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

3. 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

4. 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

5. 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.

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

7. 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

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

9. 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

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

11. Earth’s tilt on its axis plays a role in seasonal change.
Solar heating causes movements in both water and air.
wind
ocean currents
Earth’s rotation also has effects on the winds and currents

12. KEY CONCEPT Biomes are land-based, global communities of organisms.

13. Earth has six major biomes.
A biome is a major community of organisms.

14. Tropical rain forest biomes produce lush forests.
Source: World Meteorological Organization
Tropical rain forest biomes produce lush forests.
warm temperature
abundant precipitation all year

15. Grassland biomes are where the primary plant life is grass.
Rapid City, South Dakota
Source: National Oceanic Atmospheric Administration

16. Grassland biomes are where the primary plant life is grass.
Temperate grasslands are dry and warm during the summer; most precipitation falls as snow.
Tropical grasslands are warm through the year, with definite dry and rainy seasons.

17. KEY CONCEPT Marine ecosystems are global.

18. The ocean can be divided into zones.
Ocean zones can be determined by their distance from shoreline and water depths.
intertidal zone—between low and high tide
neritic zone—from intertidal zone to continental shelf
bathyal zone—from neritic zone to base of continental shelf
abyssal zone –lies below 2000 m
intertidal zone
neritic zone
bathmat zone
abyssal zone

19. The neritic zone harbors more biomass than any other zone.
Plankton make up most of the biomass.
zooplankton
phytoplankton

20. Coastal waters contain unique habitats.
Coral reefs are found in warm waters.
tropical climate zone
great amount of biomass

21. Kelp forests are found in cold, nutrient-rich waters.
large communities of seaweed
great amount of biomass

22. KEY CONCEPT Freshwater ecosystems include estuaries as well as flowing and standing water.

23. Estuaries are dynamic environments where rivers flow into the ocean.
An estuary is a partially enclosed body of water.
mixture of fresh water with salt water
Chesapeake Bay
Louisiana bayous

24. Estuaries are highly productive ecosystems.
Estuaries provide a protected refuge for many species.
birds migration
spawning grounds
Estuaries are primarily threatened by land development.

25. Freshwater ecosystems include moving and standing water.
A watershed is a region of land that drains into a body of water.
Ecosystems may be different along a river’s course

26. Wetlands are among the most productive ecosystems.
provide a home for many species
filter dirty water
renew underground water supply
Some animals have adaptations suited to the freshwater they inhabit.

27. Ponds and lakes share common features.
Freshwater bodies are divided into three zones.
littoral zone
limnetic zone
benthic zone

28. All lakes “turn over” periodically.
Turn over happens due to changes in density.
In both autumn and spring, surface water flows downward and bottom water flows upward.
The upwelling brings up nutrients.