Current Research

I am a Physical Scientist in the Forest Inventory and Analysis (FIA) Research Work Unit. The FIA program at the Northern Research Station is responsible for the forest land inventories of 24 states extending from the Great Plains to the northeastern United States. My current research interest is the application of geospatial and remote sensing technologies to improving the precision and efficiency of inventories.

Research Interests

I work with a variety of airborne and spaceborne sensors including multi-spectral and optical imagery, lidar, and radar. I'm exploring digital stereo imagery (specifically, photogrammetrically-derived point clouds) and the potential for improved estimates of forest volume and biomass over large areas. I work at the intersection of GIS, data science, and remote sensing with the aim of applying best practices from these fields to improve the efficiency of workflows and to analyze large amounts of information.

Past Research

I have worked in several different areas of research either supporting forest inventory operations or utilizing inventory data to address ecological questions:

• semi-automated approaches to mapping the landscape using high-resolution imagery, particularly in areas with tree cover that do not meet a traditional definition of forest (e.g., narrow windbreaks in the Great Plains)
• determining the best methods for combining climate data with forest inventory information (e.g., to support analysis of elevated tree mortality related to drought)
• canopy cover modeling (formerly as the Forest Service science team leader for the NLCD canopy cover dataset)

Why This Research is Important

The FIA program fills critical forest information needs for a variety of customers in state government, the timber industry, environmental organizations, and many more. As a neutral provider of data, FIA seeks to constantly improve the inventory efficiency and utility in order to maximize the return on taxpayer dollars. Integrating geospatial and remote sensing technologies into inventory processes aids in achieving this objective.

Education

• University of Minnesota, M.S. Department of Soil, Water, & Climate 1999
• University of North Dakota, B.S. Department of Atmospheric Science 1996

Professional Experience

Professional Organizations

• Minnesota GIS/LIS Consortium, Member (2001 - Current)

Awards & Recognition

Featured Publications & Products

• Liknes, Greg C.; Meneguzzo, Dacia M.; Kellerman, Todd A. 2017. Shape indexes for semi-automated detection of windbreaks in thematic tree cover maps from the central United States.
• Riemann, Rachel; Liknes, Greg C.; O'Neil-Dunne, Jarlath; Toney, Chris; Lister, Tonya. 2016. Comparative assessment of methods for estimating tree canopy cover across a rural-to-urban gradient in the mid-Atlantic region of the USA.
• Meneguzzo, Dacia M.; Liknes, Greg C.; Nelson, Mark D. 2013. Mapping trees outside forests using high-resolution aerial imagery: a comparison of pixel- and object based classification approaches.
• Liknes, Greg C.; Perry, Charles H.; Meneguzzo, Dacia M. 2010. Assessing tree cover in agricultural landscapes using high-resolution aerial imagery.
• Yang, Limin ; Jin, Suming ; Danielson, Patrick ; Homer, Collin ; Gass, Leila ; Bender, Stacie M.; Case, Adam ; Costello, Catherine ; Dewitz, Jon ; Fry, Joyce ; Funk, Michelle ; Granneman, Brian ; Liknes, Greg C.; Rigge, Matthew ; Xian, George . 2018. A new generation of the United States National Land Cover Database: Requirements, research priorities, design, and implementation strategies.

Publications

• Goff, Thomas C.; Nelson, Mark D.; Liknes, Greg C.; Feeley, Tivon E.; Pugh, Scott A.; Morin, Randall S. 2021. Rapid Assessment of Tree Damage Resulting from a 2020 Windstorm in Iowa, USA.
• Derwin, Jill M.; Thomas, Valerie A.; Wynne, Randolph H.; Coulston, John W.; Liknes, Greg C.; Bender, Stacie ; Blinn, Christine E.; Brooks, Evan B.; Ruefenacht, Bonnie ; Benton, Robert ; Finco, Mark V; Megown, Kevin . 2020. Estimating tree canopy cover using harmonic regression coefficients derived from multitemporal Landsat data.
• Lister, Andrew J.; Andersen, Hans ; Frescino, Tracey ; Gatziolis, Demetrios ; Healey, Sean ; Heath, Linda S.; Liknes, Greg C.; McRoberts, Ronald ; Moisen, Gretchen G.; Nelson, Mark ; Riemann, Rachel ; Schleeweis, Karen ; Schroeder, Todd A.; Westfall, James ; Wilson, B. Tyler. 2020. Use of Remote Sensing Data to Improve the Efficiency of National Forest Inventories: A Case Study from the United States National Forest Inventory.
• McRoberts, Ronald E.; Næsset, Erik ; Liknes, Greg C.; Chen, Qi ; Walters, Brian F.; Saatchi, Sassan ; Herold, Martin . 2019. Using a Finer Resolution Biomass Map to Assess the Accuracy of a Regional, Map-Based Estimate of Forest Biomass.
• McRoberts, Ronald E.; Stehman, Stephen V; Liknes, Greg C.; Næsset, Erik ; Sannier, Christophe ; Walters, Brian F. 2018. The effects of imperfect reference data on remote sensing-assisted estimators of land cover class proportions.
• Crocker, Susan J.; Liknes, Greg C. 2017. Forests of New Jersey, 2016.
• Crocker, Susan J.; Liknes, Greg C.; McKee, Fraser R.; Albers, Jana S.; Aukema, Brian H. 2016. Stand-level factors associated with resurging mortality from eastern larch beetle (Dendroctonus simplex LeConte).
• Liknes, Greg C.; Crocker, Susan J.; Morin, Randall S.; Walters, Brian F. 2015. Hurricane impacts on forest resources in the Eastern United States: a post-sandy assessment.
• Schrader-Patton, Charlie; Liknes, Greg C.; Gatziolis, Demetrios; Wing, Brian M.; Nelson, Mark D.; Miles, Patrick D.; Bixby, Josh; Wendt, Daniel G.; Kepler, Dennis; Schaaf, Abbey. 2015. Refining FIA plot locations using LiDAR point clouds.
• Meneguzzo, Dacia M.; Liknes, Greg C. 2015. Research Activities in Support of High-Resolution Land Cover Mapping in the North Central United States.
• Meneguzzo, Dacia M.; Liknes, Greg C. 2015. Status and trends of eastern redcedar (Juniperus virginiana) in the central United States: Analyses and observations based on Forest Inventory and Analysis data.
• Liknes, Greg C.; Meneguzzo, Dacia M.; Nimerfro, Kevin. 2015. Woody encroachment in the Central United States.
• Butler, Brett J.; Hewes, Jaketon H.; Liknes, Greg C.; Nelson, Mark D.; Snyder, Stephanie A. 2014. A comparison of techniques for generating forest ownership spatial products.
• Stein, Susan M.; Carr, Mary A.; Liknes, Greg C.; Comas, Sara J. 2014. Islands on the edge: housing development and other threats to America's Pacific and Caribbean Island forests: a Forests on the Edge report.
• Hewes, Jaketon H.; Butler, Brett J.; Liknes, Greg C.; Nelson, Mark D.; Snyder, Stephanie A. 2014. Map of distribution of six forest ownership types in the conterminous United States.
• McRoberts, Ronald E.; Liknes, Greg C.; Domke, Grant M. 2014. Using a remote sensing-based, percent tree cover map to enhance forest inventory estimation.
• Liknes, Greg C.; Nelson, Mark D.; Kaisershot, Daniel J. 2013. Net change in forest density, 1873-2001. Using historical maps to monitor long-term forest trends..
• Liknes, Greg C.; Morin, Randall S.; Canham, Charles D. 2013. Trend analyses and projections using national forest inventory data.
• Goeking, Sara A.; Liknes, Greg C.; Lindblom, Erik; Chase, John; Jacobs, Dennis M.; Benton, Robert. 2012. A GIS-based tool for estimating tree canopy cover on fixed-radius plots using high-resolution aerial imagery.
• Meneguzzo, Dacia M.; Liknes, Greg C. 2012. A framework for reporting tree cover attributes in agricultural landscapes.
• Morin, Randall S.; Liknes, Greg C. 2012. Abstracts of Moving from status to trends: Forest Inventory and Analysis (FIA) symposium 2012.
• Toney, Chris; Liknes, Greg; Lister, Andy; Meneguzzo, Dacia. 2012. Assessing alternative measures of tree canopy cover: Photo-interpreted NAIP and ground-based estimates.
