In the rugged landscapes of southern Haiti, the Massif de la Hotte emerges as a beacon of botanical wonder, harboring an extraordinary concentration of plant species found nowhere else on Earth. This relatively young mountain range, having risen from a marine plateau only about six million years ago, defies traditional assumptions about biodiversity accumulation. Contrary to the notion that ancient mountains harbor the richest endemic flora, recent research reveals that the diversity of plants here reflects dynamic biogeographical processes shaped by both geological history and ecological interactions.
A recent study published in the Botanical Journal of the Linnean Society presents compelling evidence that the Massif de la Hotte’s exceptional plant diversity is closely linked to the dispersal capabilities of birds navigating the Caribbean. Using the melastome family—a group of shrubby plants renowned for their resilience and adaptability—as a focal point, researchers uncovered patterns of seed dispersal and species evolution that challenge previous notions about island biogeography. Their findings highlight a complex network of avian-mediated seed transportation routes, notably a recurrent corridor between eastern Cuba and southwestern Hispaniola.
The mechanism behind this floristic exchange lies in the anatomy and ecology of melastome plants. These species produce small, berry-like fruits with seeds highly resistant to digestive processes. Birds feeding on these fruits inadvertently act as carriers, transporting viable seeds across daunting expanses of open ocean—flights spanning more than a hundred miles. One striking example detailed in the study describes a successful dispersal event approximately 1.6 million years ago, where a bird consumed Miconia fruits in southern Cuba and deposited the seeds in the mountainous Tiburon Peninsula. This founding individual of Miconia in Hispaniola subsequently radiated into 18 endemic species, predominantly concentrated in Massif de la Hotte.
This biogeographical connectivity suggests that the Caribbean islands, often regarded as isolated ecosystems, experience significant gene flow facilitated by avian vectors. In addition to Cuba and Hispaniola, melastomes have also migrated among Jamaica, Puerto Rico, and even the Lesser Antilles, tracing ancient flight routes that have shaped the region’s floristic composition. These inter-island migrations are not random but seem preferentially directed along specific pathways shaped by both migratory bird behavior and ecological suitability of habitats.
The evolutionary success of melastomes in the Massif de la Hotte is further underscored by their unique adaptations to challenging edaphic conditions. The mountainous terrain is dominated by limestone substrates with high pH calcareous soils, environments typically inhospitable to most plants. Intriguingly, some melastome groups appear to be descendants of populations originally adapted to serpentine soils in eastern Cuba—a soil type notorious for heavy metal toxicity. This ecological preadaptation likely conferred a competitive advantage, enabling melastomes to colonize and thrive in the calcium-rich, nutrient-poor landscapes of the newly emergent mountain range.
The evolutionary timelines delineated in the study were reconstructed using DNA sequencing techniques on 102 Hispaniolan melastome species, enabling precise phylogenetic trees cross-referenced with fossil age data. These dating analyses reveal a complex mosaic of speciation events spanning millions of years, disproving the simplistic view of a sole ancient lineage populating the range. Instead, the Massif de la Hotte hosts a dynamic assembly of species arising from multiple dispersal and divergence episodes, each imprinting upon the region’s floristic fabric.
Beyond the biological intricacies, the study casts a sobering light on the conservation status of this biodiversity hotspot. La Hotte’s forests, despite official protections within Pic Macaya National Park, have suffered severe deforestation—approximately 75% loss—primarily due to human activities including charcoal production for subsistence. This environmental degradation, coupled with escalating climatic shifts, imperils the endemic plant communities whose altitudinal niches are narrow and increasingly constrained.
Historically, botanical exploration in Hispaniola owes much to the early 20th-century efforts of Swedish botanist Erik Ekman, whose painstaking field collections documented thousands of specimens under arduous conditions. Ekman’s pioneering work laid the foundation for contemporary studies and inspired subsequent expeditions in the 1980s, notably coordinated by the Florida Museum of Natural History. These later surveys, which included leading experts such as Walter Judd, renewed scientific focus on the island’s botanical wealth, contributing invaluable herbarium collections still instrumental for current genetic and ecological analyses.
The geological context of the Massif de la Hotte further elucidates the mechanisms of diversification found there. Emerging from a marine limestone platform through tectonic uplift, the massif’s topography encompasses a gradient from sinkhole-riddled karst foothills to cloud forests and pine savannahs at higher elevations. Each habitat mosaic provides niches that foster speciation and endemism. Notably, high-altitude melastomes exhibit heightened rates of endemism, suggesting elevation-linked speciation patterns sensitive to climatic parameters.
Beyond taxonomy and biogeography, this research integrates interdisciplinary perspectives, combining molecular phylogenetics, historical geology, and avian ecology to decode the evolutionary narrative of an insular flora. It also underscores the pivotal role of seed dispersal as an evolutionary driver, mediated by mutualisms between plants and birds—a theme resonant across island ecosystems worldwide. Understanding such dynamics is not only academically enriching but vital for informed conservation strategies, particularly in the face of anthropogenic pressures and global climate change.
This comprehensive investigation into the patterns of melastome endemism and ancestral areas within Hispaniola exemplifies how modern analytical methods can unravel the complex evolutionary histories underpinning biodiversity hotspots. The insights have broader implications for island biogeography, illustrating how relatively recent geological formations can harbor rich, endemic biotas through repeated colonization and adaptive radiation. Moreover, it accentuates the fragile connectivity between species and environments—a relationship increasingly threatened in a rapidly changing world.
As the species within the Massif de la Hotte face mounting threats from habitat loss and climatic instability, their evolutionary resilience and ecological uniqueness underscore an urgent need for heightened conservation efforts. Protecting these plants entails not only preserving the physical habitat but also maintaining the biological corridors—particularly avian ones—that sustain the flows of life that have shaped the Caribbean’s rich botanical heritage.
Subject of Research: Plant biodiversity and biogeography in the Massif de la Hotte, Hispaniola, focusing on melastome species and their dispersal patterns.
Article Title: Patterns of endemism and ancestral areas of Hispaniolan Melastomes (Melastomataceae) and the role of the Massif de la Hotte in shaping diversity
News Publication Date: 9-Nov-2025
Web References: http://dx.doi.org/10.1093/botlinnean/boaf084
Image Credits: Florida Museum photo by Lucas Majure
Keywords: Biodiversity, Endemic species, Plant sciences, Biogeography, Birds, Science history, Islands, Evolution
