US Forest Service Research & Development
Contact Information
  • US Forest Service Research & Development
  • 1400 Independence Ave., SW
  • Washington, D.C. 20250-0003
  • 800-832-1355
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Mike Ryan

Michael G. Ryan

Volunteer Research Ecologist
240 West Prospect Road
Fort Collins
United States

Phone: 970-498-1012
Contact Michael G. Ryan

Current Research

  • Effects of spruce and mountain pine beetle outbreaks on ecosystem carbon and water fluxes.
  • How does tree mortality change carbon storage and ecosystem water balance?
  • Climate, Fire and Carbon: Tipping Points and Landscape Vulnerability in the Greater Yellowstone Ecosystem.
  • Will climate change increase fire frequency enough to lower forest carbon storage?
  • Ecosystem effects of chipping and mastication treatments for forest restoration.
  • What are the effects of the fuels treatments on understory vegetation, tree regeneration, fuels, potential fire behavior, carbon storage, and water balance?
  • Implications of precipitation changes on the carbon balance of piñon-juniper ecosystems.
  • How does decreased and increased precipitation change photosynthesis, respiration and carbon storage?
  • Landscape forest carbon assessment: effects of climate, species, and management.
  • How does carbon vary across subalpine forest landscapes?
  • Tree species effects on ecosystem processes in lowland Costa Rica.
  • How do tree species affect productivity and carbon storage in trees and soil?
  • Brazil Eucalyptus Productivity Project. How do water, nutrients and heterogeneity affect forest growth through time?

Research Interests

My primary research interest is understanding what controls ecosystem metabolism-the exchange of carbon and water between forests and the atmosphere. I'm interested in understanding how changes in climate, land use, forest age, and disturbance will affect forest productivity and the role of forests in the global carbon cycle. Within this area, I've focused on understanding what controls changes in productivity and carbon cycling with stand development, the role of plant respiration in controlling productivity, ecosystem respiration, carbon and nitrogen interactions, and decomposition of soil carbon.

Past Research

CO2 is a "greenhouse" gas, responsible for warming the climate. Forests store about 60% of the carbon that is in plants and soil. Climate, disturbance, land use, and forest age can change this storage and move CO2 from the forest to the atmosphere or from the atmosphere to the forest. Understanding how these factors affect the carbon cycle allows for better predictions of future atmospheric CO2 levels and better predictions of the effects of forest management on forest carbon storage. I've also spent a lot of research effort to understand why trees grow more slowly as they age. This pattern of growth is the basis for many economic decisions in commercial forestry (the slowdown helps set the harvest interval), but we still do not understand the mechanism.

Why This Research is Important

Over the past 25 years, I've studied changes in physiology and structure as trees age; carbon allocation to leaves, wood, roots and respiration; methods for measuring tree respiration, forest photosynthesis, and the flux of carbon belowground; the response of soil carbon storage to changes in temperature; and, fire and ecosystem carbon storage. I've led two synthesis efforts, one on the effects of climate change on forests and arid lands and one on using forests to lower the increase in atmospheric CO2.


  • University of Pittsburgh, B.S. Biology 1975
  • Northern Arizona University, Flagstaff, M.S. Forestry 1978
  • Oregon State University, Corvallis, Ph.D. Forestry 1988

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Last updated on : 12/18/2019