Module 12: Natural Disruptions to Ecosystems

Periodic disruptions

occurring regularly

Episodic disruptions

occurring somewhat regularly

Random disruptions

occurring with no regular pattern

Periodic disruption example

The cycles of the day/night or the daily and monthly cycles of the moon’s effect on ocean tides.

Episodic disruption example

Cycles of high rain and low rain that occur every 5 to 10 years.

Random disruption example

Volcanic eruptions or hurricanes.

Resistance

A measure of how much a disruption can affect the flows of energy and matter in an ecosystem.

Resilience

The rate at which an ecosystem returns to its original state after a disruption.

Intermediate disturbance hypothesis

States that ecosystems experiencing intermediate levels of disturbance will favor a higher diversity of species than those with high or low disturbance levels.

What is the relationship between a natural disruption’s duration and its spatial coverage?

Disruptions with a large spatial coverage generally last longer.

Ice cores

The long-term source for carbon dioxide levels in the atmosphere.

Long-term data for temperature comes from _______ found in ocean sediments.

Foraminifera exoskeletons