Please enable JavaScript.
Coggle requires JavaScript to display documents.
community ecology (metapopulations in patchy environments (assisted…
community ecology
metapopulations in patchy environments
conservation biology
preserving endangered species
metapopulation crucial
several local populations interconnected
gene flow b/t patches
migrations
source habitat
high quality patch
sink habitat
low quality patch
fugitive species
survives by colonizing new patches
flourishing temporarily
before it dies out in older patches
assisted dispersal
animals captured in one area then released into a new area
plant seeds of whole plants can be moved
aka assisted migration
predator prey interactions
One predator, One prey
functional response
handling time
time taken to consume
prey dependent
feeding rate increases
feeding rate
how quick to find new prey
Lotka Volterra model
N is prey individuals in a community
r is intrinsic growth rate
P is predator individuals
dN/dt is rate of prey pop change in time
zero growth isocline
line indicating population stability
dN/dt = 0
prey and predatory coexist stably
paradox of enrichment
predator prey interaction becomes unstable
may lead to predator overexploit of prey
prey zero growth , isocline rises
both species will be lost
max sustained yield
inflection point
harvest just enough to determine the inflection
populations max per capita productivity
fixed effort harvesting
alternative way to determine population health
fixed quota harvesting
fisherman / hunters allowed to harvest particular amount
competition between species
several species often compete for the same resources
interference competition
one organism restricts access to resources
example: leaves blocking light to another
invasive species
species increases from low to high population density
even with resource competitors present
exploitation competition
less available for other organisms
organisms consume shared resource
predator selection among multiple prey
most animals
omnivores
eat plants and animals
humans
vertebrate herbivores
eat plants
optimal forging theories
interaction between 3 factors:
decision to attack individual
probability that attacked prey is successfully eaten
probability that particular prey is encountered
optimal diet model
If high yield prey is scarce then, predator more successful by broadening its diet
some prey always eaten/ others never eaten even if encountered
1.predators prefer prey that yields the most energy/ handling time
less profitable prey ignored if more profitable prey is available
apparent competition
prey pop low = predator pop low
prey pop high = predator pop low
prey species share a predator
interconnectedness of species: Food chains and food webs
food chain
diect line of consumption
food web
network of numerous interrelationships
energy flow web
difficult to construct for real communities
how energy flows through a community
keystone species
dramatically affects structure of the community
reduce population of sea urchins
urchin grazing minimized
kelp spores allowed to germinate
extensive underwater forests
presence/ absence of certain species
beneficial interactions b/t species
mutualism/ mutualistic relationships
two organisms interact and both benefit
facilitation
first organism facilitates the presence of the other
one organism helps another but does not benefit
nurse plants
primary succession
organisms establishing on new substrates
diversity
diversity and scale
scale
larger areas more diverse than smaller
beta diversity - differences b/t several small sites in a larger region
gamma diversity - number of species in region
alpha beta diversity - local small site
species abundance distribution
number of species in each abundance class
diversity and latitude
theories
tropical regions have benign environments
abundant rainfall
hundreds of millions of years to adapt
warm
higher latitudes have more severe conditions
freezing
water stress
only tens of millions of years to adapt
checklist
all national parks/ wildlife preserves have checklists
always incomplete
not enough trained specialists
impossible/ unnecessary to catalog every microbe
a count of species present in a community
#
#
predator and prey
#
#
example
example
he was definitely eaten by the tigers
this is gonna be weird if you haven't seen the tiger king
