Patterns of endemism and ancestral areas of Hispaniolan Melastomes (Melastomataceae) and the role of the Massif de la Hotte in shaping diversity

Abstract Understanding biodiversity is critical for the proper conservation of ecosystems experiencing extreme stress from global change. Few other ecosystems are at such high risk of disappearing, especially due to logging and agricultural activities, as the Massif de la Hotte, a chain of mountains in Haiti on the island of Hispaniola, located within the Caribbean Biodiversity Hotspot. We used the hyperdiverse tropical plant family Melastomataceae to understand the biogeographical history and endemism patterns in a major hotspot for the family, the Massif de la Hotte, Haiti. Our goal was to determine the number, timing, and geographical origin of introductions of Melastomataceae (particularly Miconieae) into the Massif de la Hotte. We also aimed to identify whether the Massif de la Hotte and neighbouring ranges on Hispaniola and Cuba were so-called museums or cradles of biodiversity, and determine the extent that areas of high diversity and endemism overlap with currently conserved lands. In total, our analyses uncovered 19 independent dispersal events of Miconieae to the Massif de la Hotte. The Mecranium, Brevycima, and Meriania clades all had rapid radiations consisting of narrow endemics inferred to be of Massif de la Hotte origin. Species of the Chaenopleura clade in the Massif de la Hotte were mostly products of solitary dispersal events from eastern Cuba or the Massif de la Selle. The Massif de la Hotte endemics in the Caribbean Clade were largely the result of dispersal events from central and eastern Cuba. Eastern Cuba is also inferred as the ancestral area for many Massif de la Hotte endemic clades. A total of 25 10 × 10-km grid cells were found by CANAPE to contain significant endemism, with a high proportion of endemism hotspots over the Massif de la Hotte and eastern Cuba. Overlap of these significant CANAPE cells with currently protected areas was high (∼90%). Elucidating phylogenetic diversity and endemism patterns across the vastly different ecosystems of this biodiversity hotspot will aid in our understanding of how these biodiverse forests were formed.