2.5: Natural Disruptions to Ecosystems

Natural disruption examples include

forest fires, floods, tornadoes, hurricanes, droughts, asteroids, & disease.

Human disruption (anthropogenic) examples include

overfishing, deforestation, habitat destruction, pollution, & climate change.

Periodic

occurs with regular frequency (ex: spring rains lead to flooding and deposition of sediment).

Episodic

occasional events with irregular frequency (ex: earthquakes can result in landslides and soil erosion).

Random

no regular frequency (ex: a tornado moves through an area resulting in downed trees).

Earth’s climate has changed over geological time, examples include

slight changes in Earth's orbit & tilt, causing mini-ice ages & warmer periods as earth shifts slightly closer to/further from the sun.

sea level has varied over geological time as

glacial ice on earth melts and forms.

major environmental disturbances result in

widespread habitat changes or loss, ex: rising sea level floods coastal and estuary habitats.

migration

wildlife may migrate to a new habitat as a result of natural disruptions.

examples of migration include

1. wildebeests migrating to follow rain patterns of African savanna
2. ocean species moving further north as water temperature warms
3. bird migration and breeding shifting earlier as insect hatching shifts earlier with warming climate