Forest carbon uptake recovers from modest tree losses
A paper titled “Disturbance and the resilience of coupled carbon and nitrogen cycling in a north temperate forest,” was published Oct. 29, 2011 in the Journal of Geophysical Research – Biogeosciences by Luke Nave, postdoctoral fellow, and colleagues. A recent editor’s highlight from the journal is excerpted here:
By manipulating an experimental forest at the University of Michigan Biological Station, Nave and colleagues determined how forests' carbon and nitrogen cycles respond to subtle disruptions. In 2008, the authors and their team culled 39 percent of the forest's tree population using stem girdling—the process of removing a ring of the tree's bark and starving it of its nutrient and water supplies. The aim was to accelerate the loss of short-lived tree species, driving the forest into a more complex state, commonly found in older forests, rather than the homogeneous conditions that result from clear-cutting or a forest-clearing fire.
Initially, the authors found that the forest's carbon uptake declined and soil nitrogen availability and leaching increased, reminiscent of severe disturbances. However, most forest ecosystems are inherently limited by the availability of nitrogen, and the newly liberated stores were drawn up by the remaining longer-lived trees, producing new leaf area and mitigating the decrease in carbon uptake. The authors suggest that, as the forest structure continues to change in the wake of subtle disturbances, the forest's carbon uptake will continue to increase.
"Because we implemented the experimental treatment several years ago, we are gaining this knowledge a decade or two before most similar forests throughout the region undergo similar successional transition, making this study quite useful for forecasts of regional carbon cycling and interactions with the climate,” said Nave.Co-researchers and co-authors include: Jim Le Moine, UMBS; Professor Knute Nadelhoffer, UMBS director; Chris Vogel, UMBS; and colleagues from Ohio State University, Columbus; Columbia University, New York City; Cornell University, Ithaca, New York; Virginia Polytechnic Institute and State University, Blacksburg, Virginia.
U-M News Service Future forests video, Sept. 2008 (project initiation)