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Published byLoreen McDonald Modified over 9 years ago
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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
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A. Tropical rain forest 1. richest and most organismal diversity 2. about half of living species 3. often equatorial 4. slow to recover after disturbance - weak soil
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B. Savannas 1. grasslands bordering the tropics - open landscape - some trees, mostly scattered 2. often transition between rain forest and desert
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C. Deserts 1. often on continental interiors - many around 30˚ latitude 2. organisms adapted to little water - dry feces
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D. Chaparral 1. near mid-latitude coastal areas 2. mild, rainy winters and long, hot, dry summers 3. dense, spiny shrubs with evergreen leaves
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E. Temperate grassland (prairie) 1. more temperate than savannas 2. few trees 3. very fertile - important for agriculture
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F. Temperate forests (broadleaf, hardwoods) 1. deciduous trees 2. loss of leaves decreases water loss during the winter 3. recover well after disturbance
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G. Taiga 1. coniferous forests - evergreens with needle leaves 2. 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
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H. Tundra 1. open grassland 2. ground frozen (permafrost) - plant roots cannot get deep penetration 3. rain collects in bogs - permafrost and slow evaporation 4. grazing animals and some predators - musk ox, caribou, reindeer, arctic fox - mosquitoes can be overwhelming in summer
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I. Elevation effect
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II. Man’s Impact on Ecosystems (Chap 38) A. Habitat destruction B. Introduction of non-native species
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C. Pollution 1. acid rain a. sulfur from burning coal - from tall stacks into upper atmosphere - Clean Air Act of 1990
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b. nitric oxide from burning fossil fuels c. lowers pH of ecosystems - kills mycorrhizae
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2. biological magnification a. PCBs (polychlorinated biphenyls) - industrial chemicals
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b. DDT
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D. Ozone layer 1. protective layer in the upper atmosphere a. O 3 b. shield for solar UV 2. CFCs (chlorofluorocarbons) - catalyze conversion of O 3 O 2 - ozone hole over the south pole
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III. Greenhouse Effect A. CO 2 released from burning fossil fuels and wood B. Trapping heat global warming
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Well-known data:
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Not-so well known facts: % of the atmosphere that is CO 2 = % of the atmosphere that is water vapor = 0 - 4% 0.05%
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IV. Nuclear Alternative A. Relatively cheap and “clean” B. Must meet three criteria 1. safety 2. proper waste disposal 3. security
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