i. biomes (chap 34.8-17) - land ecosystems occurring over broad areas - combination of mountain,...
DESCRIPTION
B. Savannas 1. grasslands bordering the tropics - open landscape - some trees, mostly scattered 2. often transition between rain forest and desertTRANSCRIPT
I. Biomes (Chap 34.8-17)- land ecosystems occurring over broad areas- combination of mountain, climatic, and current effects- similar types or organisms within biomes
A. Tropical rain forest1. richest and most organismal diversity2. about half of living species3. often equatorial4. slow to recover after disturbance
- weak soil
B. Savannas1. grasslands bordering the tropics
- open landscape- some trees, mostly scattered
2. often transition between rain forest and desert
C. Deserts1. often on continental interiors
- many around 30˚ latitude2. organisms adapted to little water
- dry feces
D. Chaparral1. near mid-latitude coastal areas2. mild, rainy winters and long, hot, dry summers3. dense, spiny shrubs with evergreen leaves
E. Temperate grassland (prairie)1. more temperate than savannas2. few trees3. very fertile
- important for agriculture
F. Temperate forests (broadleaf, hardwoods)1. deciduous trees2. loss of leaves decreases water loss during the winter3. recover well after disturbance
G. Taiga1. coniferous forests
- evergreens with needle leaves2. long, cold winters and short, wet summers
- many familiar Montana wildlife- wolf, deer, bear, elk, moose
3. in coastal regions some are actually temperate rain forests
H. Tundra1. open grassland2. ground frozen (permafrost)
- plant roots cannot get deep penetration3. rain collects in bogs
- permafrost and slow evaporation4. grazing animals and some predators
- musk ox, caribou, reindeer, arctic fox- mosquitoes can be overwhelming in summer
I. Elevation effect
II. Man’s Impact on Ecosystems (Chap 38)A. Habitat destructionB. Introduction of non-native species
C. Pollution1. acid rain
a. sulfur from burning coal- from tall stacks into upper atmosphere- Clean Air Act of 1990
b. nitric oxide from burning fossil fuelsc. lowers pH of ecosystems
- kills mycorrhizae
2. biological magnificationa. PCBs (polychlorinated biphenyls)
- industrial chemicals
b. DDT
D. Ozone layer1. protective layer in the upper atmosphere
a. O3b. shield for solar UV
2. CFCs (chlorofluorocarbons)- catalyze conversion of O3 O2- ozone hole over the south pole
III. Greenhouse EffectA. CO2 released from burning fossil fuels and woodB. Trapping heat global warming
Well-known data:
Not-so well known facts:% of the atmosphere that is CO2 =% of the atmosphere that is water vapor = 0 - 4%
0.05%
IV. Nuclear AlternativeA. Relatively cheap and “clean”B. Must meet three criteria
1. safety2. proper waste disposal3. security