APES Vocabulary Chapter 3 House
Intrinsic Value
Value of an organism, species, ecosystem, or the earth's biodiversity based on its existence, regardless of whether it has any usefulness to us.
Instrumental Value
Value of an organism, species, ecosystem, or the earth's biodiversity based on its usefulness to us.
Watershed
a ridge of land that separates two adjacent river systems
Provisions
a stock or supply of foods
Ecosystem
a system formed by the interaction of a community of organisms with their physical environment
Resistance
an environments unwillingness to change
Heterotroph
an organism that depends on complex organic substances for nutrition
Scavengers
an organism that feeds on the dead bodies of other organisms.
Trophic Level
each step in a food chain or food web
Resilience
how quickly an environment recovers from change
Trophic Pyramid
illustrates the flow of energy through an ecosystem, energy is lost at each level
Decomposers
organisms that break down wastes and dead organisms and return raw materials to the environment
Detritivores
organisms that consume organic litter debris and dung.
Autotroph
plant capable of synthesizing its own food from simple organic substances
Biogeochemical Cycles
process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
Leaching
removal of dissolved materials from soil by water moving downwards
Limiting Nutrient
single nutrient that either is scarce or cycles very slowly, limiting the growth of organisms in an ecosystem
Photosynthesis
synthesis of compounds with the aid of radiant energy (especially in plants)
Nitrogen Fixation
the assimilation of atmospheric nitrogen by soil bacteria and its release for plant use on the death of the bacteria
Transpiration
the emission of water vapor from the leaves of plants
Cellular Respiration
the metabolic processes whereby certain organisms obtain energy from organic moelcules
Hydrologic Cycle
the natural process by which water is purified and made fresh through evaporation and precipitation. The cycle provides all the fresh water available for biological life.
Runoff
the occurrence of surplus liquid (as water) exceeding the limit or capacity
Biosphere
the regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist
Net Primary Product
the remaining energy available for consumers
Gross Primary Product
the total amount of chemical energy stored by photosynthesis, much of which is used by producers
Biomass
the total mass of living matter in a given unit area
Standing Crop
total biomass of photosynthetic autotrophs present at a given time
Food Chain
(ecology) a community of organisms where each member is eaten in turn by another member
Food Web
(ecology) a community of organisms where there are several interrelated food chains
Macronutrients
A chemical substance that an organism must obtain in relatively large amounts
Primary Consumer
An organism that eats producers
Restoration Ecology
Applying ecological principles in an effort to return ecosystems that have been disturbed by human activity to a condition as similar as possible to their natural state.
Ecological Efficiency
Percentage of energy transferred from one trophic level to another in a food chain or web
Intermediate Disturbance Hypothesis
The concept that moderate levels of disturbance can foster greater species diversity than low or high levels of disturbance.