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).
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).
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.
nuclei of isotopes split apart when struck by neutrons.
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.
a rock that contains a large enough concentration of a mineral making it profitable to mine.
identified deposits currently profitable to extract.
cheaper, can remove more minerals, less hazardous to workers.
organic, dark material remaining after decomposition by microorganisms.
removal of dissolved materials from soil by water moving downwards through soil.
perfect agricultural soil with equal portions of sand, silt, and clay.
Soil Conservation Methods
conservation tillage, crop rotation, contour plowing, organic fertilizers.
Hydrologic Cycle Components
evaporation, transpiration, runoff, condensation, precipitation, and infiltration.
any water-bearing layer in the ground.
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.
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.
“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.
because atmospheric N cannot be used directly by plants, it must first be converted into ammonia by bacteria.
decomposers covert organic waste into ammonia.
ammonia is converted to nitrate ions (NO3-).
inorganic N is converted into organic molecules such as DNA/amino acids & proteins.
bacteria convert ammonia back into N.
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.
plants convert CO2 (atmospheric C) into complex carbohydrates (glucose C6H12O6).
oxygen consuming producers, consumers & decomposers break down complex organic compounds & convert C back into CO2.
Largest reservoirs of Carbon
(1) carbonate rocks (2)oceans
living & nonliving components of an ecosystem.
organisms that make their own food—photosynthetic life.
producers primary consumer secondary
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), not all biomass is digested & absorbed, predators expend energy to catch prey.
development of communities in a lifeless area not previously inhabited by life (ex. lava).
life progresses where soil remains (ex. clear-cut forest, old farm).
symbiotic relationship where both organisms benefit.
symbiotic relationship where one organism benefits & the other is unaffected.
relationship in which one organism (the parasite) obtains nutrients at the expense of the host.
the number of individuals that can be sustained in an area.
reproductive strategy in which organisms reproduce early, bear many small, unprotected offspring (ex. insects, mice).
reproductive strategy in which organisms reproduce late, bear few, cared for offspring (ex. humans, elephants).
organisms that possess favorable adaptations pass them onto the next generation.
“human population cannot continue to increase. Consequences will be war, famine & pestilence (disease).”
(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 (2.1 more developed, 2.7 less).
slightly over 6 billion.
Demographic Transition Model
preindustrial stage, transitional stage, industrial stage, and industrial stage
birth & death rates high, population grows slowly, infant mortality high.
death rate (infant mortality) lower, birth rates remain high, better health care, population grows fast.
decline in birth rate, population growth slows.
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
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.
in arid regions, water evaporates leaving salts behind. (ex. Fertile crescent, southwestern US)
from specific location such as pipe or smokestack
from over an area such as agricultural (farm) runoff, traffic.
Biological Oxygen Demand, amount of dissolved oxygen needed by aerobic decomposers to break down organic materials.
rapid algal growth caused by an excess of nitrogen & phosphorus.
when aquatic plants die, the BOD rises as aerobic decomposers break down the plants, the DO drops & the water cannot support life
Primary Air Pollutants
produced by humans & nature (CO, CO2, SO2, NO, hydrocarbons, particulates).
Secondary Air Pollutants
formed by reaction of primary pollutants.
sources include burning fossil fuels and car exhaust. Effects include reduced visibility, respiratory irritation. Methods of reduction include filtering, electrostatic precipitators, alternative energy).
(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.
Secondary pollutant, NO2 + UV NO + O; O + O2 O3, with VOCs. Causes respiratory irritation and plant damage. Reduced by reducing NO emissions and VOCs.
(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
(CO2 and CO) Sources include burning fossil fuels, incomplete combustion. Effects : CO binds to hemoglobin reducing bloods ability to carry O; CO2 contributes to global warming. Reduction accomplished by catalytic converters, oxygenated fuel, mass transit (reduction).
found in cities that burn large amounts of coal
formed by chemical reactions involving sunlight (NO, VOC, O)
caused by sulfuric and nitric acids resulting in lowered pH of surface waters
Most significant: H2O, CO2, O3, methane (CH4), CFCs. Trap outgoing infrared energy (heat) causing earth to warm.
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.
caused by CFCs, methyl chloroform, carbon tetrachloride, halon, methyl bromide all of which attack stratospheric ozone.
Effects of Ozone Depletion
increased UV, skin cancer, cataracts, and decreased plant growth.
Municipal Solid Waste
is mostly paper and mostly put into landfills.
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.
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.
species whose role in an ecosystem is more important than others.
species that serve as early warnings that an ecosystem is being damaged.
Most Endangered Species
have a small range, require large territory or live on an island.
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
saves lives from insect transmitted disease, increases food supply, and increases profits for farmers.
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.
steam, from water boiled by fossils fuels or nuclear energy, or falling water is used to turn a generator.
microscopic aquatic organisms in sediments converted by heat & pressure into a mixture of hydrocarbons.
cheap, easily transported, high-quality energy.
reserves depleted soon, pollution during drilling, transport and refining, burning makes CO2.
peat, lignite, bituminous coal, anthracite coal.
consists of a core, control rods, moderator, steam generator, turbine, containment building.
Alternate Energy Sources
wind, solar, waves, biomass, geothermal, fuel cells
the amount of a chemical that kills 50% of the animals in a test population
causes hereditary changes.
causes fetus deformities.
Mutiple 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
Volcanoes and Earthquakes
Occur at tectonic plate boundaries: divergent—spreading (ex. mid-ocean ridges); convergent (ex. trenches); transform fault,—sliding (ex. San Andreas).
most abundant at convergent plate boundaries.
interbreeding with and competition from escaped farm-raised salmon from the aquaculture industry threaten the wild salmon population.
reasons for decline include shootings, poisoning, lead poisoning, collisions with power lines, egg collecting, pesticides, habitat loss, and the decline of large and medium-size native mammals due to encroachments of agriculture and urbanization.
Delhi Sands Flower-Loving Fly
a 1-inch long insect currently restricted to only 12 known populations in San Bernardino and Riverside counties. An estimated 98% of its habitat has been converted to residential, agricultural, and commercial use.
hunting and development that resulted in habitat loss and fragmentation.
subject of predator eradication programs sponsored by the Federal government. Prior to Endangered Species Act (1973), exterminated from the lower 48 states except for a few hundred inhabiting extreme northeastern Minnesota and a small number on Isle Royale, Michigan
conflict with humans and development that resulted in habitat loss and fragmentation
predation and human disturbance are thought to be the main causes of the plover’s decline. It is listed as endangered in the Great Lakes region and as threatened in the Great Plains and on the Atlantic coast
initial population decreases resulted from overharvesting for meat, oil, and leather. Today, heavy mortality occurs from accidental collisions with boats and barges, and from canal lock operations.
drainage of wetlands, conversion of grasslands to agriculture, and hunting for feathers.
overhunting and destruction of habitat caused original listing, removed from the list of endangered species by the Fish and Wildlife Service in 1987.
ingested DDT by eating contaminated fish. The pesticide caused the shells of the bird’s eggs to thin and resulted in nesting failures. Loss of nesting habitat and hunting for feathers also contributed to the population decline. Reclassified from endangered to threatened (1995).
ingested DDT by eating smaller birds, which had eaten contaminated prey. The pesticide caused the shells of the bird’s eggs to thin and resulted in nesting failures. Removed from the list of endangered species by the Fish and Wildlife Service in August 1999.
the eastern North Pacific stock of gray whale has the distinction of being the first population of a marine mammal species to be removed from the List of Endangered and Threatened Species.
large distinct terrestrial region having similar climate, soil, plants & animals.
Tropical Rain Forests
characterized by the greatest diversity of species, believed to include many undiscovered species. Occur near the equator. Soils tend to be low in nutrients. Distinct seasonality: winter is absent, and only two seasons are present (rainy and dry).
occur in eastern North America, Japan, northeastern Asia, and western and central Europe. Dominated by tall deciduous trees. Well-defined seasons include a distinct winter. Logged extensively, only scattered remnants of original temperate forests remain.
Boreal Forests or Taiga
represent the largest terrestrial biome. Dominated by needleleaf, coniferous trees. Found in the cold climates of Eurasia and North America: two-thirds in Siberia with the rest in Scandinavia, Alaska, and Canada. Seasons are divided into short, moist, and moderately warm summers and long, cold, and dry winters. Extensive logging may soon cause their disappearance.
