Importance of yam in the role of agrobiodiversity in Mayombe and Batéké Plateau ecozones in Democratic Republic of Congo

The Mayombe and Batéké Plateau ecozones of the Democratic Republic of Congo (DRC) are experiencing differentiated deforestation and forest degradation, together with a trend toward homogenization of their agricultural diversity. These may undermine efforts to sustainably reverse household food, nutrition, and livelihood insecurity. In this context, this study seeks to assess the importance of yam in the role of agrobiodiversity among populations in the two contrasting ecozones. A sample of 351 households was surveyed. A dataset of about 202 testimonies from six focus groups and observations in 86 peasant agroforestry fields was also analyzed using descriptive statistics, correlation and regression, and calculations of different indices of crop importance. Overall, plant, animal, and fish species represent respectively 60.9%, 26.7% and 12.4% of genetic resources. About 50 of 72 species of these resources are found in both study areas. Regarding the overall use of species, the five top-ranked species that were utilized as food included Manihot esculenta, followed by Arachis hypogaea, Zea mays, Dioscorea alata, and Musa acuminata. Living in the Mayombe ecozone increases the household's preference for growing yams by up to 5.7 times. Population density was correlated with agricultural diversity. Villages with a high population density showed greater crop diversity than those with a low population density. In short, yam remains an important but under-represented crop, the contribution of which could be increased to secure sustainable livelihoods through biodiversity-rich peasant agroforestry systems.