Life as we know it, from the most basic microbes to our human neighbors, is carbon based. By investigating how carbon cycles through ecosystems, scientists can learn valuable information about food chains, nutrient cycling, and productivity. Because carbon dioxide is a greenhouse gas, with the ability to influence temperature, an accurate global carbon budget is needed to address climate change.
On Earth, carbon is continually cycling through terrestrial systems, inland waters, the ocean, and the atmosphere. Until little over a decade ago, when calculating the terrestrial component of the global carbon budget, inputs were limited to the ocean and the land. Because inland water bodies cover less than 1% of the Earths surface, it was assumed that their contribution was inconsequential.
This view was recently challenged in an Ecosystems paper highlighting the findings of a National Center for Ecological Assessment and Synthesis analysis. Carried out by a team of international scientists, including Institute of Ecosystem Studies Biogeochemist Dr. Jonathan J. Cole, the papers senior author, the group reveals that inland water bodies are important areas of terrestrial carbon transformation that deserve inclusion in global carbon cycle assessments.
While rivers were introduced into global carbon budget assessments in the late 90s, Cole and colleagues argue that current models are limited by a narrow definition of how rivers transport carbon. By depicting rivers as "pipes" that passively deliver terrestrial carbon to the sea, models fail to capture the complex transformations that occur on the journey toward the ocean. The fact is, according to the authors, that half of the terrestrial carbon entering inland waters is destined for a fate outside of the oceans salty shores.
Where does the remaining terrestrial carbon go? Approximately 40% is returned to the atmosphere as CO2 and 12% is stored in sediments. This holds true
Contact: Lori Quillen
Institute of Ecosystem Studies