Seed exchange networks as important processes for maize diversity conservation and seed access in a highland region of Mexico

Seed exchanges that smallholder households perform form networks that are central to in situ agrobiodiversity conservation. Sociodemographic factors such as market accessibility and household assets could be shaping the structure of these networks and impacting diversity, however formal evidence is scarce. Through surveys in nine rural communities in the Cofre de Perote highland region in Mexico, we modeled seed exchange networks for native maize and conducted a social network analysis followed by statistical modeling. Results show that access to urban centers is negatively related to the robustness of community networks. Within communities, households with bigger plots, more time producing, sufficient maize for self-consumption, and fewer members were able to save seeds for the next cropping season and were more likely to donate seeds. Additionally, households that exchanged more produced more maize morphotypes. We conclude that the maize seed networks under study are serving as seed reservoirs for families in case of scarcity, thus contributing to food security. They are also important for in situ agrobiodiversity conservation of six maize morphotypes. However, it is necessary to promote seed exchanges between households of communities with more access to urban centers, to strengthen networks, and preserve their maize diversity and seed scarcity-dampening function.