L8 - population ecology part 2 Flashcards
what is the equation for exponential growth
Nt = N0e^rt
what is the equation for logistic growth?
Nt = K/ 1+ [(k-No)/No]e^-rt
what two variables does a survivor ship curve correlate
number of offspring to age of the species
what does a type one survivorship curve look like?
high infant and adult survivorship until end end of life
- most dying are old
what does type two survivorship curve look like?
mortality is evenly distributed over age and classes
- constant number of deaths over time
what does a type three survivorship curve look like?
high juvenile deaths, followed by constant mortality for rest of life span
- high reproduction rates offset high mortality.
what is a reproductive value?
reproductive value = present progeny + future expected progeny
changes with age.
what is a matrix model?
matrix models use estimates of vital rates at different ages to project future growth.
what is a population viability analysis (PVA)
use of a population models to estimate the probability of extinction for populations of different sizes.
what is a metapopulation?
A network of semi-isolated populations with some level of regular exchange, immigration, emigration and gene flow.
populations of populations
what are the two types of metapopulations?
sources- grow the population and export individuals
Sinks- decline the population and depends on immigration
what are the organizational hierarchy of ecology
species < population < communities < ecosystem < biosphere