| A | B |
|---|
| carrying capacity | the maximum population of a particular species that a given habitat can sustain |
| preindustrial demographic stage | very slow population growth; birth rate and death rates are both high |
| transitional demographic stage | rapid population growth; high birth rate but dropping death rate due to improved food production and health |
| industrial demographic stage | population grow slowing as birth rates drop due to education |
| postindustrial demographic state | population growth levels off and then declines as birth rates fall below death rates |
| r-selected species | small size, short-lived, low parent care, mature rapidly, many offspring |
| K-selected species | large sized, long lived, high parent care, mature slowly, few offspring |
| biotic potential | maximum rate at which a species' population can increase when no limits are placed on its growth |
| succession | the process where plants & animals of a particular area are replaced by more complex species over time |
| species richness | the # of different species a community contains |
| species evenness | the abundance of individuals within each species in a community |
| indicator species | species whose decline serves as early warning systems in a community |
| keystone species | species that play roles affecting many other species in a community |
| foundation species | type of keystone species that creates and enhances habitats that may benefit other species in a community |
| habitat | place where an organism lives |
| niche | total way of life, or role, of a species within in an ecosystem, including all conditions needed to live and reproduce |
| generalist species | those that can live within a broad niche, such as cockroaches and rats |
| specialist species | those that are only able to live within a narrow niche |
| detrivore | last stage of food chain; eats partially decomposing organic material for nutrients; earthworms, fiddler crabs, dung flies |
| decomposer | takes in decomposing organic material by absorption and makes it into inorganic compounds; bacteria and fungi |
| net primary productivity (NPP) | rate at which energy for use by consumers is stored in biomass; net glucose |
| nitrogen fixation | conversion of atmospheric nitrogen gas (by lightning, bacteria, or cyanobacteria) into ammonium and ammonia |
| nitrification | specialized bacteria in soil convert ammonium in soil into nitrates that are then taken up by plant roots to make DNA, RNA, and proteins |
| ammonification | decomposing bacteria in soil convert detritus back into inorganic ammonia and ammonium |
| denitrification | specialized bacteria in soil convert ammonia and ammonium back into nitrogen gas that is released back into the atmosphere |
| natural capital degradation | damage or disturbance of a terrestrial community by human activities |
| salinization | accumulation of salts in soil after evaporation that can eventually make the soil unable to support plant growth |
| conservation | sensible and careful use of natural resources by humans |
| speciation | a new species arises when members become isolated for a long period of time |
| selective cutting | harvesting individual trees from a forest |
| strip cutting | harvesting portions of a forest |
| hot spot | important and endangered center of biodiversity |
| restoration | purpose is to return a damaged ecosystem to a condition as similar as possible to its original state |
| reclamation | purpose is the recovery of useful substances from waste products (recylcling) or waste land into land capable of being cultivating |
| rehabilitation | purpose is to return a damaged ecosystem to a FUNCTIONAL state |
| preservation | purpose is to set aside an UNDISTURBED area & protect it from all human activities |
| bioremediation | bacteria or enzymes help destroy toxic and hazardous waste or convert them to more benign substances |
| phytoremediation | involves using natural or genetically engineered plants to absorb, filter and remove contaminants from polluted soil and water |
| mitigation | allows the destruction of an ecosystem as long as an equal area is created or restored elsewhere; usually refers to wetlands |
| bioaccumulation | an increase in the concentration of a chemical in organs or fatty tissues of a single organism at a higher level than expected; can be passed to offspring |
| biomagnification | an increase in the concentration of a slow degradable, fat-soluble chemical in organisms at successively higher trophic levels of a food chain |
| LD50 | median lethal dose; amount of a toxic material per unit of body weight that kills half the test population in a certain time |
| threshold level | the dose level below which no toxic effects are observed and above which toxic effects are apparent |
| permeability | the rate at which water and air moves from upper to lower soil layers |
| porosity | a measure of the volume of soil and the average distances between the spaces within it |
| texture | the percentages (by weight) of different sized particles of sand, silt and clay that it contains |
| Green Revolution | the introduction of scientifically bred or selected varieties of grain that, with adequate water and fertilizer, can greatly increase crop yields |
| soil horizon | arrangement of soil into horizontal layers based on its content |
| no-till farming | crop cultivation in which the soil is not disturbed in an effort to reduce soil erosion |
| terracing | planting crops on a long, steep slope that has been converted into a serious of broad, nearly level steps with short vertical drops so as to retain water and reduce soil erosion |
| strip-cropping | planting regular crops and close-growing plants in alternating rows to help reduce depletion of soil nutirents from runoff |
| hydroponics | growing plants suspended in fertilized water |
| cogeneration | the production of two useful forms of energy from the same fuel source |
| fracking | process of blasting pressurized water, industrial additives, and sand down a well into bedrock to create fractures and release natural gas |
| MSW | municipal solid waste; produced directly by homes |
| ISW | industrial solid waste; produced indirectly by industries that supply people w/ goods and services |
| leachate | downward, percolating groundwater containing contaminates from the soil or material overlying soil |
| hydrology | the properties, distribution and effects of water on the earth's surface, in its lithosphere and in its atmosphere |
| point source pollutant | pollutant that can be traced to a single, identifiable source; smokestacks, drainage pipes, exhaust pipes |
| nonpoint source pollutant | pollutants that cannot be traced to a single site of discharge but instead cover broad areas; runoff from cropland, streets, and feedlots |
| ocean acidification | ongoing decrease in ocean pH due to uptake of anthropogenic CO2 from the atmosphere or sources such as concrete |
| eutrophication | process where inorganic nutrients within runoff cause algal blooms that then die, decay, and deplete oxygen within the water column |
| red tide | harmful algal blooms of red, brown or green toxic tides that release waterborne and airborne toxins that poison seafood |
| primary sewage treatment | a physical process that uses screens and a grit tank to remove large floating objects and allows settling |
| secondary sewage treatment | a biological process in which aerobic bacteria remove as much as 90% of dissolved and biodegradable, oxygen demanding organic wastes |
| tertiary sewage treatment | uses series of chemical and physical processes to remove specific pollutants left (especially nitrates and phosphates) & purify wastewater so that it can be reused in communities where water is scarce |
| hard water | calcium and magnesium dissolved in the water |
| turbidity | a measure of water clarity, primarily effected by sediment suspension |
| ozone depletion | decrease in concentraton of ozone in the STRATOSPHERE; major cause involves chlorofluorcarbons |
| global warming | longterm warming of the TROPOSPHERE by anthropogenic greenhouse gases |
| primary pollutant | a chemical that has been added DIRECTLY to the atmosphere in harmful quantities by either natural events or human activities |
| secondary pollutant | a harmful chemical formed IN the atmosphere by reactions with air molecules or primary pollutants |
| acid deposition | secondary air pollutant that contributes to chronic respiratory disease and can leach toxic metals (such as lead and mercury) from soils and rocks |
| greenhouse gas | CO2, CFC's, groundlevel ozone, CH4, H2O, N2O |
| positive feedback loop | causes a system to change further in the same direction (amplifies problem); global warming and melting sea ice |
| negative feedback loop | causes a system to change in the opposite direction from which it is moving (dampens); recycling |
| albedo | the proportional reflectance of the Earth’s surface, primarily due to ice and snow |
| DDT | insecticide banned in some countries but still widely used; bioaccumulates AND biomagnifies |
| BPA | found in plastics that exert weak, hormone-like properties |
| PCB | found in coolants, contain benzenes, cancer-causing, runoff has lead to endangerment of Puget Sound killer whales |
