By Antoine Doncieux
Agrobiodiversity (i.e., agricultural diversity from gene to species and from fields to landscapes) is a promising nature-based solution in the pursuit of sustainable agriculture. A fast-growing literature in agroecology highlights the manifold benefits of crop diversification for farmers and agricultural landscapes, including greater wild biodiversity, ecosystem services delivery and more stable year-to-year production: in a diversified system, one crop may fail, but multiple failures are less likely. However, the modernization of agriculture combined with market demand and policies have led to the general homogenization of crop species and varieties across regions and an alarming loss of 75% of global agrobiodiversity have been reported since the 1900s.
Wine-growing systems are not exception. In particular, the increased focus of the global wine industry on a few major varieties (e.g., Chardonnay, Cabernet-Sauvignon) and varietal regulations (i.e., lists of permitted varieties) have narrowed grape diversity in vineyards. If drivers of grape diversity change are well-understood at national to global scales, little is known about local, past or anticipated trajectories that drive agrobiodiversity dynamics according to growers’ cultural values, practices and choices. At these large scales, countervailing trends may occur.
We used quantitative agricultural census data in order to describe and analyse the spatio-temporal dynamics in the diversity of grape varieties between 1960 and 2020 in Gaillac, a French wine-growing region located in the Tarn department (Figure 1). We compared the diversity of grapevine variety from 1960 to 2020 using diversity indexes widely used in ecology that account for both the number and the abundance of varieties. Then, we used a qualitative approach (review of historical documents and semi-structured interviews with 38 winegrowers) to decipher the drivers of change and future expectation for the next 30 years.
Figure 1. Location of the Gaillac wine-growing region. The delimitation of the terroirs is represented with very thick lines: a) Plaine du Tarn (silty-sandy soils), b) Rive droite (carved out of clay-limestone hills), c) Plateau cordais (limestone plateau), d) Rive gauche (high stony and rolled pebbles) and e) Cunac (red clay soil with gravel) terroirs.
By analysing changes in areas devoted to grapevine, number of farms, number and abundance (in ha) of varieties, we found radical transformation of the wine-growing system. In Gaillac, between 1960 and 2020, the wine-growing area decreased almost three-fold and the number of growers 22-fold; meanwhile, the number of varieties dropped from 211 to 62 (Table 1). A decrease in the range of the potential ripening period between the earliest and the latest grape varieties of two weeks between 1960 and 2020 was also reported.
Table 1. Characteristics of Gaillac at wine-growing and communal scales for 1960 and 2020
Overall, 174 grape varieties were discarded, mainly hybrids varieties (77.6% of the total grape varietal losses), which were originally cultivated in response to the phylloxera outbreak that devastated French vineyards at the end of the 19th century. While two varieties (Mauzac blanc for white varieties and Jurançon noir for red varieties) dominated the landscape in 1960, the distribution of the cultivated areas between the different grape varieties was more even in 2020 (Figure 2). Moreover, 37 grape varieties were common to both dates, of which some of them have experienced a sharp decline (e.g., Valdiguié) and others an overwhelmingly increase (e.g., Fer). Lastly, growers introduced 25 new varieties, including disease resistant varieties selected by research (e.g., Floreal) and varieties from other French wine-growing regions (e.g., Gamay from Beaujolais).
Figure 2. Grape varieties turnover between 1960 and 2020. Barplots are coloured depending on the ripening period of each variety: purple (early-season; < 237 DOY); green (mid-season (238-247); yellow (late-season; > 248 DOY) and grey (NA; missing values).
The investigation of archives and interviews revealed that growers account for external drivers (e.g., market changes, regulation and policy, technology, environmental; Table 2) but also cultural values when they choose which grape varieties to plant. These drivers can synergistically interact across times and spatial scales in order to increase and decrease both the number and the abundance of grape varieties.
Table 2. Documented drivers of change in grape diversity over the 1960-2020 period. Change: A, addition; M, maintenance; L, loss.
We further shown that grape diversity was maintained despite market integration as an insurance to spread production risk, mitigate market volatility, and to address environmental uncertainties. In addition, we described that some growers are continually on the lookout for alternative varieties and expressed a strong feeling about the importance of experimentation with new grape varieties in the area. Last but not least, growers’ habituation can lead to maintaining specific grape varieties and a reluctance to adopt new ones.
For the future, we expect that environmental factors may play a more important role in grape selection and planting sites regarding climate change issues. As a grower noted: “I want to plant Chenin […] But when I think about the evolution of the climate, I wonder if it is wise to plant Chenin in Gaillac, because it appreciates cool temperatures and it is sensitive to late-spring frost. […] Ten years ago, I would have done it without thinking about it”.
To conclude, wine-growing is often perceived as a fixed system, whereas it has never stopped adapting. To adapt to an ever-changing future, it is pivotal to pave the way for a dynamic grape diversity management involving collaborative relationships between growers, researchers, conservatories and institutions that control regulations.
Read the paper here: https://doi.org/10.20870/oeno-one.2022.56.4.5557
Antoine Doncieux holds a M.Sc. in Tropical Botany and Ethnoecology, 2018, University of Montpellier and AgroParisTech). He is currently (2019-2023) a Predoctoral Research Fellow of the AgrobiodiverSity for a food-Secure planeT (ASSET) project at CEFE-CNRS (France, Montpellier). He focus his Ph.D on the processes underlying grapevine diversity dynamics over time in the Gaillac wine-growing region (France) in the context of global change. His work aims to understand how and why winegrowers manage a wide diversity of grape varieties. Especially, he described the drivers underpinning grape varieties turnover, the motivations prevailing for grape varieties choice and the winegrowers’ social networks for acquiring information on agrobiodiversity (weed management, variety, rootstock and clone). His research is interdisciplinary at the crossroad between ecology, agronomy and human and social sciences by mixing quantitative and qualitative approaches (e.g. agricultural census analyses, surveys, social network analysis).
Description of the other authors of the study can be found here: