Keywords: Agroecology, agrobiodiversity, ethnoecology, landscape ecology, adaptation and resilience
Small-scale agriculture sustains the livelihoods of most of the population in the tropics, and produces an estimated 50 % of the food calories at the global scale. This form of agriculture largely depends from the management of agrobiodiversity, including crop diversity, the diversity of auxilliaries organisms that spontaneously colonize agroecosystems, such as pollinators or pest predators, and the diversity of associated knowledge systems.
Scholars increasingly call for getting a better understanding of the role played by agrobiodiversity in the resilience of agroecosystems in the face of global changes, especially climatic ones. Their is especially a lack of knowledge concerning how smallholder farmers use and manage agrobiodiversity at the local scale to adapt, and how the local management systems affect the availability and accessibility of this resource for small farms. Such understanding is crucial to build agricultural development policies and initiatives that fit smallholders' specific needs for adaptation.
My research aims to address this gap by :
i. documenting the changes in agrobiodiversity and in its management implemented by smallholder farmers over time, and analyzing the interplay between their different drivers ;
ii. analyzing the local agrobiodiversity management systems, including farmers' practices, knowledge, and their interactions with a diversity of stakeholders, and exploring their impacts on the dynamics of this ressource. I am especially developing research on the social networks involved in the circulation of biological resources(e.g., crops), and of the knowledge concerning their management.
As a researcher in the SENS research group, I contribute in developing multi-actor
companion modeling approaches for sharing knowledge, enhancing the dialogue between different stakeholders, and exploring scenarios for agrobiodiversity management to enhance agroecosystems' resilience.
I am also actively involved in the interdisciplinary GDR ReSoDiv network that aims at developing statistical methods based on network models for the study of agrobiodiversity dynamics.
I am currently conducting research on crop diversity trajectories in diversified agroecosystems in Madagascar (SoLDivA project), and Senegal (CoEx project). I also contribute to the LICCI (Local Indicators of Climate Change Impact) project, coordinated by Victoria Reyes-Garçìa from ICTA, Universitat Autònoma de Barcelona.
The role of crop diversity in climate change adaptation:
insights from local observations to inform decision making in agriculture
Labeyrie, V., Renard, D., Aumeeruddy-Thomas, Y., Benyei, P., Caillon, S., Calvet-Mir, L., M. Carrière, S., Demongeot, M., Descamps, E., Braga Junqueira, A., Li, X., Locqueville, J., Mattalia, G., Miñarro, S., Morel, A., Porcuna-Ferrer, A., Schlingmann, A., Vieira da Cunha Avila, A. & Reyes-García, V. (2021). The role of crop diversity in climate change adaptation: insights from local observations to inform decision making in agriculture. Current Opinion in Environmental Sustainability, 51, 15-23.
Homogenization of crop portfolios from the field to the global scale is raising concerns about agricultural adaptation to climate change. Assessing whether such trends threaten farmers’ long-term adaptive capacity requires a thorough understanding of changes in their crop portfolios, identification of the drivers of change, and the implications such changes have for local nutrition and food production. We reviewed the available literature on farmers’ reports of climate-driven crop changes. Small-scale farmers tend to adopt water-demanding crops, even in areas where models predict that reduced rainfall will reduce yields. The adoption of horticultural cash-crops combined with the abandonment of subsistence cereals modifies farmers’ nutritional inputs in terms of calories and nutrients, potentially undermining their food security. Farmers’ knowledge contributes to understand trends in crop diversity and support the design of strategies for adaptation to climate change.
Networking agrobiodiversity management to foster biodiversity-based agriculture. A review
Vanesse Labeyrie, Martine Antona, Jacques Baudry, Didier Bazile, Örjan Bodin, Sophie Caillon, Christian Leclerc, Christophe Le Page, Sélim Louafi, Juliette Mariel, François Massol, Mathieu Thomas.
Biodiversity-based agriculture is the main form of agriculture practiced by smallholder farmers, who produce half the world’s food, especially in the Global South. This form of agriculture relies on planned biodiversity intentionally managed by farmers and on the associated biodiversity that spontaneously colonizes the agroecosystem. In recent decades, there have been increasing calls from researchers and society to support biodiversity-based agriculture as an alternative paradigm to today’s industrial agriculture. Building adapted governance and management systems for enhancing farmers’ access to agrobiodiversity is a key challenge for the development of biodiversity-based agriculture. To achieve this, a better understanding of how farmer’s access agrobiodiversity is needed, and in particular, how this access is affected by interactions between farmers and with institutions, i.e., social networks. In this article, we first review the literature on the role of social networks in farmers’ access to agrobiodiversity, in the form of crop diversity and associated biodiversity, and the related knowledge to manage this diversity. This review points at a major knowledge gap concerning how the composition and structure of these networks affect farmers’ access to agrobiodiversity. Then, we review literature on social-ecological networks to identify how this framework developed for environmental management could contribute in getting a better understanding of the role of social networks’ structure and composition in farmers’ access to agrobiodiversity. Based on this review, we propose a social-ecological network framework dedicated to crop diversity. Finally, we present potential applications of this framework to develop new participatory approaches for agrobiodiversity management and governance, adapted to biodiversity-based agriculture.
