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First Law of Thermodynamics

energy is neither created nor destroyed, but may be converted from one form to another.

Second Law of Thermodynamics

when energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat).

Ionizing radiation

radiation w/enough energy to free electrons from atoms forming ions, may cause cancer (ex. gamma, X-rays, UV).

High Quality Energy

organized & concentrated, can perform useful work (ex. fossil fuels & nuclear).

Low Quality Energy

disorganized, dispersed (ex. heat in ocean or air/wind, solar).

Natural radioactive decay

unstable radioisotopes decay releasing gamma rays, alpha & beta particles (ex. Radon).

Half-life

the time it takes for 1⁄2 of the mass of a radioisotope to decay. A radioactive isotope must be stored for approximately 10 half-lives until it decays to a safe level.

Nuclear Fission

nuclei of isotopes split apart when struck by neutrons.

Nuclear Fusion

2 isotopes of light elements (H) forced together at high temperatures till they fuse to form a heavier nucleus. Happens in the Sun, very difficult to accomplish on Earth, prohibitively expensive.

Ore

a rock that contains a large enough concentration of a mineral making it profitable to mine.

Mineral Reserve

identified deposits currently profitable to extract.

Surface mining

cheaper, can remove more minerals, less hazardous to workers.

Humus

organic, dark material remaining after decomposition by microorganisms.

Leaching

removal of dissolved materials from soil by water moving downwards through soil.

Loam

perfect agricultural soil with equal portions of sand, silt, and clay.

Soil Conservation Methods

conservation tillage, crop rotation, contour plowing, organic fertilizers.

Soil Salinization

in arid regions, water evaporates leaving salts behind. (ex. Fertile crescent, southwestern US)

Water Logging

water completely saturates soil starves plant roots of oxygen, rots roots

Hydrologic Cycle Components

evaporation, transpiration, runoff, condensation, precipitation, and infiltration.

Watershed

all of the land that drains into a body of water.

Aquifer

underground layers of porous rock allow water to move slowly.

Cone of Depression

lowering of the water table around a pumping well.

Salt Water Intrusion

near the coast, overpumping of groundwater causes saltwater to move into the aquifer.

ENSO

El Nino Southern Oscillation, trade winds weaken & warm surface water moves toward South America. Diminished fisheries off South America, drought in western Pacific, increased precipitation in southwestern North America, fewer Atlantic hurricanes.

La Nina

"Normal" year, easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West coast of South America.

Nitrogen Fixation

because atmospheric N cannot be used directly by plants, it must first be converted into ammonia by bacteria.

Ammonification

decomposers covert organic waste into ammonia.

Nitrification

ammonia is converted to nitrate ions (NO3-).

Assimilation

inorganic N is converted into organic molecules such as DNA/amino acids & proteins.

Denitrification

bacteria convert ammonia back into N.

Phosphorus

does not exist as a gas; released by weathering of phosphate rocks, it is a major limiting factor for plant growth. Phosphorus cycle is slow, and not atmospheric.

Photosynthesis

plants convert CO2 (atmospheric carbon) into complex carbohydrates (glucose C6H12O6).

Aerobic Respiration

oxygen consuming producers, consumers & decomposers break down complex organic compounds & convert C back into CO2.

Biotic

the living components of an ecosystem.

Abiotic

the nonliving components of an ecosystem.

Producer/Autotroph

organisms that make their own food—photosynthetic life (plants).

Trophic Levels

producers → primary consumer → secondaryconsumer → tertiary consumer.

Energy Flow through Food Webs

10% of the usable energy is transferred to the next trophic level. Reason: usable energy lost as heat (2nd law of Thermodynamics), not all biomass is digested & absorbed, predators expend energy to catch prey.

Primary succession

development of communities in a lifeless area not recently inhabited by life (ex. lava flow, retreating glacier).

Secondary succession

life progresses where soil remains (ex. clear-cut/burned forest, old farm, vacant lot).

Mutualism

symbiotic relationship where both organisms benefit.

Commensalism

symbiotic relationship where one organism benefits & the other is unaffected.

Parasitism

relationship in which one organism (the parasite) obtains nutrients at the expense of the host.

Carrying Capacity

the number of individuals that can be sustained in an area.

r-strategist

reproductive strategy in which organisms reproduce early, bear many small, unprotected offspring (ex. insects, mice).

