Current Research

Broadly, my research focuses on the effects of forest management and other ecosystem stressors on stand development and soil functions, and the development of mitigative actions or adaptive systems to minimize detrimental effects. Most of my research is conducted using experimental manipulation to directly quantify ecosystem responses. Current projects include assessment of ecological impacts of the invasive emerald ash borer in black ash wetlands, determining the effects of invasive Scotch broom on soil and plant communities and options for its control, and effects of intensive management (vegetation control, organic matter removal, soil compaction) on soil and stand factors in Douglas-fir and aspen forests. I am currently developing a research emphasis evaluating the influence of genotype, soil properties, and management practices on seedling drought susceptibility.

Research Interests

- Adaptive silviculture
- Site-soil classifications
- Soil-plant resource dynamics
- Quantifying uncertainty

Past Research

My past research includes similar work to my current research, but also includes many additional topics relevant to sustainable resource management. These include evaluation of erosion following forest harvesting (traditional and salvage logging), use of remote sensing products (Landsat, Lidar) to evaluate forest disturbance patterns and harvesting impacts, development of diagnostic criteria for tree nutrition, and evaluation of the effectiveness of forest management guidelines to achieve intended outcomes.

Why This Research is Important

Forest ecosystems and the services they provide are constantly threated by changing conditions and stressors associated with management, natural disturbances, and climate change. My research is inherently focused on mitigating these threats by providing science-based information for the development of effective management practices and policy in operational settings. Forest managers use my research to make complex decisions to maintain the future supply of benefits that forest provide. To that end, I am keenly interested in improving the application of research in operational settings, including use of experiments that are expressly designed with research application as a primary objective.

https://www.fs.usda.gov/pnw/groups/genetics-and-silvicultural-foundations-management

Education

• Oregon State University, PhD Forest Soils Effects of intensive management practices on soil properties and stand development 2009
• State University of NY, College of Environmental Science and Forestry, MS Forest Ecosystem Science soil-plant nutrition diagnostics 2004
• State University of NY, College of Environmental Science and Forestry, BS Forest Resources Management Forest Management 2002
• SUNY-ESF Ranger School , AAS Forest Technology forest tech disciplines and techniques 2000

Professional Experience

Professional Organizations

• Society of American Foresters (SAF)

Featured Publications & Products

• Carter, David R.; Slesak, Robert A.; Harrington, Timothy B.; Peter, David H.; D’Amato, Anthony W. 2019. Scotch broom (Cytisus scoparius) modifies microenvironment to promote nonnative plant communities.
• Kolka, Randall K.; D'Amato, Anthony W.; Wagenbrenner, Joseph W.; Slesak, Robert A.; Pypker, Thomas G.; Youngquist, Melissa B.; Grinde, Alexis R.; Palik, Brian J. 2018. Review of ecosystem level impacts of emerald ash borer on black ash wetlands: What does the future hold.
• Diamond, Jacob S.; McLaughlin, Daniel L.; Slesak, Robert A.; D'Amato, Anthony W.; Palik, Brian J. 2018. Forested versus herbaceous wetlands: Can management mitigate ecohydrologic regime shifts from invasive emerald ash borer.
• Slesak, Robert A.; Palik, Brian J.; D'Amato, Anthony W.; Kurth, Valerie J. 2017. Changes in soil physical and chemical properties following organic matter removal and compaction: 20-year response of the aspen Lake-States Long Term Soil Productivity installations.
• Slesak, Robert A.; Harrington, Timothy B.; Peter, Dave; DeBruler, Daniel G.; Schoenholtz, Stephen H.; Strahm, Brian D. 2016. Effects of intensive management practices on 10-year Douglas-fir growth, soil nutrient pools, and vegetation communities in the Pacific Northwest, USA.

