Chap48biosphere - NOTE: in this chapter you are only...

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Unformatted text preview: NOTE: in this chapter you are only responsible for the DEFINITIONS given in this power point presentation AND the information on PAGES: 870,871,884,885,893,897(Chernobyl information) information) Chapter 48 The Biosphere DEFINITIONS DEFINITIONS BIOGEOGRAPHY::THE STUDY OF FACTORS THAT GIVE RISE TO PATTERNS THE IN THE DISTRIBUTION OF ORGANISMS THROUGH THE ENVIRONMENT. IN BIOSPHERE:SUM OF ALL PLACES WHERE LIFE IS FOUND CLIMATE:AVERAGE WEATHER CONDITIONS (INCLUDES TEMP. PPT. WIND ETC.) OZONE THINNING:OZONE LAYER DESTROYED AND MORE UV OZONE RADIATION HITS THE EARTH IN THOSE AREAS RADIATION SULFURIC OR NITRIC ACID SULFURIC ACID RAIN::ACIDIC PERCIPITATION, RAIN OR SNOW WITH HIGH LEVELS OF ACIDIC SMOG: WHEN WINDS CANNOT DISPERSE POLLUTANTS AND THEY GET TRAPPED DESERTIFICATION::CONVERSION OF GRASSLAND OR IRRIGATED OR CONVERSION RAIN-FED CROPLAND INTO DESERTLIKE CONDITIONS RAIN-FED EUTROPHICATION::NUTRIENT ENRICHMENT OF A BODY OF WATER NUTRIENT THAT PROMOTES OVERGROWTH OF PHYTOPLANKTON WHICH LEADS TO DEATH OF THE NATURAL POPULATIONS NATURAL Biosphere Biosphere Sum total of the places in which organisms Sum live live Includes portions of the hydrosphere, Includes lithosphere, and atmosphere lithosphere, Something to think about Something Biogeography: The study of the distribution of organisms Biogeography: and the processes that underlie distribution patterns and FACTORS THAT AFFECT DISTRIBUTION: Geologic history,Topography,Climate, Species interactions ORGANISMS HAVE EVOLVED TO FIT THEIR NICHE…THEY ORGANISMS USUALLY CAN NOT OVERCOME ANY MAJOR DISRUPTION DISRUPTION The following includes mans impact on those niches Ozone Layer Ozone Region 17 to 27 kilometers above sea level in the Region stratosphere stratosphere Molecules of ozone absorb most layers of ultraviolet light Protects living organisms from excess exposure to UV light OZONE THINNING: CFC’S released into the atmosphere OZONE react with the ozone and destroy the protective layer. react Ozone Thinning Ozone In early spring and In summer ozone layer over Antarctica thins over South America Seasonal loss of ozone Seasonal is at highest level ever recorded recorded Antarctica Figure 48-6 Page 870 Effect of Ozone Thinning Effect Increased amount of UV radiation Increased reaches Earth’s surface reaches UV damages DNA and negatively UV affects human health affects UV also affects plants, lowers primary UV productivity productivity Protecting the Ozone Layer Protecting CFC production has been halted in developed CFC countries, will be phased out in developing countries Methyl bromide will be phased out Even with bans it will take more than 50 years Even for ozone levels to recover for Pollutants Pollutants Substances with which an ecosystem has had no prior Substances evolutionary experience evolutionary No adaptive mechanisms are in place to deal with them SOME AIR POLLUTANTS Carbon oxides, Sulfur oxides, Nitrogen oxides, Volatile organic compounds, Photochemical oxidants, Suspended particles particles Smog Smog Gray-air smog=INDUSTRIAL SMOG Forms over cities that burn large amounts of coal and heavy fuel oils; mainly in Forms developing countries. 45 MILLION TONS/YEAR generated by coal combustion developing Main components are sulfur oxides and suspended particles Brown-air smog = PHOTOCHEMICAL SMOG Forms when sunlight interacts with components from automobile exhaust Forms Nitrogen oxides are the main culprits Hot days contribute to formation SMOG RESULTS IN RESPIRATORY DISORDERS Acid Deposition Acid Affects much of eastern North America Affects Caused by the release of sulfur and Caused nitrogen oxides nitrogen Coal-burning power plants and motor Coal-burning vehicles are major sources vehicles Deforestation Deforestation Removal of all trees from large tracts of land 38 million acres logged each year Wood is used for fuel, lumber Land is cleared for grazing or crops Effects of deforestation Increased leaching and soil erosion Increased flooding and sedimentation of downstream rivers Regional precipitation declines Possible amplification of the greenhouse effect Huge loss of biodiversity in rainforests Regions of Deforestation Regions Rates of forest loss are greatest in Brazil, Indonesia, Mexico, and Rates Columbia Columbia Highly mechanized logging is proceeding in temperate forests of the Highly United States and Canada United REVERSING DEFORESTATION Coalition of groups dedicated to saving Brazil’s remaining forests Smokeless wood stoves have saved firewood in India Kenyan women have planted millions of trees Desertification Desertification Conversion of large tracts of grassland to desertlike conditions Conversion Conversions of cropland that result in more than 10 percent decline Conversions in productivity in Over 9 million square kilometers have been desertified in only the Over last 50 years. 200,000 more per yr. Most is NOT reversible!!!! last DESERTIFICATION TODAY Sahel region of Africa is undergoing rapid desertification Causes are overgrazing, overfarming, and prolonged drought One solution may be to substitute native herbivores for imported cattle Fig. 48-26, p.885 Water Pollutants Water Sewage Animal wastes Fertilizers Pesticides Industrial chemicals Radioactive material Excess heat (thermal pollution) Excess Fig. 48-30d, p.888 Chernobyl nuclear meltdown 1998 Chernobyl In two months the radioactive fallout spread: red area 300-400 million people were put at risk for different 300-400 cancers/leukemia/and other abnormalities cancers/leukemia/and Fig. 48-42, p.897 ...
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