Scientists & Staff

Randy Kolka
Current Research
I study the effect of land management (forest, agriculture and urban land uses) on the terrestrial and aquatic cycling of nutrients, carbon, heavy metals (notably mercury) and water.
Currently I'm working on numerous studies to assess nutrient, carbon and mercury pools and processes in variety of ecosystems. Nutrient work includes studies related to Forestry Best Management Practices in riparian and wetland systems and work aimed at understanding the influence of strategically placed perennial vegetation in agricultural watersheds. Nutrient work also includes the effect of stream restoration on nutrient cycling. My carbon work includes studies looking at landscape level carbon pools and emissions across number of ecosystems including peatlands, and a variety upland vegetation types. The ecosystem carbon work also extends into characterizing the pools of coarse woody debris in forested riparian areas and streams. My mercury work is focused on two main efforts, one to characterize the mercury cycle under increased sulfate deposition and a second to understand the influence of prescribed fire on mercury cycling.
Why This Research is Important
The transport on nonpoint source pollutants including nutrients such as nitrogen and phosphorus are the number one concern regarding the impacts on aquatic ecosystems. This is demonstrated by the numerous issues surrounding the development of Best Management Practices for forest and agricultural systems and regulations that are being imposed by the Environmental Protection Agency (e.g. Total Maximum Daily Loads).In the Lake States, mercury is of high concern because of its potential to bioaccumulate in the aquatic food chain. Understanding how management can lessen mercury inputs and/or increase storage in terrestrial systems is critical for human health and the fishing industry.
Investigating the landscape level influences on carbon storage and processing will lead to a better understanding of implications of climate change. One of the great uncertainties in climate modeling is the feedbacks that terrestrial systems have on atmospheric carbon, most notably on the green house gases carbon dioxide and methane. Our work is helping fill this important knowledge gap.
Education
- University of Minnesota, Ph.D. Soil Science, 1996
- University of Minnesota, M.S. Soil Science, 1993
- University of Wisconsin - Stevens Point, B.S. Soil Science, 1990
Professional Experience
- Faculty of Graduate Studies, Faculty of Natural Resources Management, Lakehead University 2012 - Current
- Faculty of Graduate Studies, Faculty of Natural Resources Management, Lakehead University 2012 - Current
- Adjunct Professor, Department of Biological Sciences, North Dakota State University 2008 - Current
- Associate Faculty, Department of Natural Resource Ecology and Management, Iowa State University 2004 - Current
- Adjunct Faculty, School of Forest Resources and Environmental Science, Michigan Technological University 2004 - Current
- Adjunct Professor, Department of Forest Resources, University of Minnesota 2002 - Current
- Graduate Faculty, Department of Forestry, University of Kentucky 2002 - Current
- Adjunct Professor, Department of Soil, Water and Climate, University of Minnesota 2002 - Current
Professional Organizations
- Soil Science Society of America
- Society of Wetland Scientists
- American Water Resources Association
- Society of American Foresters (SAF)
- Ecology and Biology Subject Area
- Society of American Foresters, Forest Science and Technology Board (2006 - Present)
- Wetlands (2006 - Present)
- Ecosystems Restoration and Creation, Annual Conference Editorial Review Committee (1997 - Present)
Featured Publications & Products
- Kolka, Randall K.; Haight, Robert G.; Chun, Chan Lan; Berens, Matthew J.; Rogers, Elizabeth R.; Vinhal, Ryan A.; Zalesny, Ronald S.; Nislow, Keith H.; Perry, Charles H.; Connolly, Stephanie J. 2022. Mercury sulfur initiative: suggested program of research for the Upper Great Lakes States. Gen. Tech. Rep. NRS-206. Madison, WI: U.S. Department of Agriculture, Forest Service, Northern Research Station. 28p.
- McCarter, Colin P. R.; Eggert, Susan L.; Sebestyen, Stephen D.; Kolka, Randall K.; Mitchell, Carl P. J. 2022. Effects of Clearcutting and Residual Biomass Harvesting on Hillslope Mercury Mobilization and Downgradient Mercury Accumulation. Journal of Geophysical Research: Biogeosciences
- Pierce, Caroline E.; Furman, Olha S.; Nicholas, Sarah L.; Wasik, Jill Coleman; Gionfriddo, Caitlin M.; Wymore, Ann M.; Sebestyen, Stephen D.; Kolka, Randall K.; Mitchell, Carl P. J.; Griffiths, Natalie A.; Elias, Dwayne A.; Nater, Edward A.; Toner, Brandy M. 2022. Role of Ester Sulfate and Organic Disulfide in Mercury Methylation in Peatland Soils. Environmental Science & Technology
- Wilson, Rachel M.; Griffiths, Natalie A.; Visser, Ate ; McFarlane, Karis J.; Sebestyen, Stephen D.; Oleheiser, Keith C.; Bosman, Samantha ; Hopple, Anya M.; Tfaily, Malak M.; Kolka, Randall K.; Hanson, Paul J.; Kostka, Joel E.; Bridgham, Scott D.; Keller, Jason K.; Chanton, Jeffrey P. 2021. Radiocarbon Analyses Quantify Peat Carbon Losses With Increasing Temperature in a Whole Ecosystem Warming Experiment. Journal of Geophysical Research: Biogeosciences
- Griffis, T.J. ; Roman, D.T. ; Wood, J.D. ; Deventer, J. ; Fachin, L. ; Rengifo, J. ; Del Castillo, D. ; Lilleskov, E. ; Kolka, R. ; Chimner, R.A. ; del Aguila-Pasquel, J. ; Wayson, C. ; Hergoualc'h, K. ; Baker, J.M. ; Cadillo-Quiroz, H. ; Ricciuto, D.M. 2020. Hydrometeorological sensitivities of net ecosystem carbon dioxide and methane exchange of an Amazonian palm swamp peatland. Agricultural and Forest Meteorology
- Hanson, Paul J.; Griffiths, Natalie A.; Iversen, Colleen M.; Norby, Richard J.; Sebestyen, Stephen D.; Phillips, Jana R.; Chanton, Jeffrey P.; Kolka, Randall K.; Malhotra, Avni ; Oleheiser, Keith C.; Warren, Jeffrey M.; Shi, Xiaoying ; Yang, Xiaojuan ; Mao, Jiafu ; Ricciuto, Daniel M. 2020. Rapid Net Carbon Loss From a Whole‐Ecosystem Warmed Peatland. AGU Advances
- Kolka, Randall ; Trettin, Carl ; Tang, Wenwu ; Krauss, Ken W.; Bansal, Sheel ; Drexler, Judith Z.; Wickland, Kimberly P.; Chimner, Rodney A.; Hogan, Dianna M.; Pindilli, Emily J.; Benscoter, Brian ; Tangen, Brian A.; Kane, Evan S.; Bridgham, Scott ; Richardson, Curtis J. 2018. Terrestrial wetlands. U.S. Global Change Research Program
- Kolka, Randall K.; Riggs, Charlotte E.; Nater, Edward A.; Wickman, Trent R.; Witt, Emma L.; Butcher, Jason T. 2019. Temporal fluctuations in young-of-the-year yellow perch mercury bioaccumulation in lakes of northeastern Minnesota. Science of The Total Environment
- 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?. Forests
- Schulte, Lisa A.; Niemi, Jarad; Helmers, Matthew J.; Liebman, Matt; Arbuckle, J. Gordon; James, David E.; Kolka, Randall K.; O'Neal, Matthew E.; Tomer, Mark D.; Tyndall, John C.; Asbjornsen, Heidi; Drobney, Pauline; Neal, Jeri; Van Ryswyk, Gary; Witte, Chris. 2017. Prairie strips improve biodiversity and the delivery of multiple ecosystem services from corn-soybean croplands. Proceedings of the National Academy of Sciences
Publications & Products
- Benalcazar, P. ; Diochon, A.C. ; Kolka, R. ; Schindelbeck, R.R. ; Sahota, T. ; McLaren, B.E. 2022. The impact of land conversion from boreal forest to agriculture on soil health indicators. Canadian Journal of Soil Science
- Helbig, M. ; Živković, T. ; Alekseychik, P. ; Aurela, M. ; El-Madany, T. S.; Euskirchen, E. S.; Flanagan, L. B.; Griffis, T. J.; Hanson, P. J.; Hattakka, J. ; Helfter, C. ; Hirano, T. ; Humphreys, E. R.; Kiely, G. ; Kolka, R.; Laurila, T. ; Leahy, P. G.; Lohila, A. ; Mammarella, I. ; Nilsson, M. B.; Panov, A. ; Parmentier, F. J. W.; Peichl, M. ; Rinne, J. ; Roman, D.; Sonnentag, O. ; Tuittila, E.-S ; Ueyama, M. ; Vesala, T. ; Vestin, P. ; Weldon, S. ; Weslien, P. ; Zaehle, S. 2022. Warming response of peatland CO2 sink is sensitive to seasonality in warming trends. Nature Climate Change
- Hofmeister, Kathryn L.; Eggert, Sue L.; Palik, Brian J.; Morley, David ; Creighton, Emily ; Rye, Marty ; Kolka, Randall K. 2022. The Identification, Mapping, and Management of Seasonal Ponds in Forests of the Great Lakes Region. Wetlands
- Kolka, Randy ; Trettin, Carl ; Windham-Myers, Lisamarie. 2022. The importance of wetland carbon dynamics to society: insight from the second state of the carbon cycle science report. In: Krauss, Ken W.; Zhu, Zhiliang; Stagg, Camille L. Wetland carbon and environmental management. Geophysical Monograph 267. First Edition. Hoboken, NJ: John Wiley & Sons, Inc.: 421-436.
- McCarter, Colin P. R.; Sebestyen, Stephen; Coleman Wasik, Jill K.; Engstrom, Daniel R.; Kolka, Randall K.; Jeremiason, Jeff D.; Swain, Edward B.; Monson, Bruce A.; Branfireun, Brian A.; Balogh, Steven J.; Nater, Edward A.; Eggert, Susan L.; Ning, Paris ; Mitchell, Carl P. J. 2022. Long-Term Experimental Manipulation of Atmospheric Sulfate Deposition to a Peatland: Response of Methylmercury and Related Solute Export in Streamwater. Environmental Science & Technology
- Shannon, Joseph ; Kolka, Randall ; Van Grinsven, Matthew ; Liu, Fengjing. 2022. Joint impacts of future climate conditions and invasive species on black ash forested wetlands. Frontiers in Forests and Global Change
- Shannon, Joseph ; Liu, Fengjing ; Van Grinsven, Matthew ; Kolka, Randall ; Pypker, Thomas. 2022. Magnitude, consequences and correction of temperature‐derived errors for absolute pressure transducers under common monitoring scenarios. Hydrological Processes
- Shelley, Sarah J.; Brice, Deanne J.; Iversen, Colleen M.; Kolka, Randy K.; Sebestyen, Stephen D.; Griffiths, Natalie A. 2022. Deciphering the shifting role of intrinsic and extrinsic drivers on moss decomposition in peatlands over a 5‐year period. Oikos
- Stockstad, Anna B.; Slesak, Robert A.; Toczydlowski, Alan J.; Blinn, Charles R.; Kolka, Randall K.; Sebestyen, Stephen D. 2022. Limited effects of precipitation manipulation on soil respiration and inorganic N concentrations across soil drainage classes in northern Minnesota aspen forests. Forests. 13(8): 1194.
