questions 1-4. detoxifying wastes bioremediation microorganisms break down wastes ...
TRANSCRIPT
Questions 1-4
Detoxifying WastesDetoxifying Wastes
BioremediationBioremediation
Microorganisms break down wastesMicroorganisms break down wastes
PhytoremediationPhytoremediation
Removal of wastes from the soilRemoval of wastes from the soil
Argument for biodiversity
• Ecosystem function, role, food web, food chain
• Future meds, foods• Economic potential, ecotourism• Aesthetic value• Minimize the spread of diseases
66
why has biodiversity decreased
• Loss of food resources• Food web disruption• Fragmentation • Introduction of a invasive species
• Waterlog/salinization • Over grazing
Laws of thermodynamics
• First law Energy can neither created nor destroyed, but you may change from one form to another
• When energy is changed from one form to another, some of the energy is degraded to a lower-quality, more dispersed energy form– No reaction can be 100% efficient– All reactions lose energy (usually as heat)– Systems only go spontaneously in the direction of decreasing order (increasing entropy)
21-24
Types of Water Pollution(fresh water mainly)
• Infectious agents
• Oxygen demanding wastes
• Plant nutrients and Eutrophication
• Toxic inorganic materials
• Organic chemicals
• Sediment and suspended solids
• Thermal pollution/ thermal shock
Air pollutants
• Sulfur Oxides• Carbon Oxides• Particulates• Hydrocarbons (VOCs)• Nitrogen Oxides• Photochemical Oxidants - Ozone• Lead• RadonIndoor list see page 12 and 13 of 2001 scoring
guidelines
25-2825-28
Acid rain
Some Effects on Aquatic Life:• aquatic ecosystems are the ultimate repository for various air
pollutants;• in particular high acidity (low pH) can leach harmful minerals
such as aluminum into the environment, kill fish & other organisms, inhibit reproduction, disrupt food chains, & decrease productivity;
Some Effects on Property:• air pollutants cause billions of dollars of damage to various
materials (e.g., damage to buildings in U.S. estimated at $5 billion annually);
• breaks down paints on cars and buildings, deteriorates roofing, etches stained glass windows, dissolves & discolors marble
Acid rain
NEPA
It is an Oversight board that looks at every major federal project and asses the environmental impact that project might have.
3131
extinction
• See question a 3, 2000 • Habitat alteration
– Urban sprawl– Fragmentation– Monoculture
• Poaching• Invasive species• Specialized feeding• Requires a large territory• Fixed migration • Feeds high on the trophic level, biomagnification • Limited range of tolerance • K strategist
3434
Endangered or threaten
• Giant panda• Elephant • Whooping crane• Manatee• Condor• Bald eagle
Harvesting TreesHarvesting Trees
¬ Selective cutting¬ Selective cutting
¬ High-grading¬ High-grading
¬ Shelterwood cutting¬ Shelterwood cutting
¬ Seed-tree cutting¬ Seed-tree cutting
¬ Clearcutting ¬ Clearcutting
¬ Strip cutting¬ Strip cutting Fig. 23-14 p. 603Fig. 23-14 p. 603
Selective Cutting
Figure 23-14aPage 603
Shelterwood Cutting
Cut 1
Cut 2
Figure 23-14bPage 603
Seed-Tree Cutting
Figure 23-14cPage 603
Clear-Cutting
Figure 23-14dPage 603
Strip Cutting
Uncut Cut Cut Cut Uncut
6–10 years ago3–5 years ago 1 year ago
Figure 23-14ePage 603
Types of US Public LandsTypes of US Public Lands
¬ Multiple-use lands: National Forests;National Resource Lands
¬ Multiple-use lands: National Forests;National Resource Lands
¬ Moderately-restricted use lands:National Wildlife Refuges
¬ Moderately-restricted use lands:National Wildlife Refuges
¬ Restricted-use lands: National Park System;National Wilderness Preservation System
¬ Restricted-use lands: National Park System;National Wilderness Preservation System
Pop transition 36-3836-38
Global warming
• CO2, CFCs, methane (CH4) Ozone, nitrous oxide
(N2O)
• Shift of habitat to higher latitudes
• Shift of habitat to higher elevations
• Potential large loss of biodiversity
4040
Global warming
• Temperature• Sea level• Food Production• Earth’s Albedo• Weather/Climate• Human health• Biodiversity
Soil management
• Contour plowing– plowing across the field instead of up and down
• Strip farming– planting different types of crops in rows (only one is harvested and other maintains soil
• Terracing– shaping land to make flat shelves to hold water
• Alley cropping– a form of intercropping where trees that can provide shade and nutrients for crops
4141
desertification
• Things leading to desertification– overgrazing of rangelands– deforestation– surface mining– soil compaction– salt buildup and waterlogging
Soil Horizons
3. Carbon Cycle3. Carbon Cycle
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Role of Carbon?
