Abstract
Haitian Coffee-based agroforestry systems (CAFS) are important contributors to rural livelihoods and provide several ecosystem services, despite facing significant challenges. They contribute to households’ economic resilience and food security, but also to the maintenance of natural processes and biodiversity conservation. There has been little scientific study of these systems and the genetic composition and variety mixtures of their coffee plots. To that end, we sought to characterize the agrobiodiversity and genetic resources of historically important coffee growing regions of northern and southern Haiti.We sampled 28 CAFS to capture the local diversity of cultivated coffee and performed KASP-genotyping of SNP markers and HiPlex multiplex amplicon sequencing for haplotype calling. By comparing field samples to reference specimens from international collections using genetic structure analyses, we assigned them to one of five varietal groups, both traditional and more recent. We also identified inter-varietal hybrids. Our analyses revealed considerable genetic diversity in Haitian farms, higher in fact than many farmers realized.We then compared this diversity (also using KASP genotyping) to that found across coffee-growing regions of Guadeloupe, as well as their respective bioclimatic contexts, and investigated the historical determinants of the islands’ genetic resources. By contrast to Haiti’s complex varietal mixtures, only two Arabica groups occurred in Guadeloupe. The traditional Typica variety is still present on both islands, growing across a variety of climatic environments. We also found C. canephora on both islands, with multiple likely origins, and identified C. liberica var. liberica in Guadeloupe. Overall, Guadeloupe experienced fewer, but older introductions of non-Typica coffee while several recent introductions took place in Haiti, driven by local and global factors and reflecting the history of Arabica varietal development and spread.We also characterized the broader agrobiodiversity of 39 Haitian farms (including the genotyped ones). To that end, CAFS typologies were established using variables pertaining to coffee genetic diversity, stand structure and injury profiles, shade tree and associated crop diversity, bioclimate, and delivery of ecosystem service related to coffee performance, species and nutritional diversity, tree uses, carbon storage, and nitrogen availability. Associations between typologies were investigated. Surveyed coffee plots were generally varietally diverse, aging, and subject to pest and diseases. Most CAFS occurred on a spectrum of farm regeneration (old to renewed coffee plots) tied to the adoption of “modern” coffee varieties, with implications for ecosystem services. We described 3 distinct ecosystem service bundles delivered by CAFS, focused on maximizing subsistence, coffee performance, and tree utility, respectively.