APES Unit 2

biodegradation

the breaking down of dead organic matter by living organisms such as bacteria
bio=living (Latin)
de=from (Latin)
grade=step (Latin)

consumer

an organism that eats other organisms

decomposers

organisms (eg. bacteria and fungi) that break down wastes and dead organisms and change them into usable nutrients available to other organisms

food chain

a model that shows the flow of energy from plant to animal and from animal to animal

food pyramid

a model that show the loss of energy from one trophic level to another; often called an ecological pyramid

food web

a model of the feeding relationships within an ecosystem; formed from interconnected food chains

producers (plants)

organisms that produce food in the form of carbohydrates during photosynthesis

trophic level

steps in a food chain that show feeding and niche relationships among organisms
trophic=nourishment (Greek)

krill

tiny, shrimp-like organisms that are the main food source for salmon, squid and many species of whale

primary producers

organisms in the first trophic level, such as plants and algae

primary consumers (herbivores)

organisms in the second trophic level (eg., grasshoppers and zooplankton ), which obtain their energy by eating primary producers

secondary consumers (carnivores)

organisms in the third trophic level (eg, frogs and crabs), which obtain their energy by eating primary consumers

tertiary consumers (carnivores)

organisms in the fourth trophic level (eg, hawks and sea otters), which obtain their energy by eating secondary consumers

detrivores

consumers that feed at every trophic level, obtaining their energy and nutrients by eating dead organic matter

herbivores

primary consumers that eat plants

carnivores

secondary consumers that eat primary consumers and often other secondary consumers. They are often at the tertiary level of a food chain; also known as top carnivores

omnivores

consumers that eat both plants and animals

food webs

a model of the feeding relationships within an ecosystem; formed from interconnected food chains

food pyramid

a model that shows the loss of energy from one trophic level to another; often called an ecological pyramid

ecological pyramid

a model that shows the loss of energy from one trophic level to another; often called an ecological pyramid

nutrients

substances such as the chemicals nitrogen and phosphorus that are required by plants and animals for energy, growth, development, repair, or maintenance; important components of nutrient cycles in the biosphere

stores

nutrients that are accumulated for short or long periods of time in Earth's atmosphere, oceans, and land masses

nutrient cycle

the way nutrients are cycled in the biosphere; the continuous flows (exchanges) of nutrients in and out of stores

biogeochemical cycles

bio= life
geo=earth
chem=chemistry
biogeochemical cycles involve interactions between the biotic and abiotic components of the biosphere

carbon cycle

the nutrient cycle in which carbon is moved through the biosphere

nitrogen cycle

the nutrient cycle in which nitrogen is moved through the biosphere

phosphorus cycle

the nutrient cycle in which phosphorus is moved through the biosphere

sedimentation

the process in which soil particles and decaying organic matter accumulate in layers on the ground or at the bottom of large bodies of water, contributing to the formation of sedimentary rock

carbonate

a combination of carbon and oxygen that is dissolved in ocean water

photosynthesis

a process in which carbon dioxide enters the leaves of plants and reacts with water in the presence of sunlight to produce carbohydrates and oxygen; photosynthesis also occurs in some micro-organisms

cellular respiration

the process in which both plants and animals release carbon dioxide back into the atmosphere by converting carbohydrates and oxygen into carbon dioxide and water

nitrogen fixation

the process in which nitrogen gas is converted into compounds that contain nitrate (NO3-) or ammonium (NH4+)

nitrogen-fixing bacteria

bacteria that convert nitrogen gas (N2) into ammonium (NH4+) during decomposition, playing a significant role in nitrogen fixation

nitrification

the process in which ammonium (NH4+) is converted into nitrate (NO3-)

nitrifying bacteria

soil bacteria involved in TWO stages of nitrification.
In the first stage, certain species convert ammonium (NH4+) into nitrite (NO2-);
in the second stage, different species convert nitrite (NO2-) into nitrate(NO3-)

denitrification

the process in which nitrogen (N2) is returned to the atmosphere

denitrifying bacteria

bacteria that convert nitrate (NO3-) back into nitrogen gas

leaching

removal by water of substances that have dissolved in moist soil

eutrophication

eu=good,well (Greek)
trophic=nourishment
the process by which excess nutrients in aquatic ecosystems result in increased plant production and decay

geologic uplift

the process of mountain building in which Earth's crust folds and deeply buried rock layers rise and are exposed

pesticides

a general term for chemicals that are used to eliminate pests, such as insecticides that kill insects and herbicides that kill weeds

bioaccumulation

the gradual build-up of synthetic and organic chemicals in living organisms

Keystone species

species (eg, salmon) that can greatly affect population numbers and the health of an ecosystem

biomagnification

the process in which chemicals not only accumulate but become more concentrated at each trophic level in a food pyramid

PCB's
polychlorinated biphenyls

synthetic chemicals containing chlorine that are used in the manufacture of plastics and other industrial products, become stored in the tissue of animals, and also persist in the environment

half-life

the time it takes for a living tissue,organ, organism,or ecosystem to eliminate of half of a substance that has been introduced into it

persistent organic pollutants (POPs)

carbon-containing compounds that remain in water and soil for many years

DDT
dichlorodiphenyl trichloroethane

an insecticide and well-known persistent organic pollutant now banned in many countries

ppm

parts per million

heavy metals

metallic elements with a high density that are toxic to organisms at low concentrations

bioremediation

the use of organisms-usually micro-organisms or plants- to break down chemical pollutants in water of soil to reverse or lessen environmental damage

energy flow

the flow of energy from an ecosystem to an organism and from one organism to another

Gross primary productivity

All of the matter produced by producers

Net primary productivity

The gross primary productivity minus the energy used by the producers for cellular respiration; represents the storage of chemical energy in an ecosystem available to consumers.