Earthworms in the Rainforest

Nutrient Recycling

• Earthworms play a major role in the rainforest. They effectively recycle nutrients from rotting material. They aerate the soil and help incorporate leaf litter into the upper layers of the soil, which encourages fungi and bacteria to decompose the material. Some earthworms can digest cellulose.

Earthworm Homes

• Earthworms are found under objects such as logs and rocks. During drier periods, they are usually found in moist areas. But they are mostly found in the first 40 centimeters of soil. They are not as common in rainforests as in temperate regions. Rainforests with too much flooding will drive off earthworms altogether. Earthworms migrate to deeper soil layers during heavier rains and rise to shallower layers during dry periods. If the rainforest does not have seasonal rains, the earthworms are more evenly distributed throughout the soil. Chemicals such as polyphenols can influence earthworm populations.

Populations

• In rainforests, earthworms are the most important organism in terms of biomass and the third most important in terms of abundance. Tropical countries tend to have more earthworm species variety than temperate ones. India has more than 400 species of earthworms. But the total earthworm biomass is less in tropical regions. Temperature determines the earthworm populations across different areas. However, when areas have a similar temperature, the number of earthworms in a given area depends on how many nutrients are in the soil. The wet tropics region has about 40 species of earthworms, though there might be hundreds not yet discovered, according to the Australian Wet Tropics Management Authority.

Diet

• Some rainforests have more earthworms that live off of leaf litter, while other rainforests have earthworms that live off of soil microflora. Earthworms are more likely to eat leaf litter when the soil does not have a lot of microorganisms. They are more likely to consume nutrients and microorganisms from the soil when there are more nutrients.

Quirky Facts

• Some earthworms release a fluid that gives off greenish light. Green trains are found in rainforests after heavy rains, when these earthworms are driven out of their habitats by floods. The largest earthworms in the world, such as the Terriswalkerius terrareginae, are found in the wet tropics. This worm can get as long as 6 1/2 feet and is blue. It is mostly not seen unless a very prolonged rain drives it to the surface.