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Chapter 10 Outline

Case Study: A Sea in Trouble

Patterns of Population Growth

CONCEPT 10.1 Populations exhibit a wide range of growth patterns, including exponential growth, logistic growth, fluctuations, and regular cycles.

Exponential growth can occur when conditions are favorable
In logistic growth, the population approaches an equilibrium
All populations fluctuate in size
Some species exhibit population cycles

Delayed Density Dependence

CONCEPT 10.2 Delayed density dependence can cause populations to fluctuate in size.

The effect of population density is often delayed in time
Delayed density dependence affects blowfly populations

Population Extinction

CONCEPT 10.3 The risk of extinction increases greatly in small populations.

In a model, fluctuation in the population growth rate increases the risk of extinction
Small populations are at much greater risk of extinction than large populations
Chance events can drive small populations to extinction

Metapopulations

CONCEPT 10.4 Many species have a metapopulation structure in which sets of spatially isolated populations are linked by dispersal.

Metapopulations are characterized by repeated extinctions and colonizations
A metapopulation can go extinct even when suitable habitat remains
Extinction and colonization rates often vary among patches