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.