- Stockstad, Anna B.; Slesak, Robert A.; Toczydlowski, Alan J.; Blinn, Charles R.; Kolka, Randall K.; Sebestyen, Stephen D. 2022. The effects of combined throughfall reduction and snow removal on soil physical properties across a drainage gradient in aspen forests of northern Minnesota, USA. Forest Ecology and Management. 524(8): 120538.
- Stuart, Julia E. M.; Tucker, Colin L.; Lilleskov, Erik; Kolka, Randall; Chimner, Rodney A.; Heckman, Katherine A.; Kane, Evan S. 2022. Evidence for older carbon loss with lowered water tables and changing plant functional groups in peatlands. Global Change Biology
- Tata, Hesti L.; Nuroniah, Hani S.; Ahsania, Diandra A.; Anggunira, Haning ; Hidayati, Siti N.; Pratama, Meydina ; Istomo, Istomo ; Chimner, Rodney A.; van Noordwijk, Meine ; Kolka, Randall. 2022. Flooding tolerance of four tropical peatland tree species in a nursery trial. PLOS ONE
- Verbeke, Brittany A.; Lamit, Louis J.; Lilleskov, Erik A.; Hodgkins, Suzanne B.; Basiliko, Nathan ; Kane, Evan S.; Andersen, Roxane ; Artz, Rebekka R. E.; Benavides, Juan C.; Benscoter, Brian W.; Borken, Werner ; Bragazza, Luca ; Brandt, Stefani M.; Bräuer, Suzanna L.; Carson, Michael A.; Charman, Dan ; Chen, Xin ; Clarkson, Beverley R.; Cobb, Alexander R.; Convey, Peter ; Pasquel, Jhon del Águila; Enriquez, Andrea S.; Griffiths, Howard ; Grover, Samantha P.; Harvey, Charles F.; Harris, Lorna I; Hazard, Christina ; Hodgson, Dominic ; Hoyt, Alison M.; Hribljan, John ; Jauhiainen, Jyrki ; Juutinen, Sari ; Knorr, Klaus‐Holger ; Kolka, Randall K.; Könönen, Mari ; Larmola, Tuula ; McCalley, Carmody K.; McLaughlin, James ; Moore, Tim R.; Mykytczuk, Nadia ; Normand, Anna E.; Rich, Virginia ; Roulet, Nigel ; Royles, Jessica ; Rutherford, Jasmine ; Smith, David S.; Svenning, Mette M.; Tedersoo, Leho ; Thu, Pham Q.; Trettin, Carl C.; Tuittila, Eeva‐Stiina ; Urbanová, Zuzana ; Varner, Ruth K.; Wang, Meng ; Wang, Zheng ; Warren, Matt ; Wiedermann, Magdalena M.; Williams, Shanay ; Yavitt, Joseph B.; Yu, Zhi‐Guo ; Yu, Zicheng ; Chanton, Jeffrey P. 2022. Latitude, elevation, and mean annual temperature predict peat organic matter chemistry at a global scale. Global Biogeochemical Cycles
- Deventer, M Julian; Roman, Tyler ; Bogoev, Ivan ; Kolka, Randall K.; Erickson, Matt ; Lee, Xuhui ; Baker, John M.; Millet, Dylan B.; Griffis, Timothy J. 2021. Biases in open-path carbon dioxide flux measurements: Roles of instrument surface heat exchange and analyzer temperature sensitivity. Agricultural and Forest Meteorology
- Eggert, Sue L.; Heiskary, Steven A.; Kolka, Randy K.; Hill, Brian H.; Monson, Bruce A.; Swain, Edward B. 2021. Chapter 2: Ecoregion 5.2.1 Northern lakes and forests: Marcell Experimental Forest, Minnesota. In: Ryan, Douglas F., ed. 2021. Biological responses to stream nutrients: a synthesis of science from experimental forests and ranges. Gen. Tech. Rep. PNW-GTR-981. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 15-44. Chapter 2.
- 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. Geoderma. 394(1): 1-12.
- Krause, Liam ; McCullough, Kevin J.; Kane, Evan S.; Kolka, Randall K.; Chimner, Rodney A.; Lilleskov, Erik A. 2021. Impacts of historical ditching on peat volume and carbon in northern Minnesota USA peatlands. Journal of Environmental Management
- Lamit, Louis J.; Romanowicz, Karl J.; Potvin, Lynette R.; Lennon, Jay T.; Tringe, Susannah G.; Chimner, Rodney A.; Kolka, Randall K.; Kane, Evan S.; Lilleskov, Erik A. 2021. Peatland microbial community responses to plant functional group and drought are depth‐dependent. Molecular Ecology
- López-Ramírez, Sergio Miguel; Mayer, Alex ; Sáenz, Leonardo ; Muñoz-Villers, Lyssette Elena; Holwerda, Friso ; Looker, Nathaniel ; Schürz, Christoph ; Berry, Z. Carter; Manson, Robert ; Asbjornsen, Heidi ; Kolka, Randall ; Geissert, Daniel ; Lezama, Carlos. 2021. A comprehensive calibration and validation of SWAT-T using local datasets, evapotranspiration and streamflow in a tropical montane cloud forest area with permeable substrate in central Veracruz, Mexico. Journal of Hydrology
- Maillard, François ; Fernandez, Christopher W.; Mundra, Sunil ; Heckman, Kate ; Kolka, Randy ; Kauserud, Håvard ; Kennedy, Peter G. 2021. Warming drives a 'hummockification' of microbial communities associated with decomposing mycorrhizal fungal necromass in peatlands. New Phytologist
- McCarter, Colin P. R.; Sebestyen, Stephen D.; Eggert, Susan L.; Kolka, Randall K.; Mitchell, Carl P. J. 2021. Differential subsurface mobilization of ambient mercury and isotopically enriched mercury tracers in a harvested and residue harvested hardwood forest in northern Minnesota. Biogeochemistry
- Quigley, Kathleen M.; Kolka, Randall ; Sturtevant, Brian R.; Dickinson, Matthew B.; Kern, Christel C.; Miesel, Jessica R. 2021. Restoring open canopy pine barrens from the ground up: Repeated burns correspond with increased soil hydraulic conductivity. Science of The Total Environment
- Ricciuto, Daniel M.; Xu, Xiaofeng ; Shi, Xiaoying ; Wang, Yihui ; Song, Xia ; Schadt, Christopher W.; Griffiths, Natalie A.; Mao, Jiafu ; Warren, Jeffrey M.; Thornton, Peter E.; Chanton, Jeff ; Keller, Jason K.; Bridgham, Scott D.; Gutknecht, Jessica ; Sebestyen, Stephen D.; Finzi, Adrien ; Kolka, Randall ; Hanson, Paul J. 2021. An Integrative Model for Soil Biogeochemistry and Methane Processes: I. Model Structure and Sensitivity Analysis. Journal of Geophysical Research: Biogeosciences
- Richard, Robert P.; Kane, Evan S.; Bronson, Dustin R.; Kolka, Randall K. 2021. Long-Term Ecosystem Nutrient Pool Status for Aspen Forest Harvest Simulations on Glacial Till and Sandy Outwash Soils. Forests
- Richard, Robert P.; Kane, Evan S.; Bronson, Dustin R.; Maclean, Ann L.; Kolka, Randall K. 2021. Plant communities and landform relationships delineate the components of soil complexes subject to whole‐tree harvest restriction. Soil Science Society of America Journal
- Salmon, Verity G.; Brice, Deanne J.; Bridgham, Scott ; Childs, Joanne ; Graham, Jake ; Griffiths, Natalie A.; Hofmockel, Kirsten ; Iversen, Colleen M.; Jicha, Terri M.; Kolka, Randy K.; Kostka, Joel E.; Malhotra, Avni ; Norby, Richard J.; Phillips, Jana R.; Ricciuto, Daniel ; Schadt, Christopher W.; Sebestyen, Stephen D.; Shi, Xiaoying ; Walker, Anthony P.; Warren, Jeffrey M.; Weston, David J.; Yang, Xiaojuan ; Hanson, Paul J. 2021. Nitrogen and phosphorus cycling in an ombrotrophic peatland: a benchmark for assessing change. Plant and Soil
- Sebestyen, Stephen D.; Lany, Nina K.; Roman, Daniel Tyler; Burdick, Jacob M.; Kyllander, Richard L.; Verry, Elon Sandy; Kolka, Randall K. 2021. Hydrological and meteorological data from research catchments at the Marcell Experimental Forest, Minnesota, USA. Hydrological Processes
- Stockstad, Anna ; Gray, Ella ; Sebestyen, Stephen ; Lany, Nina ; Kolka, Randall ; Windmuller-Campione, Marcella. 2021. Analyzing Trends in Water Table Elevations at the Marcell Experimental Forest, Minnesota, U.S.A.. American Journal of Undergraduate Research
- Wilson, Rachel M.; Tfaily, Malak M.; Kolton, Max ; Johnston, Eric R.; Petro, Caitlin ; Zalman, Cassandra A.; Hanson, Paul J.; Heyman, Heino M.; Kyle, Jennifer E.; Hoyt, David W.; Eder, Elizabeth K.; Purvine, Samuel O.; Kolka, Randall K.; Sebestyen, Stephen D.; Griffiths, Natalie A.; Schadt, Christopher W.; Keller, Jason K.; Bridgham, Scott D.; Chanton, Jeffrey P.; Kostka, Joel E. 2021. Soil metabolome response to whole-ecosystem warming at the Spruce and Peatland Responses under Changing Environments experiment. Proceedings of the National Academy of Sciences
- Yu, Xueying ; Millet, Dylan B.; Wells, Kelley C.; Henze, Daven K.; Cao, Hansen ; Griffis, Timothy J.; Kort, Eric A.; Plant, Genevieve ; Deventer, Malte J.; Kolka, Randall K.; Roman, D. Tyler; Davis, Kenneth J.; Desai, Ankur R.; Baier, Bianca C.; McKain, Kathryn ; Czarnetzki, Alan C.; Bloom, A. Anthony. 2021. Aircraft-based inversions quantify the importance of wetlands and livestock for Upper Midwest methane emissions. Atmospheric Chemistry and Physics
- Altrichter, Emily A.; Mabry, Catherine M.; Thompson, Janette R.; Kolka, Randall K. 2020. Genetic Differentiation and Phenotypic Plasticity of Forest Herbaceous Species in Iowa, Central United States. Ecological Restoration
- Carter Berry, Z. ; Jones, Kelly W.; Gomez Aguilar, Leon Rodrigo; Congalton, Russell G.; Holwerda, Friso ; Kolka, Randall ; Looker, Nathaniel ; Lopez Ramirez, Sergio Miguel; Manson, Robert ; Mayer, Alex ; Muñoz-Villers, Lyssette ; Ortiz Colin, Perla ; Romero-Uribe, Humberto ; Saenz, Leonardo ; Von Thaden, Juan Jose; Vizcaíno Bravo, Mariana Quetzalli; Williams-Linera, Guadalupe ; Asbjornsen, Heidi. 2020. Evaluating ecosystem service trade-offs along a land-use intensification gradient in central Veracruz, Mexico. Ecosystem Services
