Exam Review Flashcards
confined aquifer
impermeable to water
Water table
Uppermost level at which the water fully saturates the rock or soil
groundwater recharge
when water from precipitation can percolate through the soil and work its way into an aquifer
artesian well
drilling a hole into a confined aquifer that releases its water into a well
cone of depression
an area where there is no longer any groundwater
unconfined aquifers
water can easily flow in and out
saltwater intrusion
when the salt water adjacent to a freshwater zone is able to infiltrate an area of rapid pumping where the depth and pressure on groundwater has been reduced
floodplain
when a river naturally overflows its banks during periods of spring snowmelt or heavy rainfall. improve fertility of the soil
oligotrophic lakes
lakes that have low productivity due to low amounts of nutrients such as phosphorus and nitrogen
mesotrophic lakes
lakes with a moderate level of productivity
eutrophic lakes
lakes with high level of productivity
impermeable surfaces
pavement or buildings that do not allow water penetration may cause flooding
levee
an enlarged bank built up on each side of a river to prevent flooding - can no longer fertilize an area and simply relocate flooding
dikes
built to prevent ocean waters from flooding adjacent land
dam
a barrier that runs across a river or stream to control the flow of water
reservoir
a large body of water behind a dam
benefits of dams: large amount of electricity generated through hydroelectric power
harm of dams: interrupts natural flow of water into habitats
desalination
the process by which we remove salt from salt water
(1) distillation uses heat to create salt free steam that is later condensed (2) reverse osmosis forces water through semiperm membrane w/ pressure
furrow irrigation
water flows through trenches - 65% efficient
flood irrigation
flooding an entire area with water - 70-80% efficient
spray irrigation
pumping water through spray nozzles - 75-90% efficient
drip irrigation
slowly dripping hose buried or laid on the surface - over 95% efficient
hydroponic agriculture
cultivation of crop plants under greenhouse conditions with roots immersed in soil less nutrient-rich solutions.
oxygen-demanding waste
organic matter that enters a body and feeds the growth of the microbes that are decomposers
PCBs
polychlorinated biphenyls, a group of industrial compounds that have caused many environmental problems and are carcinogenic
PBDEs
used as flame retardants — have been found in organisms and can cause brain damage
maximum sustainable yield (MSY)
the max amount that can be harvested without compromising the future availability of that resource
National Environmental Policy Act (NEPA)
mandates an environmental assessment of all projects involving federal money or federal permits
environmental impact statement (EIS)
outlines the scope and purpose of the project, describes the environmental content, suggests alternative approaches to the project, and analyzes the environmental impact of each alternative
zoning
a planning tool developed int he 1920s to separate industry and business from residential neighborhoods and create quieter, safer communities
sulfur dioxide
a corrosive gas that comes primarily from combustion of fuels such as coal and oil. respiratory irritant
nitrogen oxides
NO: colorless, odorless gas NO2: a pungent, reddish-brown gas. Play a role in forming troposphere ozone and photochemical smog.
carbon oxides
CO: colorless odorless gas-result of incomplete combustion CO2: colorless, odorless gas that is formed during complete combustion of fossil fuels and biomass.
