My latest research article (co-authored with Chris McCarty and Charles Clement) is to be published in the December 2013 issue of Current Anthropology. It’s already available ahead of print through JSTOR. This is the abstract:
Social exchange networks play a critical role in the maintenance and distribution of crop diversity in smallholder farming communities throughout the world. The structure of such networks, however, can both support and constrain crop diversity and its distribution. This report examines varietal distribution of the staple crop manioc among rural households in three neighboring caboclo communities in Brazilian Amazonia. The results show that the centrality of households in exchange networks had no significant correlation with the number of manioc varieties maintained by households. However, household centrality did show a significant correlation with households’ perceived knowledge of manioc cultivation as well as the total area of manioc they cultivated. Although households with the most knowledgeable and active producers played a central role in the distribution of planting materials and manioc varieties, they did not maintain higher varietal diversity than more peripheral households in this study. This case study represents an important example of how social networks can constrain varietal distribution and contribute to low crop diversity in agricultural communities.