Ecology - Lecture 10: Population ecology part 3

What does this equation do?

predicts the size of an exponentially growing population at any time t

What is carrying capacity?

maximum population size that an environment can sustainably support under a given set of environmental conditions

what is r-max?

the per capita intrinsic rate of increase under ideal conditions

what is r-obs?

the per capita intrinsic rate of increase under actual conditions

why does population size fluctuate around an average value of K?

for K to be constant, birth rates and death rates must be constant over any given time

what does it mean when birth and death rate lines cross at k?

births = deaths, so r-obs = 0

what happens below k?

births > deaths so population is growing towards K

what happen above K?

deaths > births, so the population shrinks toward K

What do fluctuations in population growth rate indicate?

a greater risk of extinction

allee effects

another form of density dependence, occur when the growth rate of a population decreases as population density decreases