photochemical oxidants
class of air pollutants formed as a results of sunlight acting on compounds such as nitrogen oxides and sulfur dioxides
smog
mixture of oxidants and particulate matter
photochemical smog
dominated by oxidants such as ozone (Los Angeles-type smog and brown smog)
sulfurous smog
dominated by sulfur dioxide and sulfate compounds sometimes called London-type smog or gray smog
volatile organic compounds (VOCs)
organic compounds that become vapors at typical atmospheric temperatures (many are hydrocarbons). can lead to formation of photochemical oxidants that can be harmful
chlorofluorocarbons (CFCs)
family of organic compounds whose properties make them ideal for use in refrigeration and air conditions
global change
change that occurs in the chemical biological, and physical properties of the planet
global climate change
changes in the climate of the earth (natural or anthropogenic climate change)
global warming
the warming of the oceans, landmasses, and atmosphere of Earth
Natural Sources of Greenhouse Gases
volcanic eruptions: can release significant amounts of PM and CO2 into the atmosphere. effects only last a couple years
methane: produced when there’s not enough oxygen to produce carbon dioxide
nitrous oxide: nitrate can be converted to nitrous oxide gas and released into the atmosphere as a powerful greenhouse gas
water vapor: most abundant greenhouse gas and the greatest natural contributor to global warming
Anthropogenic Sources of Greenhouse Gases
fossil fuels: the rate of putting CO2 into the atmosphere is much greater than the rate at which producers are consuming CO2. coal produces the most CO2, oil 85% as much, natural gas 56% as much
agricultural practices: can produce nitrous oxides + methane (livestock)
deforestation: net destruction of vegetation will increase CO2 levels
landfills: contributors of methane (low oxygen areas)
industrial production of new greenhouse chemicals: CFCs are potent greenhouse gases with very high greenhouse warming potentials
Intergovernmental Panel on Climate Change (IPCC)
a group of scientists assessing climate change
Kyoto Protocol
agreement that stated that global emissions of greenhouse gases from all industrialized countries will be reduced to 5.2% below their 1990 levels by 2012
carbon sequestration
taking CO2 out of the atmosphere by storing it in agricultural soils or retiring agricultural land
A horizon
a soil horizon; the layer below the O layer is called the A layer. The A layer is formed of weathered rock, with some organic material; often referred to as topsoil.
aquifer
an underground layer of porous rock, sand, or other material that allows the movement of water between layers of nonporous rock or clay. Aquifers are frequently tapped for wells.
arable
land that’s fit to be cultivated
asthenosphere
part of the mantle that lies just below the lithosphere
barrier island
a long, relatively narrow island running parallel to the mainland-built up by the action of waves and currents and serving to protect the coast from erosion by surf and tidal surges.
B horizon
a soil horizon; B receives the minerals and organic materials that are leached out of the A horizon.
C horizon
a soil horizon, horizon C is made up of larger pieces of rock that have not undergone much weathering.
clay
the finest soil, made up of particles that are less than 0.002 mm in diameter.
convection currents
air currents caused by the vertical movement of air due to atmospheric heating and cooling.
coral reef
an erosion-resistant marine ridge or mound consisting chiefly of compacted coral together with algal material and biochemically deposited magnesium and calcium carbonates.
Coriolis effect
The observed effect of the Coriolis force, especially the deflection of an object moving above the Earth, rightward in the Northern Hemisphere, and leftward in the Southern Hemisphere.
crop rotation
the practice of alternating the crops grown on a piece of land - for example, corn one year, legumes for two years, and then back to corn.
delta
a usually triangular alluvial deposit at the mouth of a river.
doldrums
a region of the ocean near the equator, characterized by calms, light winds, or squalls.
El Nino
a climate variation that takes place in the tropical Pacific about every three to seven years, for a duration of about one year.
estuary
the part of the wide lower course of a river where its current is met by the tides.
Green Revolution
the development and introduction of new varieties of (mainly) wheat and rice that has increased yields per acre dramatically in countries since the 1960s.
greenhouse effect
the phenomenon whereby the Earth’s atmosphere traps solar radiation, caused by the presence in the atmosphere of gases such as carbon dioxide, water vapor, and methane that allow incoming sunlight to pass through, but absorb heat radiated back from the Earth’s surface.
Hadley cell
a system of vertical and horizontal air circulation predominating in tropical and subtropical regions and creating major weather patterns.
humus
the dark, crumbly, nutrient-rich material that results from the decomposition of organic material.
land degradation
when soil becomes water-logged and then dries out, and salt forms a layer on its surface.
La Nina
a cooling of the ocean surface off the western coast of South America, occurring periodically every 4 to 12 years and affecting Pacific and other weather patterns.
lithosphere
the outer part of the Earth, consisting of the crust and upper mantle, approximately 100 km (62 miles) thick
loam
soil composed of a mixture of sand, clay, silt, and organic matter.
monoculture
the cultivation of a single crop on a farm or in a region or country; a single, homogeneous culture without diversity or dissension.
