Coupled Biogeochemical Cycles

Coupled biogeochemical cycle is an emerging scientific discipline that looks at how Earth's biogeochemical cycles interact. Researchers are discovering that biogeochemical cycles--whether the water cycle, the nitrogen cycle, the carbon cycle, or others--happen in concert with one another. Biogeochemical cycles are "coupled" to each other and to Earth's physical features. Studying cycles as coupled is more important that studying them as separate entities because the study of coupled biogeochemical cycles has direct management applications.The "dead zone" in the Gulf of Mexico is one example. Nitrogen-based fertilizers make their way from Iowa cornfields to the Mississippi River, where they are transported to the Gulf of Mexico. Once deposited in the Gulf, nitrogen stimulates algal blooms. When the algae die, their decomposition consumes oxygen, creating an area of water roughly the size of New Jersey that is inhospitable to aquatic life. Protecting the Gulf's fisheries--with an estimated annual value of half-a-billion dollars--relies on understanding how coupled biogeochemical cycles interact.