- Feng, Xue ; Deventer, M. Julian; Lonchar, Rachel ; Ng, G. H. Crystal; Sebestyen, Stephen D.; Roman, D. Tyler; Griffis, Timothy J.; Millet, Dylan B.; Kolka, Randall K. 2020. Climate Sensitivity of Peatland Methane Emissions Mediated by Seasonal Hydrologic Dynamics. Geophysical Research Letters
- McCarter, Colin P. R.; Sebestyen, Stephen D.; Eggert, Susan L.; Kolka, Randall K.; Mitchell, Carl P. J. 2020. Changes in hillslope hydrology in a perched, shallow soil system due to clearcutting and residual biomass removal. Hydrological Processes
- McPartland, Mara ; Montgomery, Rebecca; Hanson, Paul; Phillips, Jana ; Kolka, Randy ; Palik, Brian. 2020. Vascular plant species response to warming and elevated carbon dioxide in a boreal peatland. Environmental Research Letters
- Quigley, Kathleen M.; Kolka, Randall ; Sturtevant, Brian R.; Dickinson, Matthew B.; Kern, Christel C.; Donner, Deahn M.; Miesel, Jessica R. 2020. Prescribed burn frequency, vegetation cover, and management legacies influence soil fertility: Implications for restoration of imperiled pine barrens habitat. Forest Ecology and Management
- Sirota, Jennie I; Kolka, Randall K.; Sebestyen, Stephen D.; Nater, Edward A. 2020. Mercury dynamics in the pore water of peat columns during experimental freezing and thawing. Journal of Environmental Quality
- 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. Applied Soil Ecology
- 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. Forest Ecology and Management
- Trettin, Carl C.; Kolka, Randall K.; Marsh, Anne S.; Bansal, Sheel ; Lilleskov, Erik A.; Megonigal, Patrick ; Stelk, Marla J.; Lockaby, Graeme ; D'Amore, David V; MacKenzie, Richard A.; Tangen, Brian ; Chimner, Rodney ; Gries, James. 2020. Wetland and hydric soils. Forest and rangeland soils of the United States under changing conditions: A comprehensive science synthesis. Springer, Cham. p. 99-126
- Boche, Mikayla J.; DeSutter, Thomas M.; Kolka, Randall K. 2019. Factors Affecting Soil Total Mercury in Seasonal Pond Basins within a Northern Hardwood Forest in Minnesota, USA. Soil Science Society of America Journal
- Davis, Joshua C.; Shannon, Joseph P.; Van Grinsven, Matthew J.; Bolton, Nicholas W.; Wagenbrenner, Joseph W.; Kolka, Randall K.; Pypker, Thomas G. 2019. Nitrogen cycling responses to simulated emerald ash borer infestation in Fraxinus nigra-dominated wetlands. Biogeochemistry
- Deventer, M. Julian; Griffis, Timothy J.; Roman, D. Tyler; Kolka, Randall K.; Wood, Jeffrey D.; Erickson, Matt ; Baker, John M.; Millet, Dylan B. 2019. Error characterization of methane fluxes and budgets derived from a long-term comparison of open- and closed-path eddy covariance systems. Agricultural and Forest Meteorology
- Dymond, S.F. ; D'Amato, A.W. ; Kolka, R.K. ; Bolstad, P.V. ; Sebestyen, S.D. ; Gill, K. ; Curzon, M.T. 2019. Climatic controls on peatland black spruce growth in relation to water table variation and precipitation. Ecohydrology
- Fernandez, Christopher W.; Heckman, Katherine ; Kolka, Randall ; Kennedy, Peter G. 2019. Melanin mitigates the accelerated decay of mycorrhizal necromass with peatland warming. Ecology Letters
- Haynes, Kristine M.; Kane, Evan S.; Potvin, Lynette ; Lilleskov, Erik A.; Kolka, Randall K.; Mitchell, Carl P.J. 2019. Impacts of experimental alteration of water table regime and vascular plant community composition on peat mercury profiles and methylmercury production. Science of The Total Environment
- Kane, E. S.; Veverica, T. J.; Tfaily, M. M.; Lilleskov, E. A.; Meingast, K. M.; Kolka, R. K.; Daniels, A. L.; Chimner, R. A. 2019. Reduction‐Oxidation Potential and Dissolved Organic Matter Composition in Northern Peat Soil: Interactive Controls of Water Table Position and Plant Functional Groups. Journal of Geophysical Research: Biogeosciences
- Lewandowski, Tera E.; Forrester, Jodi A.; Mladenoff, David J.; Marin-Spiotta, Erika ; D'Amato, Anthony W.; Palik, Brian J.; Kolka, Randall K. 2019. Long term effects of intensive biomass harvesting and compaction on the forest soil ecosystem. Soil Biology and Biochemistry
- Lilleskov, Erik ; McCullough, Kevin ; Hergoualc'h, Kristell ; del Castillo Torres, Dennis ; Chimner, Rodney ; Murdiyarso, Daniel ; Kolka, Randy ; Bourgeau-Chavez, Laura ; Hribljan, John ; del Aguila Pasquel, Jhon ; Wayson, Craig. 2019. Is Indonesian peatland loss a cautionary tale for Peru? A two-country comparison of the magnitude and causes of tropical peatland degradation. Mitigation and Adaptation Strategies for Global Change
- McPartland, Mara ; Falkowski, Michael ; Reinhardt, Jason ; Kane, Evan ; Kolka, Randy ; Turetsky, Merritt ; Douglas, Thomas ; Anderson, John ; Edwards, Jarrod ; Palik, Brian ; Montgomery, Rebecca. 2019. Characterizing Boreal Peatland Plant Composition and Species Diversity with Hyperspectral Remote Sensing. Remote Sensing
- McPartland, Mara Y.; Kane, Evan S.; Falkowski, Michael J.; Kolka, Randy ; Turetsky, Merritt R.; Palik, Brian ; Montgomery, Rebecca A. 2019. The response of boreal peatland community composition and NDVI to hydrologic change, warming and elevated carbon dioxide. Global Change Biology
- Murdiyarso, Daniel ; Lilleskov, Erik ; Kolka, Randy. 2019. Tropical peatlands under siege: the need for evidence-based policies and strategies. Mitigation and Adaptation Strategies for Global Change
- Noh, Nam Jin; Shannon, Joseph P.; Bolton, Nicholas W.; Davis, Joshua C.; Van Grinsven, Matthew J.; Pypker, Thomas G.; Kolka, Randall K.; Wagenbrenner, Joseph W. 2019. Temperature responses of carbon dioxide fluxes from coarse dead wood in a black ash wetland. Wetlands Ecology and Management
- Pischke, Erin C.; Berry, Z. Carter; Kolka, Randall K.; Salcone, Jacob ; Córdoba, Diana ; Shinbrot, Xoco ; López Ramirez, Sergio Miguel; Jones, Kelly W.; Congalton, Russell G.; Manson, Robert H.; Von Thaden Ugalde, Juan José; Selfa, Theresa ; Avila Foucat, V. Sophie; Asbjornsen, Heidi. 2019. Lessons learned about collaborating across coupled human-natural systems research on Mexico's Payments for Hydrological Services Program. In: Perz, Stephen; Macmillan, Palgrave, eds. Collaboration Across Boundaries for Interdisciplinary Environmental Systems Science: Experiences Around the World: 35-77.
- Quigley, K.M. ; Wildt, R.E. ; Sturtevant, B.R. ; Kolka, R.K. ; Dickinson, M.B. ; Kern, C.C. ; Donner, D.M. ; Miesel, J.R. 2019. Fuels, vegetation, and prescribed fire dynamics influence ash production and characteristics in a diverse landscape under active pine barrens restoration. Fire Ecology
- Bertolet, Brittni L.; Corman, Jessica R.; Casson, Nora J.; Sebestyen, Stephen D.; Kolka, Randy K.; Stanley, Emily H. 2018. Influence of soil temperature and moisture on the dissolved carbon, nitrogen, and phosphorus in organic matter entering lake ecosystems. Biogeochemistry
- Bolton, Nicholas; Shannon, Joseph; Davis, Joshua; Grinsven, Matthew; Noh, Nam; Schooler, Shon; Kolka, Randall; Pypker, Thomas; Wagenbrenner, Joseph. 2018. Methods to Improve Survival and Growth of Planted Alternative Species Seedlings in Black Ash Ecosystems Threatened by Emerald Ash Borer. Forests
- Chen, Zichong; Griffis, Timothy J.; Baker, John M.; Millet, Dylan B.; Wood, Jeffrey D.; Dlugokencky, Edward J.; Andrews, Arlyn E.; Sweeney, Colm; Hu, Cheng; Kolka, Randall K. 2018. Source partitioning of methane emissions and its seasonality in the U.S. Midwest. Journal of Geophysical Research: Biogeosciences. 123(2): 646-659.
- Corman, J. R.; Bertolet, B. L.; Casson, N. J.; Sebestyen, S. D.; Kolka, R. K.; Stanley, E. H. 2018. Nitrogen and Phosphorus Loads to Temperate Seepage Lakes Associated With Allochthonous Dissolved Organic Carbon Loads. Geophysical Research Letters
- Iversen, Colleen M.; Childs, Joanne ; Norby, Richard J.; Ontl, Todd A.; Kolka, Randall K.; Brice, Deanne J.; McFarlane, Karis J.; Hanson, Paul J. 2018. Fine-root growth in a forested bog is seasonally dynamic, but shallowly distributed in nutrient-poor peat. Plant and Soil
- Kolka, Randall ; Trettin, Carl ; Tang, Wenwu ; Krauss, Ken ; Bansal, Sheel ; Drexler, Judith ; Wickland, Kimberly ; Chimner, Rodney ; Hogan, Diana ; Pindilli, Emily J.; Benscoter, Brian ; Tangen, Brian ; Kane, Evan ; Bridgham, Scott ; Richardson, Curtis. 2018. Terrestrial wetlands. In: Cavallaro, N.; Shrestha, G.; Birdsey, R.; Mayes, A.M.; Najjar, R.G.; Reed, S.C.; Romero-Lankao, P.; Zhu, Z, eds. Second state of the carbon cycle report (SOCCR2): A sustained assessment report. Washington, DC: U.S. Global Change Research Program: 507-567.
