Information on the Nitrogen Cycle

http://esa.sdsc.edu/tilman.htm

http://www.geog.ouc.bc.ca/physgeog/contents/9s.html

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/NitrogenCycle.html

Information on the Carbon Cycle

http://www.geog.ouc.bc.ca/physgeog/contents/9r.html

http://muextension.missouri.edu/xplor/envqual/wq0252.htm

Information on the Water Cycle and Humidity

http://www.personal.psu.edu/users/j/m/jmh280/title.html

http://www.usatoday.com/weather/whumdef.htm

http://http://mbgnet.mobot.org/fresh/cycle/index.htm

http://www.eurekalert.org/pub_releases/2002-10/du-spa102402.php

Ball, Phillip. "Nature": Making Waves. 2 October 2000.

Various Authors, The Ecology of a Tropical Forest. Washington D.C.: the Smithsonian Institution, 1982.