POPULATION ECOLOGY Flashcards
a constant for a population which represents the loss under ideal or non-limiting conditions
minimum mortality
important population characteristic which influences both natality and mortality
population age distribution
characteristic patterns of increase
population growth forms
density increases rapidly in exponential or compound interest, stops abruptly as environmental resistance; no equilibrium
J-shaped growth form
populations increases slowly at first, then more rapidly, but soon slows down gradually until a more or less equilibrium level is reached and maintained
S-shaped growth form
geometric or exponential growth of all populations
population growth
population is regulated by physical components (weather, water, currents, chemical limiting factors)
low diversity, physically stressed ecosystem
population tend to be biologically controlled
high diversity ecosystems
populations evolve through natural selection towards self regulation (since overpopulation id not in the best interests of any population)
in all ecosystems
growth rate for a population under ideal conditions; theoretical value that would hold if shelter, food, and other resources were unlimited, and there were no predators and pathogens
biotic potential
if the effect or action is independent of the size of the population (climate)
density-independent (density-legislative)
if the effect on the population is a function of density (biotic-competition, pathogens, parasites)
density-dependent (density-governing)
movement of individuals into or out of the population
population dispersal
one way outward movement
emigration
one way inward movement
immigration
periodic departure and return
migration
change in the population due to movements of individuals; caused by decrease and increase in number
population change
atypical (unusual) in nature; indicates lack of interactions among individuals in the populations
random
aggregation in certain areas; concentration of resources in small areas, irregular, non-random, commonest pattern
clumped
almost equal spacing; result of competition and territoriality, may occur where competition between individuals are severe
uniform
very common relationship between different species in which both species benefit from the interaction
Mutualism (obligate symbiosis)
only one of the two species involved receives a benefit from the relationship
commensalism
interaction between organisms where one organism, the parasite benefits at the expense of another organism, the host, which supplies resources
parasitism
interaction of two organisms striving for the same thing
competition
competition between two or more species populations
interspecific
refers to the flow of energy between two organisms - predator and prey; prey loses energy and the predator gains energy
predation
an animals eats a plant or plants
herbivory