- Miesel, Jessica R.; Kolka, Randy ; Townsend, Phil. 2018. Chapter 10 - Wildfire and fire severity effects on post-fire carbon and nitrogen cycling in forest soil (Project NC-EM-F-14-1). In: Potter, Kevin M.; Conkling, Barbara L., eds. 2018. Forest health monitoring: national status, trends, and analysis 2017. General Technical Report SRS-233. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. Pages 151-156.
- Shannon, Joseph; Van Grinsven, Matthew; Davis, Joshua; Bolton, Nicholas; Noh, Nam; Pypker, Thomas; Kolka, Randall. 2018. Water Level Controls on Sap Flux of Canopy Species in Black Ash Wetlands. Forests
- Van Grinsven, Matthew ; Shannon, Joseph ; Bolton, Nicholas ; Davis, Joshua ; Noh, Nam ; Wagenbrenner, Joseph ; Kolka, Randall ; Pypker, Thomas. 2018. Response of black ash wetland gaseous soil carbon fluxes to a simulated emerald ash borer infestation. Forests. 9(6): 324
- Woerndle, Glenn E.; Tsz-Ki Tsui, Martin ; Sebestyen, Stephen D.; Blum, Joel D.; Nie, Xiangping ; Kolka, Randall K. 2018. New Insights on Ecosystem Mercury Cycling Revealed by Stable Isotopes of Mercury in Water Flowing from a Headwater Peatland Catchment. Environmental Science & Technology
- Anwar, Usman; Schulte, Lisa A.; Helmers, Matthew; Kolka, Randall K. 2017. The Effect of Five Biomass Cropping Systems on Soil-Saturated Hydraulic Conductivity Across a Topographic Gradient. BioEnergy Research
- Comas, Xavier; Terry, Neil; Hribljan, John A.; Lilleskov, Erik A.; Suarez, Esteban; Chimner, Rodney A.; Kolka, Randy K. 2017. Estimating belowground carbon stocks in peatlands of the Ecuadorian páramo using ground-penetrating radar (GPR). Biogeosciences. 122. 17 p.
- Davis, Joshua C.; Shannon, Joseph P.; Bolton, Nicholas W.; Kolka, Randall K.; Pypker, Thomas G. 2017. Vegetation responses to simulated emerald ash borer infestation in Fraxinus nigra dominated wetlands of Upper Michigan, USA. Canadian Journal of Forest Research
- Dymond, Salli F.; Bradford, John B.; Bolstad, Paul V.; Kolka, Randall K.; Sebestyen, Stephen D.; DeSutter, Thomas M. 2017. Topographic, edaphic, and vegetative controls on plant-available water. Ecohydrology. e1897. 12 p. https://doi.org/10.1002/eco.1897.
- Haynes, Kristine M.; Kane, Evan S.; Potvin, Lynette ; Lilleskov, Erik A.; Kolka, Randall K.; Mitchell, Carl P. J. 2017. Mobility and transport of mercury and methylmercury in peat as a function of changes in water table regime and plant functional groups. Global Biogeochemical Cycles
- Haynes, Kristine M.; Kane, Evan S.; Potvin, Lynette; Lilleskov, Erik A.; Kolka, Randall K.; Mitchell, Carl P.J. 2017. Gaseous mercury fluxes in peatlands and the potential influence of climate change. Atmospheric Environment. 154: 247-259.
- Hobbs, Trevor; Lynch, Jason; Kolka, Randy. 2017. Site-specific critical acid load estimates for forest soils in the Osborn Creek watershed, Michigan. Gen. Tech. Rep. NRS-171. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 49 p.
- Kolka, Randall K.; Sturtevant, Brian R.; Miesel, Jessica R.; Singh, Aditya; Wolter, Peter T.; Fraver, Shawn; DeSutter, Thomas M.; Townsend, Phil A. 2017. Emissions of forest floor and mineral soil carbon, nitrogen and mercury pools and relationships with fire severity for the Pagami Creek Fire in the Boreal Forest of northern Minnesota. International Journal of Wildland Fire
- Olson, J. C.; Marcarelli, A. M.; Timm, A.L.; Eggert, S.L.; Kolka, R.K. 2017. Evaluating the Effects of Culvert Designs on Ecosystem Processes in Northern Wisconsin Streams. River Research and Applications
- Powers, Matthew; Kolka, Randall; Bradford, John; Palik, Brian; Jurgensen, Martin. 2017. Forest floor and mineral soil respiration rates in a northern Minnesota red pine chronosequence. Forests. 9(1): 16. 15 p.
- Riggs, Charlotte E.; Kolka, Randall K.; Nater, Edward A.; Witt, Emma L.; Wickman, Trent R.; Woodruff, Laurel G.; Butcher, Jason T. 2017. Yellow perch (Perca flavescens) mercury unaffected by wildland fires in northern Minnesota. Journal of Environment Quality. 46(3): 623-631.
- Timm, A.; Higgins, D.; Stanovick, J.; Kolka, R.; Eggert, S. 2017. Quantifying fish habitat associated with stream simulation design culverts in northern Wisconsin. River Research and Applications
- Van Grinsven, Matthew J.; Shannon, Joseph P.; Davis, Joshua C.; Bolton, Nicholas W.; Wagenbrenner, Joseph W.; Kolka, Randall K.; Grant Pypker, Thomas. 2017. Source water contributions and hydrologic responses to simulated emerald ash borer infestations in depressional black ash wetlands. Ecohydrology. 10(7): e1862
- Warren, Matthew; Hergoualc'h, Kristell; Kauffman, J. Boone; Murdiyarso, Daniel; Kolka, Randall. 2017. An appraisal of Indonesia's immense peat carbon stock using national peatland maps: uncertainties and potential losses from conversion. Carbon Balance and Management
- Adkins, Joshua; Barton, Christopher; Grubbs, Scott; Stringer, Jeffrey; Kolka, Randy. 2016. Assessment of streamside management zones for conserving benthic macroinvertebrate communities following timber harvest in eastern Kentucky headwater catchments. Water. 8(6): 261.
- Dymond, S.F.; D'Amato, A.W.; Kolka, Randy; Bolstad, P.V.; Sebestyen, Stephen; Bradford, J.B. 2016. Growth-climate relationships across topographic gradients in the northern Great Lakes. Ecohydrology. 9(6): 918-929.
- Gerken Golay, Michaeleen; Thompson, Janette; Kolka, Randall; Verheyen, Kris. 2016. Carbon, nitrogen and phosphorus storage across a growing season by the herbaceous layer in urban and preserved temperate hardwood forests. Applied Vegetation Science
- Hanson, P. J.; Gill, A. L.; Xu, X.; Phillips, J. R.; Weston, D. J.; Kolka, Randy; Riggs, J. S.; Hook, L. A. 2016. Intermediate-scale community-level flux of CO2 and CH4 in a Minnesota peatland: putting the SPRUCE project in a global context. Biogeochemistry. 129(3): 255-272.
- Hill, Brian H.; Jicha, Terri M.; Lehto, LaRae L.P.; Elonen, Colleen M.; Sebestyen, Stephen D.; Kolka, Randy. 2016. Comparisons of soil nitrogen mass balances for an ombrotrophic bog and a minerotrophic fen in northern Minnesota. Science of The Total Environment. 550: 880-892.
- Kim, Dong-Gill; Taddese, Habitamu; Belay, Abrham; Kolka, Randy. 2016. The impact of traditional fire management on soil carbon and nitrogen pools in a montane forest, southern Ethiopia. International Journal of Wildland Fire. 7 p.
- Kolka, Randy; Bridgham, Scott D.; Ping, Chien-Lu. 2016. Soils of peatlands: histosols and gelisols. In: M.J. Vepraskas, M.J.; Craft, C.L., eds. Wetlands soils: genesis, hydrology, landscapes and classification. Boca Raton, FL: CRC Press/Lewis Publishing: 277-309.
- Kolka, Randy; Mitchell, Carl; Nater, Ed. 2016. Watershed cycling of mercury and controls on methylmercury production in Northern Minnesota landscapes. In: Stringer, Christina E.; Krauss, Ken W.; Latimer, James S., eds. 2016. Headwaters to estuaries: advances in watershed science and management -Proceedings of the Fifth Interagency Conference on Research in the Watersheds. March 2-5, 2015, North Charleston, South Carolina. e-General Technical Report SRS-211. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 302 p.
- Kolka, Randy; Murdiyarso, D.; Kauffman, J. B.; Birdsey, Richard. 2016. Tropical wetlands, climate, and land-use change: adaptation and mitigation opportunities. Wetlands Ecology and Management. 24(2): 107-112.
- Psarska, Sona; Nater, Edward A.; Kolka, Randy. 2016. Impacts of invasive earthworms on soil mercury cycling: Two mass balance approaches to an earthworm invasion in a northern Minnesota forest. Water, Air, and Soil Pollution. 227(6). http://dx.doi.org/10.1007/s11270-016-2885-0 (12 p.).
- Puhlick, Joshua J.; Fraver, Shawn; Fernandez, Ivan J.; Weiskittel, Aaron R.; Kenefic, Laura S.; Kolka, Randy; Gruselle, Marie-Cecile. 2016. Factors influencing organic-horizon carbon pools in mixed-species stands of central Maine, USA. Forest Ecology and Management. 364: 90-100.
- Puhlick, Joshua J.; Weiskittel, Aaron R.; Fernandez, Ivan J.; Fraver, Shawn; Kenefic, Laura S.; Seymour, Robert S.; Kolka, Randall K.; Rustad, Lindsey E.; Brissette, John C. 2016. Long-term influence of alternative forest management treatments on total ecosystem and wood product carbon storage. Canadian Journal of Forest Research
- Sebestyen, Stephen; Kolka, Randy. 2016. Thirty-year results from a paired-catchment study of upland flowpath responses to forest cover conversion in northern Minnesota. In: Stringer, Christina E.; Krauss, Ken W.; Latimer, James S., eds. 2016. Headwaters to estuaries: advances in watershed science and management -Proceedings of the Fifth Interagency Conference on Research in the Watersheds. March 2-5, 2015, North Charleston, South Carolina. e-General Technical Report SRS-211. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 302 p.
- Timm, Anne; Hallerman, Eric; Dolloff, Andy; Hudy, Mark; Kolka, Randall. 2016. Identification of a barrier height threshold where brook trout population genetic diversity, differentiation, and relatedness are affected. Environmental Biology of Fishes
- Wilson, R. M.; Hopple, A. M.; Tfaily, M. M.; Sebestyen, S. D.; Schadt, C. W.; Pfeifer-Meister, L.; Medvedeff, C.; McFarlane, K. J.; Kostka, J. E.; Kolton, M.; Kolka, R.K.; Kluber, L. A.; Keller, J. K.; Guilderson, T. P.; Griffiths, N. A.; Chanton, J. P.; Bridgham, S. D.; Hanson, P. J. 2016. Stability of peatland carbon to rising temperatures. Nature Communications. 7: 13723. 10p.
