What makes a tropical forest?
Tropical rainforests are very wet places, receiving heavy rainfall either seasonally or throughout the year. They are close to the equator and get lots of sunlight and warmth. Temperatures are uniformly high - between 20 and 35°C. They usually receive more than 200 cm rainfall per year.
Rainforest trees are quite different from trees of the temperate forests. In the rainforest, trees grow to gigantic size, supported by strong, strut-like buttresses at the base of the trunk that help to stabilize them in the shallow forest soils. Huge creepers twine themselves around the trunks of trees.
Some are parasites, but others merely use the trees for support. Many rainforest trees have dark green, often leathery, leaves which taper sharply so that water drains quickly from the surface. Flowers like orchids and bromeliads (members of the pineapple family) grow directly on trunks and larger branches - they are called epiphytes.
Birds and butterflies insects easily reach these flowers and act as pollinators. Where rain falls all year round, the forests are evergreen - the trees do not lose their leaves, or do so at different times.
A mature lowland tropical forest consists of several layers. The top layer of vegetation consists of scattered tall trees which tower above a closed canopy layer formed by the crowns of other trees. The canopy is the most exciting part of the rainforest, it is here that most of the flowering and fruiting of the trees takes place, attracting a variety of spectacular creatures.
Below the canopy is a third layer, formed by smaller trees whose crowns do not meet. Below this is a layer is composed of woody and herbaceous shrubs. Finally, there is the ground layer, which receives very little sunlight.