1. KEY CONCEPT The biosphere is one of Earth’s four interconnected systems.

2. The biosphere is the portion of Earth that is inhabited by life.
The biosphere includes all ecosystems.
one of Earth’s systems
includes the biota, all the living things in the biosphere

3. There are three other Earth systems.
hydrosphere—water, ice, and water vapor
atmosphere—air blanketing Earth’s solid and liquid surface
geosphere—geologic features above and below Earth’s surface

4. Biotic and abiotic factors interact in the biosphere.
All four Earth systems are interconnected.
The Gaia hypothesis considers Earth as a kind of living organism.
Earth systems interact to yield a biosphere capable of supporting life.
It was developed by James Lovelock and Lynn Margulis.

5. KEY CONCEPT Climate is a key abiotic factor that affects the biosphere.

6. Climate is the prevailing weather of a region.
Climate is the long-term pattern of weather conditions.
average temperature
precipitation
relative humidity
Key factors shape an area’s climate.
temperature
sunlight
water
wind

7. A microclimate is the climate of a small specific place within a larger area.

8. Earth has three main climate zones.
The three main zones are the polar, tropical, and temperate climates.
polar climate: the far northern and southern regions of Earth
tropical zone: surrounds the equator
temperate zone: the wide area in between the polar and tropical zones

9. The angle of the Sun’s rays help determine an area’s climate.
temperate
polar
tropical
90 N

10. Earth’s tilt on its axis plays a role in seasonal change.
Solar heating causes movements in both water and air.
wind
ocean current
Warm air and warm water are less dense than cooler air and water, and therefore they rise.
Earth’s rotation, water temperature and salinity levels also interact to form currents.

11. Landmasses also shape climates.
Areas closer to water have a different climate than areas further away because land tends to heat and cool more quickly.
Inland Areas:
larger changes in temperatures
less precipitation
Coastal Areas:
smaller changes in temperatures
higher humidity
more precipitation

12. Mountains have an effect on climate.
As warm, moist air nears a mountain, it rises and cools.
Precipitation occurs on the side of the mountain facing the wind.
On the downwind side, drier and cooler air produce a rain shadow.
A rain shadow is an area of decreased precipitation.
western slope
eastern slope

13. Many organisms survive in a specific climate due to their adaptations.
Water holding frog
Lives in dry grassland and desserts of Australia, rainy season once a year.
Frog survives by burrowing underground where water evaporates more slowly.
Moisture loss is further reduced by a cocoonlike structure formed from the frogs shed skin.