Andrew Gray, PhD

Research Ecologist, Team Leader

Pacific Northwest Research Station

0009-0002-8804-8270

andrew.gray@usda.gov

Publications & Products
Related
Education

Treesearch Publications

Andrew Gray, Taylor K. Lucey, David V. D'Amore, John B. Kim, David L. Nicholls, Nadia A. Tase, Andrew C. Yost, Jeffrey D. Kline, Jeremy S. Fried, Daniel E.B. Swann. 2026. Forest ecosystem carbon models: structure and suitability for current issues on the West Coast of North America
Daniel J. Herrera, Christopher Schalk, Andrew Gray, Margaret Woodbridge, Deanna H. Olson, Michael V Cove. 2025. Leveraging United States Forest Inventory Analysis data to project mature and old-growth forest conditions, with three wildlife case studies showing utility
Poonam Khatri, Richard Bergman, Prakash Nepal, David L. Nicholls, Andrew Gray. 2025. Evaluating life cycle greenhouse gas emissions from alternative forest residue utilization: Energy and product pathways
Jennifer Costanza, Kevin M. Potter, David Walker, Frank H. H. Koch, Andrew Gray, John W. Coulston. 2025. Old-growth forest area projected to increase on United States federal lands under alternative future scenarios
Daniel Swann, Jeremy S. Fried, Andrew Gray. 2025. Evaluating Forest Vegetation Simulator (FVS) calibration options for predicting biomass accumulation across diverse Oregon landscapes
Paul J. Chisholm, Andrew Gray. 2025. Populations of large-diameter trees are increasing across the United States
Jim Westfall, John W. Coulston, Andrew Gray, John D. Shaw, Philip J. Radtke, David M. Walker, Aaron R. Weiskittel, David W. MacFarlane, David L.R. Affleck, Dehai Zhao, Hailemariam Temesgen, Krishna P. Poudel, Jereme M. Frank, Stephen P. Prisley, Yingfang Wang, Andrew J. Sánchez Meador, David Auty, Grant M. Domke. 2024. A national-scale tree volume, biomass, and carbon modeling system for the United States
Paul J. Chisholm, Andrew Gray. 2024. Forest carbon sequestration on the west coast, USA: Role of species, productivity, and stockability
Harold Zald, Carolina J. May, Andrew Gray, Malcolm P. North, Matthew D. Hurteau. 2024. Thinning and prescribed burning increase shade-tolerant conifer regeneration in a fire excluded mixed-conifer forest
Taylor K. Lucey, Nadia Tase, Prakash Nepal, Richard Bergman, David L. Nicholls, Poonam Khatri, Kamalakanta Sahoo, Andrew Gray. 2024. A synthesis of harvested wood product carbon models
Randall Morin, Sean P. Healey, Steve Prisley, KaDonna Randolph, Jim Westfall, Andrew Gray. 2023. Editorial: Monitoring and responding to global change to promote resilient and productive forests through innovative forest inventory
Christopher W. W. Woodall, A.G. Kamoske, G.D. Hayward, Thomas M. Schuler, C.A. Hiemstra, M. Palmer, Andrew Gray. 2023. Classifying mature federal forests in the United States: The forest inventory growth stage system
Andrew Gray, Kristen A. Pelz, Gregory D. Hayward, Thomas M. Schuler, Wade Salverson, Marin Palmer, Christian Schumacher, Christopher W. W. Woodall. 2023. Perspectives: The wicked problem of defining and inventorying mature and old-growth forests
Carolina J. May, Harold Zald, Malcolm P. North, Andrew Gray, Matthew D. Hurteau. 2023. Repeated burns fail to restore pine regeneration to the natural range of variability in a Sierra Nevada mixed‐conifer forest, U.S.A.
Andrea Watts, Jeffrey D. Kline, Andrew Gray. 2023. Does housing development influence how private forest landowners manage forest land?