• Riemann, Rachel; O'Neil-Dunne, Jarlath; Liknes, Greg C. 2012. Building capacity for providing canopy cover and canopy height at FIA plot locations using high-resolution imagery and leaf-off LiDAR.
• Goeking, Sara A.; Liknes, Greg C. 2012. Is lodgepole pine mortality due to mountain pine beetle linked to the North American Monsoon.
• Morin, Randall S.; Liknes, Greg C. 2012. Moving from status to trends: Forest Inventory and Analysis (FIA) symposium 2012.
• Meneguzzo, Dacia M; Crocker, Susan J.; Nelson, Mark D.; Barnett, Charles J.; Butler, Brett J.; Domke, Grant M.; Hansen, Mark H.; Hatfield, Mark A.; Liknes, Greg C.; Lister, Andrew J.; Lister, Tonya W.; Piva, Ronald J.; Wilson, Barry T. (Ty); Woodall, Christopher W. 2012. Nebraska's Forests 2010.
• Morin, Randall S.; Liknes, Greg C. 2012. Poster abstracts of Moving from status to trends: Forest Inventory and Analysis (FIA) symposium 2012.
• Liknes, Greg C.; Woodall, Christopher W.; Walters, Brian F.; Goeking, Sara A. 2012. Unlocking the climate riddle in forested ecosystems.
• Liknes, Greg C.; Woodall, Christopher W.; Perry, Charles H. 2012. Using inventory data to determine the impact of drought on tree mortality.
• Crocker, Susan J.; Liknes, Greg C.; Meneguzzo, Dacia M. 2011. Retrospective analysis of EAB spread: understanding the effect of landscape pattern on invasion and propagation.
• Meneguzzo, Dacia M.; Crocker, Susan J.; Liknes, Greg C. 2010. A technique for mapping urban ash trees using object-based image analysis.
• Woodall, C.J.; Nowak, D.J.; Liknes, G.C.; Westfall, J.A. 2010. Assessing the potential for urban trees to facilitate forest tree migration in the eastern United States.
• Liknes, Greg C.; Crocker, Susan J.; Meneguzzo, Dacia M. 2010. Climatic controls on emerald ash borer dispersal.
• Nelson, Mark D.; Liknes, Greg C.; Butler, Brett J. 2010. Map of forest ownership in the conterminous United States. Scale 1:7,500,000 ..
• Crocker, Susan J.; Meneguzzo, Dacia M.; Liknes, Greg C. 2010. Patterns among the ashes: Exploring the relationship between landscape pattern and the emerald ash borer.
• Liknes, Greg C.; Nelson, Mark D.; Butler, Brett J. 2010. Public and private forest ownership in the conterminous United States. Chapter 6..
• Zimmerman, Patrick L.; Liknes, Greg C. 2010. The role of misclassification in estimating proportions and an estimator of misclassification probability.
• Nelson, Mark; Liknes, Greg; Perry, Charles H. 2009. Combining forest inventory, satellite remote sensing, and geospatial data for mapping forest attributes of the conterminous United States.
• Ruefenacht, Bonnie; Liknes, Greg; Lister, Andrew J.; Fisk, Haans; Wendt, Dan. 2009. Evaluation of open source data mining software packages.
• Liknes, Greg C.; Nelson, Mark D. 2009. Improving Forest Inventory and Analysis efficiency with common land unit information.
• Liknes, Greg C.; Woodall, Christopher W.; Perry, Charles H. 2009. Predicting forest attributes from climate data using a recursive partitioning and regression tree algorithm.
• Goeking, Sara A.; Liknes, Greg C. 2009. The role of pre-field operations at four forest inventory units: We can see the trees, not just the forest.
• Liknes, Greg C.; Nelson, Mark D.; Gormanson, Dale D.; Hansen, Mark. 2009. The utility of the cropland data layer for Forest Inventory and Analysis.
• Woodall, Christopher W.; Liknes, Greg C. 2008. Climatic regions as an indicator of forest coarse and fine woody debris carbon stocks in the United States.
• Perry, C.H.; Woodall, C.W.; Liknes, G.C.; Schoeneberger, M.M. 2008. Filling the gap: improving estimates of working tree resources in agricultural landscapes.
• Woodall, C.W.; Liknes, G.C. 2008. Relationships between forest fine and coarse woody debris carbon stocks across latitudinal gradients in the United States as an indicator of climate change effects.
• Perry, Charles H. (Hobie); Everson, Vern A.; Brown, Ian K.; Cummings-Carlson, Jane; Dahir, Sally E.; Jepsen, Edward A.; Kovach, Joe; Labissoniere, Michael D.; Mace, Terry R.; Padley, Eunice A.; Rideout, Richard B.; Butler, Brett J.; Crocker, Susan J.; Liknes, Greg C.; Morin, Randall S.; Nelson, Mark D.; Wilson, Barry T. (Ty); Woodall, Christopher W. 2008. Wisconsin's forests, 2004.
• Nelson, Mark D.; Liknes, Greg C. 2007. Forest Land Ownership in the Conterminous United States map.
