Essay - Characteristics of a Biome (Tropical Rainforest)

  • A tropical forest is a forest of very tall trees found in regions of year-round heat, plentiful rainfall and high humidity (they have no dry seasons at all)

  • Tropical rainforests are found between 0° and 5° north and south of the equator

  • Their locations can be broken roughly into three geographical areas in the world:

  1. Central America & the Amazon Basin in Brazil

  2. The Congo Basin in Africa

  3. The Indo-Malaysia west coast of India, south-east Asia, New Guinea and Queensland in Australia

  • They exist in tropical climates where the weather is always very hot, wet and humid. Average temperatures hover between 27°C and 34°C. The sun is high in the sky all year round as these regions all lie near the equator. As a result, the sun’s rays hit the earth at a high angle, heating the surface intensely and leading to high levels of evaporation. These elevated levels of evaporation result in convectional rainfall every day. This means that annual rainfall amounts total approximately 6600mm but may very between 2,000mm and 10,000mm. Humidity levels fluctuate between 77% and 88% on a daily basis. There are no seasons and there are equal hours of daylight and darkness every single day (12 hours each).

  • A great variety of vegetation exists in the rainforest, with four distinct layers:

  1. The emergent layer - Consists of the tops of the tallest trees, ranging from 40m to 80m in height. These giant trees have straight smooth trunks with few branches, except near the top. The trees are spaced far apart with umbrella shaped outlines that grow well above the forest floor. Since they are exposed to hot, dry winds, they have small pointed leaves in order to preserve moisture. Their root system is very shallow. To support their vast size, they grow buttresses (above ground roots which spread out to a distance of more than 9m)