Poonam Khatri, Prakash Nepal, Kamalakanta Sahoo, Richard Bergman, David L. Nicholls, Andrew Gray. 2023. California's harvested wood products: A time-dependent assessment of life cycle greenhouse gas emissions
Daniel L. Perret, David M. Bell, Andrew Gray, John D. Shaw, Harold Zald. 2023. Range-wide population assessments for subalpine fir indicate widespread disturbance-driven decline
Sean MP. Cahoon, Kathryn C. Baer, Kate Legner, Loretta Winton, Garret Dubois, Will Putman, Patrick Sullivan, Kate C. Marcille, Hans Andersen, Jacob L. Strunk, Richard Smith, John M. Chase, Glenn Christensen, Jane Terzibashian, Andrew Gray. 2022. Forest resources of the Tanana unit, Alaska: 2018
Francisco Mauro, Vicente Monleon, Andrew Gray, Olaf Kuegler, Hailemariam Temesgen, Andrew T. Hudak, Patrick A. Fekety, Zhiqiang Yang. 2022. Comparison of model-assisted endogenous poststratification methods for estimation of above-ground biomass change in Oregon, USA
Raymond J. Davis, David M. Bell, Matthew J. Gregory, Zhiqiang Yang, Andrew Gray, Sean P. Healey, Andrew E. Stratton. 2022. Northwest Forest Plan—the first 25 years (1994–2018): status and trends of late-successional and old-growth forests
Jason Barker, Andrew Gray, Jeremy S. Fried. 2022. The effects of crown scorch on post-fire delayed mortality are modified by drought exposure in California (USA)
Kathryn C. Baer, Andrew Gray. 2022. Biotic predictors improve species distribution models for invasive plants in Western U.S. Forests at high but not low spatial resolutions
Sean MP. Cahoon, Patrick F. Sullivan, Andrew Gray. 2022. Interactions among wildfire, forest type and landscape position are key determinants of boreal forest carbon stocks
Elijah Allensworth, Hailemariam Temesgen, Bryce Frank, Andrew Gray. 2021. Imputation to predict height to crown base for trees with predicted heights
Andrew Gray, Anne C.S. McIntosh, Steven L. Garman, Michael A. Shettles. 2021. Predicting canopy cover of diverse forest types from individual tree measurements
Robert J. Smith, Andrew Gray. 2021. Strategic monitoring informs wilderness management and socioecological benefits
Paul F. Hessburg, Susan Charnley, Andrew Gray, Thomas Spies, David W. Peterson, Rebecca Flitcroft, Kendra Wendel, Jessica Halofsky, Eric M. White, John Marshall. 2021. Climate and wildfire adaptation of inland Northwest US forests
Jeffrey D. Kline, Laurie L. Houston, Andrew Gray, Vicente Monleon. 2021. Evaluating empirical evidence for housing development effects on the management of remaining private-owned forest in the U.S.
Robert J. Smith, Andrew Gray, Mark E. Swanson. 2020. Peak plant diversity during early forest development in the western United States
Paul F. Hessburg, Susan Charnley, Kendra Wendel, Eric M. White, Peter Singleton, David W. Peterson, Jessica Halofsky, Andrew Gray, Thomas Spies, Rebecca Flitcroft, Rachel White. 2020. The 1994 Eastside Screens large-tree harvest limit: review of science relevant to forest planning 25 years later
Jason Barker, Jeremy S. Fried, Andrew Gray. 2019. Evaluating model predictions of fire induced tree mortality using wildfire-affected forest inventory measurements
Andrew Gray, Warren B. Cohen, Zhiqiang Yang, Eric Pfaff. 2019. Integrating TimeSync disturbance detection and repeat forest inventory to predict carbon flux
Krishna P. Poudel, Hailemariam Temesgen, Philip J. Radtke, Andrew Gray. 2019. Estimating individual-tree aboveground biomass of tree species in the western U.S.A.
Sabrina B. Turner, David Turner, Andrew Gray, Will Fellers. 2019. An approach to estimating forest biomass change over a coniferous forest landscape based on tree-level analysis from repeated lidar surveys
Robert Smith, Andrew Gray. 2019. Combining potentially incompatible community datasets when harmonizing forest inventories in subarctic Alaska, USA
Andrew Gray, Frank K. Lake, Jonathan W. Long. 2018. Recent trends in large hardwoods in the Pacific Northwest, USA
Krishna P. Poudel, Hailemariam Temesgen, Andrew Gray. 2018. Estimating upper stem diameters and volume of Douglas-fir and Western hemlock trees in the Pacific northwest
Robert Pattison, Hans Andersen, Andrew Gray, Bethany K. Schulz, Robert Smith, Sarah Jovan. 2018. Forests of the Tanana Valley State Forest and Tetlin National Wildlife Refuge, Alaska: results of the 2014 pilot inventory
Bill Zielinski, Andrew Gray. 2018. Using routinely collected regional forest inventory data to conclude that resting habitat for the fisher (Pekania pennanti) in California is stable over ∼20 years
Sheel Bansal, Leslie C. Brodie, Sharon Stanton, Karen Waddell, Marin Palmer, Glenn Christensen, Olaf Kuegler, John M. Chase, Joel Thompson, Sarah Jovan, Andrew Gray, Morgan Todd. 2017. Oregon’s forest resources, 2001–2010: ten-year Forest Inventory and Analysis report
Robert J. Smith, Sarah Jovan, Andrew Gray, Bruce McCune. 2017. Sensitivity of carbon stores in boreal forest moss mats - effects of vegetation, topography and climate
Andrew Gray. 2017. Avances en el conocimiento de la dinámica forestal: el papel del monitoreo regional
Andrea Watts, Andrew Gray, Thomas Whittier. 2017. There’s carbon in them thar hills: But how much? Could Pacific Northwest forests store more?
David Turner, William D. Ritts, Robert E. Kennedy, Andrew Gray, Zhiqiang Yang. 2016. Regional carbon cycle responses to 25 years of variation in climate and disturbance in the US Pacific Northwest
David M. Bell, Andrew Gray. 2016. Assessing intra- and inter-regional climate effects on Douglas-fir biomass dynamics in Oregon and Washington, USA
Jens Stevens, Hugh D. Safford, Malcolm P. North, Jeremy S. Fried, Andrew Gray, Peter M. Brown, Christopher R. Dolanc, Solomon Z. Dobrowski, Donald A. Falk, Calvin A. Farris, Jerry F. Franklin, Peter Z. Fulé, R. Keala Hagmann, Eric E. Knapp, Jay D. Miller, Douglas F. Smith, Thomas W. Swetnam, Alan H. Taylor, Julia A. Jones. 2016. Average stand age from forest inventory plots does not describe historical fire regimes in ponderosa pine and mixed-conifer forests of western North America
Heather E Lintz, Andrew Gray, Andrew Yost, Richard Sniezko, Chris Woodall, Matt Reilly, Karen Hutten, Mark Elliott. 2016. Quantifying density-independent mortality of temperate tree species
Andrew Gray, Thomas R. Whittier, Mark E. Harmon. 2016. Carbon stocks and accumulation rates in Pacific Northwest forests: role of stand age, plant community, and productivity
Thomas R. Whittier, Andrew Gray. 2016. Tree mortality based fire severity classification for forest inventories: A Pacific Northwest national forests example
Robert Pattison, Andrew Gray, Lori Tango. 2015. A baseline assessment of forest composition, structure, and health in the Hawai‘i experimental tropical forests
Mikhaill A. Yatskov, Mark E. Harmon, Olga N. Krankina, Tara M. Barrett, Kevin Dobelbower, Andrew Gray, Becky Fasth, Lori Trummer, Toni L. Hoyman, Chana M. Dudoit. 2015. Regional biomass stores and dynamics in forests of coastal Alaska
Andrew Gray, Joel Thompson, Gary J. Lettman. 2015. Land-use change and new houses on forestland: contrasting trends over 30 years in Oregon and Washington
David M. Bell, Andrew Gray. 2015. Examining Pseudotsuga menziesii biomass change dynamics through succession using a regional forest inventory system
Andrew Gray. 2015. The role of old forests and big trees in forest carbon sequestration in the Pacific Northwest
C.W. Woodall, G.M. Domke, J. Coulston, M.B. Russell, J.A. Smith, Charles H. (Hobie) Perry, S. Healey, Andrew Gray. 2015. The great carbon push-pull: where science is pushing and policy is pulling the official forest carbon inventory of the US
Robert Pattison, Andrew Gray, Patrick F. Sullivan, Kristen L. Manies. 2015. Down woody material, soil and tree core collection and analysis from the 2014 Tanana pilot plots
Raymond J. Davis, Janet Ohmann, Robert Kennedy, Warren B. Cohen, Matthew J. Gregory, Zhiqiang Yang, Heather M. Roberts, Andrew Gray, Thomas Spies. 2015. Northwest Forest Plan–the first 20 years (1994-2013): status and trends of late-successional and old-growth forests
