The 51-square kilometer (20-square-mile) pileup is an important yet poorly quantified part of the carbon cycle, scientists say.
Throughout the Arctic, fallen trees make their way from forests to the ocean by way of rivers. Those logs can stack up as the river twists and turns, resulting in long-term carbon storage. A new study has mapped the largest known woody deposit, covering 51 square kilometers (20 square miles) of the Mackenzie River Delta in Nunavut, Canada, and calculated that the logs store about 3.4 million tons (about 3.1 million metric tons) of carbon.
“To put that in perspective, that’s about two and a half million car emissions for a year,” said Alicia Sendrowski, a research engineer who led the study while at Colorado State University. “That’s a sizeable amount of carbon,” she said, but it’s not a carbon pool we know much about. “We have great knowledge about carbon in other forms, like dissolved or particulate organic carbon, but not what we call ‘large carbon’ — large wood.” That’s starting to change.
Scientists have known for decades that driftwood can really get around in the Arctic, but they are just beginning to quantify how much wood there is and how much of its carbon storage we risk losing to climate change. The Arctic’s cold, often dry or icy conditions mean trees can be preserved for tens of thousands of years; a tree that fell a thousand years ago might look just as fresh as one that fell last winter, Sendrowski said.
Read more at American Geophysical Union
Image: Scientists have mapped the world’s biggest cumulative logjam that we know of, as reported in a new study in the AGU journal Geophysical Research Letters. The woody debris stores more than 3 million tons of carbon. (Credit: Alicia Sendrowski)