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Tropical Rainforests

Tropical rainforests are found around the equator, between the tropics. They are hot and wet all year round, with incredibly high biodiversity. The ecosystem is interdependent -- all parts rely on each other. Plants and animals have adapted to the physical conditions. Deforestation is a major threat, but rainforests can be sustainably managed.

The climate of tropical rainforests has distinct characteristics that support a unique ecosystem of plants, animals, soil and people.

Key Terms

Climate — The climate is the same all year round -- there are no definite seasons. It's hot (the temperature is generally between 20-28 degrees C and only varies by a few degrees over the year). This is because the sun's energy is more intense near the equator as it is overhead all year round. Rainfall is very high, around 2000 mm per year. It rains every day.

Characteristics of Tropical Rainforests

ComponentDetails
ClimateSame all year round, no definite seasons. Temperature generally 20-28 degrees C. Sun's energy more intense near equator as it is overhead all year round. Rainfall very high -- around 2000 mm per year, rains every day.
Plants1) Most trees are evergreen to help them take advantage of the continual growing season. 2) Many trees are really tall and the vegetation cover is dense -- very little light reaches the forest floor. 3) There are lots of epiphytes (plants that grow on other living plants and take nutrients and moisture from the air), e.g. orchids and ferns.
SoilThe soil isn't very fertile as heavy rain washes nutrients away. There are surface nutrients due to decayed leaf fall, but this layer is very thin as decay is fast in the warm, moist conditions.
AnimalsRainforest ecosystems are believed to contain more animal species than any other ecosystem. Gorillas, jaguars, anacondas, tree frogs, sloths and howler monkeys are all found here, and there are also many species of insects and birds.
PeopleMany indigenous people have adapted to life in the rainforests. They make a living by hunting and fishing, gathering nuts and berries, and growing vegetables in small garden plots.

Case Studies

Exam Tips

  • •You may be given a picture in the exam and asked to describe how an organism is adapted to its environment. Don't panic if you don't know what it is -- think how the features shown might be adaptations to help it survive.
  • •Sustainability sounds complex but it's simple really -- present needs shouldn't negatively impact future needs.
  • •Make sure you know the characteristics of a rainforest ecosystem and how those characteristics are interdependent.
  • •Check you understand how changing one thing, like deforestation, can affect the rest of the rainforest ecosystem.