Community Ecology Flashcards
Primary producers
thing that get eaten: plants
2 types of NONsymbiotic interspecific interactions
- predation
2. competition
INTRAspecific interactions:
interactions between members of the same species
Competition:
1 of 2 types of NONsymbiotic interspecific interactions
a -/-interaction between individuals of different species competing for shared resources
Ectoparasites:
1 of 2 types of parasites in parasitism
parasites that feed externally on their host
e.g. from class: ticks feed on blood from host’s skin
Savanna:
open/unstable grassy ecosystem that supports large grazers and shelter seeking organisms
state between 2 extremes: grassland (no trees) and woodland (too/many trees)
NONsymbiotic interspecific interactions
species do NOT live in prolonged intimate contact, but still periodically associate with each other
Symbioses/symbiotic interactions
Type of INTERspecies interaction
when individuals of two species live in direct, intimate contact with each other for prolonged periods of time
2 types of parasites
ectoparasite
endoparasite
Resource partitioning:
when differentiation of niches occurs in response to limited resources and interspecific competition
e.g. from class: warblers foraging at different portions of christmas tree looking tree
Trophic cascades interaction diagram
looks like a big web of solid lines between orgs (to represent direct interactions) and dotted lines between orgs (to represent indirect interactions).
Also has + and - to indicate whether interactions are beneficial or harmful
exp. from class: diagram we drew of wolf, beaver, elk, and bison.
keystone species:???
Species that exert strong control over community structure as function of their niches such that habitat is maintained/created not by physically altering the community
Have disproportionately large impact on ecosystem relative to number/biomass of individuals present
exp. from class: the ants who successfully reduced herbivory on behalf of the trees they lived in
What was the CONCLUSION of the elephant/ant experiment from class?
After reducing the ants in certain trees by a measurable amount, the trees with fewer ants were eaten more by elephants.
“Acacia/ant mutualism integral to maintenance of savanna ecosystems by preventing overbrowsingof acacias by elephants”
Primary consumers
things that eat plants: herbivores
Parasitism:
1 of 3 types of symbiotic interaction
+/-relationship (good for the parasite, bad for the host)
Ecosystem engineers:
species that directly and dramatically alter their physical environment such that habitat is maintained or created
exp. from class: elephants knocking down trees to eat them, tipping the balance of savanna towards grassland or woodland
Ecological niche:
the sum of a species’ use of its biotic and abiotic environment
competitive exclusion principle
Two species cannot share a niche because one always outcompetes the other competitive exclusion
Community:
a group of populations of different species that live close enough to one another to interact
Interspecific interactions:
interactions between individuals of different species
Defined by the effects the interaction has on the organisms involved
What was the point of the elephant/ant experiment from class?
To test H0: The savanna is not lost to elephant overbrowsingbecause ants viciously protect their acacia hosts and prevent elephants from eating them
Grassland
Grassy, extreme opposite of woodland.
Trophic cascades:
type of indirect interaction
when the effects of higher trophic level trickle down to lower levels
predators limit the density/behavior of their prey, thus enhance survival of next lower trophic level
exp. from class: otters eat urchin eat kelp; removing otter leaves too many urchin who eat too many kelp
Tertiary consumers
Things that eat things that eat things that eat the things that eat plants: carnivore eaters
exp. from class: sharks (eat otters eat urchin eat kelp)
