APES 2.5 Natural Disruptions to Ecosystems

Enduring Understanding:

  • Ecosystems have structure and diversity that change over time.

Learning Objective:

  • Explain how natural disruptions, both short and long term, impact an ecosystem.

Essential Knowledge:

  • Natural disruptions to ecosystems have environmental consequences that may, for a given occurrence, be as great as, or greater than, many human made disruptions.
  • Earth system processes operate on a range of scales in terms of time.  Processes can be periodic episodic, or random.
  • Earth’s climate has changed over geological time for many reasons.
  • Sea level has varied significantly as a result of changes in the amount of glacial ice on Earth over geological time.
  • Major environmental change or upheaval commonly results in large swathes of habitat changes.
  • Wildlife engages in both short and long term migration for a variety of reasons, including natural disturbances.

  • Natural disruptions to ecosystems have environmental consequences that may be as great as or greater than any human made disruptions.

  • Natural Disasters: Hurricanes, tornadoes, hailstorms, cyclones, blizzards, drought, tsunamis, floods, mudslides, avalanches, earthquakes, volcanic eruptions, communicable disease epidemics, forest fires (lighting induced)

  • Anthropogenic Disturbances: Development, air pollution, habitat fragmentation, invasive species, deforestation, climate change

  • Man-Made Disasters: Nuclear disasters, biological disasters, chemical disasters, fire accidents, road accidents, terrorism epidemic, etc.

  • Earth system processes operate on a range of scales in terms of time. Processes can be periodic, episodic, or random.

  • For example, rivers.

    • Permanent rivers flow all year round.
    • Periodic rivers flow during the rainy season
    • Episodic rivers flow for a short period of time only after heavy storms

  • As related to climate change, the Earth’s climate has changed over geological time for many reasons.

    • We are currently in a period of cold climate, relative to the history of the Earth, although it is on the rise…
    • Both from human activities and the natural return to heat that generally follows an ice age.

  • Sea level has varied significantly as a result of changes in the amount of glacial ice on Earth over time.

  • Major environmental change or upheaval commonly results in large swathes of habitat change

  • Wildlife engages in both short and long term migration for a variety of reasons, one being natural disturbances.