Hispaniolan dry forests

Hispaniolan dry forests
Name	Hispaniolan dry forests
Biome	Tropical and subtropical dry broadleaf forests
Countries	Dominican Republic; Haiti

Hispaniolan dry forests are a mosaic of seasonally dry tropical and subtropical broadleaf forests on the island of Hispaniola shared by the Dominican Republic and Haiti. They occupy lowland rain-shadow basins, coastal plains, and xeric valleys adjacent to the Cordillera Central, Sierra de Bahoruco, and Massif de la Selle, forming a distinct ecoregion important for endemic flora and fauna and for the historical development of settlements such as Santo Domingo, Port-au-Prince, and Barahona. The forests have experienced extensive conversion for agriculture, ranching, and urbanization since contact during the Columbian Exchange, with ongoing conservation attention from groups including World Wildlife Fund and national agencies like the Secretaría de Estado de Medio Ambiente y Recursos Naturales.

Overview and geography

The ecoregion spans parts of the southern and southwestern coastal plains of Hispaniola, encompassing basins near Bay of Samaná, Enriquillo Basin, Gulf of Gonâve, and the Yaque del Sur River valley, and lies adjacent to the Hispaniolan moist forests and Hispaniolan pine forests. Major urban centers and ports such as Santo Domingo and Les Cayes border or intrude into dry forest remnants, while protected areas including Parque Nacional Jaragua, Parque Nacional Sierra de Bahoruco, and Parque Nacional Lago Enriquillo contain critical habitat. The geology includes limestone karst of the Cayuco Formation, marl and alluvial plains, and rift basins associated with the Enriquillo-Plantain Garden fault zone and the tectonic setting that produced the Hispaniola orogeny, influencing soil salinity and drainage that favor xeric-adapted communities.

Climate and ecology

Climate is strongly seasonal, with pronounced dry seasons controlled by the subtropical ridge and trade winds such as the Northeast trade winds, and episodic rainfall from Caribbean hurricanes and tropical cyclones like Hurricane Flora shaping disturbance regimes. Mean annual precipitation typically ranges from arid levels near the Bahía de Neiba to semi-arid values in the Artibonite Valley, with evaporation and xericity intensified by proximity to the Hispaniola rain shadow. Soils include calcareous rendzinas, alluvial sediments, and saline flats, supporting adaptations to drought, salinity, and fire; ecological processes link to Caribbean-wide biogeographic patterns studied by institutions such as the Smithsonian Tropical Research Institute and the University of Puerto Rico.

Flora and vegetation communities

Vegetation is characterized by low, drought-deciduous canopy, thorn scrub, and cactus-rich successional assemblages dominated by genera like Prosopis, Larrea, and Haematoxylum relatives, with widespread thorny shrubs including Acacia species and spiny legumes such as Caesalpinia. Forest patches contain dry-forest trees related to taxa recorded in floristic surveys by the New York Botanical Garden and the Missouri Botanical Garden, including species allied to Bursera, Tabebuia, and Ficus lineages, and succulents like members of the Agave and Opuntia clades. Coastal mangrove stands of Rhizophora mangle and Avicennia germinans fringe some dry forest zones, while saline lagoons support halophytic communities influenced by sea-level change studies undertaken by researchers at the Woods Hole Oceanographic Institution.

Fauna and endemic species

Faunal assemblages include endemic reptiles such as the Hispaniolan hutia and the Hispaniolan solenodon in dry-forest refugia, avifauna like the Hispaniolan parakeet, Hispaniolan trogon, and dryland specialists noted by ornithologists at the Cornell Lab of Ornithology, and invertebrates with restricted ranges described in monographs from the American Museum of Natural History. Mammalian survivors include insectivores and bats recorded in surveys by the Caribbean Conservation Corporation, while herpetofauna such as Anolis lizards and endemic geckos persist in scrub and rocky outcrops cataloged by the Florida Museum of Natural History. The ecoregion provides critical habitat for migratory species protected under agreements like the Migratory Bird Treaty Act through stopover and wintering resources near coastal wetlands.

Human impacts and land use

Anthropogenic transformation accelerated during colonial and post-colonial eras tied to plantation agriculture associated with commodities like sugarcane and coffee cultivated under economic forces linked to actors in French colonial empire and Spanish Empire histories, and later expansions producing livestock ranching and charcoal production for urban centers including Port-au-Prince and Santo Domingo. Deforestation for charcoal was documented in analyses by organizations such as USAID and Food and Agriculture Organization projects, while rural livelihoods in regions like Dajabón Province and South Department, Haiti drive ongoing clearing for subsistence farming. Infrastructure developments including the Carretera Sánchez and coastal ports have fragmented habitat, and land tenure disputes rooted in policies from eras of the Trujillo Era and competing post-independence administrations complicate resource governance.

Conservation and management strategies

Conservation approaches combine establishment of protected areas like Parque Nacional Jaragua and Parque Nacional Sierra de Bahoruco with community-based initiatives supported by NGOs such as Hispaniola Conservation Foundation and international donors including the Global Environment Facility. Restoration projects emphasize reforestation using native species promoted by botanical institutions including the Missouri Botanical Garden and capacity-building through universities like the Universidad Autónoma de Santo Domingo and the Université d'État d'Haïti. Cross-border cooperation has involved bilateral dialogues between ministries of environment and programs run with multilateral partners such as the Inter-American Development Bank to address watershed management, agroforestry, and alternative livelihoods, while conservation scientists draw on remote sensing work from NASA and climate models from the Intergovernmental Panel on Climate Change to prioritize climate-resilient corridors and restoration of dryland carbon stocks.

Category:Ecoregions of the Caribbean