Rainforests for the Future
Rainforests are the Earth’s oldest and most complex ecosystem covering about 6% of the surface of the planet. Rainforests are forests with exceptionally tall trees, high rainfall and a large variety of species. The average humidity in a rainforest is 83%, with temperatures staying between 20°C – 34°C round the year. The precipitation in a rainforest is on average 200 cm per year, but can reach up to 450 cm per year in warmer areas. Since rainforests require heavy rainfall all the year round and high average temperatures, they are usually found in South-East Asia, Southern and Central America, Sub-Saharan Africa and several of the Pacific islands. Some of the subtropical and monsoon rainforests are also found on the northern coast of Australia and southern Japan.
The Structure of Rainforests
The combination of intense humidity and high temperatures in rainforests provides perfect conditions for the growth of plants, resulting in dense vegetation. This is why rainforests contain around 50% of all the Earth’s animal and plant species. Tropical rainforests are usually divided into four distinct layers: the emergent layer, the canopy, the understory and the forest floor. Each of these layers is a habitat for different biotic species.
The emergent layer of a tropical rainforest is created by the canopy. The trees reaching the top layer of the rainforest can grow up to 40 meters high, and this means that they are about 50 years old. These trees have huge branches and receive the most sunlight, rain and the highest temperatures. The majority of the trees in rainforests are evergreens with branches reaching out at the top, creating a shade of leaves, which blocks the sunlight from reaching the layers underneath. The crowns of those trees support a variety of aerial plants, which use the tree branches for support. The animals living in the top layer are howler monkeys, eagles, bats and butterflies.
The second layer...