Christian Leclerc - Academia.edu (original) (raw)
Papers by Christian Leclerc
Cet article analyse l'attitude d'agriculteurs indiens du Kerala, qui nomment et caracteri... more Cet article analyse l'attitude d'agriculteurs indiens du Kerala, qui nomment et caracterisent differemment deux varietes hybrides de cocotier alors que ces deux varietes s'averent similaires, voire identiques, du point de vue genetique. La structure genetique du materiel vegetal implique est tout d'abord discutee. Les hybrides modernes et les hybrides naturels (spontanes) de cocotiers du Sud de l'Inde sont, a plus de 95%, issus des memes cultivars parentaux. Les selections phenotypiques realisees sur ces cultivars parentaux sont de faible efficacite; elles ne peuvent expliquer les differences considerables entre hybrides moderne et hybride spontane signalees par les agriculteurs. Les resultats sont ensuite interpretes selon les perspectives ouvertes par l'anthropologie des sciences. Celles-ci s'attachent moins aux qualites de la plante en tant que fait naturel qu'a ses qualites en tant que fait social defini a l'interieur d'un collectif. Si en...
Human Ecology
In Cameroon, the African plum tree (Dacryodes edulis [G. Don] H. J. Lam) is widely cultivated for... more In Cameroon, the African plum tree (Dacryodes edulis [G. Don] H. J. Lam) is widely cultivated for its fruits, which contribute significantly to household food security and economy. In order to analyze the links between the social and ecological systems that result in the remarkable fruit diversity, we focused on how the important varietal diversity of African plums was perceived and named by tree owners. We conducted semi‑structured interviews in Center-Cameroon with 142 people belonging to the Beti ethnic group, in urban (Yaoundé), peri-urban and rural areas, and analyzed the data qualitatively and quantitatively. Along this urbanization gradient linking production to consumption regions, 158 different translated names were recorded. Most names (80%) were cited once, but some names based on fruit size and taste were common across the gradient. Although the highest total number of names was recorded in the rural site, many different names were also found along the urban–rural gradie...
Towards Responsible Plant Data Linkage: Data Challenges for Agricultural Research and Development
This chapter argues for the importance of considering conceptual and normative commitments when a... more This chapter argues for the importance of considering conceptual and normative commitments when addressing questions of responsible practice in data-intensive agricultural research and development. We consider genetic gain-focused plant breeding strategies that envision a data-intensive mode of breeding in which genomic, environmental and socio-economic data are mobilised for rapid crop variety development. Focusing on socio-economic data linkage, we examine methods of product profiling and how they accommodate gendered dimensions of breeding in the field. Through a comparison with participatory breeding methods, we argue that the conceptual commitments underpinning current methods of integrating socioeconomic data into calculations of genetic gain can preclude the achievement of key social development goals, and that better engagement with participatory approaches can help address this problem. We conclude by identifying three key avenues towards a data-intensive approach to plant ...
Nature Communications, 2020
Sustainable food production in the context of climate change necessitates diversification of agri... more Sustainable food production in the context of climate change necessitates diversification of agriculture and a more efficient utilization of plant genetic resources. Fonio millet (Digitaria exilis) is an orphan African cereal crop with a great potential for dryland agriculture. Here, we establish high-quality genomic resources to facilitate fonio improvement through molecular breeding. These include a chromosome-scale reference assembly and deep re-sequencing of 183 cultivated and wild Digitaria accessions, enabling insights into genetic diversity, population structure, and domestication. Fonio diversity is shaped by climatic, geographic, and ethnolinguistic factors. Two genes associated with seed size and shattering showed signatures of selection. Most known domestication genes from other cereal models however have not experienced strong selection in fonio, providing direct targets to rapidly improve this crop for agriculture in hot and dry environments.
