Biomes Chapter 21, Section 4

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

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

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)

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

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

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

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

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 80-400 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

Grasslands Located in the center of continents (every continent except for Antarctica!) Temperate grasslands: Average of 10-30 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!

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

Deciduous Forests Also known as a Temperate Forest (Temperate=moderate) Average of 30-60 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

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

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!**

Tundra Winter temperatures are around -30° F, Average summer temperature is 30 °F -50 °F Average winds are 30-60 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

Average Annual Rainfall in 6 Major Biomes

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

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

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

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

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”

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

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

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