45 terms

AP Environmental Science Chapter 3


Terms in this set (...)

The region of our planet where life resides, the combination of all ecosystems on Earth
An organism that uses the energy of the Sun to produce usable forms of energy (also known as autotroph)
The process by which producers use solar energy to convert carbon dioxide and water into glucose
Cellular respiration
The process by which cells unlock the energy of chemical compounds
An organism that is incapable of photosynthesis and must obtain its energy by consuming other organisms (also known as heterotroph)
A consumer that eats producers (also known as Primary consumer)
A consumer that eats other consumers
Secondary consumer
A carnivore that eats primary consumers
Tertiary consumer
A carnivore that eats secondary consumers
Trophic levels
The successive levels of organisms consuming one another
Food web
A complex model of how energy and matter move between trophic levels
An organism that consumes dead animals
An organism that specializes in breaking down dead tissues and waste products into smaller particles
The fungi and bacteria that complete the breakdown process by converting organic matter into small elements and molecules that can be recycled back into the ecosystem.
Gross Primary Productivity
The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time
Net Primary Productivity
The energy captured by produces in an ecosystem minus the energy producers respire
The total mass of all living matter in a specific area
Standing crop
The amount of biomass present in an ecosystem at a particular time
Ecological efficiency
The proportion of consumed energy that can be passed from one trophic level to another
Trophic pyramid
A representation of the distribution of biomass, numbers, or energy among trophic levels
Biogeochemical cycle
The movements of matter within and between ecosystems
Hydrologic cycle
The movement of water through the biosphere
The release of water from leaves during photosynthesis
The combined amount of evaporation and transpiration
Water that moves across the land surface and into streams and rivers
Carbon Cycle
The movement of carbon around the biosphere
Key elements that organisms need in relatively large amounts: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur
Limiting nutrient
A nutrient required for the growth of an organism but available in a lower quantity than other nutrients
Nitrogen cycle
The movement of nitrogen around the biosphere
Nitrogen fixation
A process by which some organisms can convert nitrogen gas molecules directly into ammonia
The conversion of ammonia into nitrite and then into nitrate
The process by which producers incorporate elements into their tissues
The process by which fungal and bacterial decomposers break down the organic matter found in dead bodies and waste products and convert it into inorganic compounds
The process by which fungal and bacterial decomposers break down the organic nitrogen found in dead bodies and waste products and convert it into inorganic ammonium
The conversion of nitrate in a series of steps into the gases nitrous oxide and, eventually, nitrogen gas, which is emitted into the atmosphere
The transportation of dissolved molecules through the soil via groundwater
Phosphorus cycle
The movement of phosphorus (which rarely changes form) around the biosphere
Low in oxygen
Sulfur cycle
The movement of sulfur around the biosphere
An event, caused by physical , chemical, or biological agents, resulting in changes in population size or community composition
All land in a given landscape that drains into a particular stream, river, lake, or wetland
A measure of how much a disturbance can affect flows of energy and matter in an ecosystem
The rate at which an ecosystem returns to its original state after a disturbance
Restoration ecology
The study and implementation of restoring damaged ecosystems
Intermediate disturbance hypothesis
The hypothesis that ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels

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