Springer International Publishing eBooks, Oct 27, 2022
Establishing linkage among data of diverse domains (e.g. biological, environmental, socio-economi... more Establishing linkage among data of diverse domains (e.g. biological, environmental, socio-economical, and geographical) is critical to address complex multidimensional issues such as food security or sustainable agriculture. The complexity of this challenge increases with the level of heterogeneity of the data but also with the social context of production of datasets, a dimension usually less considered. Building on the experience of a transdisciplinary project on the diversity of crop diversity management systems in West Africa (CoEx), this chapter reflects on the importance to better account for agency for more meaningful, responsible and
Ecology and Society, 2013
In studying indigenous climate knowledge, two approaches can be envisioned. In the first, traditi... more In studying indigenous climate knowledge, two approaches can be envisioned. In the first, traditional knowledge is a cultural built-in object; conceived as a whole, its relevance can be assessed by referring to other cultural, economic, or technical components at work within an indigenous society. In the second, the accuracy of indigenous climate knowledge is assessed with western science knowledge used as an external reference. However, assessing the accuracy of indigenous climate knowledge remains a largely untapped area. We aim to show how accurate the culturally built indigenous climate knowledge of extreme climatic events is, and how amenable it is to fuzzy logic. A retrospective survey was carried out individually and randomly among 195 Eastern African farmers on climatic reasons for loss of on-farm crop diversity from 1961 to 2006. More than 3000 crop loss events were recorded, and reasons given by farmers were mainly related to droughts or heavy rainfall. Chisquare statistics computed by Monte Carlo simulations based on 999 replicates clearly rejected independence between indigenous knowledge of drought and heavy rainfall that occurred in the past and rainfall records. The fuzzy logic nature of indigenous climatic knowledge appears in the clear association of drought or heavy rainfall events, as perceived by farmers, with corresponding extreme rainfall values, contrasting with a fuzzy picture in the intermediate climatic situations. We discuss how the cultural built-in knowledge helps farmers in perceiving and remembering past climate variations, considering the specificity of the contexts where extreme climatic events were experienced. The integration of indigenous and scientific climate knowledge could allow development of drought monitoring that considers both climatic and contextual data.
International Journal of Climatology, 2012
In tropical mountains, the way topographical gradients translate in terms of intra-seasonal and i... more In tropical mountains, the way topographical gradients translate in terms of intra-seasonal and interannual climate variability (especially rainfall and evapotranspiration) is relatively unknown, yet it is an important issue for agriculture and food security. The eastern slopes of Mount Kenya, in East Africa, with their wide range of agro-ecological conditions, are appropriate for the study of these aspects. Daily (monthly) rainfall data from 11 (24) stations at different elevations and exposures are collected for the period 1961-2006. For the elevation belts suitable for farming and agropastoral activities, mostly below 2000 m, it is found that not all rainfall characteristics co-vary with altitude. Four distinct behaviours are revealed: (1) Parameters which show a relatively regular increase/decrease with elevation. This is the case for the duration of the two rainy seasons found across the region, and the mean onset and cessation dates, (2) Parameters which show a relatively uniform pattern throughout the region, with little differences both horizontally and vertically. This applies to the interannual variability of the October-December seasonal rains, which are quite homogeneously modulated by Indian Ocean sea-surface temperatures (SSTs), (3) Parameters markedly influenced by exposure. This applies to daily rainfall intensities, which peak along the southeast-facing slopes, whatever the altitude. The frequency of rainy days shows both a vertical gradient and some influence of exposure, (4) Parameters which show very weak spatial coherence, or pronounced vertical discontinuities. This is obvious for the cessation date of the March-May rains, whose poorly organized interannual variability contrasts with that of the onset. Variables involved in potential evapotranspiration (ET 0) computation display either a strong (maximum temperature) or a weak (global radiation) vertical coherence, reflecting the existence/absence of an elevation control on the mean distribution of these variables. However, the interannual variations of global radiation have the strongest influence on those of ET 0 .
![Research paper thumbnail of So Close Yet So Different: Cultural Differences Among Farmers in Central Kenya Affect Their Knowledge of Sorghum (Sorghum bicolor [L.] Moench) Landrace Identification](https://attachments.academia-assets.com/93943200/thumbnails/1.jpg)
](Economic Botany, 2019
JrnlID 12231_ArtID 9453_Proof# 1-02/05/2019 marqueurs génétiques SSR. Des analyses basées sur des... more JrnlID 12231_ArtID 9453_Proof# 1-02/05/2019 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.
Agronomy for Sustainable Development, 2012
The circulation of seed among farmers is central to agrobiodiversity conservation and dynamics. A... more The circulation of seed among farmers is central to agrobiodiversity conservation and dynamics. Agrobiodiversity, the diversity of agricultural systems from genes to varieties and crop species, from farming methods to landscape composition, is part of humanity's cultural heritage. Whereas agrobiodiversity conservation has received much attention from researchers The positions and opinions presented in this article are those of the authors alone and are not intended to represent the views or scientific works of EFSA.
