Effects of farmer social status and plant biocultural value on seed circulation networks in Vanuatu

Abstract

ABSTRACT. Seed circulation among farmers, which is embedded in composite social networks, is a key process in the dynamics of seed systems that shape crop diversity. We analyzed the daily circulation of biological objects, i.e., cultivated plants (31 species, 284 landraces), within a community of first-generation migrants (16 households, 30 persons) living on the island of Vanua Lava in the South Pacific archipelago nation of Vanuatu. By combining participant observation, ethnobiological inventories, and social network analysis, we investigated how farmer social status and plant biocultural value affect plant circulation. Plant biocultural value was estimated by referring to their local classification according to uses, cultivation practices, growing environments, and biological properties. An aggregate plant circulation network (577 events) and three subnetworks (i.e., for starchy, side dish, or snack food categories) sharing the same 30 nodes were analyzed using exponential random graph models. Evidence that farmer social status influences the patterns of plant circulation was found through the distribution of structural parameters of the network, including: dyadic reciprocity; in-degree, out-degree, and their correlation; triadic cycling; and transitivity. At the scale of the aggregate network, direct or indirect reciprocity was not observed. Instead, a high out-degree (i.e., being a more frequent giver) and a negative correlation between in-degree and out-degree both confer prestige and reinforce hierarchy. These results suggest that some of the social dynamics of the Melanesian-type Big Man political system may persist, even though the system itself no longer exists in traditional form. Moreover, based on our comparative analysis of the three subnetworks, farmer social status appears to influence greatly the circulation of plants with high biocultural value while having little influence on plants with low biocultural value. Farmer social status and plant biocultural value (following their local classification) are important factors for understanding the social rules shaping seed circulation.

Methodological advances for hypothesis‐driven ethnobiology

“…Gwodegree − (edges clustered > random) for prestige: success increases popularity + (edges clustered < random) for rarity: limited sharing maintains rarity (Labeyrie et al, 2015;Levy, 2016;Thomas & Caillon, 2016) Node connectivity variables Age (count) Nodeocov + for prestige: older individuals tend to be asked for knowledge (Henrich & Broesch, 2011;Bond & Gaoue, 2020) Knowledge (count or continuous) Nodeocov + for prestige: skillful individuals tend to be asked for knowledge (Henrich & Broesch, 2011;Santoro et al, 2020;Bond & Gaoue, 2020) Knowledge uniqueness score (continuous) Nodeocov + for rarity: because individuals with unusual information tend to be asked for knowledge (Bond & Gaoue, 2020) Node pair variables Spouse/kin (binary matrix) Edgecov + for homophily: spouses and genetically related people tend to share knowledge (Salali et al, 2016;Bond & Gaoue, 2020) Age (count) Absdiff − for homophily: peers tend to share knowledge (Salali et al, 2016) + for prestige: knowledge is more likely to be shared from older to younger (Henrich & Broesch, 2011) Knowledge (count or continuous) Absdiff − as control variable: individuals who say they share knowledge should have similar knowledge (Shalizi & Thomas, 2011;Santoro et al, 2020;Bond & Gaoue, 2020).…”

Networking agrobiodiversity management to foster biodiversity-based agriculture. A review

“…how farmers carefully evaluate trade-offs among its different contributions, some positive, some negative (Ango et al 2014), and also incorporate the complexity of their norms and values. Incentives for agrobiodiversity management rarely account for the diversity of local worldviews including social, spiritual and symbolic dimensions, while they affect a variety of domains of agrobiodiversity management including the spatial organization of crops in farmers' fields and in the landscape (Bonnemaison 1996), their selection beyond a purely utilitarian motivation (Caillon and Lanouguère-Bruneau 2005) and their circulation answering to social norms (Thomas and Caillon 2016).…”

Adoption and diffusion of technical capacity-building innovations by small-scale artisanal fishers in Fiji

“…Although a higher percentage of women shared knowledge about the new methods compared to men, our analysis indicated that knowledge sharing was comparable between men and women and was not significantly related to the other characteristics examined. Work by Thomas and Caillon (2016) on the sharing of valuable plant cultivars suggests that social status may influence the degree to which valuable knowledge is shared. Further, other likely factors of importance are the ease with which (1) new processing methods can be directly observed by others (Macintyre and Foale 2013), and (2) the benefits for adopters are discernible and/or communicated by them.…”