CAS BI 107 Lecture Notes - Lecture 20: Temperate Deciduous Forest, Tropical Rainforest, Rain Shadow
4 Apr 2016
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Department
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Professor
Biology: Spilios 11/13/2014 6:54:00 PM
Chapter 57
Figure out what I missed
Earth’s axis determines seasons
Most solar energy at the equator
Heats up moist air, rises, cools, rains!
Equator has very rainy weather for this reason, rainforests
Dry 30 degrees N/S, deserts b/c air descending down has no moisture
Varying climates, prevailing winds
At the equator, the velocity of the Earth’s rotation spinning
The air mass above a point on Earth that isn’t moving in either direction is
the same velocity (ie. fastest air @ equator)
The air mass that is moving towards the equator (like 30deg N/S) is slower
than the Earth beneath it
----> Prevailing winds (alternating)
Easterlies
Trade Winds
***
Prevailing winds do determine climate
In each ocean, there are massive gires— trash gires now
There are new organisms found there!!
Upwelling
Vertically moving water
Floor → surface = nutrient rich
Rain shadow
Rain on one side of a mountain, rises, loses capacity to hold water, drops to
other side to the desert
find more resources at oneclass.com
find more resources at oneclass.com
Ie. Washington State, Cascade Mountains
Air from Pacific, hits Cascades, up, to the desert
BIOMES- Areas characterized by ecological similarities, temperature &
rainfall
Dominant terrestrial plants provide three-dimensional structure, modify
microclimates
Convergent evolution & biomes (similar environmental conditions = similar
environmental stresses) ie. Euphorbia vs. Cactus, not related, but similar
morphological characteristics due to similar environments’
DON’T MEMORIZE, KNOW GEN. AREA & CHARACTERISTICS
Tundra
One of the largest biomes on the planet
Low temperatures throughout the year, short growing season These 2
Permafrost = most
Species richness low of the world
Boreal Forest/Tiga
Trees don’t shed their leaves b/c short growing season
Species richness low
High population of migratory birds (often from tundra, close by) in summer
Huge variation in temperature, snow reflects out
Temperate Deciduous Forest
THATS US!
Mild, wet winters
Migration vs. resident 50/50
Deciduous trees (loses their leaves)
Temperate Grasslands
Many rely on fire to upkeep diversity
ie. chaparral needs fire to germinate
High species richness for plants, low for birds
Rich soil to support agriculture
find more resources at oneclass.com
find more resources at oneclass.com
Hot Deserts
30deg N/30deg S
Hot, dry climate
Organisms have v. specific water-related mechanisms
Doesn’t rain b/c warm air is so stable no space for rain
Extreme daily temperatures
The Sahara Desert is dry because the air in the region arrives from the
tropical zone where it lost water—air circulation cells at 30N/30S
Cold Desert
Low plant diversity dominated by shrubs
Chaparral
Very stable temperature, but lots of rain
Often on the west coast of continents- cool water offshore
Fire!
Tropical Savanna
Fairly diverse area
Between hot deserts & equator
Largely grassland b/c rich animal fauna due to high grazing (no massive
growth)
Tropical Deciduous Forest
Imp. for migrating birds/insects, "refueling” on migratory route
Lots of rain
Mod. high species richness
Tropical Evergreen Forest, rainforest
Most stable temperature
Most rainfall (equator air/moisture)
Most diverse area
Right at the equator usually
V. poor soil, nutrients are held by the actual growth
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Equator has very rainy weather for this reason, rainforests. Dry 30 degrees n/s, deserts b/c air descending down has no moisture. At the equator, the velocity of the earth"s rotation spinning. The air mass above a point on earth that isn"t moving in either direction is the same velocity (ie. fastest air @ equator) The air mass that is moving towards the equator (like 30deg n/s) is slower than the earth beneath it. In each ocean, there are massive gires trash gires now. Rain on one side of a mountain, rises, loses capacity to hold water, drops to other side to the desert. Air from pacific, hits cascades, up, to the desert. Biomes- areas characterized by ecological similarities, temperature & rainfall. Dominant terrestrial plants provide three-dimensional structure, modify microclimates. Convergent evolution & biomes (similar environmental conditions = similar environmental stresses) ie. euphorbia vs. cactus, not related, but similar morphological characteristics due to similar environments".
