Biotic factors are the living things in an ecosystem that have an impact on other living things and/or the environment. The tropical rainforests (also known as tropical wet forests) are found in the equatorial regions of Earth and they contain the oldest major vegetation type still in existence. Flowering plants first appeared in tropical rainforests about 100 million years ago. About 40 million years ago when the climate became cooler and drier, other types of vegetation evolved across larger areas as these forests expanded. Over 50% of the plant and animal species on Earth are found in tropical rainforests.

Biotic Factors of the Tropical Rainforest

Biotic factors in any ecosystem are classified as producers (autotrophs), consumers (heterotrophs) and decomposers (detritivores). Plants are mostly producers and the decomposers are organisms like fungi and earthworms. Consumers have to eat other organisms to get their energy.

Animals

Animals are consumers and rely on producers to make some of their food, but they eat other consumers, too. Animals that live in the tropical rainforests include birds like parrots, the collared sunbird, the keel-billed toucan, pigeons and the bird of paradise. Other animals are spider monkeys, deer, kinkajou, okapi, Western lowland gorillas, tree kangaroos, pigs, elephants, rhinoceroses, leopards, bandicoots, opossums and the three-toed sloth.

Plants

One hectare of tropical rainforest can have over 800 species of trees and 1,500 species of higher plants. Also, about two-thirds of the world’s flowering plants are in tropical rainforests. They include orchids, lilies, heliconia and bromeliads. Tropical rainforests can have various fungi, shrubs, herbs, woody vines, lichens and mosses. The trees making up the rainforest canopy include the tonka bean wood, teak, rubber and several species of evergreens and palm trees.

Insects

There can be as many as 42,000 different species of insects in one hectare of tropical rainforest. They include beetles (over 1,000 species), arachnids, scorpions, praying mantises, katydids, weaver ants, bullet ants, butterflies, centipedes, cockroaches, jeweled caterpillars, wasps and bees.

Reptiles and Amphibians

Some of the reptiles and amphibians that live in the tropical rainforest are poison dart frogs, boa constrictors, green anacondas, reticulated pythons, toads, newts, salamanders, turtles, tortoises, lizards, iguanas, chameleons and crocodiles.

Ulva Island rainforest
The image above shows the Ulva Island rainforest in New Zealand.

References

  • Tropical rainforest. (n.d.). In Wikipedia. Retrieved July 3, 2017 from https://en.wikipedia.org/wiki/Tropical_rainforest#Biodiversity_and_speciation
  • Tropical rainforest. (2017, July 3). In Encyclopedia Britannica online. Retrieved from https://www.britannica.com/science/tropical-rainforest