questions 1-4. detoxifying wastes bioremediation microorganisms break down wastes ...

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

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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

© Brooks/Cole Publishing Company / ITP

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).