OpenStax Biology 2e Chapter 45 Population and Community Ecology

age structure

proportion of population members at specific age ranges

aposematic coloration

warning coloration used as a defensive mechanism against predation

Batesian mimicry

type of mimicry where a non-harmful species takes on the warning colorations of a harmful one

biotic potential (rmax)

maximal potential growth rate of a species

birth rate (B)

number of births within a population at a specific point in time

carrying capacity (K)

number of individuals of a species that can be supported by the limited resources of a habitat

classical conditioning

association of a specific stimulus and response through conditioning

climax community

final stage of succession, where a stable community is formed by a characteristic assortment of plant and animal species

commensalism

relationship between species wherein one species benefits from the close, prolonged interaction, while the other species neither benefits nor is harmed

competitive exclusion principle

no two species within a habitat can coexist when they compete for the same resources at the same place and time

conditioned behavior

behavior that becomes associated with a specific stimulus through conditioning

death rate (D)

number of deaths within a population at a specific point in time

demographic-based population model

modern model of population dynamics incorporating many features of the r- and K-selection theory

demography

statistical study of changes in populations over time

density-dependent regulation

regulation of population that is influenced by population density, such as crowding effects; usually involves biotic factors

density-independent regulation

regulation of populations by factors that operate independent of population density, such as forest fires and volcanic eruptions; usually involves abiotic factors

Emsleyan/Mertensian mimicry

type of mimicry where a harmful species resembles a less harmful one

ethology

biological study of animal behavior

fecundity

potential reproductive capacity of an individual

fixed action pattern

series of instinctual behaviors that, once initiated, always goes to completion regardless of changes in the environment

foundation species

species which often forms the major structural portion of the habitat

habituation

ability of a species to ignore repeated stimuli that have no consequence

intersexual selection

selection of a desirable mate of the opposite sex

interspecific competition

competition between species for resources in a shared habitat or environment

intrasexual selection

competition between members of the same sex for a mate

intraspecific competition

competition between members of the same species

iteroparity

life history strategy characterized by multiple reproductive events during the lifetime of a species

J-shaped growth curve

shape of an exponential growth curve

K-selected species

species suited to stable environments that produce a few, relatively large offspring and provide parental care

keystone species

species whose presence is key to maintaining biodiversity in an ecosystem and to upholding an ecological community's structure

learned behavior

behavior that responds to changes in the environment

life history

inherited pattern of resource allocation under the influence of natural selection and other evolutionary forces

life table

table showing the life expectancy of a population member based on its age

logistic growth

leveling off of exponential growth due to limiting resources

migration

long-range seasonal movement of animal species

mortality rate

proportion of population surviving to the beginning of an age interval that die during the age interval

Müllerian mimicry

type of mimicry where species share warning coloration and all are harmful to predators

mutualism

symbiotic relationship between two species where both species benefit

operant conditioning

learned behaviors in response to positive and/or negative reinforcement

pioneer species

first species to appear in primary and secondary succession

population density

number of population members divided by the area or volume being measured

population growth rate

number of organisms added in each reproductive generation

population size (N)

number of population members in a habitat at the same time

primary succession

succession on land that previously has had no life

quadrat

square made of various materials used to determine population size and density in slow moving or stationary organisms

r-selected species

species suited to changing environments that produce many offspring and provide little or no parental care

relative species abundance

absolute population size of a particular species relative to the population sizes of other species within the community

S-shaped growth curve

shape of a logistic growth curve

secondary succession

succession in response to environmental disturbances that move a community away from its equilibrium

semelparity

life history strategy characterized by a single reproductive event followed by death

species dispersion pattern (also species distribution pattern)

spatial location of individuals of a given species within a habitat at a particular point in time

species richness

number of different species in a community

survivorship curve

graph of the number of surviving population members versus the relative age of the member

symbiosis

close interaction between individuals of different species over an extended period of time that impacts the abundance and distribution of the associating populations

zero population growth

steady population size where birth rates and death rates are equal