Natural Disruptions to Ecosystems Flashcards
are natural or anthropogenic disruptions worse?
it depends; natural disruptions to ecosystems have environmental consequences that may, for a given occurrence, be as great as, or greater than, many human-made disruptions
how do earth system processes operate?
on a range of scales in terms of time
what are the three different types of earth system processes based on their scales of time?
processes can be periodic, episodic, or random
earth’s climate has changed:
over geological time for many reasons
what causes the sea level to vary over geological time?
it has varied significantly as a result of changes in the amount of glacial ice on earth
what commonly results because of major environmental change or upheaval?
large swathes of habitat changes
what are the types of wildlife migration?
wildlife engages in both short and longterm migration
why does wildlife migrate?
for a variety of reasons, including natural disruptions
what is a natural disturbance?
a natural event that disrupts the structure and/or a function of an ecosystem
what are some examples of natural disturbances?
tornadoes, hurricanes, asteroids, forest fires, drought
what is a periodic disturbance? what’s an example
occurs with regular frequency
ex. dry-wet seasons
what is an episodic disturbance? give examples
occasional events with irregular frequency
ex. hurricanes, droughts, fires
what is a random disturbance? give examples
has no regular frequency
ex. volcanoes, earthquakes, asteroids
what are some reasons for why earth’s climate has varied over geological time?
slight changes in earth’s orbit and tilt cause mini ice ages and warmer periods
naturally increases and decreases in the amount of carbon dioxide in the atmosphere (more plant growth = less carbon dioxide and cooler temps; warmer oceans = more carbon dioxide and warmer temps)
why has the sea level varied over geological time?
increased carbon dioxide levels lead to warmer temperatures, melting of glacial ice, and sea levels rising
(earth’s climate has varied naturally over time which leads to sea level varying naturally over time)
also thermal expansion; warmer temperatures cause water molecules in the ocean to spread out, leading to sea level rise
positive feedback loop: more carbon dioxide → warmer oceans → release more carbon dioxide
