Topic 12 Ecology

What factors can alter temperature and moisture patterns associated with latitude?
1. Prevailing winds
2. Mountain Ranges
3. Presence or absence of local bodies of water (oceans and lakes).
Tropics Definition?
– Those latitudes where the sun is directly overhead at noon at least once a year.
– Occurs within 23.5°N (tropic of cancer) and 23.5°S (tropic of capricorn)
March 21 and September 21 in the tropics?
– Sun is directly overhead at the equator
– 12 hours of day light, 12 hours of night
June 21?
The longest day of the year in the northern hemisphere, the sun is directly overhead at the tropic of cancer. Shortest day of the year in the southern hemisphere.
December 21st?
The sun is directly overhead at the Tropic of capricorn.
The day is also the shortest in the Northern Hemisphere
The day is also the longest in Southern Hemisphere.
What is seasonality based on in the temperate and polar zones? in the tropics?
Temperature in the temperate and polar zones;
Rainfall in the tropics
What is the Coriolis Force?
– based on the fact that the Earth is rotating on its axis;
– Areas closer to the axis of rotation (high latitudes) are moving through the air masses more slowly than areas nearer the equator.
Prevailing Winds in the Northern hemisphere?
1. From the Northeast in the Tropics
2. From the West in the Temperate Zone (North of tropics)
3. From the East in the polar regions
Prevailing Winds in the Southern Hemisphere?
– From the Southeast in the tropics
– From the West in the temperate zone
– From the east in the Polar regions
2 Locations of deserts?
1. At or Near 30° Latitude.
2. On the leeward side (as opposed to windward side) of the prevailing winds
Examples:
– West side of mountains in the tropics
– East side of mountains in the temperate zone.
Microclimates:
In the northern hemisphere? North-facing versus south-facing?
– South facing slopes almost always face the sun and are warmer and drier.
– North-facing slopes are most always in the shade and are moister and cooler.
Evapotranspiration?
– The total amount of water vapor returned to the atmosphere by the combined processes of evaporation and plant transpiration.
Holdridge System is determined by what two parameters?
1. Mean annual biotemperature
2. Total annual precipitation.