Keystone Species
By analyzing network structures, one can determine keystone species that are of particular importance. A different class of keystone species is what are termed ‘ecosystem engineers’. Certain organisms alter the environment so drastically that it affects many interactions that take place within a habitat. This term is used for organisms that “directly or indirectly modulate availability of resources (other than themselves) to other species, by causing physical state changes in biotic or abiotic materials”. Beavers are an example of such engineers. Other examples include earthworms, trees, coral reefs, and planktonic organisms. Such 'network engineers' can be seen as “interaction modifiers”, meaning that a change in their population density affects the interactions between two or more other species.
Read more about this topic: Non-trophic Networks
Famous quotes containing the word species:
“Not only does every animal live at the expense of some other animal or plant, but the very plants are at war.... The individuals of a species are like the crew of a foundered ship, and none but good swimmers have a chance of reaching the land.”
—Thomas Henry Huxley (1825–95)