Report on the Forest Products Industry's Contribution to Ground Water Preservation and Water Use Prepared for the Florida Pulp & Paper Association, 1997 Environmental Conference Proceedings

It is the oceans, which cover three-fourths of the earth, from which most of our fresh water originates. After absorbing sufficient energy from the sun, water molecules evaporate from the ocean surface and join the hydrologic cycle: ocean to sky to land to ocean. The greatest evaporation occurs in a belt around the equator because it’s here that more of the sun’s energy is received. As the warm, moist air rises, it flows outward from the equator at high altitudes. By the time the air reaches 30° north, which is about the latitude of north Florida, it has lost enough energy that it tends to sink. The falling air brings down with it an average of 59 inches of rain annually and helps to make forest land throughout north Florida some of the world’s most productive. The water cycle is later completed when the precipitation is either evaporated, transpired by plants or pulled by gravity back to sea through streams or aquifers. The hydrologic cycle is global and the arithmetic is enormous. Scientists calculate that 24,000 cubic miles of precipitation falls annually on the world’s land surfaces alone. Forests have an important role to play in north Florida’s hydrologic cycle. The reason: well-managed forests mitigate flooding reduce erosion and aid the infiltration of water into underground aquifers. The forest is a complex biological community with its own special climate, vegetation and soil. Tree crowns and shrubs protect the top soil as does the mat of fallen leaves and twigs on the forest floor. As the Utter decays, there is an abundance of biologic activity which keeps the soil porous and gives it a structure ideal for absorbing and purifying large quantities of water. Some of the precipitation that infiltrates the forest floor is transpired by plants; some evaporates. The remainder of the water percolates downward to replenish groundwater reservoirs. These underground water supplies, stored in aquifers (permeable rock), represent the largest source of instantaneous fresh water available. By helping to collect and store the state’s abundant precipitation, forests improve the quantity and quality of the underground water supply.