Publications

• James, Jason ; Page-Dumroese, Deborah ; Busse, Matt ; Palik, Brian ; Zhang, Jianwei ; Eaton, Bob ; Slesak, Robert ; Tirocke, Joanne ; Kwon, Hoyoung . 2021. Effects of forest harvesting and biomass removal on soil carbon and nitrogen: Two complementary meta-analyses.
• Friesen, Hannah C.; Slesak, Robert A.; Karwan, Diana L.; Kolka, Randall K. 2021. Effects of snow and climate on soil temperature and frost development in forested peatlands in Minnesota, USA.
• Palik, Brian J.; D'Amato, Anthony W.; Slesak, Robert A.; Kastendick, Doug ; Looney, Chris ; Kragthorpe, Josh . 2021. Eighth-year survival and growth of planted replacement tree species in black ash (Fraxinus nigra) wetlands threatened by emerald ash borer in Minnesota, USA.
• Cianciolo, Thomas R.; Diamond, Jacob S.; McLaughlin, Daniel L.; Slesak, Robert A.; D'Amato, Anthony W.; Palik, Brian J. 2021. Hydrologic variability in black ash wetlands: Implications for vulnerability to emerald ash borer.
• Slesak, Robert A.; Harrington, Timothy B.; D'Amato, Anthony W.; Carter, David R. 2021. Legacy effects of non-native Cytisus scoparius in glacial outwash soils: Potential impacts to forest soil productivity in western Washington.
• McEachran, Zachary P.; Karwan, Diana L.; Sebestyen, Stephen D.; Slesak, Robert A.; Ng, Gene-Hua Crystal. 2021. Nonstationary flood-frequency analysis to assess effects of harvest and cover type conversion on peak flows at the Marcell Experimental Forest, Minnesota, USA.
• Palik, Brian ; D'Amato, Anthony ; Slesak, Robert A. 2021. Wide-spread vulnerability of black ash (Fraxinus nigra Marsh.) wetlands in Minnesota USA to loss of tree dominance from invasive emerald ash borer.
• Toczydlowski, Alan J.Z.; Slesak, Robert A.; Kolka, Randall K.; Venterea, Rodney T.; D'Amato, Anthony W.; Palik, Brian J. 2020. Effect of simulated emerald ash borer infestation on nitrogen cycling in black ash (Fraxinus nigra) wetlands in northern Minnesota, USA.
• Grinde, Alexis R.; Slesak, Robert A.; D'Amato, A.W. ; Palik, B.P. . 2020. Effects of tree retention and woody biomass removal on bird and small mammal communities.
• Youngquist, Melissa B.; Wiley, Chandra ; Eggert, Sue L.; D'Amato, Anthony W.; Palik, Brian J.; Slesak, Robert A. 2020. Foundation Species Loss Affects Leaf Breakdown and Aquatic Invertebrate Resource Use in Black Ash Wetlands.
• Harrington, Timothy B.; Slesak, Robert A.; Dollins, James P.; Schoenholtz, Stephen H.; Peter, David H. 2020. Logging-debris and vegetation-control treatments influence competitive relationships to limit 15-year productivity of coast Douglas-fir in western Washington and Oregon.
• Toczydlowski, Alan J.Z.; Slesak, Robert A.; Kolka, Randall K.; Venterea, Rodney T. 2020. Temperature and water-level effects on greenhouse gas fluxes from black ash (Fraxinus nigra) wetland soils in the Upper Great Lakes region, USA.
• Carter, David R.; Slesak, Robert A.; Harrington, Timothy B.; D'Amato, Anthony W. 2019. Comparative effects of soil resource availability on physiology and growth of Scotch broom (Cytisus scoparius) and Douglas-fir (Pseudotsuga menziesii) seedlings.
• Carter, David R.; Slesak, Robert A.; Harrington, Timothy B.; D’Amato, Anthony W. 2019. Effects of irrigation and phosphorus fertilization on physiology, growth, and nitrogen-accumulation of Scotch broom (Cytisus scoparius).
• Watts, Andrea ; Harrington, Tim ; Peter, Dave ; Slesak, Robert . 2019. Managing competing vegetation in Douglas-Fir plantations: The benefits of forest floor complexity.
• Engelstad, Peder S.; Falkowski, Michael J.; D'Amato, Anthony W.; Slesak, Robert A.; Palik, Brian J.; Domke, Grant M.; Russell, Matthew B. 2019. Mapping black ash dominated stands using geospatial and forest inventory data in northern Minnesota, USA.
• DeBruler, Daniel G.; Schoenholtz, Stephen H.; Slesak, Robert A.; Strahm, Brian D.; Harrington, Timothy B. 2019. Soil phosphorus fractions vary with harvest intensity and vegetation control at two contrasting Douglas-fir sites in the Pacific northwest.
