1. Section 5.4- How Ecosystems Change
Succession and Human Influence

2. Introduction Ecosystems are always changing.
Environmental change can be due to natural phenomena like weather or abandonment.
It can also be due to pollution and destruction caused by human activities.
Change in an ecosystem is often referred to as Ecological Succession

3. Ecological Succession
Defined as the gradual process of change and replacement of the types of species in a community.
May take hundreds of years or thousands of years.
There are two types: Primary and Secondary.

4. Primary Succession
Takes place in an area where no living thing has existed before.
Examples include newer volcanic islands made by the ocean.
Occurs in areas of newly exposed rock, sand dunes, cliffs, or areas with new lava.
Lichens- pioneer species which creates the soil for other organisms to grow in.

5. Over 150 years

6. Secondary Succession Takes place where an ecosystem existed before.
Examples include ecosystems changed by forest fires, plowed fields, abandoned farms, erupted volcanoes, floods.
Pioneer Species: weeds and grasses
Eventually, the ecosystem forms a climax community.

7. *Notice first box

8. Human Influence/Activity
Major influence in the change of an ecosystem.
Examples include driving cars, logging, starting forest fires, habitat destruction, and construction.
Introduction of Invasive Species -where a species is brought to live in an ecosystem it wasn’t meant to inhabit and its population goes unchecked. As a result, the community is thrown out of balance. a. Both plant and animal species can be invasive.
b. Problems associated with invasive species include:

9. Usually no predators so it consumes more than its share of resources.
Can carry disease
Introduces competition where it never existed before.
Cuban Tree Frog- introduced to Florida. Eats anything that fits into its mouth.
Red Lion Fish- originally from the Indian Ocean is now found in Florida coastal waters; poisonous

10. Invasive species can be introduced to an area intentionally or by accident.
Not all invasive species are bad. Example= The Honeybee
What can be done?
1) Nonindigenous Aquatic Nuisance Prevention and Control Act
2) Funding has become available for the control of invasive species
3) Prevention is better than trying to control their population