AP Environmental Science full review

Ionizing radiation

enough energy to knock electrons from atoms forming ions, capable of causing cancer (ex gamma-X-rays-UV)

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)

Humus

organic, dark material remaining after decomposition by microorganisms

Leaching

removal of dissolved materials from soil by water moving downwards

Illuviation

deposit of leached material in lower soil layers (B)

Loam

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

Solutions to soil problems

conservation tillage, crop rotation, contour plowing, organic fertilizers

Parts of the hydrologic cycle

evaporation, transpiration, runoff, condensation, precipitation, infiltration

Aquifer

any water bearing layer in the ground

Salt water intrusion

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

During an El Nino year

trade winds weaken & warm water sloshed back to SA

During a Non El Nino 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

Effects of El Nino

upwelling decreases disrupting food chains, N US has mild winters, SW US has increased rainfall, less Atlantic Hurricanes

Nitrogen fixing

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 (NO-3)

Denitrification

bacteria convert ammonia back into N

Largest reservoirs of C

carbonate rocks first, oceans second

Biotic/abiotic

living & nonliving components of an ecosystem

Producer/Autotroph

photosynthetic life

Major trophic levels

producers-primary consumer-secondary consumer-tertiary consumer

Phosphorus does not circulate as easily as N because

it does not exist as a gas, but is released by weathering of phosphate rocks

Ways to conserve water

(agriculture, drip/trickle irrigation)(industry, recycling)(home, use gray water, repair leaks, low flow fixtures)

Salinazation of soil

in arid regions, water evaporates leaving salts behind

Because soils contain very little phosphorus

it is a major limiting factor for plant growth

Excess phosphorus is added to aquatic ecosystems by

runoff of animal wastes, fertilizer discharge of sewage

Photosynthesis

plants convert atmospheric C (CO2) into complex carbohydrates (glucose C6H12O6)

Aerobic respiration

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

Energy flow in food webs

only 10% of the usable energy is transferred

Why is only 10% transferred

usable energy lost as heat (2nd law), not all biomass is digested & absorbed, predators expend energy to catch prey

1st & 2nd most populated countries

China & India

Most important thing affecting population growth

low status of women

Ways to decrease birth rate

family planning, contraception, economic rewards & penalties

Percent water on earth by type

97.5% seawater, 2.5% freshwater

Age structure diagrams

(broad base, rapid growth)(narrow base, negative growth)(uniform shape, zero growth)

Postindustrial Stage

low birth & death rates

Industrial stage

decline in birth rate, population growth slows

Transitional stage

death rate lower, better health care, population grows fast

Preindustrial stage

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

World population

over 6 billion

Primary succession

development of communities in a lifeless area not previously inhabited by life (lava)

Secondary succession

life progresses where soil remains (clear cut forest)

Mutualism

symbiotic relationship where both partners benefit

Commensalism

symbiotic relationship where one partner benefits & the other is unaffected

Parasitism

relationship in which one partner obtains nutrients at the expense of the host

Biome

large distinct terrestrial region having similar climate, soil, plants & animals

Carrying capacity

the number of individuals that can be sustained in an area

R strategist

reproduce early, many small unprotected offspring

K strategist

reproduce late, few, cared for offspring

Natural selection

organisms that possess favorable adaptations pass them onto the next generation

Malthus

said human population cannot continue to increase;.consequences will be war, famine & disease

Doubling time

rule of 70 (70 divided by the percent growth rate)

Replacement level fertility

the number of children a couple must have to replace themselves (2.1 developed, 2.7 developing)

Natural radioactive decay

unstable radioisotopes decay releasing gamma rays, alpha & beta particles

Half-life

the time it takes for the mass of a radioisotope to decay. Each element has a specific half-life, could be from seconds to thousands of years. Know how to calculate: If you start with 100 Ci , 50Ci will be left in one half-life

Estimate of how long a radioactive isotope must be stored until it decays to a safe level

approximately 10 half-lives

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. Expensive, not cost effective yet as an answer to the nuclear waste problem

Ore

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

Best solution to Energy shortage

conservation and increase efficiency

Ozone

(Formation: secondary pollutant, NO2+UV=NO+O O+O2=O3, with VOC's) (Effects: respiratory irritant, plant damage) (Reduction: reduce NO emissions & VOCs)