Hailemariam Temesgen, David Affleck, Krishna Poudel, Andrew Gray, John Sessions. 2015. A review of the challenges and opportunities in estimating above ground forest biomass using tree-level models
David Turner, William D Ritts, Robert Kennedy, Andrew Gray, Zhiqiang Yang. 2015. Effects of harvest, fire, and pest/pathogen disturbances on the West Cascades ecoregion carbon balance
Krishna P Poudel, Hailemariam Temesgen, Andrew Gray. 2015. Evaluation of sampling strategies to estimate crown biomass
Garrett W. Meigs, Robert Kennedy, Andrew Gray, Matthew J. Gregory. 2015. Spatiotemporal dynamics of recent mountain pine beetle and western spruce budworm outbreaks across the Pacific Northwest Region, USA
Marie Oliver, Andrew Gray. 2015. A bird’s-eye view: Land-use planning and assessments in Oregon and Washington
Andrew Gray, Thomas R. Whittier, Dave Azuma. 2014. Estimation of aboveground forest carbon flux in Oregon: adding components of change to stock-difference assessments
David L. Azuma, Andrew Gray. 2014. Effects of changing forest land definitions on forest inventory on the West Coast, USA
Andrew Gray, Thomas R. Whittier. 2014. Carbon stocks and changes on Pacific Northwest national forests and the role of disturbance, management, and growth
Heather E. Lintz, Andrew Gray, Bruce McCune. 2013. Effect of inventory method on niche models: random versus systematic error
Andrew Gray. 2013. Changes in fragmentation of western Washington forest land (Project WC-EM-08-01)
Christopher W. W. Woodall, Brian F. Walters, Sonja Oswalt, Grant M. Domke, Chris Toney, Andrew Gray. 2013. Biomass and carbon attributes of downed woody materials in forests of the United States
Bethany K. Schulz, Andrew Gray. 2013. The new flora of the northeastern USA: quantifying introduced plant species occupancy in forest ecosystems
Andrew Gray, David L. Azuma, Gary J. Lettman, Joel Thompson, Neil McKay. 2013. Changes in land use and housing on resource lands in Washington state, 1976–2006
Andrew Gray, Thomas Spies, Robert J. Pabst. 2012. Canopy gaps affect long-term patterns of tree growth and mortality in mature and old-growth forests in the Pacific Northwest
Christopher W. W. Woodall, James Smith, Grant M. Domke, Sean P. Healey, John W. Coulston, Andrew Gray. 2012. Technical aspects of the forest carbon inventory of the United States: recent past and near future
Andrew Gray, Thomas Brandeis, John D. Shaw, William McWilliams, Patrick D. Miles. 2012. Forest Inventory and Analysis Database of the United States of America (FIA)
Anne McIntosh, Andrew Gray, Steven Garman. 2012. Estimating canopy cover from standard forest inventory measurements in western Oregon
Bill Zielinski, Jeffrey R. Dunk, Andrew Gray. 2012. Estimating habitat value using forest inventory data: the fisher (Martes pennanti) in northwestern California
Heather E. Lintz, Bruce McCune, Andrew Gray, Katherine A. McCulloh. 2011. Quantifying ecological thresholds from response surfaces
Tara M. Barrett, Andrew Gray. 2011. Potential of a national monitoring program for forests to assess change in high-latitude ecosystems
Andrew Gray, Katie Barndt, Sarah H. Reichard. 2011. Nonnative invasive plants of Pacific coast forests: a field guide for identification
Bill Zielinski, Andrew Gray, Jeffrey R. Dunk, Joseph W. Sherlock, Gary E. Dixon. 2010. Using forest inventory and analysis data and the forest vegetation simulator to predict and monitor fisher (Martes pennanti) resting habitat suitability
Timothy J. Brady, Vicente Monleon, Andrew Gray. 2010. Calibrating vascular plant abundance for detecting future climate changes in Oregon and Washington, USA
Robert P. Griffiths, Andrew Gray, Thomas Spies. 2010. Soil properties in old-growth Douglas-fir gaps in the western Cascade Mountains of Oregon
Sally Campbell, Karen Waddell, Andrew Gray. 2010. Washington’s forest resources, 2002–2006: five-year Forest Inventory and Analysis report
David Azuma, James S. Menlove, Andrew Gray. 2009. Reserved and roadless forests
Jeffrey D. Kline, Alissa Moses, David L. Azuma, Andrew Gray. 2009. Evaluating satellite imagery-based land use data for describing forestland development in western Washington
W. Keith Moser, Edward L. Barnard, Ronald F. Billings, Susan Crocker, Andrew Gray, George G. Ice, Mee-Sook Kim, Richard Reid, Sue U. Rodman, William McWilliams. 2009. Impacts of nonnative invasive species on US forests and recommendations for policy and management
Anne C.S. McIntosh, Andrew Gray, Steven L. Garman. 2009. Canopy structure on forest lands in western Oregon: differences among forest types and stand ages
Andrew Gray, Vicente Monleon, Thomas A. Spies. 2009. Characteristics of remnant old-growth forests in the northern Coast Range of Oregon and comparison to surrounding landscapes.
