Environmental Science 14th Edition by Tyler Miller ,Scott Spoolman

Exercise 20

What is the key concept for this section What major ecological and economic services do freshwater systems provide What is a lake What four zones are found in most deep lakes Distinguish among oligotrophic and eutrophic lakes. What is cultural cutrophication Define surface water , runoff , and watershed ( drain-age basin ). Describe the three zones that streams and rivers pass through as they flow from highlands to the sea. Give three examples of inland wetlands and explain their ecological importance. What are four ways in which human activities are disrupting and degrading freshwater systems