Tropical dry forests are ecosystems characterized by distinct wet and dry periods. Temperatures remain consistently warm, but these forests experience several months of drought, during which many trees shed their leaves to conserve water. This deciduous nature is a defining characteristic, allowing plant life to adapt to limited moisture. Tropical dry forests are ecologically important, supporting diverse plant and animal species adapted to this fluctuating environment. They contribute significantly to global biodiversity, harboring many endemic species.
Global Distribution Patterns
Tropical dry forests are globally distributed across tropical and subtropical latitudes, primarily concentrated between 10° and 23° North and South of the equator. These ecosystems span multiple continents: the Americas, Africa, Asia, and Australia. The Americas, particularly South and Central America, contain over half of the world’s tropical dry forests. They also extend into various Caribbean Islands. In Africa, these forests are found across wide areas, including west, central, and interior regions, as well as Madagascar. The Indo-Asian Pacific realm also hosts significant expanses, encompassing parts of India, Southeast Asia, Indonesia, New Guinea, and Pacific Islands.
Key Regional Examples
Within the Americas, tropical dry forests are found in Mexico, extending southward through Central America. Countries like Costa Rica and Nicaragua host notable remnants. South America features extensive tropical dry forests, including the Caatinga biome in northeastern Brazil, which is recognized as the continent’s largest continuous dry forest. Other South American examples include the Chaco region, spanning parts of Brazil, Argentina, Paraguay, and Bolivia, along with areas in western Ecuador, northern Peru, northern Colombia, and Venezuela.
In Africa, tropical dry forests are widespread, notably in the Sudano-Zambezian region and on the island of Madagascar. The Miombo woodlands, a type of tropical dry forest, are concentrated in lower elevations across central and eastern highlands of the continent. Asia’s tropical dry forests include tracts in India, such as the South Deccan Plateau and Coromandel Coast. Southeast Asia also contains vast dry forests in Indochina, encompassing parts of Thailand, Laos, Vietnam, and Myanmar. Northern Australia and New Caledonia also feature tropical dry forest ecosystems, often dominated by eucalyptus species adapted to seasonal dryness.
Climatic and Geographic Determinants
These forests thrive in areas characterized by consistently warm temperatures year-round. A defining climatic condition is the pronounced seasonality of rainfall, with a long dry season lasting anywhere from three to nine months. During this period, precipitation is significantly reduced. Annual rainfall in these regions generally ranges from 250 to 2,000 mm, with the majority occurring during a distinct wet season.
Geographic features also play a substantial role in determining their location. Many tropical dry forests are found in areas affected by rain shadow effects, where mountain ranges block moisture-laden winds, leading to drier conditions on their leeward sides. Proximity to coastlines or mountain ranges can create localized microclimates that support these ecosystems. Tropical dry forests typically occur at lower elevations, though some pockets can be found at higher altitudes in specific regions.