pop ecology Flashcards
species
a grp of closely related organisms that can interbreed + produce viable, fertile offspring
population
a grp of organisms of the same species that occupy a particular area at a specific time and that can breed with one another
community
grps of diff species populations that interact with each other within a specific habitat
community ecology
study of interactions betw pop that form a community
biotic
living organisms
abiotic
non- living organisms
ecology
study of living organisms and their relationship to each other and the enviro
pop ecology
study of the fluctuations in pop size and the factors that regulate populations
ecological niche
functional role + position of a species within a community
habitat
enviro in which an organism completes its lifecycle (growth, repro, eventually death)
niche
specific area where an organism inhabits
natality
the % incre of a pop due to no. of births in a given season/ yr
mortality
death rate whithin a pop, usually a % of pop
fertility
no. of births per yr for all females who can produce offspring (betw age 15- 45)
immigration
one way movement of organisms into an area where they become established, either for breeding season or temp
emigration
one way movement of organisms out of an area to become established
migration
movement from one place to another at certain times of the yr or during a particular period of an organism’s life cycles
enviro resistance
all factors that are limiting the biotic potential + numerical incre of a pop (eg, lack of water, food, space)
carrying capacity
largest no. of indiv in a biological species that am ecosystem can support over an indefinite time
stable population
a pop with zero growth rate, neither growing nor shrinking in size
unstable population
a pop whose size exceeds the carrying capacity of an area
density-dependent factors
factors that have a direct correlation (relationship) to the size of the pop in an area (greater pop size= greater the influences of the factors)
density-independent factors
factors that exert an influence on a pop regardless of its size
endemic
organisms found only in specific area + nowhere else in world
pop size
total no. of indiv in a pop
pop density
no. of indiv of a pop per unit area
what 3 factors influence pop size
1- natality (birthrate )
2- mortality (death rate)
3- migration ( immigration, emigration)
what 2 factors incre pop size
1- natality - rate at which new indiv added to pop via reproduction
2- immigration - rate at which indiv join a pop from a diff area
what 2 factors decre pop size
1- mortality- rate at which indiv removed from pop due to death
2- emigration - rate at which indiv leave a pop to go to another area
what are the 2 distinct patterns of natality and what are their 4 characteristics
1) r-strategy: 1- produce many offsprings, 2- small chance survival, 3- parental care absent, 4- pioneer species
2) k- strategy: 1- produce fe offsprings, 2- high chance of survival, 3- parental care present, 4- climax species
fertility rate
no. of births per 1000 females of child bearing age
fecundity rate
ave. no. of children born one gen per females pf child bearing age
