Please enable JavaScript.
Coggle requires JavaScript to display documents.
Ch. 26 Community Ecology (Metapopulations in Patchy Environments (fugitive…
Ch. 26 Community Ecology
Metapopulations in Patchy Environments
metapopulation
several local populations
interconnected by migration & gene flow
source habitat
high-quality patch
sink habitat
low-quality patch
fugitive species
survive by colonizing new patches
flourishing temporarily
colonizing more patches
assisted dispersal
assisted migration
animals captured in one area
released in another
Predator-Prey Interactions
1 Predator, 1 Prey
2 fundamental aspects
functional response
handling time
amount of time to consume prey
feeding rate
how quickly prey is found
prey- dependent
zero growth isocline
line indicating population stability
illustrates effect of prey on predator
paradox of enrichment
both species lost
predator overexploits prey
maximum sustained yield
keeping population #'s at 1 point
fixed effort harvesting
health determined by effort
w/ amount of fish or deer
must be stopped
in certain amount of time/effort
fixed quota harvesting
people are allowed to hunt
but only allowed a particular amount
Predator Selection Among Prey
3 factors in predators choice in prey
probability
that a particular prey
will be encountered
decision
by a predator
to attack an individual
probability
that an attacked prey
will be successfully eaten
optimal foraging theory
examine the interactions
to understand why herbivores eat plants
but ignore others
optimal diet model
makes four predictions
predator picks prey with most energy
high-yield prey becomes more scarce
probability of plant that is eaten depends
on abundance of other plants
how easy they are to get
some plants will be eaten, others will not
Competition Between Species
exploitation competition
when a shared resource is consmed
interference competition
one organism restricts another's
access to resources
invasive
species increasing from low population
even with its competitor present
resource
any factor that leads
to increased growth rates
Apparent Competition
plants not competing for resorce
Beneficial Interactions Between Species
mutualism
or mutualism relationship
both parties benefit
ex. pollinators and plants
facilitation
one organism helping another
without any benefit
ex. beavers and ponds
nurse plants
primary succession
organisms establish on new substrates
ex. lava and volcanoes
Interconnectedness of Species: Food Chains and Food Webs
food chain
more direct
choose one predator
identify its main prey
& plant species that support them
food web
network of numerous interrelationships
map of who feeds on whom
energy flow web
extremely difficult to construct energy
keystone species
presence or absence of certain species
affects structure of community
Concepts
community
group of species that occur together
at the same time and place
succession
predictable sequence of changes
climax community
community restoration
restoring the place species live
habitat loss
habitat fragmentation
Diversity
diversity and scale
scale
larger areas more diverse
species-area relationship
relationship between area & species richness
S=cA^z
species abundance distribution
species in abundance class
diversity and latitude
lower diversity
Canada, Siberia, Alaska
fewer species
higher diversity
Amazon rain Forest
central Africa