Andrew Gray. 2008. Monitoring and assessment of regional impacts from nonnative invasive plants in forests of the Pacific Coast, United States
Harold S.J. Zald, Andrew Gray, Malcolm P. North, Ruth A. Kern. 2008. Initial tree regeneration responses to fire and thinning treatments in a Sierra Nevada mixed-conifer forest, USA
Marc D. Meyer, Malcolm P. North, Andrew Gray, Harold S. J. Zald. 2007. Influence of soil thickness on stand characteristics in a Sierra Nevada mixed-conifer forest
Andrew Gray, Jeremy S. Fried, Glenn Christensen, Larry Potts. 2006. Timber resource statistics for forest land in eastern Washington, January 2002.
Anne C.S. Fiala, Steven L. Garman, Andrew Gray. 2006. Comparison of five canopy cover estimation techniques in the western Oregon Cascades.
Andrew Gray. 2005. Eight nonnative plants in western Oregon forests: associations with environment and management.
Andrew Gray, David L. Azuma. 2005. Repeatability and implementation of a forest vegetation indicator.
Andrew Gray, Charles F. Veneklase, Robert D. Rhoads. 2005. Timber resource statistics for nonnational forest land in western Washington, 2001.
Andrew Gray. 2005. Nonnative Plants in the Inventory of Western Oregon Forests
Andrew Gray, Harold S.J. Zald, Ruth A. Kern, Malcolm P. North. 2005. Stand conditions associated with tree regeneration in sierran mixed-conifer forests.
Malcolm P. North, Brian Oakley, Rob Fiegener, Andrew Gray, Michael Barbour. 2005. Influence of light and soil moisture on Sierran mixed-conifer understory communities.
Malcolm P. North, Jiquan Chen, Brian Oakley, Bo Song, Mark Rudnicki, Andrew Gray, Jim Innes. 2004. Forest stand structure and pattern of old-growth western hemlock/Douglas-fir and mixed-conifer forests
Andrew Gray. 2003. Monitoring stand structure in mature coastal Douglas-fir forests: effect of plot size.
Andrew Gray, Thomas Spies, Mark J Easter. 2002. Microclimatic and soil moisture responses to gap formation in coastal Douglas-fir forests
Malcolm P. North, Brian Oakley, Jiquan Chen, Heather Erickson, Andrew Gray, Antonio Izzo, Dale Johnson, Siyan Ma, Jim Marra, Marc Meyer, Kathryn L. Purcell, Tom Rambo, Dave Rizzo, Brent Roath, Tim Schowalter. 2002. Vegetation and Ecological Characteristics of Mixed-Conifer and Red Fir Forests at the Teakettle Experimental Forest
Andrew Gray, Thomas Spies. 1997. Microsite controls on tree seedling establishment in conifer forest canopy gaps
Andrew Gray, Thomas Spies. 1995. Water content measurement in forest soils and decayed wood using time domain reflectometry

Citations of Non-Forest Service Publications

Gray, A. N. and T. A. Spies. 1996. Gap size, within-gap position, and canopy structure effects on conifer seedling establishment. Journal of Ecology 84:635-645.
