a place where a large quantity of a nutrient sits for a long period of time (e.g. in the water cycle, the ocean)
opposite of a reservoir, which is a site where a nutrient sits for only a short period of time (e.g. in the water cycle, a cloud)
amount of time a nutrient spends in a reservoir or an exchange pool
Law of Conservation of Matter
states that matter can neither be created nor destroyed
to convert or change into a vapor
the act or process of transpiring, or real easing water vapor, especially through the stomata of plant tissue or the pores of the skin.
the process in which animals (and plants!) breathe and give off carbon dioxide from cellular metabolism
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 release oxygen as a byproduct.
the process of burning
the conversion of atmospheric nitrogen into compounds, such as ammonia, by natural agencies or various industrial processes
the process in which soil bacteria convert ammonium (NH₄⁺) to a form that can be used by plants; nitrate, or NO₃
the process in which plants absorb ammonium (NH₃), ammonia ions (NH₄⁺), and nitrate ions (NO₃) through their roots.
the production of ammonia or ammonium compounds in the decomposition of organic matter, especially through the action of bacteria
the process by which specialized bacteria (mostly anaerobic bacteria) convert ammonia to NO₃, NO₂, and N₂, and release it back to the atmosphere.
organisms that can produce their own organic compounds from inorganic chemicals
organisms that obtain food energy by consuming other organisms or products created by other organisms
H₂O + CO₂ + solar energy → CH₂O + O₂
O₂ + H₂S + O₂ + energy → CH₂O + S + H₂O
(chemoautotroph) - an organism, such as a bacterium or protozoan, that obtains its nourishment through the oxidation of inorganic chemical compounds, as opposed to photosynthesis.
Gross Primary Productivity
(GPP) - the amount of sugar that plants produce in photosynthesis, and subtracting from it the amount of energy the plants need for growth, maintenance, repair, and reproduction.
Net Primary Productivity
(NPP) - the amount of energy that plants pass on to the community of herbivores in an ecosystem
this category includes organisms that consume producers (plants and algae).
organisms that consume primary consumers
organisms that consume secondary consumers or other tertiary consumers.
This organisms in this group derive energy from consuming nonliving organic matter such as dead animals or fallen leaves.
These are bacteria or fungi that absorb nutrients from nonliving organic matter such as plant material, the wastes of living organisms, and corpses. They convert these materials into inorganic forms.
each of the feeding levels in a 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 member, and, in turn, is preyed upon by a higher member.
a complex of interrelated food chains in an ecological community.
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.
the accumulation of a substance, such as a toxic chemical, in the tissues of a living organism.
the increasing concentration of toxin molecules at successively higher trophic levels in a food chain.
ecosystems that are based on land
aquatic life zones
ecosystems in aqueous environments
the transitional area where two ecosystems meet
(ecoregions) - smaller regions within ecosystems that share similar physical features
Law of Tolerance
describes the degree to which living organisms are capable of tolerating changes in their environment. Living organisms exhibit a range of tolerance, and even individuals within a population tolerate changes to their environment differently: This concept is the basis for natural selection, which drives evolution.
Law of the Minimum
states that living organisms will continue to live, consuming available materials until the supply of these materials is exhausted.
the number and variety of organisms found within a specified geographic region, or ecosystem. It also refers to the variability among living organisms, including the variability within and between species and within and between ecosystems.
change in a population's genetic composition over time
process in which new species are formed
a group of organisms that are capable of breeding with one another—and incapable of breeding with other species
Concept formulated by Charles Darwin that individual organisms that are better adapted for their environment will live and reproduce, ensuring that their genes are part of their population's next generation.
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.
total genetic makeup of the population
the accumulation of changes in the frequency of alleles (versions of a gene) over time due to sampling errors—changes that occur as a result of random chance.
when a population displays small scale changes over a relatively short period of time
large-scale patterns of evolution within biological organisms over a long period of time
occurs when a species cannot adapt quickly enough to environmental change and all members of the species die.
a group of organisms of the same species
formed from populations of different species occupying the same geographic area.
the total sum of a species' use of biotic and abiotic resources in its environment. Describes where the species lives, what it eats, and all of the other resources the species utilizes in an ecosystem.
the area or environment where an organism or ecological community normally lives or occurs.
arises when two individuals—of the same species or of different species—are competing for resources in the environment.
competition between two individuals of the same species
competition between two individuals of different species
when two different species in a region compete, and the better adapted species wins.
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 relocate, die out, or occupy a smaller niche.
when a species occupies a smaller niche than it would in the absence of competition
niche a species would have if there were no competition
occurs when on especies feeds on another
close, prolonged associations between two or more different organisms of different species that may, but do not necessarily, benefit each member.
both species benefit, e.g. clownfish and sea anemone
one organism benefits while the other is neither helped nor hurt, e.g. trees and epiphytes (bromeliads and some orchids)
one species is harmed and the other benefits, e.g. fleas and dogs
species whose very presence contributes to an ecosystem's diversity and whose extinction would consequently lead to the extinction of other forms of life, e.g. wolves, fig trees
species that are used as a standard to evaluate the health of an ecosystem. They are more sensitive to biological changes within their ecosystems than are other species, so they can be used as an early warning system to detect dangerous changes to a community, e.g. trout
species that originate and live or occur naturally in an area or environment.
an introduced, nonnative species.
transition in species composition of a biological community, often following ecological disturbance of the community; the establishment of a biological community in any area virtually barren of life
when ecological succession begins in a virtually lifeless area, such as the area behind a moving glacier.
ecological succession that takes place where an existing community has been cleared (by events such as fire, tornado, or human impact), but the soil has been left intact.
organisms in the first stages of primary of secondary succession
the final stage of succession, in which there is a dynamic balance between the abiotic and biotic components of the community
when the size of an organism's natural habitat is reduced, or when, for example, development occurs that isolates the habitat
the condition in which, at ecosystem boundaries, there is greater species diversity and biological density than there is in the heart of ecological communities.
the part of the earth and its atmosphere where living organisms exist or that is capable of supporting life.
an animal that only consumes other animals.
an organism that must obtain food energy from secondary sources, for example, by eating plant or animal matter.
organisms that consume both producers and primary consumers.
an organism that is capable of converting radiant energy or chemical energy into carbohydrates