Labeyrie, V., Thomas, M., Muthamia, Z. K., & Leclerc, C. (2016). Seed exchange networks, ethnicity, and sorghum diversity. Proceedings of the National Academy of Sciences, 113(1), 98-103.
Recent studies investigating the relationship between crop genetic diversity and human cultural diversity patterns showed that seed exchanges are embedded in farmers’ social organization. However, our understanding of the social processes involved remains limited. We investigated how farmers’ membership in three major social groups interacts in shaping sorghum seed exchange networks in a cultural contact zone on Mount Kenya. Farmers are members of residence groups at the local scale and of dialect groups clustered within larger ethnolinguistic units at a wider scale. The Chuka and Tharaka, who are allied in the same ethnolinguistic unit, coexist with the Mbeere dialect group in the study area. We assessed farmers’ homophily, propensity to exchange seeds with members of the same group, using exponential random graph models. We showed that homophily is significant within both residence and ethnolinguistic groups. At these two levels, homophily is driven by the kinship system, particularly by the combination of patrilocal residence and ethnolinguistic endogamy, because most seeds are exchanged among relatives. Indeed, residential homophily in seed exchanges results from local interactions between women and their in-law family, whereas at a higher level, ethnolinguistic homophily is driven by marriage endogamy. Seed exchanges and marriage ties are interrelated, and both are limited between the Mbeere and the other groups, although frequent between the Chuka and Tharaka. The impact of these social homophily processes on crop diversity is discussed.
Past and present dynamics of sorghum and pearl millet diversity in Mount Kenya region
Labeyrie, V., Deu, M., Dussert, Y., Rono, B., Lamy, F., Marangu, C., Kiambi, D., Calatayud, C., Coppens d’Eeckenbrugge, G., Robert, T. & Leclerc, C. (2016). Past and present dynamics of sorghum and pearl millet diversity in Mount Kenya region. Evolutionary Applications.
Crop populations in smallholder farming systems are shaped by the interaction of biological, ecological and social processes, occurring on different spatiotemporal scales. Understanding these dynamics is fundamental for the conservation of crop genetic resources. In this paper we investigated the processes involved in sorghum and pearl millet diversity dynamics on Mount Kenya. Surveys were conducted in ten sites distributed along two elevation transects and occupied by six ethnolinguistic groups. Varieties of both species grown in each site were inventoried and characterized using SSR markers. Genetic diversity was analyzed using both individual and population based approaches. Surveys of seed lot sources allowed characterizing seed-mediated gene flow. Past sorghum diffusion dynamics were explored by comparing Mount Kenya sorghum diversity with that of the African continent. The absence of structure in pearl millet genetic diversity indicated common ancestry and/or important pollen and seed-mediated gene flow. On the contrary, sorghum varietal and genetic diversity showed geographic patterns, pointing to different ancestry of varieties, limited pollen-mediated gene flow, and geographic patterns in seed-mediated gene flow. Social and ecological processes involved in shaping seed-mediated gene flow are further discussed.
Labeyrie, V., Deu, M., Barnaud, A., Calatayud, C., Buiron, M., Wambugu, P., ... & Leclerc, C. (2014). Influence of ethnolinguistic diversity on the sorghum genetic patterns in subsistence farming systems in Eastern Kenya. PLoS One, 9(3), e92178.
Summary (in french):
Understanding the effects of actions undertaken by human societies on crop evolution processes is a major challenge for the conservation of genetic resources. This study investigated the mechanisms whereby social boundaries associated with patterns of ethnolinguistic diversity have influenced the on-farm distribution of sorghum diversity. Social boundaries limit the diffusion of planting material, practices and knowledge, thus shaping crop diversity in situ.
To assess the effect of social boundaries, this study was conducted in the contact zone between the Chuka, Mbeere and Tharaka ethnolinguistic groups in eastern Kenya. Sorghum varieties were inventoried and samples collected in 130 households. In all, 297 individual plants derived from seeds collected under sixteen variety names were characterized using a set of 18 SSR molecular markers and 15 morphological descriptors. The genetic structure was investigated using both a Bayesian assignment method and distance-based clustering. Principal Coordinates Analysis was used to describe the structure of the morphological diversity of the panicles. The distribution of the varieties and the main genetic clusters across ethnolinguistic groups was described using a non-parametric MANOVA and pairwise Fisher tests.
