species interactions & community structure (exam4) Flashcards
Top-down hypothesis
Environments change in response to the organisms at the top of the food chain
Bottom-up hypothesis
Environments change in response to organisms at the bottom of the food chain
Commensalism
(+/0)
Competition
(-/-)
fundamental niche
total theoretical range a species can occupy
realized niche
the portion of the fundamental niche that a species actually occupies (given limiting factors)
competition hypothesis
the presence of a strong predator overrides the presence of a weak competitor
nice differentiation
The niches of two species that overlap can move away from each other over time. There is strong natural selection to avoid competition.
consumption
(+/-)
when one organism eats another
predation/herbivory/parasitism
batesian mimics
looks dangerous, not dangerous
mullerian mimics
look dangerous, are dangerous
mutualism
(+,+)
species evenness
are the number of individuals of each species in a community similar?
species richness
how many species are in a community?
species diversity
accounts for richness + evenness
keystone species
some species have a larger impact relative to the other species in the community
climax community
the optimal disribution of species that occurs over and over
Individualistic successional theory
the theory that communities are made of organisms that share similar abiotic needs
GPP (gross primary production)
the total amount of chemical energy produced in a given area and time period
NPP (net primary productivity)
represents the total amount of chemical energy that is stored in organic material or biomass
NPP=GPP-R
-R: energy used in cellular respiration or lost
-GPP: chemical energy produced
-NPP: chemical energy stored in biomass
Primary succession
soil and organisms are removed
Secondary succession
organisms are removed but soil stays
What terrestrial biome is the most productive?
tropical forests
