Natural Disruptions to Ecosystems Notes

Natural disruptions are non-anthropogenic (not man-made) events that alter ecosystem structure and diversity over micro and macro scales.
Examples include hurricanes, non-human caused forest fires, volcanic eruptions, floods, tsunamis, droughts, insect pests, and meteor or asteroid strikes.
The environmental consequences of natural disruptions can be equal to or greater than human disruptions, often causing widespread habitat change or fragmentation.

Periodic Disruptions: Predictable events occurring at regular intervals (e.g., seasonal temperature and precipitation shifts, annual monsoon rains in Southern Asia).
Episodic Disruptions: Occasional disruptions occurring with no regular pattern or frequency (e.g., hurricanes striking coastal regions like Florida and the Gulf Coastal areas).
Random Disruptions: Unpredictable events occurring without warning (e.g., earthquakes, volcanic eruptions, and the offshore earthquake that triggered the 2004 tsunami in Southeast Asia).

Climate and Sea Level Fluctuation: Earth's climate and sea levels have naturally shifted many times over geological history due to natural processes, such as glacial ice freezing and melting.
Habitat Submersion: Sea level rises of just a few meters can submerge large swaths of low-lying coastal land, such as Florida.
Cataclysmic Impacts: Meteor or asteroid strikes can kick up dust that blocks sunlight, interrupting plant energy production—upon which $99.9\%$ of species depend—causing cascading ecosystem collapse and contributing to 5 or 6 mass extinctions in Earth's history.

Migration: Short- or long-term movement to escape disruptions.
- Neotropical migrants like the scissor tail flycatcher (also referred to as the sizzling tail flycatcher) fly from Oklahoma to South America during winter.
- Monarch butterflies fly south to overwinter in the high mountains of Mexico before returning north to Canada in the spring.
Adaptation: Population-level genetic shifts over time (e.g., species developing thicker fur to survive ice ages).
Extinction: Complete elimination of a species occurring when environmental disruptions happen too rapidly for populations to migrate or adapt, as occurred with dinosaurs.