Temperate Shrub Lands
occurs along the coast of Southern California and the Mediterranean region. Characterized by areas of Chaparral-miniature woodlands dominated by dense stands of shrubs.
grassland with scattered individual trees. Cover almost half the surface of Africa and large areas of Australia, South America, and India. Warm or hot climates where the annual rainfall is 20-50 inches per year. The rainfall is concentrated in six or eight months of the year, followed by a long period of drought when fires can occur.
dominated by grasses, trees and large shrubs are absent. Temperatures vary more from summer to winter, and the amount of rainfall is less than in savannas. Temperate grasslands have hot summers and cold winters. Occur in South Africa, Hungary, Argentina, the steppes of the former Soviet Union, and the plains and prairies of central North America.
covers about one fifth of the Earth’s surface and occur where rainfall is less than 50 cm/year. Most deserts occur at low latitudes, have a considerable amount of specialized vegetation, as well as specialized animals. Soils have abundant nutrients, need only water to become productive, and have little or no organic matter. Common disturbances include occasional fires or cold weather, and sudden, infrequent, but intense rains that cause flooding.
treeless plains that are the coldest of all the biomes. Occur in the arctic and Antarctica. Dominated by lichens, mosses, sedges, and dwarfed shrubs Characterized by extremely cold climate, permanently frozen ground (permafrost) low biotic diversity, simple vegetation structure, limitation of drainage, short season of growth and reproduction.
areas of standing water that support aquatic plants including marshes, swamps, and bogs. Species diversity is very high.
defined as having a low salt concentration (less than 1%). Plants and animals are adjusted to the low salt content and would not be able to survive in areas of high salt concentration (i.e., ocean). There are different types of freshwater regions: ponds and lakes, streams and rivers, and estuaries.
the largest of all the ecosystems. The ocean regions are separated into separate zones : intertidal, pelagic, abyssal, and benthic. All four zones have a great diversity of species.
April 26, 1986, unauthorized safety test (irony), leads to fire and explosion at nuclear power plant—millions exposed to unsafe levels of radiation.
Three-Mile Island, Pennsylvania
March 29, 1979, nuclear power plant loses cooling water 50% of core melts, radioactive materials escape into atmosphere, near meltdown (disaster).
Yucca Mountain, Nevada
controversial as proposed site for permanent storage of high-level nuclear waste, 70-miles northwest of Las Vegas, near volcano and earthquake faults.
Love Canal, NY
chemicals buried in old canal, school and homes built over it led to birth defects and cancers.
Aswan High Dam, Egypt
The silt that made the Nile region fertile fills the reservoir. Lack of irrigation controls causes waterlogging and salinization. The parasitic disease schistosomiasis thrives in the stagnant water of the reservoir.
Mental impairments, birth defects, and deaths caused by mercury dumped in Minamata Bay by factory. Mercury entered humans through their diet (fish).
December 2,1984, methyl isocyanate released accidentally by Union Carbide pesticide plant kills over 5,000.
March 24, 1989, tanker Exxon Valdez hits submerged rocks in Prince William Sound—worst oil spill in US waters.
Safe Drinking Water Act
set maximum contaminant levels for pollutants that may have adverse effects on human health.
Water Quality Act
attempt to reduce non-point source pollution.
Ocean Dumping Ban Act
bans ocean dumping of sewage sludge & industrial waste.
Clean Water Act
set maximum permissible amounts of water pollutants that can be discharged into waterways. Aim: to make surface waters swimmable and fishable.
Surface Mining Control & Reclamation Act
requires coal strip mines to reclaim the land.
Moratorium on mineral exploration for 50 years in Antarctica.
National Environmental Policy Act (NEPA)
Environmental Impact Statements must be done before any project affecting federal lands can be started.
Clean Air Act
Set emission standards for cars, and limits for release of air pollutants.
controlling global warming by setting greenhouse gas emissions targets for developed countries.
phase out of ozone depleting substances.
Resource Conservation & Recovery Act (RCRA)
controls hazardous waste with a cradle to grave system.
Comprehensive Environmental Response, Compensation & Liability Act (CERCLA)
Superfund, designed to identify and clean up abandoned hazardous waste dumpsites.
Endangered Species Act
identifies threatened and endangered species in the US, and puts their protection ahead of economic considerations.
Convention on International Trade in Endangered Species
(CITES) lists species that cannot be commercially traded as live specimens or wildlife products.
prohibits interstate transport of wild animals dead or alive without federal permit.
Federal Insecticide, Fungicide, and Rodenticide Act
regulates the effectiveness of pesticides.
Food Quality Protection Act
set pesticide limits in food, & all active and inactive ingredients must be screened for estrogenic/endocrine effects.
Low-Level Radioactive Policy Act
all states must have facilities to handle low-level radioactive wastes.
Nuclear Waste Policy Act
US government must develop a high level nuclear waste site by 2015 (see Yucca Mountain).