Ecosystems Explained

An ecosystem consists of all living organism and their physical environment within a defined area. These living organisms form a complex, evolving web of relationships supported by the energy flow captured from the physical the environment or from other biotic members. The biotic community in turn modifies its physical environment creating a secession of plant and other biotic forms.

Biodiversity refers to all the living organisms in an ecosystem. The biotic community and abiotic platform with their interrelations and energy flows constitute an ecosystem.

The boundary of an ecosystem is determined by the shift in biological community constituents and a change in the nature of the environment.

The biotic components generally include representatives from several trophic levels; primary producers (autotrophs, mainly green plants), macroconsumers (heterotrophs, mainly animals) which ingest other organisms or particulate organic matter, microconsumers (saprotrophs, again heterotrophic, mainly bacteria and fungi) which break down complex organic compounds upon death of the above organisms, releasing nutrients to the environment for use again by the primary producers.

-The Penguin Dictionary of Biology, 1994, 9th edition, M. Thain and M. Hickman, New York

Biodiversity Fosters Ecosystem Health

“Disease incidence is often lower in more diverse communities of plants and animals....As biodiversity is lost from ecological systems, the species most likely to persist may tend to be those most likely to harbor and transmit pathogens at high rates.”


1) Is Biodiversity Good For Your Health?, Science

How Wolves Changed Yellowstone's Geography

This four-minute video shows the effects of the re-introduction of wolves in Yellowstone National Park. Not only did they affect the entire life of the park—increasing the number of species in it!—but they actually changed the geography of the park itself, affecting the rivers in a way that positively affected everything.

For more information see the article “Lessons from the Wild Lab: Yellowstone Park is a Real-World Laboratory of Predator-Prey Relations” in Science volume 347, issue 6228, March 2015.


1) How Wolves Changed Yellowstone, Gizmodo
2) Lessons from the Wild Lab: Yellowstone Park is a Real-World Laboratory of Predator-Prey Relations, Science