Exam2 Flashcards
(23 cards)
Abundance
Now many individuals
Distribution
Location of individuals
Why measure abundance?
Fundamental to ecology, management of resources, species conservation, control of pests
Vital rates are
Rates of births deaths and migration typically calculated per - capital (per individual).
Vital rates canbe used to predict?
Abundance change in the future through mathematical equations
Method of measuring abundance
Plots, transects, traps, complete sampling
What does each portion of the geometric growth equation mean?
Nt=Nt+bNf-(dNf)
N= number of individuals in population
t= unit of time
b=births per induvidual
d= deaths per individual
When does lambda mean an increasing or decreasing population?
Lambda =1 pop stable
Lambda <1 population decreasing
Lambda >1 population increasing
Lambda=0 population extinct
Density-dependent vital rates are when…
Population growth rates change as population density changes
Density independence is…
Population growth rates are not a function of density
Deterministic extinction is…
A decline to extinction of the population is predicted by the current vital rates
Stochastic vital rates are when
Variation is unpredictable. More likely to be experienced by small pop. Will lead to lower growth rate than expected
Stochastic vital rates are when
Variation is unpredictable. More likely to be experienced by small pop. Will lead to lower growth rate than expected
Stochastic extinction…
Extinction due to variation in vital rates
Environmental stochasticity
Vital rates vary with environment
Demographic stochasticity
.Vital rates vary among individuals in the same environment
Metapopulations:
A network of populations that can individually go extinct but be recolonized through dispersal. Also a group of several populations that are linked by immigration
The levins model represents
Population - level vital rates (metapopulations).
What do metapopulations depend on?
The persistence of entire metapopulations depends on empty patches being available
Matts Ta talk… Hypothesis
Fish in urban environments will experience population shifts in response to Alan exposure.
Maximum sustainable yield (msy):
Conditions under which we can maximize harvest without driving the population down
MSY is predicted at
1/2 k
Potential model problems with MSY
Problems with model
Practical problems (by catch, measuring, economics, compliance & enforcment)
Enviorment& evolution changes
