Exam 3 Flashcards
community
graphed partnership in a given place/time
interspecific interaction: mutualism
++: both organisms are benefited
mutualism (obligatory): both species depend on each other survival
protocooperation (facultative): get benefits for each other but can live without the other
ex. clownfish & anemones
interspecific interaction: commensalism
+0: one population benefits, the other is neither benefited/harmed
bird making a nest in a tree (bird gets protection, tree is unbothered)
interspecific interaction: neutralism
00: neither is benefited/harmed
ex.Bactrian camel & long-tailed tadpole shrimp (both live in desert but have minimal interactions)
what are the three symbioses
mutualism
commensalism
neutralism
interspecific interaction: amensalism
0-: one is not harmed/benefited, one is harmed
ex. you walking thru a garden (has no effect to u, but u hurt the plant)
interspecific interaction: predation/ parasitism
+-: one is benefited, one is harmed
predation: kill its prey & eats it (sheep pull out roots)
parasitism: does not kill, but consume/ harm host (cow eat grass/ tapeworm)
interspecific interaction: competition
–: both are harmed, none benefited
what is the order of ecological levels?
organismal->population->community->ecosystem
competition: resources
limited
limiting
competition: niche
grinnel 1917: considered as a subdivision of ecosystem (habitat)
elton 1927: function in an ecosystem
Hutchison 1957: hyper volume (3 dimensions)
of resource utilization
—> look at many resource axis
what are 2 possible outcomes when niche overlap is significant?
a. competitive exclusion: gauses principle
b. resource partitioning: niche shifts
competitive exclusion: gauses principle
two species competing for the same resource cannot coexist
no 2 species may occupy identical niches individually
(the superior competitor drive inferior to extinction
resource partitioning: niche shifts
a process of natural selection that will force competitors to use resources differently
fundamental niche: niche to which the gene pool has adapted
—-> represent all the environmental conditions where a species is able to live
realized niche: niche occupied in the presence of competition
—–> where the species actually live due to competition
interspecific interaction: predator-prey cycle
lynx: predator
snowshoe hare: prey
lotka-voltera predation model: the prey consumption rate by a predator is directly proportional to the prey abundance
when the population of hare decrease, the population of lynx also decreases but a few years after (a lag)
=predator lag prey (the density of one population is affecting the growth of another
x-axis: N(prey/predator)
y-axis: dN/dt (predator/prey)
prey on y-axis: down
predator on y-axis: up
predation: lemming cycle
mainly applies to the prey population
when the prey population reaches its peak, their food resources become low (when pop gets crowded, young gets killed due to crowding)
nutrient recovery hypothesis:
decomposes breaks down the chewed-up plants
(take a long time due to colder climates: takes time to recover the nutrients= causing the lag)
x-axis: time
y-axis: N
predator responses to prey density
who? buzz hollings
functional response: the amount of prey eaten has to do w/ prey eaten in proportion to the density
numerical response: a change in predator density)
functional response: Type I
linear line
x-axis: N(prey)—low/high
y-axis: the amount of prey eaten—low high
=prey are eaten in a fixed number of availability
(low prey availability, low # of prey being eaten)
functional response: Type II
linear line, then plateau
x-axis: N(prey)—low/high
y-axis: the amount of prey eaten—low high
=a maximum amount of prey predators can eat
(the rate of prey consumption by a predator rises as prey density increases, but eventually plateaus)
——> the rate of prey consumption remains constant/ does not matter if there’s more prey density
functional response: Type III
linear line, then plateau
x-axis: N(prey)—low/high
y-axis: the amount of prey eaten—low high
SSI: specific searching image
refugitive: not exposed to predators due to hiding prey
=low number of prey being eaten due to hiding