1. AQUATIC BIOMES 34.7 Oceans occupy most of Earth's surface
Abiotic factors influencing the distribution of aquatic biomes
Light
Distance from shore
Availability of nutrients
Oceanic zones
Intertidal zone: where land meets ocean

3. Contains phytoplankton and zooplankton
Pelagic zone: open ocean
Contains phytoplankton and zooplankton
Benthic zone: seafloor
Photic zone: illuminated regions of the pelagic and benthic zones
Photosynthesis occurs
Aphotic zone: vast, dark region underlying the photic zone
Most extensive part of the biosphere

4. Intertidal zone Photic zone 200 m Continental Pelagic shelf zone
LE 34-7b
Intertidal zone
Photic zone
200 m
Continental
shelf
Pelagic
zone
Benthic zone
(seafloor)
Aphotic
zone
2,500–6,000 m

5. Continental shelf: submerged part of a continent
Coral reef: found in warm waters above continental shelf
Biologically very diverse
Estuary: area where freshwater stream or river merges with ocean
Among the most productive biomes on Earth

6. Video: Clownfish and Anemone
Wetland: area that is transitional between an aquatic and terrestrial ecosystem
Aquatic communities are environmentally threatened
Video: Coral Reef
Video: Clownfish and Anemone

9. 34.8 Freshwater biomes include lakes, ponds, rivers, streams, and wetlands
Light has a significant effect on freshwater biomes
All but the most shallow ponds and lakes have photic and aphotic zones
Temperature creates stratification of water
Availability of nutrients and dissolved oxygen influence organic growth
Nitrogen and phosphorus runoff create algal blooms

10. Freshwater wetlands range from swamps to marshes and bogs
Rivers and streams support communities quite different from those of lakes and ponds
Freshwater wetlands range from swamps to marshes and bogs
Great ecological and economic value

13. TERRESTRIAL BIOMES
34.9 Terrestrial biomes reflect regional variations in climate
Many biomes are named for climatic features and predominant vegetation
Each biome is also characterized by the organisms adapted to that environment
The distribution of biomes depends largely on climate
Within each biome there is local variation

14. LE 34-9 30°N Tropic of Cancer Equator Tropic of Capricorn 30°S
Tropical forest
Temperate grassland
High mountains
Savanna
Temperate broadleaf forest
Polar ice
Desert
Coniferous forest
Chaparral
Tundra

15. 34.10 Tropical forests cluster near the equator
Rainfall generally determines the type of vegetation in a tropical forest
Tropical rain forests are the most complex of all biomes
Very high diversity
Complex structure
Human impact is of great concern

17. 34.11 Savannas are grasslands with scattered trees
Savannas are dry and warm
Frequent fires inhibit invasion by trees
Large grazing animals migrate during seasonal droughts

19. 34.12 Deserts are defined by their dryness
Deserts are the driest terrestrial biomes
Can be hot or cold
Cycles of growth and reproduction are keyed to rainfall
Animals are adapted to drought and extreme temperatures
Desertification is a significant environmental problem

21. 34.13 Spiny shrubs dominate the chaparral
The chaparral is a region of dense, spiny shrubs with tough, evergreen leaves
In midlatitude coastal areas
Cool, rainy winters and dry, hot summers
Vegetation adapted to periodic fires

23. 34.14 Temperate grasslands include the North American prairie
Temperate grasslands are found where winters are cold
Similar to savannas but mostly treeless
Periodic drought, fires, and grazing inhibit growth of woody plants
Amount of annual rainfall influences height of vegetation

25. 34.15 Broadleaf trees dominate temperate forests
Temperate broadleaf forests grow throughout midlatitude regions
Need sufficient moisture to support the growth of large trees
Mix of tree species depends on abiotic factors
Most original North American broadleaf forests were destroyed by logging, agriculture, and development

27. 34.16 Coniferous forests are often dominated by a few species of trees
Cone-bearing trees dominate northern coniferous forest, or taiga
Found where there are short, wet summers and long, cold winters
Logging is eliminating old-growth coniferous trees

29. 34.17 Long, bitter-cold winters characterize the tundra
Arctic tundra is a treeless biome
Found at the northernmost limits of plant growth and at high altitudes
Characterized by extreme cold, wind, and permafrost
Animals have good insulation that retains heat