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Community Ecology - Coggle Diagram
Community Ecology
Metapopulations in Patchy Environments
The high-quality patch is a source habitat
Low quality patch is sink habitat
makes four assumptions
some patches are occupied by species
whereas
suitable patches are not
Empty patches will become colonized
migration from occupied patches
a region of the environment
composed of
discrete patches where species can live
Populations within individual patches
probability of going extinct within that patch
fugitive species
survives by
flourishing temporarily
colonizing more patches before it does out
colonizing new patches
population sizes always vary
with time due to predators, competition, and disturbance
assisted dispersal
animals are captured in one area
released into the new area
Empty patches are not surplus
Beneficial Interactions Between Species
facilitation
one organism; helps another without benefit
primary succession
Facilitation plays a role in succession
mutualism
Eg: pollinators
two organisms interact to benefit both
Many pioneers assocations with nitrogen-fixing bacteria
Predator-Prey Interactions
Three factors important in a predator's choice of prey
the decision by the predator to attack an individual once it has been encountered
probability that an attacked prey item will be successfully eaten
probability that a particular prey individual will be encountered
Predator selection among multiple prey
exploitation competition
organisms consume a shared resource
interference competition
organism restricts another organism's access to resources
One predator, one prey
Lotka-Volterra model
net rate of change in prey numbers as dN/dt=rN-aNP
equation for the net rate of change of predator number p/dt=faNP-qp
the predator population will be stable when the density of prey equals
helps to understand harvesting process of prey
Competition between species
apparent competition
the prey species share a predator
prey populations are low
means population of the predator is probably low
plants are not competing using a resource
Diversity and Latitude
varies in latitude
provide idea of process of community ecology
tropical regions have relatively benign environment
Diversity and Scale
species abundance distribution
species-area relationship
beta diversity
differences between small sites within a larger region
gamma diversity
number of species within a region
alpha diversity
growth forms that occur at a local
Larger areas
higher diversity in larger areas
have more variation
more diverse than smaller ones
have more types of organisms
Interconnectedness of Species: Food chains and Food Webs
three trophic levels
primary consumers
hervores
secondary consumers
carnivores
primary producers
plant, algae, cyanobacteria
study of species interaction across trophic level
Species-area relationship
S=cAsquare
Relationship between area and species
Diversity
Have maximum sustained yield
fixed efforts harvesting
fixed quota harvesting