K-strategist

reproductive strategy in which organisms reproduce late, bear few, cared for offspring (ex. humans, elephants).

Natural Selection

organisms that possess favorable adaptations pass them onto the next generation.

Thomas Malthus

"human population cannot continue to increase. Consequences will be war, famine & pestilence (disease)."

Doubling Time

(rule of 70) doubling time equals 70 divided by percent growth rate. (ex. a population growing at 5% annually doubles in 70 ÷ 5 = 14 years)

Replacement Level Fertility

the number of children a couple must have to replace themselves (averages 2.1 in more developed nations, 2.7 in less developed nations).

World Population

a little over 6 billion.

Preindustrial stage

birth & death rates high, population grows slowly, infant mortality high.

Transitional stage

death rate (infant mortality) lower, birth rates remain high, better health care, population grows fast.

Industrial stage

decline in birth rate, population growth slows.

Postindustrial stage

low birth & death rates.

Age Structure Diagrams

broad base → rapid growth; narrow base → negative growth; uniform shape → zero growth

Most Populous Nations

(1) China; (2) India; (3) U.S.; (4) Indonesia

Low Status of Women

Most important factor keeping population growth rates high.

Methods to Decrease Birth Rates

family planning, contraception, economic rewards & penalties.

Composition of Water on Earth

97.5% seawater, 2.5% freshwater.

Aquaculture

farming aquatic species, commonly salmon, shrimp, tilapia, oysters.

Point Source

source from specific location such as pipe or smokestack

Non-Point Source (Area/Dispersed Source)

source spread over an area such as agricultural/feedlot runoff, urban runoff, traffic.

Primary Sewage Treatment

first step of sewage treatment; eliminates most particulate material from raw sewage using grates, screens, and gravity (settling).

Secondary Sewage Treatment

second step of sewage treatment; bacteria breakdown organic waste, aeration accelerates the process.

BOD

Biological Oxygen Demand, amount of dissolved oxygen needed by aerobic decomposers to break down organic materials.

Eutrophication

rapid algal growth (algal bloom) caused by an excess of nitrogen & phosphorus, blocks sunlight, causing the death/decomposition of aquatic plants, decreasing dissolved oxygen (DO), suffocating fish.

Hypoxia

water with very low dissolved oxygen levels, the end result of eutrophication, for example.

CAFE standards

Corporate Average Fuel Economy standards enacted into law in 1975, established fuel efficiency standards for passenger cars and light trucks. The fuel economy ratings for a manufacturer's entire line of passenger cars must currently average at least 27.5 mpg for the manufacturer to comply with the standard.

Primary Air Pollutants

produced by humans & nature (CO, CO2, SO2, NO, hydrocarbons, particulates).

Secondary Air Pollutants

formed by reaction of primary pollutants.

Particulate Matter

sources include burning fossil fuels and car exhaust. Effects include reduced visibility, respiratory irritation. Methods of reduction include filtering, electrostatic precipitators, alternative energy).

Nitrogen Oxides

(NOx) Major source is auto exhaust. Primary and secondary effects include acidification of lakes, respiratory irritation, leads to smog and ozone. Reduced using catalytic converters.

Equation for acid formation

NO + O2 → NO2 + H2O → HNO3.

Ozone

Secondary pollutant, NO2 + UV → NO + O; O + O2 → O3, with VOCs. Causes respiratory irritation and plant damage. Reduced by reducing NO emissions and VOCs.

Sulfur Oxides

(SOx) Primary source is coal burning. Primary and secondary effects include acid deposition, respiratory irritation, plant damage. Reduction methods include: scrubbers, burn low sulfur fuel.

Equation for acid formation

SO2 + O2 → SO3 + H2O → H2SO4

Carbon Dioxide

(CO2) Sources include the combustion of fossil fuels. Effects: greenhouse gas-contributes to global warming. Reduction accomplished by increased fuel efficiency (gas mileage), mass transit (reduction).

Carbon Monoxide

(CO) Sources include incomplete combustion of fossil fuels. Effects: binds to hemoglobin reducing bloods ability to carry O2. Reduction accomplished by catalytic converters, oxygenated fuel, mass transit (reduction).

