1. Interactions in Ecosystems
Chapter 14 Review
Interactions in Ecosystems

2. 14.1: Habitat and Niche Every organism has a habitat and a niche.
A habitat differs from a niche.
A habitat is where a species lives. Example: the habitat of a lion is the savannah.
An ecological niche is how a species lives.
An ecological niche includes food, temperature, water, and behavior.

3. 14.2: Community Interactions
Organisms interact as individuals and as populations.
Competition and predation are two important ways in which organisms interact.
Symbiosis is a close relationship between species.

4. 14.2: Community Interactions
The ways in which organisms interact include competition, predation, mutualism, commensalism,and parasitism.
Competition is when organisms fight each other for resources. E.g. hyenas fighting lions for territory.
Predation is when organisms feed on each other. E.g. lion eating zebra
Mutualism is when organisms help each other so that they both benefit. E.g. gazelle warns zebra that lion is coming.

5. 14.2: Community Interactions
Commensalism is when one organism benefits from another, and the other is not harmed.
E.g. barnacle and whale
Parasitism is when one organism benefits and the other is harmed.
E.g. flea and dog, mosquito and human

6. 14.4: Population Growth Patterns
Populations grow in predictable patterns.
Changes in a population’s size are determined by immigration, births, emigration, and deaths.
Immigration is the movement of individuals into a population from another population.
Emigration is the movement of individuals out of a population and into another population.

7. 14.4: Population Growth Patterns
Population growth is based on available resources.
Exponential growth is when a population size increases dramatically over time because resources are abundant.
Ecological factors limit population growth.
Logistic growth is when the growth of the population is limited by lack of resources.
The carrying capacity of an environment is the maximum number of individuals in a species that the environment can support.

8. 14.5: Ecological Succession
Ecological Succession is a process of change in the species that make up a community.
Succession occurs following a disturbance in an ecosystem.
Succession is the sequence of biotic changes that regenerate a damaged community or create a community in a previously uninhabited area.

9. 14.5: Ecological Succession
There are two types of succession: primary and secondary.
Primary succession is the establishment and development of an ecosystem in an area that was previously uninhabited.
Secondary succession is the reestablishment of a damaged ecosystem in an area where the soil was left intact.