Day 23 December 4th Chapter 16Last class

Dr. Amy B Hollingsworth

The University of Akron

Fall 2014

16.4 Island biogeography helps us understand the maintenance and loss of biodiversity.

Island Recolonization

1. The closer islands were recolonized more quickly than the distant islands.

2. On all of the islands, the number of insect species after fumigation returned to about the same number of insect species prior to fumigation.

3. The composition of insects on each island changed over the course of the study, even on the two control islands.

16.5−16.6

Extinction

reduces

biodiversity.

16.5 There are multiple causes of extinction.

16.6 We are in the midst of a mass extinction.

Current rates of extinction in every well-studied group of plants and animals support the hypothesis that a mass extinction is underway.

This mass extinction seems to be the result of the activity of one species—humans.

16.7–16.12 Human interferencegenerally reduces biodiversity.

16.7 Some ecosystem disturbances are reversible, others are not.

Once land is cultivated or developed, can it ever return to its natural state?

Ecological Succession

16.8 Disruptions of ecosystems can be disastrous.

1. Introductions of exotic species

Why should we worry about exotic species?

Like the brown tree snake?

WHOOPS!

16.9 Disruptions of ecosystems can be disastrous.

2. Acid rain and the burning of fossil fuel

Why do we blame global warming on humans?

Biological systems are also showing the effects of climate change.

Trees and flowers

Migratory birds

Birds and butterflies

16.11 Disruptions of ecosystems can be disastrous.

4. Depletion of the Ozone Layer

Should you be concerned about an ozone hole in our atmosphere?

16.12 Disruptions of ecosystems can be disastrous.

5. Deforestation of Tropical Rain Forests

Destruction of tropical rain forests has two serious environmental impacts:

1. Reducing biodiversity

2. Increasing greenhouse gases

16.13−16.14

We can develop

strategies for

effective

conservation.

16.13 With limited conservation resources, we must prioritize which species should be preserved.

• Thank you for a wonderful semester!

• I enjoyed meeting and talking with each one of you

• You’ve provided such valuable information for me on the value of teaching and learning

• Best of luck on your finals