1. Biomes
Chapter 21, Section 4

2. Distribution of Life on Earth
Influenced by:
1. weather (short term)
2. climate (long term weather
patterns)
Weather affects:
individuals’ climate
influences and limits the overall distribution of entire species

3. Weather & Climate are driven by….
The SUN!!
Solar energy that reaches Earth drives the wind, ocean currents, and global water cycle.

4. Physical Factors that Influence Climate
Latitude
determines the angle at which the sun’s rays hit the earth
changes the temperature
(closer to the equator= warmer
farther away=colder)

5. Air Currents generated by earths rotation cause large regions to be:
warm & dry
warm & wet
cold & dry or
cold & wet

6. Ocean currents moderate near shore climates
coastal areas tend to have steadier temperatures because of the heat retained in the water

7. Continents and Mountains
Irregularly shaped continents alter the flow of wind & water and contribute to the irregular distribution of biomes
Mountains cause variation in altitude which affects temperature and modifies rainfall patterns- rain shadows

8. Terrestrial Biomes Terrestrial= land
Biomes are generally named after the dominant vegetation

9. Tropical Rain Forests On & around the equator
(between the Tropic of Cancer and the Tropic of Capricorn)
Warm & humid all year long-Average temperature stays
between 77°F- 86°F
Rainfall: average of inches per year!!
Dominated by huge broad leaf evergreens
Cover 6% of Earth’s surface
Largest amount of biodiversity (2/3 of worlds total species)
Soil is nutrient poor

11. Grasslands
Located in the center of continents (every continent except for Antarctica!)
Temperate grasslands: Average of in. of rain each year (prairie)
Tropical grasslands: savanna- has a wet season
Large, open spaces of grasses-trees are only found near rivers & streams.
Hot & dry summers tolerated by grasses, but kills trees
Most fertile soil in the world-these areas usually grow a lot of crops!

13. Deserts Less than 10 inches (or 25 cm) of rain each year
Defined by lack of rain not heat
Found on every continent
Shallow rooted plants- areas of dirt surrounding them
Dominant plants cacti & other succulents
(Succulent plants, also known as succulents or sometimes fat plants, are plants having some parts that are more than normally thickened and fleshy, usually to retain water in arid climates or soil conditions. Example: Aloe)
Most animals burrow during the day & are active at night

15. Deciduous Forests
Also known as a Temperate Forest (Temperate=moderate)
Average of in. of rain each year
Deciduous trees are the dominant species
4 distinct seasons
Warm summer, cold winter (changing climate requires lots of adaptations)
50° F- average temperature
Oak, Beech, Maple
Deer, squirrels, fox, black bears, frogs, snakes, brown bears, rabbits

16. Located in:
eastern half of the United States
Canada
Europe
&parts of Russia, China, and Japan.

17. Taiga: Northern Coniferous Forest or Boreal Forest
Winter= long & cold, Growing Season=Short
Dominated by needle bearing evergreen coniferous trees
Not many species live there because the conditions are too harsh
Lynx, grizzly bear, moose, wolf, wolverine, snowshoe hare
30 inches of rain annually
Winter temperature s range from -65°F-30 ° F
Summer temperatures range from 30° F- 70° F.
**can be below freezing at night in the summer!**

19. Tundra
Winter temperatures are around -30° F, Average summer temperature is 30 °F -50 °F
Average winds are mph
10 inches (or 25 cm) of rain or less annually
Permafrost-permanently frozen ground
Growing season is only 50 days (which means the temperature is above freezing for only 50 days out of the year!)
Shallow root growth-shrubs, plants are all low to the ground
Variety of plant & animal life:
Lichens, caribou, mosquitoes, birds, wolves, snowy owls, artic foxes, grizzly bears

21. Average Annual Rainfall in 6 Major Biomes

22. Freshwater Covers less than 1% of the earths surface
Fresh water ecosystems include: Rivers, streams, ponds, lakes & marshes
Distribution of life depends on light, nutrients & access to the bottom

23. Streams & Rivers Freshwater starts at the top of mountains in streams
Fast moving & cold
Other streams join in and form rivers.
Water in the river moves more slowly, plants (producers) are able to grow on the bottoms

24. Ponds & Lakes Standing water
Lakes are usually larger & deeper than ponds
Producers live on bottoms and tops
Lakes have three life zones:
Littoral- edge
Limnetic- to the depth in which light penetrates the water
Profundal- too deep for photosynthesis

25. Marine Ecosystems Any water with salt in it is called marine
Marine ecosystems include:
Estuaries
Intertidal zones
Neritic zones
Open ocean

26. Estuaries An estuary is where fresh and salt water meet and mix.
Example: Chesapeake Bay
Usually has lots of nutrients and producers
Many organisms go into the estuary from the ocean to lay their eggs
Sometimes called “nature’s nursery”

27. Intertidal Zone The area between the high tide and low tide line.
Organisms must be adapted to being wet and dry everyday

28. Neritic Zone Goes from the shore to the edge of the continental shelf
SHALLOW- light can penetrate to the bottom
Lots of things live here

29. Open Ocean Broken into two zones:
Surface zone – light penetrates, algae live on the surface
Deep water zone- no light, hardly anything lives here