Another problem, which is also usually caused by human involvement, is the spreading of invasive species. An invasive species is a plant or animal that does not belong in an ecosystem and which ends up dominating. Sometimes this is done by accident, as when seeds get dispersed through shipping containers. Other times it is done purposefully, as when someone thinks that bringing in an animal in one area will help control a pest problem.
Check out this one:
or this one...
Go to the following website: Invasive.org
Search through the website and find 7-10 interesting facts about invasive species. Write the facts in your own words. [I recommend clicking on the tab called "Invasive 101"]