Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account

aesthetic justification

An argument for the conservation of nature on the grounds that nature is beautiful and beauty is important and valuable to people

carrying capacity

largest number of individuals of a population that a environment can support, largest number of individuals of a population that a environment can support

ecological justification

an argument based on the idea that there is a value to a certain factor that my not benefit an individual directly but is crucial for maintaining the species

Gaia Hypothesis

States that the environment on a global level has been changed for the better by life over the history of life on earth.


Cities, mostly characteristic of the developing world, where high population growth and migration have caused them to explode in population since World War II. All megacities are plagued by chaotic and unplanned growth, terrible pollution, and widespread poverty.

Moral justification

Various aspects of the environment have the right to exist.

Precautionary Principle

When a threat is of serious environmental damage, we should not wait for scientific proof before taking action.


The ability of an ecosystem to maintain stability among its biological resources so that there is a steady optimun yield

sustainable ecosystem

An ecosystem that can maintain its essential functions while being harvested

sustainable resource harvest

the same quantity of a resource can be harvested each year

utilitarian justification

Sees some aspect of the environment as valuable because it benefits individuals economically or are necessary for human survival

controlled experiment

a test of the effect of a single variable by changing it while keeping all other variables the same

deductive reasoning

reasoning from the general to the particular (or from cause to effect)

dependent variable

variable that is measured and depends on the independent variable


The ability to be disproved

experimental controls

condition that insures the manipulated variable actually caused an observed change in the responding variable


a concept whose truth can be proved


a proposal intended to explain certain facts or observations

independent variable

the experimental factor that is manipulated; the variable whose effect is being studied

inductive reasoning

reasoning based on patterns you observe


logical interpretation based on prior knowledge and experience

manipulated variable

factor in an experiment that a scientist purposely changes; also known as independent variable


a symbolic representation of an idea, system, or structure to make somthing understandable


a personal experience as seen through one of the senses, influenced by background knowledge and personal experiences

operational definitions

clear, precise definitions and instructions about how to observe and measure concepts and variables


the statements that set forth the reasons or evidence


a measure of how likely it is that some event will occur


Ideas that are claimed to have scientific validity, but are inherently untestable and/ or lack empirical support and/ or were arrived at through faulty reasoning or poor scientific methodolog

qualitative data

Data associated with a more humanistic approach to geography, often collected through interviews, empirical observations, or the interpretation of texts, artwork, old maps

quantitative data

Data represented as numerical figures that can be expressed in numerical terms, counted, or compared on a scale

responding variable

factor in an experiment that a scientist wants to observe, which may change in response to the manipulated variable; also known as a dependent variable

scientific method

a method of investigation involving observation and theory to test scientific hypotheses

scientific theory

a theory that explains scientific observations


a widely accepted explanatory idea that is broad in scope and supported by a large body of evidence


factor being testes

average residence time

how long it takes for a material to move through a system


the regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist


all the plant and animal life of a particular region

closed system

Matter is not allowed to enter or leave

doubling time

the time required for a population to double in size


a system formed by the interaction of a community of organisms with their physical environment

environmental unity

everything affects each other.

exponential growth

growth pattern in which the individuals in a population reproduce at a constant rate


response to an inquiry or experiment

gaia hypothesis

Life controls the environment for the continuation of life

lag time

The time between a stimulus and the response of a system.

negative feedback

feedback in opposite phase with (decreasing) the input

open system

matter can enter from or escape to the surroundings

overshoot and collapse

This occurs when growth in one part of a system over time exceeds carrying capacity, resulting in sudden decline in one or both parts of the system.

positive feedback

feedback in phase with (augmenting) the input

steady state

A state in which members of a population die as quickly as new members are born


set of components or parts that function together to act as a whole.


is the idea that the geologic processes that operate today also operated in the past

age structure

proportion of people in different age groups in a population

birth rate

the ratio of live births in an area to the population of that area

death rate

the ratio of deaths in an area to the population of that area

demographic transition

change in a population from high birth and death rates to low birth and death rates

growth rate

the rate of increase in size per unit time

human carrying capacity

Theoretical estimates of the numbers of humans who could inhabit Earth at the same time

life expectancy

The estimated average number of years (or other time period used as a measure) that an individual of a specific age can expect to live.

logistic carrying capacity

in terms of the logistic curve, the population size at which births equal deaths and there is no net change in the population

logistic growth curve

phase A is exponental growth, Phase B is when population reaches carrying capacity and stops increasing rapidly

maximum lifetime

genetically determined maximum possible age to which an individual of a species can live


a group of organisms of the same species populating a given area

population dynamics

The study of changes in population sizes and the cause of these changes.


A group of individuals capable of interbreeding.

zero population growth

when the birth rate equals the death rate

Biogeochemical Cycle

the cycling of chemical elements or compounds through the atmosphere, hydrosphere, biosphere, and lithosphere

Carbon-Silicate Cycle

The cycling of carbon over long period of time, which gets involved with the cycling of silicon.

Carbon Cycle

the circulation and reutilization of carbon atoms especially via the process of photosynthesis and respiration.

Chemical Reaction

the process by which one or more substances change to produce one or more different substances


process in which fixed nitrogen compounds are converted back into nitrogen gas and returned to the atmosphere

Drainage Basin

The area that contributes to surface runoff to a stream or river

Geologic Cycle

four sequences of Earth processes: the hydrologic, rock, tectonic, and geochemical cycles

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.

Limiting Factor

condition that restricts a population's growth, such a space, disease, and food availability.


A chemical substance that an organism must obtain in relatively large amounts


Nutrients required in small or trace amounts. Some examples are phosphorus, sulfur, and potassium.

Missing Carbon Sink

Substantial amounts of carbon dioxide released into the atmosphere but apparently not reabsorbed and thus remaining unaccounted for.

Nitrogen Cycle

the circulation and reutilization of nitrogen in both inorganic and organic places.

Nitrogen Fixation

process of converting nitrogen gas into ammonia or nitrate

Phosphorus Cycle

Cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment

Plate Tectonics

the theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle

Rock Cycle

sequence of events in which rocks are formed, destroyed, altered, and reformed by geological processes

Tectonic Cycle

creation and destruction of lithosphere


Organisms that are able to make their own food

Community Level Interactions

the indirect and complicated interactions within a community. Ex: a predator feeding on its prey, which feeds on autotrophs


organisms that break down wastes and dead organisms and return raw materials to the environment

Ecological Community

A group of populations of different species living in the same area with varying degrees of interactions with others

Food Chains

a series of steps in which organisms transferring energy by eating or being eaten.

Food Webs

A complex diagram representing the many energy pathways in an ecosystem

Keystone Species

a species whose impact on its community or ecosystem are much larger and more influential than would be expected from mere abundance


the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established

Trophic Level

organism that represents a feeding step in the movement of energy and materials through an ecosystem


A boundary of an ecosystem on land; within this area all the water that reaches this area will flow out the same stream

Biological diversity

The variety and complexity of species present and interacting in an ecosystem and the relative abundance of each.

Biological Evolution

Basically, the theory that present days species developed from earlier, very different species over the course of earth's history.

Competitive Exclusion Principle

ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time

Ecological Niche

(ecology) the status of an organism within its environment and community (affecting its survival as a species)


(genetics) a segment of DNA that is involved in producing a polypeptide chain

Genetic Drift

The gradual changes in gene frequencies in a population due to random events


the type of environment in which an organism or group normally lives or occurs


the movement of persons from one country or locality to another


a change or alteration in form or qualities

Obligate Symbionts

two species that cannot survive without each other

Natural Selection

a natural process resulting in the evolution of organisms best adapted to the environment


a specific kind of something


the relation between two different species of organisms that are interdependent


The smaller participant in a symbiotic relationship, living in or on the host.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording