• sunlight hits the equator directly
• everywhere on earth has the exact smae day length

ecosystems around the world that have the same structure and function

ex. grasslands and rainforests

• every 100,000 years when the earths orbit elongates

• 25,000 years ago; Pleistocene Ice Age
• set up the stage for our current ecosystems

• 12,000 to 9,000 years ago
• group of people with domesticated planst and animals
• no longer hunter-gatherers
• climate became favorable to grass crops

ex. wheat, rice, corn for carbs

ex. legumes like peas and soybeans for amino acids

• the sun shines short wavelength light at earth
• the earth reflects long wavelength and much of it is caught in the atmosphere by CO₂

• 30° N and S
• Its a high pressure area where air descends from its rise at the equator.
• The air warms as it falls and so holds all the moisture, ergo little to no rain

What are the annual precipitation amounts for:

• deserts
• grasslands
• forests
• rainforests

• deserts: 0-10 in
• grasslands: 10-30 in
• forests: 31-50 in
• rainforests: +50 in

• Tropic of Cancer @ 23.5° N
• Tropic of Capricorn @ 23.5° S

• where you have the most rain; monsoons
• as the earth tilts the zone shifts
• affects areas with dry and wet seasons - 6 months of rain followed by 6 months of dry weather

ex. The Serengeti Plain

1. 30° latitude
2. high altitude
3. mountain rain shadow

• up to 376 ft tall
• tallest trees in the world
• 200,000,000 years old

• visible light within 400-700 nm
• leaves absorb blue (400) and red (700) light; reflect green (500) light

• a measure of the filtering capacity of the leaves OR ability of plants to intercept and use light for photosynthesis
• LAI = total leaf area/projected ground area
• typical LAI values:

1. pine forest: (2-4)
2. temperate forest (3-5)
3. tropical rainforest (6-10)

• daily activities at dawn and dusk
• controls physiology: release of cortisol in the morning stimulates sugar levels and makes you more alert/awake
• certain leaves will open & close at different times; in general plants tend to close their leaves at night
• phytoplankton and zooplankton float higher at night and sink lower during the day

• seasonal activities: spring, summer, fall and winter
• contrast of time ofday and time of night
• controls fur color in animals
• controls what season certain plants flower

• amount of energy it takes to raise the temperature of water by 1 degree

• important to aquatic animals b/c it acts as a buffer to extreme temperature changes

• evaporation, freezing of liquid
• important to animals that use water to cool down
• takes a lot of energy but has a cooling effect

• water is most dense at 4°C
• important to aquatic organisms b/c it keeps ice from drifting to the bottom and killing the organisms there

• surface tension

• important for certain animals that walk on water

• resistance to movement
• important to aquatic animals like sperm whales; their body shape helps to lower viscosity so they can swim faster

• objects less dense than water float on the top
• important to aquatic plants and animals

• IS NOT DIRT
• supports ecosystems
• huge complex of biotic and abiotic elements; contains lots of detritovores
• allows O₂ to get to plant roots
• forms from weathering of rocks

• volcanic origin
• formed by the cooling and solidification of magma

ex. granite, basalt

• formed when sediments are created by the deposit of weathered particles
• over time it becomes cemented and compacted into solid rock
• usually forms from marine deposits

ex. sandstone, limestone

• formed when igneous or sedimentary rock is altered at high temperature and pressure

ex. marble - formed from limestone

1. climate
2. parent material
3. topography - slope or flat
4. vegetation- create microcracks in rocks
5. time - weathering, mineralization

• soil forms faster in hot/wet climates

O

A

B

C

D

• top soil
• contains partially decomposed organic matter (humus)

• dark top soil
• high in organic matter and nutirent content
• contains roots of plants

• high clay content/ lighter in color
• only tree roots reach to this level

• very similar to parent material
• nutirent level is decreased significantly

• Parent material/bedrock

• relates to sand, silt and clay
• defined by diameter of particles

1. very coarse sand - 2 to 1 mm
2. very fine sand - 0.5 to 0.1 mm
3. silt - 0.05 to 0.002 mm
4. clay - <0.002 mm

• diameter is between 2 - 0.1 mm
• advantage: allows O₂ to enter soil
• disadvantage: doesn't hold many nutrients

• diameter is <0.002 mm
• advantage: contains many nurtients and charged particles
• disadvantage: little O₂ in the soil

• particles are (-) charges and attract (+) particles

• best soil for average plants - has good amount of nutirents and pleanty of O₂
• equal parts sand, silt and clay

water that perculates through the soil; rainwater

• moves through the soil through capillary action
• avaliable to plants

• attached very tightly to soil particles
• not available to plants

• nutirents needed in small quantities

ex. cobalt, iron, boron, iodine, copper

• nutirents needed in larger quantities

ex. potassium, nitrogen, sulfur, calcium, oxygen

1. Surface fire
2. Ground fire
3. Crown fire
4. Prairie fire
5. Northern Bogs
6. Western Forests

• burn dead organic matter
• release nutrients
• promote release of seeds
• promote germination of seeds

• occur in pine forests/northern conifers; dependent on fires
• restores nutrients to soil
• creates new diveristy every 40-200 yrs
• get extremely hot; can create their own weather patterns and fire tornados and cause tress to explode

describes pine cones that need fire to open up

ex. spruce, loblolly pine

• occurs in tundra and northern forests
• slow moving but very hot
• destroys root systems
• usually started by lightning strikes

• most beneficial for ecosystem
• spread very rapidly

• set up by the rotation of the earth
• causes air currents in the northern hemisphere to go clockwise
• causes air patterns in the southern hemisphere to go counter clockwise

• predictable rate in the temperature of air as it increases in alitutde
• predictive increase in precipitation as altitude increases

• recieves the greatest amount of sunlight
• low pressure - not much wind occurs here; doldrums
• warm air cools as it rises and forms clouds and rain occurs
• has the most precipitation annually
• rainforests occur here

• Prevailing Westerlies
• W → E
• clockwise air currents

• Roaring 40's
• Strong winds due to lack of landmass at 40°S
• W → E
• air currents run counter-clockwise

What winds occur at 15° N & S?

• Trade Winds
• W ← E