- Witt, Emma L.; Barton, Christopher D.; Stringer, Jeffrey W.; Kolka, Randy; Cherry, Mac A. 2016. Influence of Variable Streamside Management Zone Configurations on Water Quality after Forest Harvest. Journal of Forestry. 114(1): 41-51.
- Asbjornsen, Heidi; Mayer, Alex S.; Jones, Kelly W.; Selfa, Theresa; Saenz, Leonardo; Kolka, Randall K.; Halvorsen, Kathleen E. 2015. Assessing impacts of payments for watershed services on sustainability in coupled human and natural systems. BioScience. 65 (6): 579-591.
- Babcock, Chad; Finley, Andrew O.; Bradford, John B.; Kolka, Randy; Birdsey, Richard; Ryan, Michael G. 2015. LiDAR based prediction of forest biomass using hierarchical models with spatially varying coefficients. Remote Sensing of Environment. 169: 113-127.
- Coleman Wasik, J.K.; Engstrom, D.R.; Mitchell, C.P.J.; Swain, E.B.; Monson, B.A.; Balogh, S.J.; Jeremiason, J.D.; Branfireun, B.A.; Kolka, R.K.; Almendinger, J.E. 2015. The effects of hydrologic fluctuation and sulfate regeneration on mercury cycling in an experimental peatland. Journal of Geophysical Research: Biogeosciences. 120(9): 1697-1715.
- Comas, X.; Terry, N.; Warren, M.; Kolka, R.; Kristiyono, A.; Sudiana, N.; Nurjaman, D.; Darusman, T. 2015. Imaging tropical peatlands in Indonesia using ground-penetrating radar (GPR) and electrical resistivity imaging (ERI): implications for carbon stock estimates and peat soil characterization. Biogeosciences. 12: 2995-3007.
- Desai, Ankur R.; Xu, Ke; Tian, Hanqin; Weishampel, Peter; Thom, Jonathan; Baumann, Dan; Andrews, Arlyn E.; Cook, Druce D.; King, Jennifer Y.; Kolka, Randall. 2015. Landscape-level terrestrial methane flux observed from a very tall tower. Agricultural and Forest Meteorology. 201: 61-75.
- Kristensen, Terje; Naesset, Erik; Ohlson, Mikael; Bolstad, Paul V.; Kolka, Randall. 2015. Mapping above- and below-ground carbon pools in boreal forests: The case for airborne lidar. PLOS ONE. 10(10): e0138450.
- Miesel, Jessica R.; Hockaday, William C.; Kolka, Randy; Townsend, Philip A. 2015. Soil organic matter composition and quality across fire severity gradients in coniferous and deciduous forests of the southern boreal region. Journal of Geophysical Research-Biogeosciences. 120(6): 1124-1141.
- Miesel, Jessica R.; Kolka, Randall K.; Townsend, Philip A.; Hockaday, William C. 2015. Fire severity effects on soil organic matter in northern Minnesota, USA. FLAMMA. 6(1): 23-25.
- Ontl, Todd A.; Cambardella, Cynthia A.; Schulte, Lisa A.; Kolka, Randall K. 2015. Factors influencing soil aggregation and particulate organic matter responses to bioenergy crops across a topographic gradient. Geoderma. 255-256: 1-11.
- Palik, Brian J.; Haworth, Brooke K.; David, Andrew J.; Kolka, Randall K. 2015. Survival and growth of northern white-cedar and balsam fir seedlings in riparian management zones in northern Minnesota, USA. Forest Ecology and Management, 337: 20-27.
- Potvin, Lynette R.; Kane, Evan S.; Chimner, Rodney A.; Kolka, Randall K.; Lilleskov, Erik A. 2015. Effects of water table position and plant functional group on plant community, aboveground production, and peat properties in a peatland mesocosm experiment (PEATcosm). Plant and Soil. 387(1-2): 277-294.
- Romanowicz, Karl J.; Kane, Evan S.; Potvin, Lynette R.; Daniels, Aleta L.; Kolka, Randy; Lilleskov, Erik A. 2015. Understanding drivers of peatland extracellular enzyme activity in the PEATcosm experiment: mixed evidence for enzymic latch hypothesis. Plant and Soil. 397(1-2): 371-386.
- Ross, D.S.; Bailey, S.W.; Briggs, R.D.; Curry, J.; Fernandez, I.J.; Fredriksen, G.; Goodale, C.L.; Hazlett, P.W.; Heine, P.R.; Johnson, C.E.; Larson, J.T.; Lawrence, G.B.; Kolka, R.K.; Ouimet, R.; Pare, D.; Richter, D. deB; Schirmer, C.D.; Warby, R.A. 2015. Inter-laboratory variation in the chemical analysis of acidic forest soil reference samples from eastern North America. Ecosphere. 6(5): 73.
- Wu, Jiayu; Stewart, Timothy W.; Thompson, Janette R.; Kolka, Randy; Franz, Kristie J. 2015. Watershed features and stream water quality: Gaining insight through path analysis in a Midwest urban landscape, USA. Landscape and Urban Planning. 143: 219-229.
- Chimner, Rodney A.; Ott, Cassandra A.; Perry, Charles H.; Kolka, Randall K. 2014. Developing and evaluating rapid field methods to estimate peat carbon. Wetlands. 34(6): 1241-1246.
- Dymond, Salli F.; Kolka, Randall K.; Bolstad, Paul V.; Sebestyen, Stephen D. 2014. Long-term soil moisture patterns in a northern Minnesota forest. Soil Science Society of America Journal, 78 (S1): S208-S216.
- Gottfried, Gerald J.; Ffolliott, Peter F.; Brooks, Kenneth N.; Kolka, Randall K.; Raish, Carol B.; Neary, Daniel G. 2014. Contributions of studies on experimental forests to hydrology and watershed management [Chapter 14]. In: Hayes, D.C.; Stout, S.L.; Crawford, R.H.; Hoover, A.P., eds. USDA Forest Service experimental forests and ranges research for the long term. New York, NY: Springer. p. 311-340.
- Hagerty, Shannon B.; van Groenigen, Kees Jan; Allison, Steven D.; Hungate, Bruce A.; Schwartz, Egbert; Koch, George W.; Kolka, Randall K.; Dijkstra, Paul. 2014. Accelerated microbial turnover but constant growth efficiency with warming in soil. Nature Climate Change. 4(10): 903-906.
- Handler, Stephen; Duveneck, Matthew J.; Iverson, Louis; Peters, Emily; Scheller, Robert M.; Wythers, Kirk R.; Brandt, Leslie; Butler, Patricia; Janowiak, Maria; Shannon, P. Danielle; Swanston, Chris; Barrett, Kelly; Kolka, Randy; McQuiston, Casey; Palik, Brian; Reich, Peter B.; Turner, Clarence; White, Mark; Adams, Cheryl; D'Amato, Anthony; Hagell, Suzanne; Johnson, Patricia; Johnson, Rosemary; Larson, Mike; Matthews, Stephen; Montgomery, Rebecca; Olson, Steve; Peters, Matthew; Prasad, Anantha; Rajala, Jack; Daley, Jad; Davenport, Mae; Emery, Marla R.; Fehringer, David; Hoving, Christopher L.; Johnson, Gary; Johnson, Lucinda; Neitzel, David; Rissman, Adena; Rittenhouse, Chadwick; Ziel, Robert. 2014. Minnesota forest ecosystem vulnerability assessment and synthesis: a report from the Northwoods Climate Change Response Framework project. Gen. Tech. Rep. NRS-133. Newtown Square, PA; U.S. Department of Agriculture, Forest Service, Northern Research Station. 228 p.
- Hill, Brian H.; Elonen, Colleen M.; Jicha, Terri M.; Kolka, Randall K.; Lehto, LaRae L.P.; Sebestyen, Stephen D.; Seifert-Monson, Lindsey R. 2014. Ecoenzymatic stoichiometry and microbial processing of organic matter in northern bogs and fens reveals a common P-limitation between peatland types. Biogeochemistry. 120(1-3): 203-224.
- Hill, Brian H.; Kolka, Randall K.; McCormick, Frank H.; Starry, Matthew A. 2014. A synoptic survey of ecosystem services from headwater catchments in the United States. Ecosystem Services. 7: 106-115.
- Jackson, C. Rhett; Thompson, James A.; Kolka, Randall K. 2014. Wetland soils, hydrology and geomorphology. In: Batzer, D.; Sharitz, R., eds. Ecology of freshwater and estuarine wetlands. Berkeley, CA: University of California Press: 23-60. Chapter 2.
- Kastendick, Douglas N.; Palik, Brian J.; Zenner, Eric K.; Kolka, Randy K.; Blinn, Charles R.; Kragthorpe, Joshua J. 2014. Regeneration responses in partially-harvested riparian management zones in northern Minnesota. Journal of Water Resource and Protection. 6(6): 556-564.
- Kolka, Randy; Sturtevant, Brian; Townsend, Philip; Miesel, Jessica; Wolter, Peter; Fraver, Shawn; DeSutter, Tom. 2014. Post-fire comparisons of forest floor and soil carbon, nitrogen, and mercury pools with fire severity indices. Soil Science Society of America Journal 78: S58-S65
- Mazur, M.; Mitchell, C.P.J.; Eckley, C.S.; Eggert, S.L.; Kolka, R.K.; Sebestyen, S.D.; Swain, E.B. 2014. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment. Science of The Total Environment. 496: 678-687.
- Pérez-Suárez, Marlín; Castellano, Michael J.; Kolka, Randall; Asbjornsen, Heidi; Helmers, Matthew. 2014. Nitrogen and carbon dynamics in prairie vegetation strips across topographical gradients in mixed Central Iowa agroecosystems. Agriculture, Ecosystems & Environment. 188: 1-11.
- Seifert-Monson, L.R.; Hill, B.H.; Kolka, R.K.; Jicha, T.M.; Lehto, L.L.; Elonen, C.M. 2014. Effects of sulfate deposition on pore water dissolved organic carbon, nutrients, and microbial enzyme activities in a northern peatland. Soil Biology and Biochemistry. 79: 91-99.
- Smith, Tomorra E.; Kolka, Randall K.; Zhou, Xiaobo; Helmers, Matthew J.; Cruse, Richard M.; Tomer, Mark D. 2014. Effects of native perennial vegetation buffer strips on dissolved organic carbon in surface runoff from an agricultural landscape. Biogeochemistry. 120(1-3): 121-132.
- Vose, James M.; Swank, Wayne T.; Adams, Mary Beth; Amatya, Devendra; Campbell, John; Johnson, Sherri; Swanson, Frederick J.; Kolka, Randy; Lugo, Ariel E.; Musselman, Robert; Rhoades, Charles. 2014. The role of experimental forests and ranges in the development of ecosystem science and biogeochemical cycling research. In: Hayes, D.C.; Stout, S.L.; Crawford, R.H.; Hoover, A.P., eds. USDA Forest Service Experimental Forests and Ranges Research for the Long Term: 387-404.
- Vose, James M.; Swank, Wayne T.; Adams, Mary Beth; Amatya, Devendra; Campbell, John; Johnson, Sherri; Swanson, Frederick J.; Kolka, Randy; Lugo, Ariel E.; Musselman, Robert; Rhoades, Charles. 2014. The role of experimental forests and ranges in the development of ecosystem science and biogeochemical cycling research [Chapter 17]. In: Hayes, D.C.; Stout, S.L.; Crawford, R.H.; Hoover, A.P., eds. USDA Forest Service experimental forests and ranges research for the long term. New York, NY: 387-403.
- Zhou, X.; Helmers, M.J.; Asbjornsen, H.; Kolka, R.; Tomer, M.D.; Cruse, R.M. 2014. Nutrient removal by prairie filter strips in agricultural landscapes. Journal of Soil and Water Conservation. 69(1): 54-64.
- Cole, Jason A.; Johnson, Kristopher D.; Birdsey, Richard A.; Pan, Yude; Wayson, Craig A.; McCullough, Kevin; Hoover, Coeli M.; Hollinger, David Y.; Bradford, John B.; Ryan, Michael G.; Kolka, Randall K.; Wieshampel, Peter; Clark, Kenneth L.; Skowronski, Nicholas S.; Hom, John; Ollinger, Scott V.; McNulty, Steven G.; Gavazzi, Michael J. 2013. Database for landscape-scale carbon monitoring sites. Gen. Tech. Rep. NRS-119. Newtown square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 12 p.
- Fissore, Cinzia; Giardina, Christian P.; Kolka, Randall K. 2013. Reduced substrate supply limits the temperature response of soil organic carbon decomposition. Soil Biology and Biochemistry. 67: 306-311.
- Golay, M.E.G.; Thompson, J.R.; Mabry, C.M.; Kolka, R.K. 2013. An investigation of water nutrient levels associated with forest vegetation in highly altered landscapes. Journal of Soil and Water Conservation. 68(5): 361-371.
- Golay, Michaeleen Gerken; Manatt, Robert; Mabry, Catherine; Thompson, Janette; Kolka, Randall. 2013. Restoration of herbaceous woodland plants: persistence, growth, and reproductive success of local and non-local propagules. Ecological Restoration. 31(4): 378-387.
- Hernandez-Santana, V.; Zhou, X.; Helmers, M.J.; Asbjornsen, H.; Kolka, R.; Tomer, M. 2013. Native prairie filter strips reduce runoff from hillslopes under annual row-crop systems in Iowa, USA. Journal of Hydrology. 477: 94-103.
- Laacouri, Aicam; Nater, Edward A.; Kolka, Randall K. 2013. Distribution and uptake dynamics of mercury in leaves of common deciduous tree species in Minnesota, U.S.A.. Environmental Science & Technology. 47(8): 10462-10470.
- Olson, D.M.; Griffis, T.J.; Noormets, A.; Kolka, R.; Chen, J. 2013. Interannual, seasonal, and retrospective analysis of the methane and carbon dioxide budgets of a temperate peatland. Journal of Geophysical Research: Biogeosciences. 118: 226-238.
- Ontl, Todd A.; Hofmockel, Kirsten S.; Cambardella, Cynthia A.; Schulte, Lisa A.; Kolka, Randall K. 2013. Topographic and soil influences on root productivity of three bioenergy cropping systems. New Phytologist. 199(3): 727-737.
- Wickland, Kimberly P.; Krusche, Alex V.; Kolka, Randall K.; Kishimoto-Mo, Ayaka W.; Chimner, Rodney A.; Ogle, Stephen; Srivastava, Nalin. 2013. Inland wetland mineral soils. In: 2013 Supplement to the 2006 IPCC guidelines for national greenhouse gas inventories: wetlands. [Place of publication unknown]: Intergovernmental Panel on Climate Change: 5.1-5.34. Chapter 5.
- Wu, J.Y.; Thompson, J.R.; Kolka, R.K.; Franz, K.J.; Stewart, T.W. 2013. Using the storm water management model to predict urban headwater stream hydrological response to climate and land cover change. Hydrology and Earth System Sciences. 17(12): 4743-4758.
- Brooks, Robert T.; Eggert, Susan L.; Nislow, Keith H.; Kolka, Randall K.; Chen, Celia Y.; Ward, Darren M. 2012. Preliminary assessment of mercury accumulation in Massachusetts and Minnesota seasonal forest pools. Wetlands 32: 653-663.
- Coleman Wasik, Jill K.; Mitchell, Carl P.J.; Engstrom, Daniel R.; Swain, Edward B.; Monson, Bruce A.; Balogh, Steven J.; Jeremiason, Jeffrey D.; Branfireun, Brian A.; Eggert, Susan L.; Kolka, Randall K.; Almendinger, James E. 2012. Methylmercury declines in a boreal peatland when experimental sulfate deposition decreases. Environmental Science & Technology. 46(12): 6663-6671.
- Gabriel, Mark; Kolka, Randy; Wickman, Trent; Woodruff, Laurel; Nater, Ed. 2012. Latent effect of soil organic matter oxidation on mercury cycling within a southern boreal ecosystem. Journal of Environment Quality. 41(2): 495-505.
- Guy, A.C.; DeSutter, T.M.; Casey, F.X.M.; Kolka, R.; Hakk, H. 2012. Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the north. Journal of Environment Quality. 41(2): 554-563.
- Helmers, Matthew J.; Zhou, Xiaobo; Asbjornsen, Heidi; Kolka, Randy; Tomer, Mark D.; Cruse, Richard M. 2012. Sediment removal by prairie filter strips in row-cropped ephemeral watersheds. Journal of Environment Quality. 41(5): 1531-1539.
- Jurgensen, Martin; Tarpey, Rachel; Pickens, Jim; Kolka, Randy; Palik, Brian. 2012. Long-term effect of silvicultural thinnings on soil carbon and nitrogen pools. Soil Science Society of America Journal. 76(4): 1418-1425.
- Kastendick, Douglas N.; Zenner, Eric K.; Palik, Brian J.; Kolka, Randall K.; Blinn, Charles R. 2012. Effects of harvesting on nitrogen and phosphorus availability in riparian management zone soils in Minnesota, USA. Canadian Journal of Forest Research. 42(10): 1784-1791.
- Kolka, R. K. 2012. Effects of fire and fuels management on water quality in eastern North America. In: LaFayette, Russell; Brooks, Maureen T.; Potyondy, John P.; Audin, Lisa; Krieger, Suzanne L.; Trettin, Carl C. Eds. 2012. Cumulative watershed effects of fuel management in the Eastern United States. Gen. Tech. Rep. SRS-161. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 282-293.
- Kolka, Randy; Steber, Aaron; Brooks, Ken; Perry, Charles H.; Powers, Matt. 2012. Relationships between Soil compaction and harvest season, soil texture, and landscape position for aspen forests. Northern Journal of Applied Forestry. 29(1): 21-25.
- Miesel, Jessica; Goebel, P.; Corace, R.; Hix, David; Kolka, Randall; Palik, Brian; Mladenoff, David. 2012. Fire effects on soils in Lake States forests: A compilation of published research to facilitate long-term investigations. Forests. 3(4): 1034-1070.
- Mitchell, Carl P.J.; Kolka, Randall K.; Fraver, Shawn. 2012. Singular and combined effects of blowdown, salvage logging, and wildfire on forest floor and soil mercury pools. Environmental Science & Technology. 46(15): 7963-7970.
- Palik, Brian; Martin, Michelle; Zenner, Erik; Blinn, Charles; Kolka, Randall. 2012. Overstory and regeneration dynamics in riparian management zones of northern Minnesota forested watersheds. Forest Ecology and Management. 271: 1-9.
- Parsekian, Andrew D.; Slater, Lee; Ntarlagiannis, Dimitrios; Nolan, James; Sebestyen, Stephen D.; Kolka, Randall K.; Hanson, Paul J. 2012. Uncertainty in peat volume and soil carbon estimated using ground-penetrating radar and probing. Soil Science Society of America Journal. 76: 1911-1918.
- Powers, Matthew D.; Kolka, Randall K.; Bradford, John B.; Palik, Brian J.; Fraver, Shawn; Jurgensen, Martin F. 2012. Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands. Ecological Applications. 22(4): 1297-1307.
- Risch, Martin R.; DeWild, John F.; Krabbenhoft, David P.; Kolka, Randall K.; Zhang, Leiming. 2012. Litterfall mercury dry deposition in the eastern USA. Environmental Pollution. 161: 284-290.
- Andrews, Danielle M.; Barton, Christopher D.; Kolka, Randy; Rhoades, Charles C.; Dattilo, Adam J. 2011. Soil and water characteristics in restored canebrake and forest riparian zones. Journal of the American Water Resources Association (JAWRA). 47(4): 772-784.
- Goychuk, Denys; Kilgore, Michael A.; Blinn, Charles R.; Coggins, Jay; Kolka, Randall K. 2011. The effect of timber harvesting guidelines on felling and skidding productivity in northern Minnesota. Forest Science. 57(5): 393-407.
- Grigal, David F.; Bates, Peter C.; Kolka, Randall K. 2011. Ecosystem carbon storage and flux in upland/peatland watersheds in northern Minnesota. Chapter 9.. In: Kolka, Randall K.; Sebestyen, Stephen D.; Verry, Elon S.; Brooks,Kenneth N., eds. Peatland biogeochemistry and watershed hydrology at the Marcell Experimental Forest. Boca Raton, FL: CRC Press: 243-296.
- Kolka, Randall K.; Mitchell, Carl P.J.; Jeremiason, Jeffrey D.; Hines, Neal A.; Grigal, David F.; Engstrom, Daniel R.; Coleman-Wasik, Jill K.; Nater, Edward A.; Swain, Edward B.; Monson, Bruce A.; Fleck, Jacob A.; Johnson, Brian; Almendinger, James E.; Branfireun, Brian A.; Brezonik, Patrick L.; Cotner, James B. 2011. Mercury cycling in peatland watersheds. Chapter 11.. In: Kolka, Randall K.; Sebestyen, Stephen D.; Verry, Elon S.; Brooks,Kenneth N., eds. Peatland biogeochemistry and watershed hydrology at the Marcell Experimental Forest. Boca Raton, FL: CRC Press: 349-370.
- Kolka, Randall K.; Palik, Brian J.; Tersteeg, Daniel P.; Bell, James C. 2011. Effects of riparian buffers on hydrology of northern seasonal ponds. Transactions of the American Society of Agricultural and Biological Engineers (ASABE). 54(5):2111-2116.
- Kolka, Randall K.; Rabenhorst, Martin C.; Swanson, David. 2011. Histosols. In: Huang, P.M.; Li, Y.; Sumner, M.E., eds. Handbook of soil sciences properties and processes, 2nd edition. Boca Raton, FL: CRC Press: 33.8-33.39. Chapter 33.2.
- Kolka, Randall K.; Sebestyen, Stephen D.; Bradford, John B. 2011. An evolving research agenda at the Marcell Experimental Forest. Chapter 3.. In: Kolka, Randall K.; Sebestyen, Stephen D.; Verry, Elon S.; Brooks,Kenneth N., eds. Peatland biogeochemistry and watershed hydrology at the Marcell Experimental Forest. Boca Raton, FL: CRC Press: 73-91.
- Powers, Matthew; Kolka, Randall; Palik, Brian; McDonald, Rachel; Jurgensen, Martin. 2011. Long-term management impacts on carbon storage in Lake States forests. Forest Ecology and Management. 262(3): 424-431.
- Sebestyen, Stephen D.; Dorrance, Carrie; Olson, Donna M.; Verry, Elon S.; Kolka, Randall K.; Elling, Art E.; Kyllander, Richard. 2011. Long-term monitoring sites and trends at the Marcell Experimental Forest. Chapter 2.. In: Kolka, Randall K.; Sebestyen, Stephen D.; Verry, Elon S.; Brooks,Kenneth N., eds. Peatland biogeochemistry and watershed hydrology at the Marcell Experimental Forest. Boca Raton, FL: CRC Press: 15-71.
- Witt, Emma L.; Barton, Christopher D.; Stringer, Jeffrey W.; Bowker, Daniel W.; Kolka, Randall K. 2011. Evaluating Best Management Practices for ephemeral channel protection following forest harvest in the Cumberland Plateau - preliminary findings. In: Fei, Songlin; Lhotka, John M.; Stringer, Jeffrey W.; Gottschalk, Kurt W.; Miller, Gary W., eds. Proceedings, 17th central hardwood forest conference; 2010 April 5-7; Lexington, KY; Gen. Tech. Rep. NRS-P-78. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 365-374.
- Bradford, John B.; Weishampel, Peter; Smith, Marie-Louise; Kolka, Randall; Birdsey, Richard A.; Ollinger, Scott V.; Ryan, Michael G. 2010. Carbon pools and fluxes in small temperate forest landscapes: Variability and implications for sampling design. Forest Ecology and Management. 259: 1245-1254.
- Kolka, Randall K.; Giardina, Christian P.; McClure, Jason D.; Mayer, Alex; Jurgensen, Martin F. 2010. Partitioning hydrologic contributions to an 'old-growth' riparian area in the Huron Mountains of Michigan, USA. Ecohydrology 3(3):315-324
- Maher, Ryan M.; Asbjornsen, Heidi; Kolka, Randall K.; Cambardella, Cynthia A.; Raich, James W. 2010. Changes in soil respiration across a chronosequence of tallgrass prairie reconstructions. Agriculture, Ecosystems & Environment. 139(4): 749-753.
- Merten, Eric C.; Hemstad, Nathaniel A.; Kolka, Randall K.; Newman, Raymond M.; Verry, Elon S.; Vondracek, Bruce. 2010. Recovery of sediment characteristics in moraine, headwater streams of northern Minnesota after forest harvest. Journal of the American Water Resources Association. 46(4): 733-743.
- Merten, Eric; Hemstad, Nathaniel; Eggert, Susan; Johnson, Lucinda; Kolka, Randall; Vondracek, Bruce; Newman, Raymond. 2010. Relations between fish abundances, summer temperatures, and forest harvest in a northern Minnesota stream system from 1997 to 2007. Ecology of Freshwater Fish. 19: 63-73.
- Richardson, Murray C.; Mitchell, Carl P. J.; Branfireun, Brian A.; Kolka, Randall K. 2010. Analysis of airborne LiDAR surveys to quantify the characteristic morphologies of northern forested wetlands. Journal of Geophysical Research. 115(G3): 03005.
- Zhou, Xiaobo; Helmers, Matthew J.; Asbjornsen, Heidi; Kolka, Randy; Tomer, Mark D. 2010. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion. Journal of Environment Quality. 39(6): 2006-2015.
- Bradford, John B.; Weishampel, Peter; Smith, Marie-Louise; Kolka, Randall; Birdsey, Richard A.; Ollinger, Scott V.; Ryan, Michael G. 2009. Detrital carbon pools in temperate forests: magnitude and potential for landscape-scale assessment. Canadian Journal of Forest Research. 39: 802-813.
- Bradford, John; Weishampel, Peter; Smith, Marie-Louise; Kolka, Randall; Birdsey, Richard A.; Ollinger, Scott V.; Ryan, Michael G. 2009. Detrital carbon pools in temperate forests: magnitude and potential for landscape-scale assessment. Canadian Journal of Forest Research. 39: 802-813.
- Fissore, Cinzia; Giardina, Christian P.; Kolka, Randall K.; Trettin, Carl C. 2009. Soil organic carbon quality in forested mineral wetlands at different mean annual temperature.. Soil Biology & Biochemistry 41: 458-466.
- Fissore, Cinzia; Giardina, Christian P.; Swanston, Christopher W.; King, Gary M.; Kolka, Randall K. 2009. Variable temperature sensitivity of soil organic carbon in North American forests. Global Change Biology. 15: 2295-2310.
- Gabriel, Mark C.; Kolka, Randy; Wickman, Trent; Nater, Ed; Woodruff, Laurel. 2009. Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield. Science of the Total Environment. 407: 4117-4126.
- Mitchell, Carl P. J.; Branfireun, Brian A.; Kolka, Randall K. 2009. Methylmercury dynamics at the upland-peatland interface: Topographic and hydrogeochemical controls. Water Resources Research. 45(2):W02406.
- Pelster, David E.; Kolka, Randall K.; Prepas, Ellie E. 2009. Overstory vegetation influence nitrogen and dissolved organic carbon flux from the atmosphere to the forest floor: Boreal Plain, Canada. Forest Ecology and Management. 259(2): 210-219.
- Perry, Charles H. (Hobie); Amacher, Michael C.; Cannon, William; Kolka, Randall K.; Woodruff, Laurel. 2009. The distribution of mercury in a forest floor transect across the central United States. In: McRoberts, Ronald E.; Reams, Gregory A.; Van Deusen, Paul C.; McWilliams, William H., eds. Proceedings of the eighth annual forest inventory and analysis symposium; 2006 October 16-19; Monterey, CA. Gen. Tech. Report WO-79. Washington, DC: U.S. Department of Agriculture, Forest Service. 103-108.
- Steil, Jeremy C.; Blinn, Charles R.; Kolka, Randy. 2009. Foresters' perceptions of windthrow dynamics in northern Minnesota riparian management zones. Northern Journal of Applied Forestry. 26(2): 76-82.
- Sumner, Jaclyn; Vepraskas, Michael J.; Kolka, Randall K. 2009. Methods to evvaluate normal rainfall for short-term wetland hydrology assessment. Wetlands. 29(4): 1049-1062.
- Weishampel, Peter; Kolka, Randall; King, Jennifer Y. 2009. Carbon pools and productivity in a 1-km2 heterogeneous forest and peatland mosaic in Minnesota, USA. Forest Ecology and Management. 257(2): 747-754.
- Wells, Gail; Hayes, Deborah; Krause, Katrina; Bartuska, Ann; LeVan-Green, Susan; Anderson, Jim; Gough, Tivoli; Adams, Mary; Schuler, Thomas; Kolka, Randy; Sebestyen, Steve; Kenefic, Laura; Brissette, John; Stout, Susan; Kanoti, Keith; Swanson, Fred; Greene, Sarah; Herring, Margaret; Ritchie, Martin; Skinner, Carl; Lisle, Tom; Keppeler, Elizabeth; Reid, Leslie; Wohlegemuth, Peter; Kitchen, Stanley; McCaughey, Ward; Guldin, Jim; Bragg, Don; Shelton, Michael; Loftis, David; Greenberg, Cathryn; Murphy, Julia. 2009. Experimental forests and ranges : 100 years of research success stories. General Technical Report FPL-GTR-182. Madison, WI: USDA-Forest Service, Forest Products
- Witt, E.L.; Kolka, R.K.; Nater, E.A.; Wickman, T.R. 2009. Influence of the forest canopy on total and methyl mercury deposition in the boreal forest. Water, Air, and Soil Pollution. 199(1-4): 3-11.
- Witt, Emma L.; Kolka, Randall K.; Nater, Edward A.; Wickman, Trent R. 2009. Forest fire effects on mercury deposition in the boreal forest. Environmental Science and Technology. 43(6): 1776-1782.
- Barton, Christopher D.; Andrews, Danielle M.; Kolka, Randall K. 2008. Evaluating hydroperiod response in restored Carolina Bay Westlands using soil physicochemical properties. Restoration Ecology. 16(4): 668-677.
- Bradford, John B.; Weishampel, Peter; Smith, Marie-Louise; Kolka, Randall; Hollinger, David Y.; Birdsey, Richard A.; Ollinger, Scott; Ryan, Michael. 2008. Landscape-scale carbon sampling strategy-lessons learned. Chapter 17. In: Hoover, Coeli M., ed. Field measurements for forest carbon monitoring: A landscape-scale approach. New York, NY: Springer Science + Business Media: 227-238.
- Fissore, Cinzia; Giardina, Christian P.; Kolka, Randall K.; Trettin, Carl C.; King, Gary M.; Jurgensen, Martin F.; Barton, Christopher D.; McDowell, S. Douglas. 2008. Temperature and vegetation effects on soil organic carbon quality along a forested mean annual temperature gradient in North America. Global Change Biology. 14: 193-205.
- Kolka, Randall; Weishampel, Peter; Froberg, Mats. 2008. Measurement and importance of dissolved organic carbon. Chapter 13. In: Hoover, Coeli M., ed. Field measurements for forest carbon monitoring: A landscape-scale approach. New York, NY: Springer Science + Business Media: 171-176.
- Mitchell, Carl P. J.; Branfireun, Brian A.; Kolka, Randall K. 2008. Total mercury and methylmercury dynamics in upland-peatland watersheds during snowmelt. Biogeochemistry
- Mitchell, Carl P.J.; Branfireun, Brian A.; Kolka, Randall K. 2008. Spatial characteristics of net methylmercury production hot spots in peatlands. Environmental Science & Technology. 42: 1010-1016.
