Lab 4: Population Growth Models: Logistic Growth Flashcards
Carrying capacity (K)
represents the maximum # of individuals a given environment can support. K for a population is usually given as a # of individuals/unit area
Logistic or sigmoid growth:
Type of population growth which leads to a stable and sustainable population size.
The value for r in a population at carrying capacity =
0
if r = 0 what happens to the birth and death rates.
b and d respectively must become equal. Either caused by the sharp increase in death rates as population approaches the carrying capacity or also come about by a decline in the birth rate as stress reduces the ability of females to reproduce.
What happens when population goes above K?
r can become negative as deaths outstrip births causing the population to move back to its carrying capacity.
Nt=
K/ 1+(K/No - 1) e^-rmt
-rmt=
ln((K-Nt)/((NtK-NtNo)/No)
In the game we played in class birth rates are —– and death rates are —–
birth rate is constant and death rates increases.
how is exponential growth and logistic growth different in rate of growth.
In exponential growth the rate of growth (rm) remains constant and is not affected by changes in population density. Environment is constant. In logistics growth rate steadily declines.
If the environment is constant
K is an equilibrium level around which the population may fluctuate if the environment is constant.
Equation for yield we can remove?
triangle N= Nt-No
No equation when doing an equation with a sustainable yield
K/2
