APES Chapter 6 (Unit 1)

a single organism

The individuals that belong to the same species and live in a given area at a particular time.

All of the populations of organisms within a given area.

all biotic and abiotic factors in an area

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

A limiting factor of a population wherein large, dense populations are more strongly affected than small, less crowded ones.

limiting factor that affects all populations in similar ways, regardless of population size

when a population becomes larger than the environment's carrying capacity

a rapid decline in a population due to death

dampens or buffers changes; this tends to bring the system to its equilibrium state, making it more stable.

enhances or amplifies changes; this tends to move a system away from its equilibrium state making it more unstable.

the point at which 50 percent of the test organisms die from a toxin.

when the size of each generations offspring is larger than the generation before it

population growth that levels off as population size approaches carrying capacity

a group of spatially distinct populations that are connected by the occasional movements of individuals between them

the number of individuals in a population

a strip of natural habitat that connects separated populations

Number of individuals per unit area

the way in which individuals of a population are spread out over an area or volume

a description of how individuals are distributed with respect to one another

the ratio of males to females in a population

Determines future growth potential (via individuals of reproductive age)

a species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity.

a species that has a high intrinsic growth rate, which often leads to population overshoots and die-offs.

large, long lives, few offspring, slow reproductive speed, type I, and parental care

small, short lives, many offspring, fast reproductive speed, type III, land little parental care

a pattern of survival over time in which there is high survival throughout most of the life span, but then individuals start to die in large numbers as they approach old age

a pattern of survival over time in which there is a relatively constant decline in survivorship throughout most of the life span

a pattern of low survivorship throughout the individuals life, few reach adulthood

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

The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species

animals that kill and eat other animals; eating most of what they kill

Consumers that eat only plants

An organism that lives in or on another organism, deriving nourishment at the expense of its host

the use of one species as a resource by another species

a species on which other species in an ecosystem largely depend, such that if it were removed, the ecosystem would change drastically.

series of gradual changes that occur in a community following a disturbance

N(0)e^(rt)

A relationship between two species in which both species benefit

A relationship between two organisms in which one organism benefits and the other is unaffected

the relationship of two species that live in close association with each other

competition in which a predator is instrumental in reducing the abundance of a superior competitor, allowing inferior competitors to persist

a keystone species that creates or maintains habitat for other species

An ecological succession that begins in an area where no biotic community previously existed. Areas devoid of soil (rocks), break up over time forming soil.

Succession follows a disturbance that destroys a community without destroying the soil. (climax community)

First species to populate an area during primary succession

The study of rates of colonization and extinction of species on islands or other isolated areas based on size, shape, and distance from other inhabited regions

An ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.

The largest number of individuals in a population that an environment can support with its available resources