O horizon
the uppermost horizon of soil. It is primarily made up of organic material, including waste from organisms, the bodies of decomposing organisms, and live organisms.
rain shadow
the low-rainfall region that exists on the leeward (downwind) side of a mountain range. This rain shadow is the result of the mountain range’s causing precipitation on the windward side.
R horizon
The bedrock, which lies below all of the other layers of soil, is referred to as the R horizon.
salinization
the process in which soil becomes saltier and saltier until, finally, the salt prevents the growth of plants. Salinization is caused by irrigation because salts brought in with the water remain in the soil as water evaporates.
sand
the coarsest soil, with particles 0.05,2.0 mm in diameter.
silt
soil with particles 0.002,0.05 mm in diameter.
Southern Oscillation
the atmospheric pressure conditions corresponding to the periodic warming of El Nino and cooling of La Nina.
thermocline
a layer in a large body of water, such as a lake, that sharply separates regions differing in temperature, so that the temperature gradient across the layer is abrupt.
topsoil
the A layer of soil is often referred to as topsoil and is most important for plant growth.
trade winds
the more or less constant winds blowing in horizontal directions over the Earth’s surface, as part of Hadley cells
upwelling
a process in which cold, often nutrient-rich, waters from the ocean depths rise to the surface.
watershed
the region draining into river system or other body of water.
weather
the day-to-day variations in temperature, air pressure, wind, humidity, and precipitation mediated by the atmosphere in a given region.
wetlands
a lowland area, such as a marsh or swamp, that is saturated with moisture, especially when regarded as the natural habitat of wildlife.
assimilation
the process in which plants absorb ammonium (NH3), ammonia ions (NH4+), and nitrate ions (NO3) through their roots.
bioaccumulation
the accumulation of a substance, such as a toxic chemical, in various tissues of a living organism.
biomagnifications
the process by which the concentration of toxic substances increases in each successive link in the food chain.
chemotroph (chemoautotroph)
an organism such as a bacterium or protozoan, that obtains its nourishment through the oxidation of inorganic chemical compounds, as opposed to photosynthesis.
climax community
a stable, mature community in a successive series that has reached equilibrium after having evolved through stages and adapted to its environment.
community
formed from populations of different species occupying the same geographic area.
competitive exclusion
the process that occurs when two different species in a region compete and the better adapted species wins.
denitrification
process by which specialized bacteria (mostly anaerobic bacteria) convert ammonia to NOy NO2, and N2 and release it back to the atmosphere.
ecological succession
transition in species composition of a biological community, often following ecological disturbance of the community; the establishment of a biological community in any area virtually barren of life.
edge effect
the condition in which, at ecosystem boundaries, there is greater species diversity and biological density than there is in the heart of ecological communities.
Gross Primary Productivity
the amount of sugar that the plants produce in photosynthesis and subtracting from it the amount of energy the plants need for growth maintenance, repair, and reproduction.
habitat fragmentation
when the size of an organism’s natural habitat is reduced, or when development occurs that isolates a habitat.
keystone species
a species whose very presence contributes to an ecosystem’s diversity and whose extinction would consequently lead to the extinction of other forms of life.
mutualism
a symbiotic relationship in which both species benefit.
net Primary Productivity (NPP)
the amount of energy that plants pass on to the community of herbivores in an ecosystem.
niche
the total sum of a species’ use of the biotic and abiotic resources in its environment.
nitrification
the process in which soil bacteria convert ammonium (NH4+) to a form that can be used by plants; nitrate, or NO3.
nitrogen fixation
the conversion of atmospheric nitrogen into compounds, such as ammonia, by natural agencies or various industrial processes.
parasitism
a symbiotic relationship in which one member is helped by the association and the other is harmed.
pioneer species
organisms in the first stages of succession.
population
a group of organisms of the same species that live in the same area.
primary succession
when ecological succession begins in a virtually lifeless area, such as the area behind a moving glacier.
realized niche
when a species occupies a smaller niche than it would in the absence of competition.
reservoir
a place where a large quantity of a resource sits for a long period of time.
species
organisms that are capable of interbreeding with one another and incapable of breeding with other species.
albedo
the fraction of solar energy that is reflected back into space.
birth/death rate
the number of live births/deaths per 1,000 members of the population in a year.
demographic transition model
a model that’s used to predict population trends based on the birth and death rates as well as economic status of a population.
ecological footprint
the amount of the Earth’s surface that’s necessary to supply the needs of, and dispose of the waste from a particular population.
genetic drift
the random fluctuations in the frequency of the appearance of a gene in a small isolated population, presumably owing to chance, rather than natural selection.
k-selected
organisms that reproduce later in life, produce fewer offspring, and devote significant time and energy to the nurturing of their offspring.
logistic population growth
when populations are well below the size dictated by the carrying capacity of the region they live in, they will grow exponentially, but as they approach the carrying capacity, their growth rate will decrease and the size of the population will eventually become stable.
replacement birth rate
the number of children a couple must have in order to replace themselves in a population.
r-selected
organisms that reproduce early in life and often and have a high capacity for reproductive growth.
total fertility rate
the number of children an average woman will bear during her lifetime; this information is based on an analysis of data from preceding years in the population in question
agroforestry
when trees and crops are planted together, creating a mutualistic symbiotic relationship between them.
Aquaculture
the raising of fish and other aquatic species in captivity for harvest.
by-catch
any other species of fish, mammals, or birds that are caught that are not the target organism.
clear-cutting
the removal of all of the trees in an area.
contour farming
a process in which rows of crops are plowed across the hillside; this prevents the erosion that can occur when rows are cut up and down on a slope.
ecosystem capital
the value of natural resources.
intercropping (also called strip cropping)
is the practice of planting bands of different crops across a hillside.
no-till
refers to when farmers plant seeds without using a plow to turn the soil.
old growth forest
one that has never been cut; these forests have not been seriously disturbed for several hundred years.
second growth forests
areas where cutting has occurred and a new, younger forest has arisen.
selective cutting
the removal of select trees in an area; this leaves the majority of the habitat in place and has less of an impact on the ecosystem.
shelter-wood cutting
when mature trees are cut over a period of time (usually10,20 years); this leaves mature trees, which can reseed the forest, in place.
silviculture
the management of forest plantations for the purpose of harvesting timber.
surface fires
fires that typically burn only the forest’s underbrush and do little damage to mature trees. Surface fires actually serve to protect the forest from more harmful fires by removing underbrush and dead materials that would burn quickly and at high temperatures.
tailings
piles of gangue, which is the waste material that results from mining.
terracing
creating flat platforms in the hillside that provide a level planting surface, which reduces soil runoff from the slope.
Uneven-aged management
the broad category under which selective cutting and shelter-wood cutting fall; selective deforestation.
anthracite
the cleanest-burning coal; almost pure carbon.
bituminous
the second-purest form of coal.
adiabatic cooling
When air rises, it cools and expands
adiabatic heating
when air sinks the pressure on it increases and it heats up
latent heat release
the energy released as water vapor condenses into liquid
gyres
ocean surface currents rotate clockwise in the northern hemisphere and counterclockwise in the Southern Hemisphere
Causes temperature changes on land - circulates warm water
thermohaline circulation
Mixing of surface water and deep water
littoral zone
Shallow area of soil and water where algae grows
limnetic zone
rooted plants can’t survive
Floating algae and phytoplankton
profundal zone
high in nutrients low in oxygen. area for decomposes
benthic zone
Muddy bottom of a lake
standing crop
Amount of biomass present in an ecosystem at a particular time
species richness
number of species in a particular area
density-dependent factors
influence an individual’s probability of survival and reproduction in a manner that depends on the size of the population
-food, shelter
density-independent factors
Have the same effect on an individuals probability of survival and amount of reproduction at any population size
