Paper short abstract:

We test the role of evolutionary, bioclimatic and sociocultural drivers in generating landscape patterns of enset landrace diversity, and parallels with cultural diversity patterns. Our findings underline the value of indigenous agrisystems for illuminating interactions between humanity and nature.

Paper long abstract:

Global patterns of agrobiodiversity differ from wild biodiversity, therefore it is unclear whether they are generated by similar processes. Understanding these processes is key to mapping and maintaining agrobiodiversity hotspots, and supporting our transition to sustainable global food systems. Here, we survey drivers of enset genetic and vernacular landrace diversity in the Ethiopian Highlands. Enset (Ensete ventricosum) is a giant clonally propagated monocarpic herb, closely related to bananas, that provides a starch staple for 20 million people. Despite a broad wild distribution, it has a remarkably restricted region of cultivation, yet smallholder farmers cultivate hundreds of distinct landraces across diverse climatic and agroecological systems, with up to 20 on a single farm. Combining vernacular and genetic diversity data from across hundreds of farms within a mixed-effects modelling framework, we investigate the relative importance of evolutionary, bioclimatic and sociocultural drivers in generating observed patterns of enset landrace diversity at multiple scales. The resulting enset diversity map is a key tool to guide agrobiodiversity conservation and germplasm management, monitor erosion of intra-specific diversity, and catalyse development of neglected regional staple. These results, and their parallels with regional patterns of cultural diversity, shed new light on the domestication of enset and underline the value of indigenous agrisystems for illuminating long term interactions between humanity and nature that generates the agrobiodiversity upon which we depend.