Gray, A. N. and J. F. Franklin. 1997. Effects of multiple fires on the structure of southwestern Washington forests. Northwest Science 71:174-185.
Gray, A. N. 2000. Adaptive ecosystem management in the Pacific Northwest: a case study from coastal Oregon. Conservation Ecology [online] 4:6.
Monleon, V. J., A. I. Gitelman, and A. N. Gray. 2002. Multi-scale relationships between coarse woody debris and presence/absence of western hemlock in the Oregon Coast Range. Pages 311-318 in C. Gatsonis, A. Carriquiry, A. Gelman, D. Higdon, R. Kaas, D. Pauler, and I. Verdinelli, editors. Case Studies in Bayesian Statistics, Volume VI. Springer-Verlag, New York.
Vance, N., A. Gray, and R. Haberman. 2002. Congruent management of multiple resources: proceedings from the Wood Compatibility Initiative workshop. USDA Forest Service Pacific Northwest Research Station, Portland, OR. General Technical Report PNW-GTR-563
Lindh, B. C., A. N. Gray, and T. A. Spies. 2003. Responses of herbs and shrubs to reduced root competition under canopies and in gaps: a trenching experiment in old-growth Douglas-fir forests. Canadian Journal of Forest Research 33:2052-2057.
Gray, A. N. and C. Miller. 2006. Vegetation change in the Blue River Landscape Study: 1998-2005. Pacific Northwest Research Station, U.S. Department of Agriculture, Forest Service, Corvallis, OR. unpublished report on file at, http://andrewsforest.oregonstate.edu/pubs/pdf/pub4202.pdf
Rudis, V. A., A. N. Gray, W. McWilliams, R. O'Brien, C. Olson, S. Oswalt, and B. K. Schulz. 2006. Regional monitoring of non-native plant invasions with the Forest Inventory and Analysis program. Pages 49-64 in R. E. McRoberts, G. A. Reams, P. C. Van Duesen, and W. H. McWilliams, editors. Proceedings of the 6th Annual Forest Inventory and Analysis Symposium. USDA Forest Service, Denver, CO. http://www.treesearch.fs.fed.us/pubs/14244
Schroeder, T. A., A. Gray, M. E. Harmon, D. O. Wallin, and W. B. Cohen. 2008. Estimating live forest carbon dynamics with a Landsat-based curve-fitting approach. Journal of Applied Remote Sensing 2:023519.
Azuma, D. L., J. Menlove, and A. N. Gray. 2009. Reserved and Roadless Forests. Pages 16-18 in W. B. Smith, P. D. Miles, C. H. Perry, and S. A. Pugh, editors. Forest Resources of the United States, 2007. US Deparment of Agriculture Forest Service, Washington D.C. http://www.treesearch.fs.fed.us/pubs/34056
Christensen, G.A.; Gray, A.N.; Kuegler, O.; Yost, A. 2019. Oregon Forest Ecosystem Carbon Inventory: 2001-2016. Salem, OR: Oregon Department of Forestry. 343 p. https://www.oregon.gov/ODF/ForestBenefits/Pages/ForestCarbonStudy.aspx.
Christensen, G.A.; Gray, A.N.; Kuegler, O.; Tase, N.A.; Rosenberg, M.; Loeffler, D.; Anderson, N.; Stockmann, K.; Morgan, T.A. 2019. AB 1504 California Forest Ecosystem and Harvested Wood Product Carbon Inventory: 2017 Reporting Period. Sacramento, CA: California Department of Forestry and Fire Protection. 552 p. https://bof.fire.ca.gov/projects-and-programs/ab-1504/.
Watts, A.; Gray, A.N.; Whittier, T.R. 2017. There’s Carbon in Them Thar Hills: But How Much? Could Pacific Northwest Forests Store More? 195. Portland, Oregon: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 6 p. http://treesearch.fs.fed.us/pubs/53931.
Christensen, G.A.; Gray, A.N.; Kuegler, O.; Tase, N.A.; Rosenberg, M. 2017. AB 1504 California Forest Ecosystem and Harvested Wood Product Carbon Inventory: 2006 – 2015. Sacramento, CA: California Department of Forestry and Fire Protection. 390 p. (“under AB 1504 Report” at: https://bof.fire.ca.gov/projects-and-programs/ab-1504/).