APES KEY TERMS FOR EXAM

locking in

first law of thermodynamics

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

second law of thermodynamics

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

ionizing radiation

radiation with enough energy to free electrons from atoms forming ions, may cause cancer

high quality energy

organized and concentrated, can perform useful work

low quality energy

disorganized, dispersed like heat in ocean

natural radioactive decay

unstable radioisotopes decay releasing gamma rays, alpha, and beta particles

half-life

the time it takes for ½ 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

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

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 ore 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, and organic fertilizers

soil salinization

in arid regions, water evaporates leaving salts behind

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 aquifer

ENSO

El Nino Southern Oscillation, trade winds weaken and warm surface water moves toward South America. Diminished fisheries off South America, drought in western Pacific, increased precipitation in southwest 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

atmospheric nitrogen cannot be used directly by plants, it must first be converted into ammonia by bacteria

Ammonification

decomposers convert organic waste into ammonia

nitrification

ammonia is converted to nitrate ions

assimilation

inorganic nitrogen is converted into organic molecules such as DNA/amino acids and proteins

dentrification

bacteria convert ammonia back into nitrogen

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 carbon dioxide into complex carbohydrates

aerobic respiration

oxygen consuming producers, consumers and decomposers break down complex organic compounds and convert carbon back into carbon dioxide

biotic

living components of an ecosystem abioti

abiotic

nonliving components of an ecosystem

producers/autotrophs

organisms that make their own food - photosynthetic life (plants)

trophic levels

producers to primary consumer to secondary consumer to tertiary consumer

energy flow through food webs

10% of the usable energy is transferred to the next trophic level (due to 2nd law of thermodynamics)

primary succession

development of communities in a lifeless area not recently inhabited by life

secondary succession

life progress where soil remains

mutualism

symbiotic relationship where both organisms benefit

commensalism

symbiotic relationship where one organism benefits and 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, unprotect offspring

K-strategist

reproductive strategy in which organisms reproduce late, bear few, cared for offspring

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, and disease

Replacement Level Fertility

the number of children a couple must have to replace themselves (2:1)

world population

a little over 6 billion

demographic transition model:

• Preindustrial stage

• Transitional stage

• Industrial stage

• Postindustrial stage

age structure diagrams

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

1. China

2. India

3. U.S.

4. Indonesia

What are the most populous nations?

low status of women

most important factor keeping population growth rates high

methods to decrease birth rates

family planning, contraception, economic rewards and penalities

composition of water on earth

97.5% saltwater, 2.5% freshwater

aquaculture

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

point source

source from specific location such as pipe or smokestack

non-point source

source spread over an area such as agricultural/gricultural

primary sewage treatment

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

secondary sewage treatment

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

BOD

biological oxygen demand, amount of dissolved oxygen needed by aerobic decomposers to break down organic materials

eutrophication

rapid algal growth caused by an excess of nitrogen and phorophorous blocks sunlight, causing the death of aquatic plants. decdissolved oxygen for 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 and 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

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

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

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

Carbon Dioxide (CO2)

Sources include the combustion of fossil fuels. Effects: greenhouse gas - contributes to global warming. Reduction accomplished by catalytic converters, oxygenated fuel, mass transit.

Carbon Monoxide

Sources include incomplete combustion of fossil fuels. Effects: binds to hemoglobin reducing blood’s ability to carry oxygen. Reduction accomplished by catalytic converters, oxygenated fuel, and mass transit

Photochemical Smog

formed by chemical reactions involving sunlight

Acid Deposition

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

Greenhouse gases

Most significant are H2O, CO2, methane, CFCs. Trap outgoing infrared energy (heat) causing Earth to heat.

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, extreme weather, droughts, and extinctions

Ozone Depletion

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

Municipial Solid Waste

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 is reduced by 90% and waste heat can be used. Disadvantages - toxic emissions, 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, and parasites

Major Insecticide Groups

chlorinated hydrocarbons

Pesticide Pros

saves lives from insect transmitted disease, increases food supply, and increases profits for farmers.

Pesticide Cons

genetic resistance, ecosystem imbalance, pesticide treadmill, persistence, bioaccumulation, and biological magnification

Natural Pest Control

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

Genetically Modified Organisms (GMOs)

new organisms created by altering the genetic material of existing organisms, usually in an attempt to remove undesirable or create desirable characteristics in the new organisms.

Electricity Generation

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

Petroleum Formation

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

Petroleum Pros

cheap, easily transported high quality energy

Petroleum 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

1. Peat

2. Lignite

3. Bituminous Coal

4. Anthracite Coal

Nuclear Reactor

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

Alternate Energy Sources

winds, solar, waves, biomass, geothermal, and fuel cells