• building block of organic molecules (carbohydrates, fats, proteins, & nucleic acid) – essential to life;
• currency of energy exchange – chemical energy for life stored as bonds in organic compounds;
• carbon dioxide (CO2) greenhouse gas – traps heat
near Earth's surface & plays a key role as "nature's thermostat".
Carbon CycleCarbon Cycle
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How is Carbon Cycled?
Fig. 5–5
Carbon cycling between the atmosphere & terrestrial ecosystems.
Nitrogen CycleNitrogen Cycle
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How is Nitrogen Cycled?
Fig. 5–6
Carbon CycleCarbon Cycle
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Fig. 5–5
Humans now play a major role in the carbon cycle through burning of fossil fuels. Natural inputs include volcanoes & wildfires.
Carbon CycleCarbon Cycle
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main processes:• movement in atmosphere: atmospheric C as CO2 (0.036%
of troposphere);
• primary production: photosynthesis (= carbon fixation) moves C from atmosphere to organic molecules in organisms;
• movement through food web: C movement in organic form from organism to organism;
• aerobic respiration: organic molecules broken down to release CO2 back to atmosphere;
• combustion: organic molecules broken by burning down to release CO2 back to atmosphere;
• dissolving in oceans: C enters as to form carbonate (CO32–)
& bicarbonate (HCO3–);
• movement to sediments: C enters sediments, primarily as calcium carbonate (CaCO3);
Phosphorus CyclePhosphorus Cycle
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main processes:• weathering: P slowly released from rock or soil minerals
as phosphate (P043-), which dissolves in H20 & is readily
leached;
• uptake: by plants to form organic phosphates;
• movement through food web: nucleic acids (including DNA & ATP), certain fats in cell membranes (phospholipids), bones/teeth/shells (calcium–phosphate);
• break down of organic forms: to phosphate (P043-) by
decomposers;
• leaching: P043- from soil;
• burial in ocean sediments: not cycled in short time scale, only over geologic time;
40
Water supply
Groundwater
Groundwater system: terms
• zone of aeration• zone of saturation• water table• aquifers (confined and unconfined)• recharge areas/zones• artesian wells• infiltration • groundwater
Ogallala
Depleting Groundwater
• 51% of fresh water for use in U.S.
• In many places, the water is being withdrawn faster than it is being replaced (Overdraft)
• Overdraft causes the water table to fall and wells to dry up
• Aquifers can take thousands of years to recharge - nonrenewable resource
Effects of Overdraft: Saltwater Intrusion
• Salt water is more dense than fresh water
• A continual supply of fresh water forces back salt water
• When fresh water is reduced, salt water can intrude into aquifer
Groundwater supplies
Consequences:
• aquifer depletion
• aquifer subsidence land sinks when water is withdrawn
• saltwater intrusion
Groundwater in the U.S. is being withdrawn at about four times its replacement rate
Fig. 13–16© Brooks/Cole Publishing Company / ITP
Supplying More WaterSupplying More WaterUsing water efficiently
• increase efficiency of irrigationdrip irrigation, central–pivot, computer monitoring
• use recycled watertreat gray water from showers, washing machines for reuse
• fix leaky pipes
• water–saving toilets, faucets, & shower heads
• xeriscapingplant drought–tolerant vegetation in residential communities located in arid & semi–arid areas
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Factors Increasing Water Supplies:
Changing the flow of water
• Aquaducts– Moving water from places that have an abundance to placed that have a scarcity
– Southern California gets its water from Northern California and the Colorado River
Factors Increasing Water Supplies:
Changing the flow of water
• Providing water for people and agriculture in Southern California has had dire consequences for Mono Lake
Factors Increasing Water Supplies:
Changing the flow of water• Dams
– Dams make water more available to places where the rainfall is highly seasonable (ex. Egypt)
– Dams have bad environ-mental consequences•Built up of silt•evaporation
– Yangtze River
4. Supplying More Water4. Supplying More WaterDams & Reservoirs
Fig. 13–10 © Brooks/Cole Publishing Company / ITP
3. Recycling See question 2 2000 3. Recycling See question 2 2000
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Recycling involves various kinds of reuse of materials.
• composting is a type of recycling in which organic materials are broken down by microorganisms to produce a humus-like material that can be used to condition soils;
• primary recycling (=closed–loop recycling) involves reusing materials, such as glass, metals, paper, & plastics, to produce materials of the same type (e.g., newspaper to make newspaper & aluminum cans to make aluminum cans);
• secondary recycling (=open–loop recycling) involves using waste materials to produce different products (e.g., glass bottles to produce aggregate for use in road construction).