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Population Ecology and Community Ecology - Coggle Diagram
Population Ecology and Community Ecology
density
—the number of individuals per unit area or volume
density independent
birth rate or death rate do NOT change with population size
density dependent
birth rate and death rate DO change with population size
mechanisms that can cause density dependent
-competition for resources
-territory
-disease
-intrinsic factors
-toxic wastes
exponential growth equation
represents a population’s growth when resources are relatively abundant
intrinsic rate of increase
and is the number of individuals in the population
carrying capacity
the maximum population size the environment can support
𝐾-selection
selection for life history traits that are advantages when density is high (near k) resources are low, and competition is strong
r-selection
refers to selections for life history traits that maximize reproduction succeess when density is low and there is little competition for resources
r+k STRATEGISTS ---> survival
r+ k SELECTION ---> reproduction
Competitive exclusion
two species whose members compete for the same resource cannot coexist permanently in the same place
Resource partitioning
is the differentiation of ecological niches that enables species to coexist in a community
ecological niche
functional space a species occupies within an ecosystem (two species cannot exist permanently in a community if their niches are identical)
fundamental niche
where it COULD be
realized niche
ACTUAL
bottom-up control
abundance of organisms at each trophic level is limited by nutrient supply or food availability
vs
top-down control
each trophic level is controlled by the abundance of consumers at higher trophic levels
life history
-age at first reproduction -how often they reproduce -how many offspring are produced per reproductive episode
semelparity
case where individuals undergo a "one shot" pattern of big-bang reproduction
iteroparity
case where individuals undergo repeatedd reproduction events throughout their lifetime
age structure
relative number of individuals of each age in a population
resource partitioning
the differentition of niches that enables similar species to coexist in a community
character displacement
tendency for characteristics to diverge more in sympatric than in allopatric populations of two species
aposematric coloration
animals with chemical defenses often exibit bright warning coloration
cryptic coloration
camouflage
batesian mimicry
harmless speicies but mimics a harmful species
mullerian mimicry
two or more unpalatable species resemble each other
species diversity
variety of organisms has two components
-species richness (number of different species in the community)
-relative abundance (proportion each species represents of all individuals in the community)
trophic structure
feeding relationships between organisms in a community a key factor affecting community structure and dynamics
food chain
the way energy moves plant-->herbivore--->carnivore
terms to know
