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
griffith’s energy maximizing model
small body=less energy BENEFIT
animals will try to maximize net energy gain at the lowest energy cost=maximzing fitness
attempts:
maximize energy gain
minimize time spent to obtain a fixed amount of energy
x-axis: prey size
y-axis: energy
==optimality theory
anti-predation strategies: crypsis
hiding
*countershading: have a color, pattern, or shape that makes predators hard to find them (bc it blends into the environment)
-deer mouse
-meadow vole
-arboreal
*disruptive coloration: a form of camouflage that works by breaking up the outlines of an organism with contrasting pattern
-tigers: vertical lines
-giraffe: patchy, irregular shadows
-zebras: vertical & horizontal lines
anti-predation strategies: aposematic coloration
the organism has an obnoxious pattern that advertises to predators that it is dangerous (not worth attacking)
-lionfish
-wasp
-poison dart frogs
anti-predation strategies: batesian mimicry
aka false advertising
the mimic gain protection from the model by resembling the model
model: - (monarch, coral snake)
mimic: + (viceroy, kingsnake)
+- interaction–> special form of parasitism
anti-predation strategies: mullerian mimicry
aka truthful advertising
when two organisms share similar anti-predator characteristics and co-mimic each other
++ protocooperation: facultative mutualism
-honeybee/ yellow jacket/ velvet ant
anti-predation strategies: classical parasitism
endoparasite: tapeworm, flukes (r-selected)
ectoparasite: mosquito, tick, leech
anti-predation strategies: parasitoid
an insect whose larvae live as parasites that eventually kill the host
- parasitoid wasps (lay eggs in caterpillars & kill it)
anti-predation strategies: other forms of + -
- batesian mimicry
- breed parasite (birds)
-> obligated: have a bird raise their young
(brown-headed cowbird, European cookoos)
-> facultative: a female that typically exhibits parental care of offspring lays eggs in another organism’s nest
-> kleptoparasitism: wired to steal
(bald eagle-astray)
how to measure communities?
- density: individual/space
2.dispersion: spatial arrangement
–>uniform
–>random
–>clumped - based on species composition
–> richness: # of species in a community
–> evenness: how evenly abundant are all the species in the area
–>diversity: combination of richness and evenness
= Shannon Weiner Diversity Index
what does the important value base on?
density
frequency
dominance
habitat type: ecotone
untogradation over an entire region (over 100 miles)
a transitional area between 2 biomes
ex:
-grassland (forest & grassland)
-estuary (freshwater & saltwater)
-riverbank/marshland (dry and wet)
habitat: edge
occurs at the boundary of two habitats
-created due to abrupt changes in the environmental condition
habitat: edge effect-natural
fire, storms, shoreline
outwest
habitat along stream edge: riparian
habitat: edge effect
between forest and meadow
can spread out 2-3 tree heights into either habitats
habitat: edge species
species that stay during in edges
ex. birds
white tailed deer
habitat: interior species
don’t do well on edges
ex. cougar, wolves, eagles: wilderness species
habitat: fragmentation
habitat is broken up into fragments
ex. sheep cattle
*8 by 4: 24km/32km^2
*4 by 2: 12km/8km^2 (all edge)
what happens to the ratio?
ratio has gone up as fragments get smaller
cal-birds: expanded habitat due to fragmentation -1km
island biography theory: species-area curve
as the size of an area increases, the number of species also increases
x-axis: area
y-axis: # of species
island biography theory
the number of species inhabiting an island is impacted by the island’s land size and degree of isolation
3 processes: colonization, extinction, evolution
-island close to a source area will have a higher number of species than islands of equivalent area that are further from the source area
-large islands will have more species than smaller islands located at similar distances from the source area
island biography theory: the equilibrium model
who? MacArthur Wilson
an equilibrium when the colonization rate equals the extinction rate
-an increase in island size–>lower extinction curves
-a decrease in distance–> raise colonization curves
x-axis: S (expected # of species on an island=equilbirum)
0-P
y-axis: rate spp/t
left side (0-S): colonization=high
extinction=low
right side (S-P): colonization=low
extinction=high
colonization: exponential decay
what is the cause for extinction? competitive inclusion
island biography theory: distance effect
expect islands near each other to have more species=better colonization
near is on top
island biography theory: area effect
large islands have more competitive interactions
large is on top (left side)
large is on bottom (right side)
2 points of S (forms a diamond)
what does Oldfield Succession mean?
abandoned agricultural fields gradually change back to forest over many years
Oldfield Succession in NJ
year 0: grasses, woody forbes (plain soil)
year 1: (early) covered with dead vegetation
–>lower soil level
–>less hot (day), warm (night)
–> less wind
–> more humidity
(late) taller herbaceous plants
year 2-3: golden rod, ragweed
year 5-10: shrubs, multiflora rose, red cedar saplings
–>low evaporation rate
year 10-25: oak, maple, hickory saplings
year 100: mature oak-hickory forest
*as years increase, height increases=compete for unlimited sunlight
year 1-25: serial communities
ecological succession: primary
talus slope
-new exposed/newly formed rocks are colonized by living things for the first time
ecological succession: secondary
an area that was previously occupied by living things is disturbed, then re-colonized following the disturbance
ecological succession: pioneer species
r-selected (high mortality)
ex. dandelion
ecological succession: climax species
aka climax community
k-selected
leaves the environment the same way they found it
ex. acorn
-faster process (soil, nutrients in place from previous)
ecological succession: disclimax
-arrested successional development
-period disturbance
a disturbance climax community that occurs at the early stages of successions that are repeated with unpredictable disturbances that prevent succession from reaching a stable climax community
ex.
turkey oak sandhills/lone pine:
-adapted to fire–> grow an extensive root system
-have pine cones–> sticky residue
another fire: becomes sharp–> bottle brushes (taller instead of a bluff)
grow in sandy soil:water perkily thru
>30: wind west
<30: wind east
disturbance: natural agents
fire
moving water (floods)
wind
lack of water (drought)
animals (beavers)
pathogens (disease-organisms)
disturbance: anthropogenic agent (humans)
urbanization, suburbanization
agriculture, silviculture
surface lining
dams, canals, drainage (mercury)
pollution (coal)
