Ecological succession | Middle school biology | Khan Academy

Courses on Khan Academy are always 100% free. Start practicing—and saving your progress—now!

Ecological succession is how ecosystems develop and change over time. Primary succession happens in areas where no life existed before, like bare rocks or a newly sunken ship. This process begins with small organisms that can tolerate harsh conditions, called early successional species. Secondary succession occurs after a disturbance in an existing ecosystem, as remaining organisms begin to grow and a new community gradually forms.

Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help!

Donate or volunteer today! Donate here: https://www.khanacademy.org/donate?utm_source=youtube&utm_medium=desc

Volunteer here: https://www.khanacademy.org/contribute?utm_source=youtube&utm_medium=desc

Credits:
“Container Ship, Cargo Boat” by freddy dendoktoor, licensed under a Creative Commons Attribution License (CC0 1.0): https://www.publicdomainpictures.net/en/view-image.php?image=497526&picture=container-ship-cargo-boat

“US Navy 040105-N-8629M-005 A tugboat tows the decommissioned aircraft carrier Midway into San Diego bay” by U.S. Navy/Rebecca J. Moat, public domain: https://commons.wikimedia.org/wiki/File:US_Navy_040105-N-8629M-005_A_tugboat_tows_the_decommissioned_aircraft_carrier_Midway_into_San_Diego_bay.jpg

“US Navy 060417-N-6031Q-010 Engineering Technicians for Computer Science Corporation (C.S.C.) Beddy Mcbride and Allen Dunbar, overlook the decommissioned aircraft carrier USS Oriskany” by U.S. Navy/David R. Quillen, public domain: https://commons.wikimedia.org/wiki/File:US_Navy_060417-N-6031Q-010_Engineering_Technicians_for_Computer_Science_Corporation_%28C.S.C.%29_Beddy_Mcbride_and_Allen_Dunbar,_overlook_the_decommissioned_aircraft_carrier_USS_Oriskany_%28CVA_34%29.jpg

“USS Oriskany sinking” by U.S. Navy, public domain: https://commons.wikimedia.org/wiki/File:USS_Oriskany_sinking.jpg

“Artificial Reefs Attract Abundant Fish” by U.S. National Park Service, public domain: https://npgallery.nps.gov/AssetDetail/945cf2b2-98b3-f05e-84dd-01d3db574455#

“Diver on a section of shipwreck” by U.S. National Park Service, public domain: https://npgallery.nps.gov/AssetDetail/280d31b0-1dd8-b71b-0b35-f870825ebcf3

“Sea lettuce and dead man's rope algae in the harbor outside Havets Hus in Lysekil” by W.carter, licensed under a Creative Commons Attribution License (CC BY-SA 4.0): https://commons.wikimedia.org/wiki/File:Sea_lettuce_and_dead_man%27s_rope_algae_in_the_harbor_outside_Havets_Hus_in_Lysekil_1.jpg

“Xenia umbellata, pólipos pulsantes” by Fernándo Herranz Martín, licensed under a General Public License (GNU GPLv3): https://commons.wikimedia.org/wiki/File:Xenia_umbellata,_p%C3%B3lipos_pulsantes.jpg

“Barnacles” by Rhododendrites, licensed under a Creative Commons Attribution License (CC BY-SA 4.0): https://commons.wikimedia.org/wiki/File:Barnacles_(52285).jpg

“Continental Divide fire” by U.S. National Park Service, public domain: https://www.nps.gov/media/photo/gallery-item.htm?pg=2630261&id=559d967a-67fa-44d1-a306-c95f65efda61&gid=FD4AF7FF-A94D-4A8A-93DB-0EDAD7EF7486

“Fire truck on bridge in the Grant Village campground” by U.S. National Park Service, public domain: https://www.nps.gov/media/photo/gallery-item.htm?pg=2630261&id=1d4f0b99-c09a-419d-8b4e-cba1f494d08f&gid=FD4AF7FF-A94D-4A8A-93DB-0EDAD7EF7486

“Lodgepole pine forest regrowth after 1988 Fire - taken in 2019” by U.S. National Park Service, public domain: https://www.nps.gov/media/photo/gallery-item.htm?pg=2630261&id=541eecfa-348a-47a9-9b07-dea9c22438c9&gid=FD4AF7FF-A94D-4A8A-93DB-0EDAD7EF7486

“Pinus contorta” by Walter Siegmund, licensed under a Creative Commons Attribution License (CC BY-SA 3.0): https://commons.wikimedia.org/wiki/File:Pinus_contorta_28289.JPG

“Lodgepole pine cone after fire” by U.S. National Park Service/Jim Peaco, public domain: https://commons.wikimedia.org/wiki/File:Lodgepole_pine_cone_after_fire.jpg

“USS Buchanan (DDG-14) sinking on 14 June 2000” by U.S. Navy, public domain: https://commons.wikimedia.org/wiki/File:USS_Buchanan_(DDG-14)_sinking_on_14_June_2000.jpg
...
https://www.youtube.com/watch?v=4J8lciSyPPc
Note: All Khan Academy content is available for free at (www.khanacademy.org)