• D'Amato, Anthony ; Palik, Brian ; Slesak, Robert ; Edge, Greg ; Matula, Colleen ; Bronson, Dustin . 2018. Evaluating Adaptive Management Options for Black Ash Forests in the Face of Emerald Ash Borer Invasion.
• Harrington, Timothy B.; Peter, David H.; Slesak, Robert A. 2018. Logging debris and herbicide treatments improve growing conditions for planted Douglas-fir on a droughty forest site invaded by Scotch broom.
• Looney, Christopher E.; D'Amato, Anthony W.; Palik, Brian J.; Slesak, Robert A. 2017. Canopy treatment influences growth of replacement tree species in Fraxinus nigra forests threatened by the emerald ash borer in Minnesota, USA.
• Youngquist, Melissa B.; Eggert, Sue L.; D'Amato, Anthony W.; Palik, Brian J.; Slesak, Robert A. 2017. Potential effects of foundation species loss on wetland communities: A case study of black ash wetlands threatened by emerald ash borer.
• Looney, Christopher E.; D'Amato, Anthony W.; Palik, Brian J.; Slesak, Robert A.; Slater, Mitchell A. 2017. The response of Fraxinus nigra forest ground-layer vegetation to emulated emerald ash borer mortality and management strategies in northern Minnesota, USA.
• Slesak, Robert A.; Harrington, Timothy B.; D′Amato, Anthony W. 2016. Invasive scotch broom alters soil chemical properties in Douglas-fir forests of the Pacific Northwest, USA.
• Looney, Christopher E.; D'Amato, Anthony W.; Palik, Brian J.; Slesak, Robert A. 2015. Overstory treatment and planting season affect survival of replacement tree species in emerald ash borer threatened Fraxinus nigra forests in Minnesota, USA.
• Telander, Andrew C.; Slesak, Robert A.; D'Amato, Anthony W.; Palik, Brian J.; Brooks, Kenneth N.; Lenhart, Christian F. 2015. Sap flow of black ash in wetland forests of northern Minnesota, USA: Hydrologic implications of tree mortality due to emerald ash borer.
• Slesak, Robert A.; Lenhart, Christian F.; Brooks, Kenneth N.; D'Amato, Anthony W.; Palik, Brian J. 2014. Water table response to harvesting and simulated emerald ash borer mortality in black ash wetlands in Minnesota, USA.
• Harrington, Timothy B., Ph.D..; Slesak, Robert A.; Schoenholtz, Stephen H. 2013. Variation in logging debris cover influences competitor abundance, resource availability, and early growth of planted Douglas-fir.
• Kirkland, John; Harrington, Timoth B.; Peter, David H.; Slesak, Robert A.; Schoenholtz, Stephen H. 2012. Logging debris matters: better soil, fewer invasive plants.
• Devine, Warren D.; Harrington, Timothy B., Ph.D..; Terry, Thomas A.; Harrison, Robert B.; Slesak, Robert A.; Peter, David H.; Harrington, Constance A.; Shilling, Carol J.; Schoenholtz, Stephen H. 2011. Five-year vegetation control effects on aboveground biomass and nitrogen content and allocation in Douglas-fir plantations on three contrasting sites.
• Slesak, Robert A.; Schoenholtz, Stephen H.; Harrington, Timothy B.; Meehan, Nathan A. 2011. Initial response of soil carbon and nitrogen to harvest intensity and competing vegetation control in douglas-fir (Pseudotsuga menziesii) plantations of the Pacific Northwest.
• Slesak, Robert A.; Schoenholtz, Stephen H.; Harrington, Timothy B., Ph.D. 2011. Soil carbon and nutrient pools in Douglas-fir plantations 5 years after manipulating biomass and competing vegetation in the Pacific Nortwest.
• Slesak, Robert A.; Harrington, Timothy B.; Schoenholtz, Stephen H. 2010. Soil and Douglas-fir (Pseudotsuga menziesii) foliar nitrogen responses to variable logging-debris retention and competing vegetation control in the Pacific Northwest.
• Slesak, Robert A.; Schoenholtz, Stephen H.; Harrington, Timothy B., Ph.D. 2010. Soil respiration and carbon responses to logging debris and competing vegetation.
• Slesak, Robert A.; Schoenholtz, Stephen H.; Harrington, Timothy B., Ph.D..; Strahm, Brian D. 2009. Dissolved carbon and nitrogen leaching following variable logging-debris retention and competing-vegetation control in Douglas-fir plantations of western Oregon and Washington.
• Slesak, Robert A.; Briggs, Russell D. 2005. Assessing Christmas Tree Response to N Fertilization.

