A mangrove forest, also known as a mangrove swamp or mangal, is a type of wetland that occurs in coastal intertidal zones. Mangroves are a group of trees and shrubs that live in the coastal intertidal zone, and there are about 80 different species of mangrove trees. They grow mainly in tropical and subtropical latitudes because they cannot withstand freezing temperatures. Mangrove forests are characterized by depositional coastal environments, where fine sediments (often with high organic content) collect in areas protected from high-energy wave action.

Mangrove forests are important ecosystems that provide a variety of ecological functions, including runoff and flood prevention, storage and recycling of nutrients and wastes, cultivation and energy conversion. They also stabilize the coastline, reducing erosion from storm surges, currents, waves, and tides. The intricate root system of mangroves makes these forests attractive to fish and other organisms seeking food and shelter from predators. Mangroves are some of the only coastal plants that can live in saltwater, and when conditions are favorable, they cover the coastline in dense patches known as mangrove forests or swamps.

Mangroves are also important for the cycling and storage of carbon in tropical coastal ecosystems, sequestering approximately 24 million metric tons of carbon each year. They are one of the most productive and ecologically important ecosystems on earth, with rates of primary production equal to those of tropical humid evergreen forests and coral reefs. Mangroves are ecosystem engineers, forming their own ecosystem and providing habitat for several other species. The dual services of coastal protection and habitat for commercially important species make mangrove forests one of the most valuable ecosystems in the world.