1. Section 4.1 Interactions within Ecosystems
Chapter 4
Section 4.1
Interactions within Ecosystems

2. Ecology
This field of biology that deals with ecosystems and interactions between living things is known as ecology.
Ecology – the study of the interactions between organisms and their living and non-living environment.
Recall that the abiotic factors are the non-living factors that influence an organism and the biotic factors are the living things that influence an organism.

3. Levels of Organization
In this unit we will be more closely examining the levels of organization within an ecosystem.
For the purposes of this unit we will be adding one more level.
Biosphere
Biome
Ecosystem
Community
Population
Organism
A biome is a region that is characterized by the dominant plant and animal life and the prevailing climate conditions.

4. Ecotones
Ecosystems rarely have sharp boundaries, and organisms can move back and forth from one ecosystem to another.
An ecotone is the transition area between ecosystems.
Because ecotones often contain species from both bordering ecosystems they tend to have greater biodiversity.

5. Ecotones
Ecotone

6. Natural vs. Artificial Ecosystems
Artificial ecosystem – is an area that is planned or maintained by humans.
Ex. Parks, farms and managed forests.
Natural ecosystem – is an area where the living community is free to interact with the physical and chemical environment.
Ex. Lakes, rivers, forests and deserts.
Case Study Pg (#1-15)

7. Roles in Ecosystems
Each organism has a specific role that it fills in its ecosystem.
These roles are known as ecological niches.
Examples of niches:
It’s place in the food chain
It’s habitat
It’s breeding area
It’s most active time of day

8. Different species inhabit different ecological niches.
Species will adapt or change so that they do not overlap niches.
An example of adaption to niches is the warblers.

9. The Warblers
Competition for food is reduced because each species of warbler prefers to feed in a different section of the tree.
This means that each warbler is filling a different ecological niche within the forest ecosystem.

10. Exotic or Introduced Species
The introduction of a new species to an ecosystem by humans is one of the main causes of species depletion and extinction.
These exotic or introduced species invade the ecological niches of native species and compete for food and other resources.