Agriculture and Human Values, 2013
Abstract The conservation of in situ crop diversity is a key issue to ensure food security. Under... more Abstract The conservation of in situ crop diversity is a key issue to ensure food security. Understanding the processes that shape it is crucial for efficiently managing such diversity. In most rural societies, crop diversity patterns are affected by farmers’ practices of seed exchange, transmission, and selection, but the role of social organization in shaping those practices has been overlooked. This study proposes an ecological anthropology approach to investigate the relation between crop diversity patterns and the social organization of Tharaka farmers in Kenya. The Tharaka are organized in neighborhood-groups, clans, and age-sets. We quantified the influence of these three major social institutions on crop diversity patterns, for both crop species and sorghum landraces. General linear models were used to test the relations between crop species richness and each social factor, while the crop species and sorghum landraces compositions of cropping systems were compared separately through a between-class correspondence analysis. Crop species and sorghum landraces are not randomly distributed among farms, and neighborhood-groups constitute a significant factor organizing crop diversity at both specific and infraspecific levels. Adjacent neighborhood-groups present significantly different crop richness and composition. The results for species were consistent with those obtained for sorghum landraces, confirming that crop diversity was socially structured. The influence of social organization on seed networks and selection processes is discussed.
Agronomy for Sustainable Development
Ethnobiology Letters
Agricultural diversification with neglected and underutilized species is a viable way to sustaina... more Agricultural diversification with neglected and underutilized species is a viable way to sustainably increase the productivity of agrosystems. Understanding the social, cultural, and ecological roles of these species is crucial for their promotion. White fonio (<em>Digitaria exilis</em>), a neglected cereal endemic to West African Sahelian countries, is recognized as a crop for the future due to its cultural, nutritional, and economic values. In this study, we described fonio farming systems in Senegal through an ethnobotanical approach. As expected in family farming systems, farmers largely practiced diversified subsistence agriculture on small plots and relied on local seed exchange networks. The importance of fonio varied among agroecological zones, ethnic groups, and gender. In the Groundnut Basin, where agriculture is more mechanized, late-maturing landraces of fonio are cultivated as a cash crop rather than a staple crop. However, in southern Senegal, where food sh...
Evolutionary Applications, 2016
Crop populations in smallholder farming systems are shaped by the interaction of biological, ecol... more 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 study, 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 populationbased 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 pollenand seed-mediated gene flow. On the contrary, sorghum varietal and genetic diversity showed geographic patterns, pointing to different ancestry of varieties, limited pollenmediated gene flow, and geographic patterns in seed-mediated gene flow. Social and ecological processes involved in shaping seed-mediated gene flow are further discussed.
Ethnies Droits De L Homme Et Peuples Autochtones, 1999
Plant Genetic Resources, 2016
Identification and characterization of the farmers’ named crop varieties cultivated around the wo... more Identification and characterization of the farmers’ named crop varieties cultivated around the world is a major issue for conservation and sustainable use of plant genetic resources. Intraspecific diversity is strongly determined by farmers’ socio-cultural environment, but this has little been documented. In this paper, we tested, on a contact zone among three ethnolinguistic groups located on the Mount Kenya region, whether farmers’ socio-cultural differences have an impact on the morphological characteristics of the farmers’ named sorghum varieties. Eighteen qualitative morphological traits of the panicles were measured. We first compared the morphological diversity of the named varieties among ethnolinguistic groups using multivariate analysis of homogeneity of groups’ dispersion and tested their differentiation using permutational multivariate analysis of variance. Discriminant analysis of principal components was then used to categorize the morphological diversity without a pri...
Proceedings of the National Academy of Sciences, 2015
Recent studies investigating the relationship between crop genetic diversity and human cultural d... more 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, particul...
Advances in Ecological Research, 2015
In this paper we develop new indicators and statistical tests to characterize patterns of crop di... more In this paper we develop new indicators and statistical tests to characterize patterns of crop diversity at local scales. Households growing a large number of species or landraces are known to contribute an important share of local available diversity of both rare and common plants but the role of households with low diversity remain little understood: do they grow only common varieties-following a nestedness pattern typical of mutualistic networks in ecology-or do 'diversity poor' households also grow rare varieties? This question is pivotal in ongoing efforts to assess the contribution of small farmers to global agrobiodiversity at local scales. We develop new network-based approaches to characterize the distribution of local crop diversity at the village level (species and infra-species) and validate these approaches using meta-data sets from 10 countries. Our results highlight the sources of heterogeneity in the local crop diversity. We often identify two or more groups of households based on their different levels of diversity. In some datasets, 'diversity poor' households significantly contribute to the local crop diversity. Generally, we find that the distribution of crop diversity is more heterogeneous at the species than at the infra-species level. This analysis reveals the absence of a general pattern of crop diversity distribution independent of agro-ecological and socio-cultural context.
