Michael G. Ryan

Laboratory for Studies of the Forest Carbon Cycle

Narural resource Ecology Lab

Colorado State University

USDA Forest Service, Rocky Mountain Research Station (Emeritus)





            Forests and long-lived wood products currently offset 310 million metric tons of US fossil fuel emissions of carbon—12-20% of the total. This is an enormous ecosystem service, as Jackson and Schlesinger (2004) estimate that it would require converting one-third of our current US cropland to forest plantations to offset another 10% of emissions.  Large forested landscapes over long periods of time should have a carbon balance of near zero (Kashian et al. 2006).  Our large carbon sink today results because past harvesting released much CO2 into the atmosphere and the regrowing forest is recovering that CO2 (Birdsey et al. 2006).  Nitrogen deposition and increased atmospheric carbon dioxide can make forests grow more and are higher than in the past.  They might also contribute to today's forest carbon sink (Canadell et al. 2007).  The persistence of this forest carbon sink is a concern, because the processes promoting the sink should taper off, while projected increases in disturbance rates, such as fires, may mobilize current carbon stocks (Canadell et al. 2007).  We understand the carbon value of keeping forests as forests, of planting forests where none existed historically (afforestation), for replanting forests where they were historically (reforestation), using forest biomass as fuel, and storing carbon in long-lived products. However, several issues remain to be solved: 1) biophysical limits on storage and a complete accounting of the global warming budget of forests; 2) the lifespan of storage (including disturbances of all kinds, and market pressures that will determine whether to harvest or not), and 3) accounting of storage and the displacement of carbon loss to other areas.

            The Laboratory for Studies of the Forest Carbon Cycle aims to understand the processes that regulate the productivity, accumulation, decay, and storage of carbon in forests at scales from the individual tree to the landscape. 

            A Primer on Forests and the Carbon Cycle can be found here.

To read a Belorussian translation Click here

Mike Ryan in the Amazon


Mike Ryan in the Brazilian Amazon



EY693 Research Methods

F510 Ecophysiology

Graduate Advising Prospectus





New Publications

McKinley DC, Ryan MG, RA Birdsey, CP Giardina, ME Harmon, LS Heath, RA Houghton, RB Jackson, JF Morrison, BC Murray, DE Pataki and KE Skog. 2011.  A synthesis of current knowledge on forests and carbon storage in the United States.  Ecological Applications 21: 1902-1924.

Westerling AL, MG Turner, EAH Smithwick, WH Romme and MG Ryan.  2011.  Continued warming could transform Greater Yellowstone fire regimes by mid-21st Century.  Proceedings of the National Academy of Sciences, In Press (July 2011).

Conant RT, MG Ryan, GI Ågren, H Birge, EA Davidson, PE Eliasson, SE Evans, SD Frey, CP Giardina, F Hopkins, R Hyvönen, MUF Kirschbaum, JM Lavallee, J Leifeld, WJ Parton, JM Steinweg, MD Wallenstein, JÅM Wetterstedt and MA Bradford.  2011.  Temperature and soil organic matter decomposition rates – synthesis of current knowledge and a way forward.  Global Change Biology.  (In Press, June 2011).

Ryan MG, ME Harmon, RA Birdsey, CP Giardina, LS Heath, RA Houghton, RB Jackson, DC McKinley, JF Morrison, BC Murray, DE Pataki and KE Skog. 2010.  A Synthesis of the Science on Forests and Carbon for U.S. Forests. Ecological Society of America, Issues In Ecology 13: 1-16. The Issues in Ecology Series is available at the Ecological Society of America’s website here. 

Ryan MG, JL Stape, D Binkley, S Fonseca, R Loos, EN Takahashi, CR Silva, S Silva, R Hakamada, JM Ferreira, AM Lima, JL Gava, FP Leite, G Silva, H Andrade, JM Alves. 2010. Factors controlling Eucalyptus productivity:  How water availability and stand structure alter production and carbon allocation.  Forest Ecology and Management 259: 1695–1703.

Stape JL, D Binkley, MG Ryan, S Fonseca, R Loos, EN Takahashi, CR Silva, S Silva, R Hakamada, JM Ferreira, AM Lima, JL Gava, FP Leite, G Silva, H Andrade, JM Alves.  2010.  The Brazil Eucalyptus Potential Productivity Project:  Influence of water, nutrients and stand uniformity on wood production.  Forest Ecology and Management 259: 1684–1694.

Binkley D, JL Stape, WL Bauerle and MG Ryan.  2010.  Explaining growth of individual trees: Light interception and efficiency of light use by Eucalyptus at four sites in Brazil.  Forest Ecology and Management 259: 1704–1713.

Hubbard RM, JL Stape, MG Ryan, AC Almeida and J Rojas.  2010.  Effects of irrigation on water use and water use efficiency in two fast growing Eucalyptus plantations.  Forest Ecology and Management 259: 1714–1721.

Ryan MG, MA Cavaleri, A Almeida de Campi, R Penchel, RS Senock and JL Stape.  2009.  Wood CO2 efflux and foliar respiration for Eucalyptus in Hawaii and Brazil.  Tree Physiology 29: 1213–1222.

Cavaleri MA, SF Oberbauer, DB Clark, DA Clark and MG Ryan.  2010.  Height is the primary determinant of leaf morphology in a tropical rain forest canopy.  Ecology 91: 1730–1739.

Bradford JB, P Weishampel, M-L Smith, R Kolka, RA Birdsey, SV Ollinger and MG Ryan.  2010.  Carbon pools and fluxes in small temperate forest landscapes: variability and implications for sampling design.   Forest Ecology and Management 259: 1245–1254.


Allen Best Article ‘Carbon Conundrum’ in Forest Magazine that quotes Mike Ryan.


Ed Stoddard Reuters Article on Mountain Pine Beetle and carbon ‘Forests fall to beetle outbreak’ that quotes Mike Ryan

Forest Service Position Description

RMRS Website for Mike Ryan




This site is courtesy of Colorado State University