exam 2 Flashcards
Survival Rate
Chance that individual at age x lives to age x+1
Survivorship
Proportion of individuals from age 0 that live to age x
Fecundity
Average # of offering produced by a female at age x
Doubling time
time for population to double in size
r
instantaneous rate of increase (instantaneous births - instantaneous deaths)
higher doubling time
larger body size
lower r
Density dependence
instantaneous birth/death rates change as a function of population size
DD effects lead to…
decreased births
increased deaths
dN/dt=rN
exponential growth equation
Nt = N_0_e^rt^
Exponential size equation
λ=(Nt+1)/Nt
Geometric growth equation
Nt=λ^t^N0
Geometric size equation
dN/dt=rN[1-(N/K)]
Logistic growth equation
K
(b-d)/(c+a)
Discrete time
interval based time
parameterized by λ
Continuous time
infinitely small time steps
parameterized by r
Time lags
Time it takes for changes to take place
Allee
Positive correlation between population density and individual fitness
Dispersal
Movement of individuals from birth site to breeding site (or vise versa). Typically a one way trip by young, but can be juveniles/adults
Migration
Round trip movement (often seasonal) for foraging/reproduction
Recruitment
Addition of new individual (usually young) into a population
Sources
Produce many migrants that disperse to other populations
Sinks
Receive more immigrants than produced immigrants
cryptos
camouflage
Symbionts
Organism that lives on/in another organism
can be mutualists or parasites
Parasites
symbiont that consumes tissues/body fluids of host
parasitoid
insect whose larvae live as parasites and kill host
Competition
Interaction of 2+ species in which all species are negatively affected by shared resource use
Resource
Required component of environment (food, space, light, nutrients…)
Fundamental Niche
Full set of resources + biotic/abiotic requirements
Realized Niche
Conditions species is restricted to in nature
always smaller than fundamental niche
Intra specific competition
negative interactions between members of same species
Inter specific competition
negative interactions between two different species
Exploitation
Individuals compete by reducing the supply of a limited resource
Interference
Individuals directly interfere with competitors
Allelopathy
Chemical inhibition of one species by another (chemical warfare)
R*
Resource requirement
Amount of limiting resource needed for population replacement
R* Rule
Species with lowest R* will prevail under equilibrium conditions
Competitive exclusion principle
two species that use a limiting respire in the same way cannot coexist indefinitely
Niche partitioning
use limiting resource differently
Mutualisms
mutually beneficial interaction between individuals of 2+ species (+/+)
Commensalism
Interaction where one specific benefits and the other species is unaffected (+/0)
Trophic mutualism
One partner receives energy/nutrients
Habitat mutualism
One partner receives shelter, a place to live, or favorable habitat
Facultative mutualism
occurring optionally
Obligate mutualism
One organism will perish without the other
Foundation species
create habitat and modify environment with positive effects on diversity, distribution, and abundance of associated organisms
Physical stress
Mechanical forces with the potential to crush/remove organisms
Physiological stress
Conditions that act on biochemical rates of an organism
