http://www.abheritage.ca/abnature/Ecosystems/intro.htm

http://www.bing.com/reference/semhtml/Ecosystem?src=abop&fwd=1&q=ecosystems&qpvt=ecosystems

http://chsweb.lr.k12.nj.us/mstanley/outlines/ecology/ecotypes/ecotypes.htm

http://www.climate.org/topics/ecosystems/index.html

http://en.wikipedia.org/wiki/Natural_environment

http://www.enchantedlearning.com/biomes/tempdecid/tempdecid.shtml

http://www.fi.edu/tfi/units/life/habitat/habitat.html

http://geography4kids.com/files/land_ecosystem.html

http://library.thinkquest.org/11353/ecosystems.htm

http://www.mbgnet.net/

http://www.nhptv.org/NatureWorks/nwepecosystems.htm

http://www.windows.ucar.edu/tour/link=/earth/ecosystems.html&edu=elem

http://www.windows.ucar.edu/tour/link=/earth/rainforest.html&edu=elem