Ecological Succession

An ecological community is defined as a group of species living close enough to interact with each other. In the previous assignment, you learned about the different types of species interactions ( predation, competition, parasitism, herbivory, commensalism, mutualism).  Now we will focus on what happens to communities after some type of disturbance. 

Disturbance

There are natural forms of disturbance such as volcanic eruptions, floods and fires.  Here is a video showing the disturbance  after  the eruption of Mt St. Helens in Washington state.

There is also disturbance caused by human activity: farming, mining, logging.

Succession

In either case, disturbance sets in motion a process called succession. This is the change in the species composition of an area after a disturbance.  Whether it is human or  natural caused, there is a predictable series of changes to each particular community after a disturbance. This video shows you what  happened in the ecological succession after Mt. St. Helens erupted.   Watch the video and answer the questions  see if you learned the important principles behind succession.