Citations of non US Forest Service Publications

• Harrington, T.B., R.A. Slesak, J. Dollins, S.H. Schoenholtz, and D. Peter. 2020. Logging-debris configuration and vegetation control influence 15-year changes in soil C and N and stand characteristics of planted coast Douglas-fir in western Washington and Oregon.  Forest Ecology and Management https://doi.org/10.1016/j.foreco.2020.118288

• Littke, K., T.B. Harrington, R.A. Slesak, S. Holub, J. Hatten, A. Gallo, W. Littke, R. Harrison, and E. Turnblom. 2020. Longer-Term Effects of Organic Matter Removal and Vegetation Control on Aboveground and Belowground Nutrients and Douglas-fir Growth at Three Contrasting Pacific Northwestern Forest Sites.  Forest Ecology and Management 468. https://doi.org/10.1016/j.foreco.2020.118176

• Youngquist, M.B., C. Wiley, S.L. Eggert, A.W. D’Amato, B.J. Palik, and R.A. Slesak. 2020. Linking emerald ash borer to changes in ecosystem function: host loss effects on leaf decomposition and invertebrate growth. Wetlands. https://doi.org/10.1007/s13157-019-01221-3

• Host, T.K., M.B. Russell, M.A. Windmuller-Campione, R.A Slesak, and J.F. Knight. 2020. Ash Presence and Abundance derived from Composite Landsat and Sentinel-2 Time Series and Lidar Surface Models in Minnesota, USA. Remote Sensing 12, 1341; doi:10.3390/rs12081341

• Grinde, A., R.A. Slesak, A.W. D’Amato, and B.J. Palik. 2020. Effects of tree retention and woody biomass removal on bird and small mammal communities in Minnesota. Forest Ecology and Management 465: https://doi.org/10.1016/j.foreco.2020.118090

• Vogeler, J.C., R.A. Slesak, P.A. Fekety, and M.J. Falkowski. 2020. Characterizing four decades of forest disturbance in Minnesota.  Forests 11(3): https://doi.org/10.3390/f11030362

• Diamond, J. S., D.L. McLaughlin, R.A., Slesak, and A. Stovall. 2020.  Microtopography is a fundamental organizing structure in black ash wetlands. Biogeosciences 17: 901-915. https://doi.org/10.5194/bg-17-901-2020

• Diamond, J., D. McLaughlin, R. Slesak, and A. Stovall.  2019. Pattern and structure of microtopography implies autogenic origins in forested wetlands. Hydrology and Earth Systems Sciences. 23 (12): 5069-5088.