Cet article analyse l'attitude d'agriculteurs indiens du Kerala, qui nomment et caracteri... more Cet article analyse l'attitude d'agriculteurs indiens du Kerala, qui nomment et caracterisent differemment deux varietes hybrides de cocotier alors que ces deux varietes s'averent similaires, voire identiques, du point de vue genetique. La structure genetique du materiel vegetal implique est tout d'abord discutee. Les hybrides modernes et les hybrides naturels (spontanes) de cocotiers du Sud de l'Inde sont, a plus de 95%, issus des memes cultivars parentaux. Les selections phenotypiques realisees sur ces cultivars parentaux sont de faible efficacite; elles ne peuvent expliquer les differences considerables entre hybrides moderne et hybride spontane signalees par les agriculteurs. Les resultats sont ensuite interpretes selon les perspectives ouvertes par l'anthropologie des sciences. Celles-ci s'attachent moins aux qualites de la plante en tant que fait naturel qu'a ses qualites en tant que fait social defini a l'interieur d'un collectif. Si en...
Human Ecology
In Cameroon, the African plum tree (Dacryodes edulis [G. Don] H. J. Lam) is widely cultivated for... more In Cameroon, the African plum tree (Dacryodes edulis [G. Don] H. J. Lam) is widely cultivated for its fruits, which contribute significantly to household food security and economy. In order to analyze the links between the social and ecological systems that result in the remarkable fruit diversity, we focused on how the important varietal diversity of African plums was perceived and named by tree owners. We conducted semi‑structured interviews in Center-Cameroon with 142 people belonging to the Beti ethnic group, in urban (Yaoundé), peri-urban and rural areas, and analyzed the data qualitatively and quantitatively. Along this urbanization gradient linking production to consumption regions, 158 different translated names were recorded. Most names (80%) were cited once, but some names based on fruit size and taste were common across the gradient. Although the highest total number of names was recorded in the rural site, many different names were also found along the urban–rural gradie...
Towards Responsible Plant Data Linkage: Data Challenges for Agricultural Research and Development
This chapter argues for the importance of considering conceptual and normative commitments when a... more This chapter argues for the importance of considering conceptual and normative commitments when addressing questions of responsible practice in data-intensive agricultural research and development. We consider genetic gain-focused plant breeding strategies that envision a data-intensive mode of breeding in which genomic, environmental and socio-economic data are mobilised for rapid crop variety development. Focusing on socio-economic data linkage, we examine methods of product profiling and how they accommodate gendered dimensions of breeding in the field. Through a comparison with participatory breeding methods, we argue that the conceptual commitments underpinning current methods of integrating socioeconomic data into calculations of genetic gain can preclude the achievement of key social development goals, and that better engagement with participatory approaches can help address this problem. We conclude by identifying three key avenues towards a data-intensive approach to plant ...
Nature Communications, 2020
Sustainable food production in the context of climate change necessitates diversification of agri... more Sustainable food production in the context of climate change necessitates diversification of agriculture and a more efficient utilization of plant genetic resources. Fonio millet (Digitaria exilis) is an orphan African cereal crop with a great potential for dryland agriculture. Here, we establish high-quality genomic resources to facilitate fonio improvement through molecular breeding. These include a chromosome-scale reference assembly and deep re-sequencing of 183 cultivated and wild Digitaria accessions, enabling insights into genetic diversity, population structure, and domestication. Fonio diversity is shaped by climatic, geographic, and ethnolinguistic factors. Two genes associated with seed size and shattering showed signatures of selection. Most known domestication genes from other cereal models however have not experienced strong selection in fonio, providing direct targets to rapidly improve this crop for agriculture in hot and dry environments.
