AP Environmental Science

ammonification
the production of ammonia or ammonia compounds in the decomposition of organic matter, especially through the action of bacteria
assimilation
the process in which plants absorb ammonium (NH3), ammonia ions (NH4+), and nitrate ions (NO3) through their roots
autotroph
producers; organisms that can produce their own organic compounds from inorganic compounds. they use energy from the sun or from the oxidation of inorganic substances
bioaccumulation
the accumulation of a substance, such as a toxic chemical, in various tissues of living organisms
biomagnification
the process by which the concentration of toxic substances increases in each successive link in the food chain
biosphere
the part of the earth and its atmosphere where living organisms exist or that is capable of supporting life
carnivore
an animal that only consumes other animals
chemotroph (chemoautotroph)
an organism, such as a bacterium or protozoan, that obtains its nourishment through the oxidation of inorganic chemical compounds, as opposed to photosynthesis
climax community
a stable, mature community in a successive series that has reached equilibrium after having evolved through stages and adapted to its environment
combustion
the process of burning
community
formed from populations of different species occupying the same geographic space
competitive exclusion
the process that occurs when two different species in a region compete and the better adapted species wins
consumer
an organism that must obtain food energy from secondary sources, for example by eating plant or animal matter
decomposer
bacteria of fungi that absorb nutrients from nonliving organic matter like plant material, the wastes of living organisms, and corpses. they convert these materials into inorganic forms
denitrification
the process by which specialized bacteria (mostly anaerobic bacteria) convert ammonia to NO3, NO2, and N2 and release it back to the atmosphere
deitrivore
organism that derives energy from consuming nonliving organic matter, such as dead animals or fallen leaves. Earthworms and many species of fungi are detrivores
ecological succession
transition in species composition of abiological community, often following ecological disturbance of the community; the establishment of a biological community in any area virtually barren of life
edge effect
the condition in which, at ecosystem boundaries, there is greater species diversity and biological density than there is in the heart of ecological communities
energy pyramid
the structure obtained if we organize the amount of energy contained in producers and consumers in an ecosystem by kilocalories per square meter, from largest to smallest
evaporation
to convert or change into vapor
evolution
change in genetic composition of a population during successive generations as a result of natural selection acting on the genetic variation among individuals and resulting in the development of new species
extinction
the death of an entire species; permanent inactivity
food chain
a succession of organisms in an ecological community that constitutes a continuation of food energy from one organism to another as each consumes a lower number and, in turn, is preyed upon by a higher member
food web
a complex of interrelated food chains in an ecological community
Gause’s Principle
states that no two species can occupy the same niche at the same time, and that the species that is less fit to live in the environment will either relocate, die out, or occupy a smaller niche
gross primary productivity
the amount of sugar that the plants produce in photosynthesis, and subtracting from it the amount of energy the plant needs for growth, maintenance, repair and reproduction
habitat
the area or environment where an organisms or ecological community normally lives or occurs
habitat fragmentation
when the size of an organism’s natural habitat is reduced, or when development occurs that isolates a habitat
heterotroph
an organism that cannot synthesize its own food and is dependent on complex organic substances for nutrition
indigenous species
species that originate and live, or occur naturally, in an area or environment
invasive species
an introduced, nonnative species
keystone species
a species whose very presence contributes to an ecosystem’s diversity and whose extinction would consequently lead to the extinction of other forms of life
la of conservation of matter
states that matter can neither be creates nor destroyed
mutualism
a symbiotic relationship in which both species benefit
natural selection
the process by which, according to Darwin’s theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations, while those less adapted tend to be eliminated
net primary productivity (NPP)
the amount of energy that plants pass on to the community of herbivores in an ecosystem
niche
the total sum of a species’ use of the biotic and abiotic resources in its environment
nitrification
the process in which soil bacteria convert ammonium (NH4-) to a form that can be used by plants; nitrate or NO3-
nitrogen fixation
the conversion of atmospheric nitrogen into compounds, such as ammonia, by natural agencies or various industrial processes
omnivores
organisms that consume both producers and primary consumers
parasitism
a symbiotic relationship in which one member is helped by the association and the other is harmed
photosynthesis
the process in green plants and certain other organisms by which carbohydrates are synthesized from carbon dioxide and water using light as an energy source. most forms of photosynthesis release oxygen as a byproduct
pioneer species
organisms in the first stage of succession
population
a group of organisms of the same species that live in the same area
predation
when one species feeds on another
primary consumers
the category includes organisms that consumes producers (plants and algae)
primary succession
when ecological succession begins in a virtually lifeless area, such as the area behind a moving glacier
producer
an organism that is capable of converting radiant energy or chemical energy into carbohydrates
producer
an organism that is capable of converting radiant energy or chemical energy into carbohydrates
realized niche
when a species occupies a smaller niche than it would in the absence of competition
reservoir
a place where a large quantity of a resource sits for a long period of time
respiration
the process in which animals and plants breathe and give off carbon dioxide from cellular metabolism
residency time
the amount of time a resource spends in a reservoir or an exchange pool
secondary consumers
organisms that consume primary consumers
species
organisms that are capable of breeding with one another and incapable of breeding with other species
symbiotic relationships
close, prolonges associations between two or more different organisms of different species that may, but do not necessarily, benefit the members
tertiary consumers
organisms that consume secondary consumers or other tertiary consumers
transpiration
the act or process of transpiring, or releasing water vapor, especially through the stomata of plant tissue or the pores of the skin
trophic level
each of the feeding levels in a food chain