Interdependence and Symbiotic Relationships

Relationships between rainforest organisms aren’t always as simple as those between producers, consumers, and decomposers. Some are based on interdependence—which means the organisms depend on each other for survival. A special form of interdependence called symbiosis occurs when two different organisms live in very close association.

Interdependence Between Animals and Plants

Agoutis, Brazil nut trees, bees, and orchids provide one example of interdependence. Agoutis primarily eat Brazil nuts—they’re the only animals able to chew through the nuts’ outer covering to release the seeds. Agoutis help Brazil nut trees by spreading their seeds throughout the forest. In addition to their dependence on agoutis, Brazil nut trees depend on a single bee species to pollinate their flowers. In turn, the bees’ survival depends on a certain orchid species. The bees get nectar from the orchid; they also pick up a special scent they need to attract mates.

The relationship between Azteca ants and cecropia trees provides another example of interdependence. The ants live inside the hollow stems of cecropia trees; a necessary part of their diet is a special juice produced by the trees. In return, the ants chase away insects that may harm the cecropias and kill climbing vines that might choke these trees.

Symbiotic Relationships

Some ant species have symbiotic relationships with certain caterpillar species. The ants feed on sweet juices produced by special spots on the caterpillars’ backs. In exchange, the ants protect the caterpillars from attack. Sometimes the ants even take the caterpillars to their nests at night for safety!

Some termite species have bacteria and other tiny organisms living inside them. The termites depend on the bacteria and other organisms to help break down the wood they eat. In turn, the bacteria and other organisms get nutrients and a place to live.

These are only a few examples of interdependence and symbiosis in Amazonia. Such relationships are very common in the rainforest.

The fig wasp spends most of its life inside a fig and is responsible for pollinating the flowers of the fig tree. Neither the tree nor the wasp can survive without the other.

The fig wasp spends most of its life inside a fig and is responsible for pollinating the flowers of the fig tree. Neither the tree nor the wasp can survive without the other.

What do trees talk about? In the Douglas fir forests of Canada, see how trees “talk” to each other by forming underground symbiotic relationships—called mycorrhizae—with fungi to relay stress signals and share resources with one another.