PELLSTON, Michigan—It is often believed that as forest ecosystems mature, they gather and retain, or “sequester,” greater amounts of carbon.
A recent investigation conducted at the University of Michigan Biological Station elucidated carbon cycling over two centuries, revealing a more complex relationship than previously understood.
The collaborative interplay of forest structure, community composition of trees and fungi, along with soil biogeochemical dynamics, exerts greater influence on the carbon being stored both above and below ground than earlier assumptions.
This study, which appeared in the journal Ecological Applications, represents the dedication of over 100 researchers from across the nation who have engaged in research at this historic field station in Pellston, Michigan, over numerous decades.
The team focused on diverse forest stands within the extensive campus, established in 1909, encompassing old reference forests dating back to the 1800s, areas that were logged in the early 1900s and have since remained undisturbed, along with stands that have undergone additional logging or burning.
Luke Nave, research associate professor at the College of Forest Resources and Environmental Science at Michigan Technological University, spearheaded the collaborative effort that integrated decades of data.
“Time does not dictate carbon cycling,” Nave explained. “Time serves more as a playing field, while the rules of that field are determined by elements such as canopy structure, composition of tree and microbial communities, as well as soil nitrogen availability. This indicates that alterations in factors such as structure, composition, and nitrogen levels in soil govern the carbon trajectories of forests, regardless of whether those changes transpire rapidly or gradually, and whether we are influencing those shifts through management or allowing them to evolve naturally.”
The research relied on data compiled and generated over decades at the U-M Biological Station in northern Michigan, which includes extensive research facilities like the 150-foot AmeriFlux tower. This tower is part of a network that monitors ecosystem carbon dioxide, water, energy “fluxes,” and other exchanges between the land surface and the atmosphere across North, South, and Central America.
UMBS, recognized as one of the largest and longest-running field research stations in the nation, oversees two towers adjacent to Douglas Lake that produce long-term data on forest carbon dynamics.
The newly published research encompassed a diverse array of forest datasets within the areas surrounding the flux towers and other locations on the property, covering aspects such as soil respiration, fungal communities, root production, leaf litterfall, carbon pools, and soil enzyme activities.
“It’s thrilling to observe the outcomes of this research. It required extensive effort and numerous years to come to fruition,” expressed Jason Tallant, data manager and research expert at UMBS, who also co-authored the study.
“At the U-M Biological Station, we put significant emphasis on data management and digitization. It is rewarding to see the carbon synthesis research team effectively utilize our historical datasets and analyze real-time carbon sequestration data to shed light on the status of our forests and guide future management strategies.”
The researchers indicated that effectively managing forests involves much more than simply accounting for their age. Both directly and indirectly, forest management entails influencing structure (both above and below ground), composition (involving plants and microbes), and the interrelations among ecosystem components, including their functional and biogeochemical outcomes.
“Given the rapid changes we are currently witnessing in areas like climate, forest health, disturbances, and species composition, management will need to address increasing challenges and limitations. Assumptions that were valid a decade or two ago cannot be taken for granted any longer,” Nave cautioned.
This initiative is financed by the National Science Foundation, the U.S. Department of Energy’s Office of Science, and the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory.
Collaborators hail from nearly a dozen institutions, including Michigan Tech, U-M, Virginia Commonwealth University, and others.
Oak Ridge National Laboratory, USDA Forest Service, Ohio State University, University of Connecticut, Purdue University, University of Texas, and University of Wisconsin.
