Intermediate Disturbance Hypothesis
The planet is constantly changing. These changes may have short or long term effects on ecosystems. The natural disruptions may be equal to or greater than their anthropogenic counterparts. Changes may happen randomly (lightning strikes cause a forest fire), periodically (hurricane season), or episodically (volcanic eruptions).
The ocean levels have changed over the course of the Earth’s history in part because of glaciers. Currently, the glaciers are melting and sea levels are rising. Coastal habitats are experiencing above normal flooding.
Animals migrate due to natural disruptions. The Canadian Geese fly south for the winter to locations that are similar to those that they just left (Canadian winters are COLD).
Resistance is a measurement of how much an ecosystem changes after a disruption (forest fire, invasive species...). If there is little change, the ecosystem has a high resistance and is considered to be quite stable.
Resilience is the measure of how quickly the ecosystem can ‘bounce back’ from the disturbance. It is ecosystem recovery time.
Image courtesy of Wikipedia
Maximum species diversity is reached when an ecosystem experiences an intermediate level of disturbance. It is because both early and late succession species are able to survive at the same time. 🎥 Watch: AP Environmental Science Streams
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