distribution + abundance Flashcards
population
group of individ. of spp. inhabiting an area
what do pops. generally consist of?
localized groups of individ., representing a fraction of the total.
endemic species
all individ. of spp. confined to particular area
extinction
no individ. of spp. are still alive.
extirpation (local extinction)
no individ. of spp. are alive/present in given area
sympatric distribution
occurs in same area. overlapping geographic distributions.
allopatric distribution
not occurring in same area. separate geographic distributions.
parapatric distribution
continguous. no overlap.
what limits distribution?
physical environment, including temp., water availability, nutrients + resources.
what are distribution limits determined by?
abiotic + biotic factors.
distributions at large scales
clumped. widespread, limited. metapopulations.
distributions at small scales
climatic variation is negligible. random (equal probability of occurring anywhere), regular (uniform spacing), clumped (high local abundance).
pop. density decreases with…
increasing organism size
plant pop. density decreases with…
increasing plant size
what are some aspects of pop. rarity?
geographic range. habitat tolerance. size of local pops.