• Stoval, A., J.S. Diamond, R.A. Slesak, D.L. McLaughlin, and H. Shugart. 2019. Quantifying wetland microtopography with terrestrial laser scanning. Remote Sensing and the Environment.

• McEachran, Z.P, R.A. Slesak, and D.L. Karwan. 2018. From skid trail to landscapes: vegetation is the dominant factor influencing erosion after forest harvest in a low relief glaciated landscape.  Forest Ecology and Management 430:299-311.

• Vogeler, J., J.D. Braaten, R.A. Slesak, and M.J. Falkowski. 2018. Extracting the full value of the Landsat archive: Inter-sensor harmonization for the mapping of Minnesota forest canopy cover (1973-2015). Remote Sensing of Environment. 209:363-374.

• Slesak, R.A., J. Corcoran, and R. Rossman. 2018. A holistic monitoring approach for water quality BMP and forest watershed risk assessment. Journal of Forestry 116(3): 283-290.

• Costanza, K.L., W.H. Livingston, D.M. Kashian , R.A. Slesak, J.C. Tardiff, J.P. Dech, A.K. Diamond, J.J. Daigle, D.J. Ranco, J.S. Neptune, L. Benedict, S.R. Fraver, M. Reinikainen, and N. Siegert. 2017. The precarious state of a cultural keystone species: tribal and biological assessments of the role and future of black ash. Journal of Forestry https://doi.org/10.5849/jof.2016-034R1

• Slesak, R.A., and T. Kaebisch. 2016. Using LiDAR to assess impacts of forest harvest landings on vegetation height and the potential for recovery over time. Canadian J. Forest Research. 46(6): 869-875.

• Slesak, R.A., S.H. Schoenholtz, and D. Evans. 2015. Hillslope erosion two and three years after wildfire, skyline salvage logging, and site preparation in southern Oregon, USA. Forest Ecology and Management 342:1-7.

• Kurth, V.J., J.B. Bradford, R.A. Slesak, and A.W. D’Amato. 2014. Initial soil respiration response to biomass harvesting and green-tree retention in aspen-dominated forests of the Great Lakes region. Forest Ecology and Management 328:342-352.  

• Slesak, R.A. 2013. Soil temperature following logging-debris manipulation and aspen regrowth in Minnesota: implications for sampling depth and alteration of soil processes. Soil Science Society of America Journal 77:1818-1824.

• Slesak, R.A. and R.D. Briggs. 2010. Foliar mass and nutrition of Abies concolor Christmas trees following application of organic and inorganic fertilizer. Northern Journal Applied Forestry 27(1): 28-33.

• Slesak, R.A. and R.D. Briggs. 2007. Christmas tree response to N fertilization and the development of critical foliar N levels in New York. Northern Journal Applied Forestry 24(3):209-217.

• Toczydlowski, A., R.A. Slesak, R.K. Kolka, R.T. Venterea, A.W. D’Amato, and B.J. Palik. 2020. Effect of simulated emerald ash borer infestation on nitrogen cycling in black ash (Fraxinus nigra) wetlands in northern Minnesota, USA. Forest Ecology and Management 458: 117769 https://doi.org/10.1016/j.foreco.2019.117769

• Carter, D.R., R.A. Slesak, T.B. Harrington and A.W. D’Amato. 2019. Effects of irrigation and phosphorus fertilization on physiology, growth, and nitrogen-fixation of Scotch broom (Cytisus scoparius). Plant Physiology Reports https://doi.org/10.1007/s40502-019-00459-7

• Carter, D.R., R.A. Slesak, T.B. Harrington and A.W. D’Amato. 2019. Comparative effects of soil resource availability on physiology and growth of Scotch broom (Cytisus scoparius) and Douglas-fir (Pseudotsuga menziesii) seedlings. Forest Ecology and Management 453. https://doi.org/10.1016/j.foreco.2019.117580