Springer International Publishing eBooks, Oct 27, 2022
Establishing linkage among data of diverse domains (e.g. biological, environmental, socio-economi... more Establishing linkage among data of diverse domains (e.g. biological, environmental, socio-economical, and geographical) is critical to address complex multidimensional issues such as food security or sustainable agriculture. The complexity of this challenge increases with the level of heterogeneity of the data but also with the social context of production of datasets, a dimension usually less considered. Building on the experience of a transdisciplinary project on the diversity of crop diversity management systems in West Africa (CoEx), this chapter reflects on the importance to better account for agency for more meaningful, responsible and
Ecology and Society, 2013
In studying indigenous climate knowledge, two approaches can be envisioned. In the first, traditi... more In studying indigenous climate knowledge, two approaches can be envisioned. In the first, traditional knowledge is a cultural built-in object; conceived as a whole, its relevance can be assessed by referring to other cultural, economic, or technical components at work within an indigenous society. In the second, the accuracy of indigenous climate knowledge is assessed with western science knowledge used as an external reference. However, assessing the accuracy of indigenous climate knowledge remains a largely untapped area. We aim to show how accurate the culturally built indigenous climate knowledge of extreme climatic events is, and how amenable it is to fuzzy logic. A retrospective survey was carried out individually and randomly among 195 Eastern African farmers on climatic reasons for loss of on-farm crop diversity from 1961 to 2006. More than 3000 crop loss events were recorded, and reasons given by farmers were mainly related to droughts or heavy rainfall. Chisquare statistics computed by Monte Carlo simulations based on 999 replicates clearly rejected independence between indigenous knowledge of drought and heavy rainfall that occurred in the past and rainfall records. The fuzzy logic nature of indigenous climatic knowledge appears in the clear association of drought or heavy rainfall events, as perceived by farmers, with corresponding extreme rainfall values, contrasting with a fuzzy picture in the intermediate climatic situations. We discuss how the cultural built-in knowledge helps farmers in perceiving and remembering past climate variations, considering the specificity of the contexts where extreme climatic events were experienced. The integration of indigenous and scientific climate knowledge could allow development of drought monitoring that considers both climatic and contextual data.
International Journal of Climatology, 2012
In tropical mountains, the way topographical gradients translate in terms of intra-seasonal and i... more In tropical mountains, the way topographical gradients translate in terms of intra-seasonal and interannual climate variability (especially rainfall and evapotranspiration) is relatively unknown, yet it is an important issue for agriculture and food security. The eastern slopes of Mount Kenya, in East Africa, with their wide range of agro-ecological conditions, are appropriate for the study of these aspects. Daily (monthly) rainfall data from 11 (24) stations at different elevations and exposures are collected for the period 1961-2006. For the elevation belts suitable for farming and agropastoral activities, mostly below 2000 m, it is found that not all rainfall characteristics co-vary with altitude. Four distinct behaviours are revealed: (1) Parameters which show a relatively regular increase/decrease with elevation. This is the case for the duration of the two rainy seasons found across the region, and the mean onset and cessation dates, (2) Parameters which show a relatively uniform pattern throughout the region, with little differences both horizontally and vertically. This applies to the interannual variability of the October-December seasonal rains, which are quite homogeneously modulated by Indian Ocean sea-surface temperatures (SSTs), (3) Parameters markedly influenced by exposure. This applies to daily rainfall intensities, which peak along the southeast-facing slopes, whatever the altitude. The frequency of rainy days shows both a vertical gradient and some influence of exposure, (4) Parameters which show very weak spatial coherence, or pronounced vertical discontinuities. This is obvious for the cessation date of the March-May rains, whose poorly organized interannual variability contrasts with that of the onset. Variables involved in potential evapotranspiration (ET 0) computation display either a strong (maximum temperature) or a weak (global radiation) vertical coherence, reflecting the existence/absence of an elevation control on the mean distribution of these variables. However, the interannual variations of global radiation have the strongest influence on those of ET 0 .
Economic Botany, 2019
JrnlID 12231_ArtID 9453_Proof# 1-02/05/2019 marqueurs génétiques SSR. Des analyses basées sur des... more JrnlID 12231_ArtID 9453_Proof# 1-02/05/2019 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.
Agronomy for Sustainable Development, 2012
The circulation of seed among farmers is central to agrobiodiversity conservation and dynamics. A... more The circulation of seed among farmers is central to agrobiodiversity conservation and dynamics. Agrobiodiversity, the diversity of agricultural systems from genes to varieties and crop species, from farming methods to landscape composition, is part of humanity's cultural heritage. Whereas agrobiodiversity conservation has received much attention from researchers The positions and opinions presented in this article are those of the authors alone and are not intended to represent the views or scientific works of EFSA.
Agriculture and Human Values, 2013
Abstract The conservation of in situ crop diversity is a key issue to ensure food security. Under... more Abstract The conservation of in situ crop diversity is a key issue to ensure food security. Understanding the processes that shape it is crucial for efficiently managing such diversity. In most rural societies, crop diversity patterns are affected by farmers’ practices of seed exchange, transmission, and selection, but the role of social organization in shaping those practices has been overlooked. This study proposes an ecological anthropology approach to investigate the relation between crop diversity patterns and the social organization of Tharaka farmers in Kenya. The Tharaka are organized in neighborhood-groups, clans, and age-sets. We quantified the influence of these three major social institutions on crop diversity patterns, for both crop species and sorghum landraces. General linear models were used to test the relations between crop species richness and each social factor, while the crop species and sorghum landraces compositions of cropping systems were compared separately through a between-class correspondence analysis. Crop species and sorghum landraces are not randomly distributed among farms, and neighborhood-groups constitute a significant factor organizing crop diversity at both specific and infraspecific levels. Adjacent neighborhood-groups present significantly different crop richness and composition. The results for species were consistent with those obtained for sorghum landraces, confirming that crop diversity was socially structured. The influence of social organization on seed networks and selection processes is discussed.
Agronomy for Sustainable Development
Ethnobiology Letters
Agricultural diversification with neglected and underutilized species is a viable way to sustaina... more Agricultural diversification with neglected and underutilized species is a viable way to sustainably increase the productivity of agrosystems. Understanding the social, cultural, and ecological roles of these species is crucial for their promotion. White fonio (<em>Digitaria exilis</em>), a neglected cereal endemic to West African Sahelian countries, is recognized as a crop for the future due to its cultural, nutritional, and economic values. In this study, we described fonio farming systems in Senegal through an ethnobotanical approach. As expected in family farming systems, farmers largely practiced diversified subsistence agriculture on small plots and relied on local seed exchange networks. The importance of fonio varied among agroecological zones, ethnic groups, and gender. In the Groundnut Basin, where agriculture is more mechanized, late-maturing landraces of fonio are cultivated as a cash crop rather than a staple crop. However, in southern Senegal, where food sh...
Evolutionary Applications, 2016
Crop populations in smallholder farming systems are shaped by the interaction of biological, ecol... more 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 study, 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 populationbased 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 pollenand seed-mediated gene flow. On the contrary, sorghum varietal and genetic diversity showed geographic patterns, pointing to different ancestry of varieties, limited pollenmediated gene flow, and geographic patterns in seed-mediated gene flow. Social and ecological processes involved in shaping seed-mediated gene flow are further discussed.
Ethnies Droits De L Homme Et Peuples Autochtones, 1999
Plant Genetic Resources, 2016
Identification and characterization of the farmers’ named crop varieties cultivated around the wo... more Identification and characterization of the farmers’ named crop varieties cultivated around the world is a major issue for conservation and sustainable use of plant genetic resources. Intraspecific diversity is strongly determined by farmers’ socio-cultural environment, but this has little been documented. In this paper, we tested, on a contact zone among three ethnolinguistic groups located on the Mount Kenya region, whether farmers’ socio-cultural differences have an impact on the morphological characteristics of the farmers’ named sorghum varieties. Eighteen qualitative morphological traits of the panicles were measured. We first compared the morphological diversity of the named varieties among ethnolinguistic groups using multivariate analysis of homogeneity of groups’ dispersion and tested their differentiation using permutational multivariate analysis of variance. Discriminant analysis of principal components was then used to categorize the morphological diversity without a pri...
Proceedings of the National Academy of Sciences, 2015
Recent studies investigating the relationship between crop genetic diversity and human cultural d... more 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, particul...
Advances in Ecological Research, 2015
In this paper we develop new indicators and statistical tests to characterize patterns of crop di... more In this paper we develop new indicators and statistical tests to characterize patterns of crop diversity at local scales. Households growing a large number of species or landraces are known to contribute an important share of local available diversity of both rare and common plants but the role of households with low diversity remain little understood: do they grow only common varieties-following a nestedness pattern typical of mutualistic networks in ecology-or do 'diversity poor' households also grow rare varieties? This question is pivotal in ongoing efforts to assess the contribution of small farmers to global agrobiodiversity at local scales. We develop new network-based approaches to characterize the distribution of local crop diversity at the village level (species and infra-species) and validate these approaches using meta-data sets from 10 countries. Our results highlight the sources of heterogeneity in the local crop diversity. We often identify two or more groups of households based on their different levels of diversity. In some datasets, 'diversity poor' households significantly contribute to the local crop diversity. Generally, we find that the distribution of crop diversity is more heterogeneous at the species than at the infra-species level. This analysis reveals the absence of a general pattern of crop diversity distribution independent of agro-ecological and socio-cultural context.