(2) http://ecolibrary.cs.brandeis.edu/display.php?id=Succession_four_years_
after_forest_fire_2_DP421. CC-BY.(3) http://www.flickr.com/photos/jurvetson/241228030/. CC-BY.(4) http://commons.wikimedia.org/wiki/Image:Naringspyramid.jpg. Public
Domain.(5) http://www.flickr.com/photos/joebackward/124849565/. CC-BY.(6) http://www.flickr.com/photos/humboldthead/420575250/. CC-BY.(7) http://commons.wikimedia.org/wiki/Image:Lichen_on_rock.jpg. GNU-FD.(8) http://commons.wikimedia.org/wiki/Image:Secondary_succesion_cm02.jpg.
GNU-FD.(9) Food web in the Arctic Ocean..(10) The carbon cycle.. Public Domain.
(11) http://ecolibrary.cs.brandeis.edu/display.php?id=Succession_fouryears
after_forest_fire_3_DP422. CC-BY.
(12) http://www.flickr.com/photos/qorize/208015347/
http://commons.wikimedia.org/wiki/Image:Diatoms_PhC_DIC.jpg. CC-BY,
CC-BY-SA.
(13) http://www.flickr.com/photos/demibrooke/2470222506/. CC-BY.
(14) http://commons.wikimedia.org/wiki/Image:Nitrogen_Cycle.png. Public
Domain.
(15) The water cycle.. Public Domain.
(16) Food web in the Arctic Ocean..
(17) CK-12 Foundation.http://commons.wikimedia.org/wiki/Image:FoodChain.svg.
GNU-FD.
