Notes on Biogeochemical Cycles and Ecology.pdf

pool. Water may reside in an ocean for thousands of years, but in a cloud for a fewdays at best. The biotic community includes all living organisms. This communitymay serve as an exchange pool (although for some chemicals like carbon, bound in asequoia for a thousand years, it may seem more like a reservoir), and also serve tomove chemicals from one stage of the cycle to another. For instance, the trees of thetropical rain forest bring water up from the forest floor to be evaporated into theatmosphere. Likewise, coral endosymbionts take carbon from the water and turn itinto limestone rock. The energy for most of the transportation of chemicals from oneplace to another is provided either by the sun or by the heat released from the mantleand core of the Earth.While all inorganic nutrients cycle, we will focus on only 4 of the most importantcycles - water, carbon (and oxygen), nitrogen, and phosphorous.The Water Cycle: