Population Growth Using Published Data/Computer Simulations

It is important to know

if population size varies or not

Data may be collected on

environmental factors

what may be related to the size of a population?

resource availbility

factors that contribute to population growth

births, deaths, immigration, emigration

growth rate (r) or intrinsic rate of increase

per capita basis the rate at which a population increases

r=

b-d

r=0

stable population

exponential growth

J-shaped curve, no limiting factors

discrete form

Nt+1 = Nt+Nt(r)

Nt+1

population size at the next time interval

Nt

population size at the current time

r

intrinsic rate of increase

continuous form/pert

Nt= Pe^rt

Nt

population size at any given point in time

P

beginning population

e

base of natural logarithm (2.718)

r

intrinsic rate of population increase

t

time

r > 0

population is growing

r < 0

population is declining

discrete form relates to

distinct breeding seasons

continuous form relates to

no distinct breeding seasons