of the EU until recently (© EuroGeographics for the country boundaries38).

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STEP 2: extraction of PDO regulatory information

In the second step, we extracted a set of regulatory information from the official documents in the eAmbrosia portal. The available information was heterogenous between the single EU countries, with some of them providing very detailed information while others provided only very little information. We collected only regulatory information that was available for all included countries and could be standardized among all PDO areas. Therefore, we had to exclude a set of information such as the training system, chemical composition of wines (e.g., sugars and acid contents), organoleptic profiles and alcoholic strength. For some PDO areas, mostly those located in Italy and France, we also found that more detailed regulations regarding planting densities or yields are available, that are specified depending on varieties, wine product or even topographic conditions (e.g., localization in steep slopes). We aggregated information from more detailed regulations to the same level of detail as in the other countries. The selected regulatory information that we extracted is presented in Table 1, including the methodology that was used for standardization. To extract the regulatory information from the legal documents and insert them into our dataset, we copied the relevant entries and pasted them in a dedicated spreadsheet table before proceeding with their standardization, using the Excel software33.

Table 1 Regulatory information included in our inventory dataset.
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Once all the regulatory information for the European wine PDOs was gathered, we aggregated them either based on their PDO identifier (PDOid field) or based on the wine product information (Category_of_wine_product field). This was necessary because we wanted to provide both, a dataset that gives an overview of the wine PDOs in Europe and their main characteristics, and a dataset that is dedicated to wine products. Therefore, two distinct files were compiled:

  1. I.

    A dataset containing 1177 entries, one for each PDO. It gives an overview of the main regulatory information, including the maximum yield, the minimum planting density and a list field with all the authorized vine varieties in a PDO. All the data regarding the remaining regulatory information are included in full detail.

  2. II.

    A dataset containing 1983 entries, with a focus on the wine products of each PDO. It includes information about maximum yield and minimum planting density per category of wine product that is produced in each PDO. The authorized vine varieties for each category of wine product are specified in a list field. All the data regarding the remaining regulatory information are fully included.

Table 2 summarizes some of the information gathered in STEP 1 and STEP 2. Figure 3 represents a selection of key variables included in our inventory for different countries.

Table 2 Summary of some characteristics gathered in the geospatial inventory, aggregated at the country level. PDO (n°): total number of PDOs per country; Municipalities (n°): number of municipalities within PDO regions per country; PDO area (km²): area of the municipalities within PDO regions per country; Cultivated varieties (n°): number of varieties allowed for cultivation in the PDOs of a country; Wine products (n°): number of wine products that can be produced in the PDOs of the respective country; CLC vineyards included in PDO boundary [%]: the percentage of vineyards from the Corine Land Cover35 that is included in the PDO area, the “−” symbol indicates countries for which no vineyard was present in the Corine Land Cover dataset. Percentages have been rounded.
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Fig. 3
figure 3

Selection of key variables included in our inventory for different countries. (a) Maximum allowed yield, (b) number of vine varieties per PDO, (c) minimum allowed planting density, (d) possibility to use irrigation. PDO areas are represented in red in the overview map and in dark grey in the inset maps. The points in the maps represent the centroids of the PDO regions.

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Data Records

We present an easily accessible and freely available inventory for the current wine PDO areas in the EU, comprising geospatial information as well as a set of regulatory information that can be used by researchers and decision makers. The data is freely available through the Figshare data publisher34.

It includes a geospatial file that contains the boundaries of the analysed PDO and two .csv files that contain the regulatory information aggregated either based on the PDO identifier or based on the category of wine product. The .csv files were saved using commas (“,”) to separate the columns, and a point (“.”) as decimal separator. Both .csv files are saved using utf-8 encoding. The files included in the inventory are:

  1. 1.

    EU_PDO.gpkg: a geopackage file that includes the boundaries for each of the 1177 PDO areas defined in the regulatory documents from eAmbrosia. The join between the spatial features and the other files is guaranteed by the common field PDOid.

  2. 2.

    PDO_EU_id.csv: a .csv file that includes the regulatory information outlined in Table 1 aggregated based on the PDO (PDOid field).

  3. 3.

    PDO_EU_cat.csv: a .csv file that includes the regulatory information outlined in Table 1 aggregated based on the category of wine product (Category_of_wine_product field).

Technical Validation

We spatialized and gathered the regulatory information about wine PDO in Europe based on the official geographical indication register eAmbrosia, that constitutes the legal basis for PDO designation in the EU. In many cases, more than 90% of all the vineyards identified by the Corine Land Cover35 map are also included in the spatialized wine PDO areas (Table 2). For each PDO, we provide the reference to the official documents from which the data was created, allowing the user to cross check pieces of information with ease. Throughout the spatialization of the PDO and the collection of related regulatory information, spot checks were conducted at various stages of the progress to verify that mistakes had been kept to a minimum.

Usage Notes

Given the amount of information included in our inventory and its coverage, this dataset will be particularly useful for researchers and decision makers in the field of viticulture. For example, the knowledge of regulatory information, such as the planting density, yield, and vine variety, can be used by researchers to calibrate crop models and generate projections of phenology and water stress indicators in PDO areas12. The results of these models can be compared to the characteristics of the authorized vine cultivars planted in a PDO to develop adaptation solutions for climate change such as the inclusion of new vine cultivars or the authorization of irrigation in the regulatory documents19. Analysing the contents of PDO documents and the related amendments can also improve our understanding of the critical factors that determine the sustainability and reputation of PDO regions. For example, Marescotti et al.7, studied the amendments of protected geographical indications in the fruit and vegetable sector and found that there is a strong need to introduce more environmental criteria in the regulatory documents, and Scozzafava et al.36, analysed how a change in PDO regulations can promote the premium products from a wine PDO region.