• Woodall, Christopher W.; Charney, Joseph; Liknes, Greg; Potter, Brian. 2006. Linking Fuel Inventories With Atmospheric Data for Assessment of Fire Danger.
• McRoberts, Ronald E.; Barbour, R. James; Gebert, Krista M.; Liknes, Greg C.; Nelson, Mark D.; Meneguzzo, Dacia M.; et al., . 2006. Using basic geographic information systems functionality to support sustainable forest management decision making and post-decision assessments.
• McRoberts, Ronald E.; Holden, Geoffrey R.; Nelson, Mark D.; Liknes, Greg C.; Gormanson, Dale D. 2006. Using satellite imagery as ancillary data for increasing the precision of estimates for the Forest Inventory and Analysis program of the USDA Forest Service.
• USDA Forest Service, ; Rummer, Bob; Prestemon, Jeff; May, Dennis; Miles, Pat; Vissage, John; McRoberts, Ron; Liknes, Greg; Shepperd, Wayne D.; Ferguson, Dennis; Elliot, William; Miller, Sue; Reutebuch, Steve; Barbour, Jamie; Fried, Jeremy; Stokes, Bryce; Bilek, Edward; Skog, Ken. 2005. A strategic assessment of forest biomass and fuel reduction treatments in Western States.
• McRoberts, Ronald E.; Liknes, Greg C.; Nelson, Mark D.; Gebert, Krista M.; Barbour, R. James; Odell, Susan L.; Yaddof, Steven C. 2005. Allocating Fire Mitigation Funds on the Basis of the Predicted Probabilities of Forest Wildfire.
• McRoberts, Ronald E.; Liknes, Greg C. 2005. Assessing the Effects of Forest Fragmentation Using Satellite Imagery and Forest Inventory Data.
• Nelson, Mark D.; McRoberts, Ronald E.; Liknes, Greg C.; Holden, Geoffrey R. 2005. Comparing Forest/Nonforest Classifications of Landsat TM Imagery for Stratifying FIA Estimates of Forest Land Area.
• McRoberts, Ronald E.; Holden, Geoffrey R.; Nelson, Mark D.; Liknes, Greg C.; Moser, Warren K.; Lister, Andrew J.; King, Susan L.; LaPoint, Elizabeth B.; Coulston, John W.; Smith, W. Brad; Reams, Gregory A. 2005. Estimating and circumventing the effects of perturbing and swapping inventory plot locations.
• Moser, W. Keith; Liknes, Greg; Hansen, Mark; Nimerfro, Kevin. 2005. Incorporation of Precipitation Data Into FIA Analyses: A Case Study of Factors Influencing Susceptibility to Oak Decline in Southern Missouri, U.S.A..
• Liknes, Greg C.; Holden, Geoffrey R.; Nelson, Mark D.; McRoberts, Ronald E. 2005. Spatially Locating FIA Plots from Pixel Values.
• McRoberts, R.E.; Wendt, D.G.; Liknes, G.C. 2005. Stratified estimation of forest inventory variables using spatially summarized stratifications.
• Woodall, Christopher W.; Charney, Joseph J.; Liknes, Greg C.; Potter, Brian E. 2005. What's the fire danger now Linking fuel inventories with atmospheric data.
• Liknes, Greg C.; Nelson, Mark D.; McRoberts, Ronald E. 2004. Evaluating Classified MODIS Satellite Imagery as a Stratification Tool.
• Rummer, Bob; Prestemon, Jeff; May, Dennis; Miles, Pat; Vissage, John; McRoberts, Ron; Liknes, Greg; Shepperd, Wayne D.; Ferguson, Dennis; Elliot, William; Miller, Sue; Reutebuch, Steve; Barbour, Jamie; Fried, Jeremy; Stokes, Bryce; Bilek, Edward; Skog, Ken. 2003. A strategic assessment of forest biomass and fuel reduction treatments in western states.
• O'Neill, Katherine; Amacher, Michael; Palmer, Craig; Conkling, Barbara; Liknes, Greg C. 2003. Soil Quality as an Indicator of Forest Health: an Overview and Initial Results from the USFS Forest Inventory and Analysis Soil Indicator Program.
• McRoberts, Ronald E.; Liknes, Greg C. 2002. The effects of forest fragmentation on forest stand attributes.

Research Highlights

Highlight	Title	Year
NRS-2015-144	Eastern Redcedar Forests are Expanding in the Central United States Monitoring of change in our nation’s forest resources is an important aspect of the Forest Inventory and Analysis (FIA) work in the Forest Ser ...	2015
NRS-2016-141	Forest Inventory and Analysis Data Helps Inform Landscape Drivers of Insect-induced Tamarack Mortality Tamarack trees have long been associated with Minnesota’s “Great North Woods” and have seen a slow but steady rise in abundance starting i ...	2016
NRS-2016-142	Partnerships Produce High-resolution Land Cover Maps of the Central Plains High-resolution maps, created by the Forest Inventory and Analysis Program and its research partners, are being used to fill a monitoring role f ...	2016