5-2~5-6

5-2
How dose climate affect the nature and location of biomes?

Differences in average annual precipitation and temperature lead to the formation of tropical , temperate , and cold deserts , grasslands , and forests , and largely determine their locations.

5-3
How have we affect the world's terrestrial ecosystems?

In many areas, human activities impairing ecological and economic services provided by the earth's desert , grasslands , forests , and mountains.

5-4
What are the major types of aquatic systems?

Saltwater and freshwater aquatic life zones cover almost three-fourths of the earth's surface with oceans dominating the planet.
Most aquatic organisms live in the surface , middle , or bottom layers of saltwater and freshwater systems.

5-5
What are the major ocean zones and how have we affected them?

In many areas , human activities are impairing ecological and economic services provided by the earth's saltwater systems , especially coastal wetlands , shorelines , mangrove forests , and coral reefs.

5-6
What are the major types of freshwater systems and how have we affected them?

Human activities are impairing ecological and economic services provided by many rivers and freshwater lakes and wetlands.