The spatial distribution of landrace names and the overall genetic spatial patterns were significantly correlated with ethnolinguistic partition. However, the genetic structure inferred from molecular makers did not discriminate the short-cycle landraces despite their morphological distinctness. The cases of two improved varieties highlighted possible fates of improved materials. The most recent one was often given the name of local landraces. The second one, that was introduced a dozen years ago, displays traces of admixture with local landraces with differential intensity among ethnic groups. The patterns of congruence or discordance between the nomenclature of farmers’ varieties and the structure of both genetic and morphological diversity highlight the effects of the social organization of communities on the diffusion of seed, practices, and variety nomenclature.
So Close Yet So Different: Cultural Differences Among Farmers in Central Kenya Affect Their Knowledge of Sorghum (Sorghum bicolor [L.] Moench) Landrace Identification
Labeyrie, V., Kamau, J.I, Dubois, C., Perrier, X.& Leclerc, C. (2019). So Close Yet So Different: Cultural Differences Among Farmers in Central Kenya Affect Their Knowledge of Sorghum (Sorghum bicolor [L.] Moench) Landrace Identification. Economis Botany.
Whether knowledge of landrace identification is shared among farmers in rural societies is a matter of debate in crop diversity research, and the influence of culture on knowledge heterogeneity remains largely misunderstood. This study analyzes the heterogeneity of farmers’ knowledge of crop landrace identification, and investigates factors involved in its patterns. It especially explores the effect of cultural differences by comparing how three ethnolinguistic groups identify and name sorghum diversity in the Mount Kenya region. A set of 293 panicles representing sorghum diversity in the study area was presented for identification to 96 farmers randomly selected in the three groups. A subset of 287 panicles was scored for morphological characteristics using 16 qualitative descriptors, and neutral genetic diversity of 170 of them was described using 18 SSR genetic markers. Distance-based analyses were applied to analyze knowledge patterns within and between groups and to describe the structure of sorghum morphological and genetic diversity. Results show that the degree of heterogeneity of knowledge among farmers varies strongly according to both their ethnolinguistic membership and panicle characteristics, despite their high geographic proximity. The effect of farmers’ experience of landraces and of pathways for social learning on inter-individual variations of knowledge is discussed.
Un débat majeur dans le domaine de l’étude de la diversité cultivée est de savoir si l'identification des variétés locales est consensuelle au sein des sociétés rurales. L’influence des facteurs culturels sur l'hétérogénéité des connaissances reste en effet largement méconnue dans ce domaine. Cet article analyse l'hétérogénéité des connaissances des agriculteurs concernant l'identification des variétés de sorgho cultivées dans une localité de la région du Mont Kenya, et examine l'effet des différences culturelles en comparant comment trois groupes ethnolinguistiques identifient les différents morphotypes de sorgho. Un échantillon de 293 panicules représentant la diversité du sorgho dans la zone d'étude a été présenté pour identification à 96 agricultrices sélectionnées au hasard dans les trois groupes. Les caractéristiques morphologiques d’un sous-ensemble de 287 panicules ont été évaluées à l'aide de 16 descripteurs qualitatifs, et la diversité génétique neutre de 170 d'entre elles a été décrite au moyen de 18 marqueurs génétiques SSR. Des analyses basées sur des mesures de distance ont été utilisées pour analyser l’hétérogénéité des connaissances au sein des groupes et entre eux, et pour décrire la structure de la diversité morphologique et génétique du sorgho. Les résultats montrent que le degré d'hétérogénéité des connaissances des agriculteurs varie fortement selon qu’ils appartiennent ou non aux même groupe ethnolinguistique et ce malgré leur grande proximité géographique, et qu’il varie aussi en fonction des caractéristiques des panicules. Le rôle de l'expérience des agriculteurs concernant les différentes variétés et de l'apprentissage social sont finalement discutés.
So Close Yet So Different: Cultural Differences Among Farmers in Exploring farmers' agrobiodiversity management practices and knowledge in clove agroforests of Madagascar
Mariel, J., Carrière, S. M., Penot, E., Danthu, P., Rafidison, V., & Labeyrie, V. (2021). Exploring farmers' agrobiodiversity management practices and knowledge in clove agroforests of Madagascar. People and Nature, 3(4), 914-928.
Talks, Teaching and Tutorial
LICCI Training: crop diversity trends group
Documenting crop diversity trends in relation with climate change based on local knowledge.
Quelle contribution des savoirs locaux à la recherche sur le changement climatique ?
Illustration sur les dynamiques de la diversité des plantes cultivée
Présentation lors du séminaire au DBEV, Université d’Antananarivo le 3 octobre 2019.
Actor networks and biodiversity-based agriculture
Talk at the International Conference of the French Society of Ecology (SFE), Rennes, October 2018.
R Tutorial: Crop diversity analysis
Bases on our data published in PLOS One
coming soon ...
R Tutorial: Seed sharing network Analysis
Based on our data on seed circulation published in PNAS
coming soon ...
Agroecologist and ethnobiologist, PhD
Researcher at UMR SENS (Savoirs, Environnement et Sociétés), January 2016 – Present
PhD at UMR AGAP, DDSE group, 2010 – 2013