The dense, evergreen tropical forest of the hot, wet equatorial belt, found near the Equator where high temperatures and heavy rainfall occur throughout the year.
- Occurs roughly within 5 to 10° of the Equator: the Amazon basin (South America), the Congo basin (Africa), and the islands of South-East Asia (Indonesia, Malaysia).
- Climate is hot and wet all year, with temperatures around 27° Celsius and annual rainfall often over 2,000 mm, and very little seasonal variation; afternoon convectional rain is typical.
- Vegetation is broadleaf evergreen, multi-layered (emergent, canopy, understorey, forest floor), with hardwoods such as mahogany, ebony, and rosewood, and abundant epiphytes and lianas.
- The richest biodiversity on Earth, called the "lungs of the planet" (especially the Amazon) for its role in oxygen production and carbon storage.
- Soils are surprisingly poor because heavy rain leaches nutrients; most nutrients are held in the vegetation, so cleared land loses fertility quickly.
The location (Amazon, Congo, South-East Asia), the year-round hot-wet climate, the multi-layered evergreen structure, and the climate-change importance of these carbon sinks are recurring world-geography and environment facts.
Equatorial rainforest is evergreen with no real dry season; the tropical monsoon forest, found further from the Equator, is deciduous and sheds leaves in the dry season. Despite lush growth, equatorial soils are infertile due to leaching.
Hot-wet evergreen forest near the Equator (Amazon, Congo, South-East Asia); the most biodiverse biome and a major carbon sink, but on poor leached soils.