Tropical Biomes: Their Classification, Description and Importance

Abstract

Tropical biome classifications are mainly based on climate, the structure and function of plant communities, and soil type, with climate being the most frequently used criterion. The most common climate classification systems are the Koppen-Geiger system, which is composed of 5 groups, and Holdridge Life Form classifications, which consist of 38 classes. The Koppen-Geiger system classification is calculated from long term averages of temperature and precipitation at annual, seasonal and monthly time-scales to delineate climatic zones, whereas the Holdridge system uses rainfall and temperature as the main determinants of vegetation type in a given location. Biome classification is also based on soil nutrient status and function of the system. These classification systems have allowed researchers to describe the major biomes that are encountered the tropics, including the Amazon Basin, the Congo Basin, the Borneo-Mekong Basin, and Oceania. Tropical biomes include forests, savannas, mosaics of forest-crop and forest-savanna, woodlands and other plant formations. Tropical savannas include savanna woodlands, savanna parkland, savanna grassland, low tree and scrub savanna, and scrub communities. Tropical forests include mangroves, dense evergreen forests, semi-deciduous, transitional, gallery and fresh swamp forests. In mountainous areas around the equator, tropical cloud forests occur. These dense evergreen forests are located at elevations between 2000 and 3500 m in humid, marine, and equatorial conditions. Tropical forests are significant carbon sinks; they also harbor biodiversity hotspots, and provide agricultural land for people living around or inside these forests. Forest products contribute significantly to tax revenues and the gross domestic products of tropical countries.