New research from Northern Arizona University shows Earth’s most northern forests have begun to shift because of warming global temperatures. KNAU’s Melissa Sevigny reports.
The researchers examined four decades of satellite observations of the boreal forests that stretch across Alaska, Canada, and Russia. They eliminated areas that were burned, logged, or otherwise disturbed to focus only on the effects of climate change.
Logan Berner of the School of Informatics, Computing and Cyber Systems is the lead author. "In essence we found, over the last 20 to 40 years, that much of the undistributed portions of the boreal forest have become progressively greener. This hasn’t occurred everywhere, but rather has tended to occur in areas that were cold and had sparse tree cover, but that became warmer in recent decades."
Generally, that means conifers on the northern edges of boreal forests are moving northward. But the southern edges became browner, indicating die-offs.
Scott Goetz, the study’s coauthor, says, "We’re showing with pretty strong evidence that these changes are taking place, and my guess is that as we continuing to monitor it over the next decade, two decades, and beyond, we’re going to see even more dramatic changes, because the system really is getting much warmer."
The changes will affect the people and wildlife that depend on northern ecosystems.
The study appeared in Global Change Biology and is part of a larger NASA-funded initiative called the Artic Boreal Vulnerability Experiment (ABoVE).