Eutrophication

rapid algal growth caused by an excess of N (nitrogen) & P (phosphorous)

Hypoxia

when aquatic plants die, the BOD rises as aerobic decomposers break down the plants, the DO drops & the water cannot support life

Sulfur oxides

(Source: coal burning) (Effects: acid deposition, respiratory irritation, damages plants) (Equation for acid formation: SO2 + O2 = SO3 + H2O = H2SO4) (Reduction: scrubbers, burn low sulfur fuel)

Nitrogen Oxides

(Source: auto exhaust) (Effects: acidification of lakes, respiratory irritation, leads to smog & ozone) ( Equation for acid formation: NO + O2 = NO2 + H2O = HNO3) (Reduction: catalytic converter)

Carbon Oxides

(Source: auto exhaust, incomplete combustion) (Effects: CO binds to hemoglobin reducing bloods ability to carry O, CO2 contributes to global warming) (Reduction: catalytic converter, emission testing, oxygenated fuel, mass transit)

Primary air pollutants

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

Secondary pollutants

formed by reaction of primary pollutants

BOD

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

Effects of global warming

rising sea level (thermal expansion), extreme weather, droughts (famine), extinctions

Ozone depletion caused by

CFC's, methyl chloroform, carbon tetrachloride, halon, methyl bromide all of which attack stratospheric ozone

In natural ecosystems, 50-90% of pest species are kept under control by

predators, diseases, parasites

Major insecticide groups and examples

(chlorinated hydrocarbons, DDT) (organophosphates, malathion) (carbamates, aldicarb)

Incineration disadvantages

toxic emissions (polyvinyl chloride�>dioxin), scrubbers & electrostatic precipitators needed, ash disposal

Best way to alleviate the waste problem

reduce the amounts of waste at the source

Keystone species

species whose role in an ecosystem are more important than others

Love Canal, NY

chemicals from a company were buried underground, school & homes built over it, the chemicals leached out leading to birth defects & cancer Led to the Superfund act

Municipal solid waste is mostly

composed of paper

Most municipal waste is

sent to landfills

Sanitary landfill problems and solutions

(leachate, liner with collection system) (methane gas, collect gas and burn) (volume of garbage, compact & reduce)

Montreal Protocol

International meeting to phase out ozone depleting substances. Relatively successful

Kyoto Protocol (agreement)

International meeting to control global warming by setting greenhouse gas emission standards. Will be expensive.

Alternate energy sources

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

Restricted Use lands

National Parks, National Wilderness Preservation System

Moderately restricted use land

National Wildlife Refuges

Multiple use US public land

National Forest & National Resource lands

Two most serious nuclear accidents

(Chernobyl, Ukraine-total meltdown) (Three Mile Island, PA - partial meltdown)

Major parts of a nuclear reactor

core, control rods, steam generator, turbine, containment building

Cons of petroleum

depleted soon, pollution during drilling, transport and refining, burning makes CO2

Pros of petroleum

cheap, easily transported, high quality energy

Acid deposition

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

Greenhouse gases

(Examples: H2O, CO2, O3, methane (CH4), CFC's) (EFFECT: they trap outgoing infrared (heat) energy causing earth to warm

Pesticide cons

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

Pesticide pros

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

LD50

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

Mutagen, Teratogen, Carcinogen

causes hereditary changes, Fetus deformities, cancer

Surface mining

cheaper & can remove more mineral, less hazardous to workers

Point VS non point sources

(Point, from specific location such as pipe)(Non-point, from over an area such as runoff, good example: storm drains)

Electricity is generated by

using steam (from water boiled by fossils fuels or nuclear). falling water or wind to turn a generator, or photovoltaic cells

Petroleum forms from

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

Volcanoes and Earthquakes occur

at plate boundaries (divergent, spreading, mid-ocean ridges) (convergent, trenches) (transform, sliding, San Andreas)

Natural pest control

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

Industrial smog

found in cities that burn large amounts of coal

Photochemical smog

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

Incineration advantages

volume of waste reduced by 90% & waste heat can be used

Indicator species

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

Effects of ozone depletion

increased UV, skin cancer, cataracts, decreased plant growth

Particulate matter (source, effect, reduction)

(burning fossil fuels & car exhaust) (reduces visibility & respiratory irritation) (filtering, electrostatic precipitators, alternative energy)