Photochemical Smog

formed by chemical reactions involving sunlight (NO, VOC, O2)

Acid Deposition

caused by sulfuric and nitric acids resulting in lowered pH of surface waters

Greenhouse Gases

Most significant: H2O, CO2, methane (CH4), CFCs. Trap outgoing infrared energy (heat) causing earth to warm.

Greenhouse Effect

a vital process, required for life to exist on Earth. If accelerated, bad, leads to global warming.

Effects of Global Warming

rising sea level (due to thermal expansion not melting ice), extreme weather, droughts (famine), and extinctions.

Ozone Depletion

caused by CFCs, methyl chloroform, carbon tetrachloride, halon, methyl bromide all of which attack stratospheric ozone. Negative effects of ozone depletion include increased UV, skin cancer, cataracts, and decreased plant growth.

Municipal Solid Waste

is mostly paper and mostly put into landfills.

Sanitary Landfill

problems include leachate, which is solved using a liner with a collection system; methane gas, which may be collected and burned; and the volume of garbage, which may be compacted and/or reduced.

Incineration

Advantages-volume of waste reduced by 90% and waste heat can be used. Disadvantages-toxic emissions (polyvinyl chloride, dioxin), scrubbers and electrostatic precipitators needed, ash disposal.

Best Solution for Waste Problem

reduce the amount of waste at the source.

Brownfield

abandoned industrial sites.

Keystone Species

species whose role in an ecosystem is more important than others.

Indicator Species

species that serve as early warnings that an ecosystem is being damaged.

In Natural Ecosystems

50-90% of pest species are kept under control by: predators, diseases, parasites.

Major Insecticide Groups

chlorinated hydrocarbons—ex. DDT; organophosphates—ex. malathion; carbamates—ex. aldicarb

Pesticide Pros

saves lives from insect transmitted disease, increases food supply, and increases profits for farmers. Cons: genetic resistance, ecosystem imbalance, pesticide treadmill, persistence, bioaccumulation, and biological magnification.

Natural Pest Control

better agricultural practices, genetically resistant plants, natural enemies, and biopesticides, sex attractants.

Genetically Modified Organisms (GMOs)

new organisms created by altering the genetic material (DNA) of existing organisms; usually in an attempt to remove undesirable or create desirable characteristics in the new organism.

Electricity Generation

steam, from water boiled by fossils fuels or nuclear energy, or falling water is used to turn a generator.

Petroleum (Crude Oil) Formation

microscopic aquatic organisms in sediments converted by heat & pressure into a mixture of hydrocarbons.

Petroleum Pros

cheap, easily transported, high-quality energy. Cons: reserves depleted soon, pollution during drilling, transport and refining, land subsidence, burning oil produces CO2.

Coal Formation

prehistoric plants buried un-decomposed in oxygen-depleted water of swamps/bogs converted by heat and pressure.

Ranks of Coal

peat, lignite, bituminous coal, anthracite coal.

Nuclear Reactor

consists of a core, control rods, moderator, steam generator, turbine, containment building.

Alternate Energy Sources

wind, solar, waves, biomass, geothermal, fuel cells

Remediation

return a contaminated area to its original state.

LD-50

the amount of a chemical that kills 50% of the animals in a test population

Troposphere

first layer of atmosphere 0-10 miles above the Earth's surface. Contains weather, greenhouse gases (bad ozone).

Stratosphere

second layer of atmosphere 10-30 miles above the Earth's surface. Contains protective ozone layer (good ozone).

Inversion Layer (Temperature Inversion)

a warm layer of air above a cooler layer traps pollutants close to the Earth's surface.

Mutagen

substances that cause changes in DNA; may result in hereditary changes.

Teratogen

substances that cause fetus deformities (birth defects).

Carcinogen

substances that cause cancer.

Dioxin

one of the most toxic human-made chemicals. Stable, long-lived, by-product of herbicide production enters environment as fallout from the incineration of municipal and medical waste and persists for many years.

PCBs (Polychlorinated Biphenyls)

Stable, long-lived, carcinogenic chlorinated hydrocarbons. Produced by the electronics industry.

Multiple Use Public Lands

National Forest & National Resource lands.

Moderately Restricted Use Public Lands

National Wildlife Refuges

Restricted Use Public Lands

National Parks & National Wilderness Preservation System

Divergent Plate Boundaries

tectonic plates spreading apart, new crust being formed (ex. mid-ocean ridges, rift valleys).

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