Chapter 15 Outline
Case Study: “Killer Algae!”
What Are Communities?
CONCEPT 15.1 Communities are groups of interacting species that occur together at the same place and time.
- Ecologists use subsets of species to define communities
Community Structure
CONCEPT 15.2 Species diversity and species composition are important descriptors of community structure.
- Species diversity is an important measure of community structure
- Species within communities differ in their commonness or rarity
- Species diversity estimates vary with sampling effort and scale
- Species composition tells us who is in the community
Interactions of Multiple Species
CONCEPT 15.3 Communities can be characterized by complex networks of direct and indirect interactions that vary in strength and direction.
- Indirect species interactions can have large effects
- BOX 15.1 Measurements of Interaction Strength
- Species interactions vary greatly in strength and direction
- Environmental context can change the outcome of species interactions
Case Study Revisited: “Killer Algae!”
Connections in Nature: Stopping Invasions Requires Commitment