- Mitchell, Carl P.J.; Branfireun, Brian A.; Kolka, Randall K. 2008. Assessing sulfate and carbon controls on net methylmercury production in peatlands: An in situ mesocosm approach. Applied Geochemistry. 23(3): 503-518.
- Schulte, Lisa; Asbjornsen, Heidi; Atwell, Ryan; Hart, Chad; Helmers, Matt; Isenhart, Tom; Kolka, Randy; Liebman, Matt; Neal, Jeri; O'Neal, Matt; Secchi, Silvia; Schultz, Richard; Thompson, Jan; Tomer, Mark; Tyndall, John. 2008. A targeted conservation approach for improving environmental quality. A Targeted Conservation Approach for Improving Environmental Quality. Iowa State University Extension PMR 1002. Ames, IA: Iowa State University, Leopold Center for Sustainable Agriculture. 20 p.
- Tarpey, Rachel A.; Jurgensen, Martin F.; Palik, Brian J.; Kolka, Randy K. 2008. The long-term effects of silvicultural thinning and partial cutting on soil compaction in red pine (Pinus resinosa Ait.) and northern hardwood stands in the northern Great Lakes Region of the United States. Canadian Journal of Soil Science. 88(5): 849-857.
- Weishampel, Peter; Kolka, Randall. 2008. Measurement of methane fluxes from terrestrial landscapes using static, non-steady state enclosures. Chapter 12. In: Hoover, Coeli M., ed. Field measurements for forest carbon monitoring: A landscape-scale approach. New York, NY: Springer Science + Business Media: 163-170.
- Landman, George B.; Kolka, Randall K.; Sharitz, Rebecca R. 2007. Soil seed bank analysis of planted and naturally revegetating thermally-disturbed riparian forests. Wetlands, 27(2): 211-223.
- Steber, Aaron; Brooks, Ken; Perry, Charles H.; Kolka, Randy. 2007. Surface compaction estimates and soil sensitivity in Aspen stands of the Great Lakes States. Northern Journal of Applied Forestry. 24(4): 276-281.
- Jeremiason, Jeff D.; Engstrom, Daniel R.; Swain, Edward B.; Nater, Edward A.; Johnson, Brian M.; Almendinger, James E.; Monson, Bruce A.; Kolka, Randy K. 2006. Sulfate Addition Increases Methylmercury Production in an Experimental Wetland. Environmental Science & Technology
- Kolka, Randall K.; Thompson, James A. 2006. Wetland geomorphology, soils, and formative processes. In: Batzer, Darold P.; Sharitz, Rebecca R., eds. Ecology of freshwater and estuarine wetlands. Berkeley, CA: University of California Press: 7-42.
- Sun, Ge; McNulty, Steve G.; Lu, J.; Amatya, Devendra M.; Liang, Y.; Kolka, R.K. 2005. Regional annual water yield from forest lands and its response to potential deforestation across the southeastern United States. Journal of Hydrology 308 (2005) 258-268
- Svec, J.R. ; Kolka, R.K. ; Stringer, J.W. 2005. Defining perennial, intermittent, and ephemeral channels in Eastern Kentucky: Application to forestry best management practices. Forest Ecology and Management
- Thompson, James A.; Kolka, Randall K. 2005. Soil carbon storage estimation in a forested watershed using quantitative soil-landscape modeling. Soil Science Society of America Journal 69:1086-1093
- Abnee, Amanda C.; Thompson, James A.; Kolka, Randall K.; D'Angelo, Elisa M.; Coyne, Mark S. 2004. Landscape Influences on Potential Soil Respiration Rates in a Forested Watershed of Southeastern Kentucky. Environmental Management
- Coulter, Chris B.; Kolka, Randy K.; Thompson James A.,. 2004. Water quality in agricultural, urban, and mixed land use watersheds. Journal of the American Water Resources Association December: 1593-1601.
- Kolka, Randy K.; Smidt, Mathew F. 2004. Effects of forest road amelioration techniques on soil bulk density, surface runoff, sediment transport, soil moisture and seedling growth. Forest Ecology and Management 202: 313-323
- McClure, J. M.; Kolka, R. K.; White, A. 2004. Effect of forest harvesting best management practices on coarse woody debris distribution in stream and riparian zones in three Appalachian watersheds. Water, Air, and Soil Pollution: Focus 4:245-261
- Sun, Ge; Riedel, Mark; Jackson, Rhett; Kolka, Randy; Amatya, Devendra; Shepard, Jim. 2004. Influences of management of Southern forests on water quantity and quality. In: Gen. Tech. Rep. SRS-75. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. Chapter 19. p. 195-234.
- Birdsey, R.; Hollinger, D.; Heath, L.; Hoover, C.; Kolka, R.; Smith, M. L.; Ryan, M. 2003. Pilot Studies for Enhanced Forest Land Measurement. North American Carbon Program, NACP_Intensive_WP_004. 9 p.
- Giese, Laura A. B.; Aust, W. M.; Kolka, Randall K.; Trettin, Carl C. 2003. Biomass and carbon pools of disturbed riparian forests. Forest Ecology and Management 180:493-508
- Giese, Laura A.B.; Aust, W.M.; Kolka, Randall K.; Trettin, Carl C. 2003. Biomass and carbon pools of disturbed riparian forests. Forest Ecology and Management 180: 493-508
- Svec, J. R.; Kolka, R. K.; Stringer, J. W. 2003. Defining perennial, intermittent and ephemeral channels in eastern Kentucky: application to forestry best management practices. In: Van Sambeek, J. W.; Dawson, Jeffery O.; Ponder Jr., Felix; Loewenstein, Edward F.; Fralish, James S., eds. Proceedings of the 13th Central Hardwood Forest Conference; Gen. Tech. Rep. NC-234. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Research Station: 132-133
- Verry, E. S.; Kolka, R. K. 2003. Importance of Wetlands to Streamflow Generation. In: Renard, Kenneth G.;et al., eds. 1st Interagency Conference on Research in the Watersheds; 2003 October 27-30; Benson, AZ. [City, State]: US Department of Agriculture, Agricultural Research Service: 126-132
- Kolka, R. K.; Trettin, C. C.; Nelson, E. A.; Barton, C. D.; Fletcher, D. E. 2002. Application of the EPA Wetland Research Program Approach to a floodplain wetland restoration assessment. Journal of Environmental Monitoring and Restoration 1(1): 37-51
- Kolka, R.K.; Trettin, Carl C.; Nelson, E.A.; Barton, C.D.; Fletcher, D.E. 2002. Application of the EPA wetland research program approach to a floodplain wetland restoration assessment. Journal of Environmental Monitoring & Restoration 1(1): 37-51
- Kolka, R. K.; Grigal, D. F.; Nater, E. A.; Verry, E. S. 2001. Hydrologic cycling of mercury and organic carbon in a forested upland-bog watershed. Soil Science Society of America journal. Vol. 65, no. 3 (May/June 2001).:p. 897-905.
- Kolka, Randy; Smidt, Mathew. 2001. Revisiting forest road retirement. Water Resources Impact, 3(3): 15-18
- Smidt, Mathew F.; Kolka, Randall K. 2001. Alternative skid trail retirement options for steep terrain logging. Proceedings of the 24th Annual COI3 Meeting: 13-17.
- Barton, Christopher; Nelson, Eric A.; Kolka, Randall K.; McLeod, Kenneth W.; Conner, William H.; Lakly, Michelle; Martin, Douglas; Wigginton, John; Trettin, Carl C.; Wisniewski, Joe. 2000. Restoration of a severely impacted riparian wetland system - The Pen Branch Project. Ecological Engineering 15 (2000) S3-S15
- Dulohery, C. J.; Kolka, Randy K.; McKevlin, M. R. 2000. Effects of a willow overstory on planted seedlings in a bottomland restoration. Ecological Engineering. Vol. 15 p. S57-S66. (2000)
- Dulohery, C.J.; Kolka, R.K.; McKevlin, M.R. 2000. Effects of a willow overstory on planted seedlings in a bottomland restoration. Ecological Engineering 15 (2000) S57-S66
- Giese, Laura A.; Aust, W. Michael; Trettin, Carl C.; Kolka, Randall K. 2000. Spatial and temporal patterns of carbon storage and species richness in three South Carolina coastal plain riparian forests. Ecological Engineering 15: S157-S170
- Grigal, D. F.; Kolka, Randy K.; Fleck, J. A.; Nater, E. A. 2000. Mercury budget of an upland-peatland watershed. Biogeochemistry. Vol. 50 p. 95-109. (2000)
- Kolka, Randy K.; Nelson, E. A.; Trettin, C. C. 2000. Conceptual assessment framework for forested wetland restoration: the Pen Branch experience. Ecological Engineering. Vol. 15 p. S17-S21. (2000)
- Kolka, Randy K.; Singer, J. H.; Coppock, C. R.; Casey, W. P.; Trettin, C. C. 2000. Influence of restoration and succession on bottomland hardwood hydrology. Ecological Engineering. Vol. 15 p. S131-S140. (2000)
- Nelson, Eric A.; Dulohery, Neil C.; Kolka, Randall K.; McKee, William H. 2000. Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting. Ecoiogical Engineering 15 (2000) S23-S33
- Knox, A.S.; Gamerdinger, A.P.; Adriano, D.C.; Kolka, R.K.; Kaplan, D.I. 1999. Sources and Practices Contributing to Soil Contamination. In: Bioremediation of Contaiminated Soils, D.C. Adriano, J.-M. Bollag, W.T. Frankenberger, Jr., and R.C. Sims Eds. No. 37, Ch. 4
- Kolka , Randy K.; Nater, E. A.; Verry, Elon S,. 1999. Atmospheric Inputs of Mercury and Organic Carbon into a Forested Upland/Bog Watershed. Water, Air, and Soil Pollution. Vol. 113 p. 273-194. (1999)
- Kolka, R. K.; Grigal, D. F.; Verry, E. S.; Nater, E. A. 1999. Mercury and Organic Carbon Relationships in Streams Draining Forested Upland/Peatland Watersheds. Journal of Environmental Quality 28: 766-775
- Kolka, Randall K.; Grigal, D.F.; Verry, E.S.; Nater, E.A. 1999. Mercury and Organic Carbon Relationships in Streams Draining Forested Upland/Peatland Watersheds. Reprinted from the Journal of Environmental Quality Volume 28, no. 3, May-June 1999.
- Kolka, Randall K.; Nater, E.A.; Grigal, D.F.; Verry, E.S. 1999. Atmospheric Inputs of Mercury and Organic Carbon into a Forested Upland/Bog Watershed. Water; Air; and Soil Pollution 113: 273-294, 1999
- Kolka, Randall K.; Nelson, Eric A.; Bonar, Ronald E.; Dulohery, Neil C.; Gartner, David. 1998. The Pen Branch Project: Restoration of a Forested Wetland in South Carolina. Resoration & Management Notes, Vol. 16, No. 2, Winter 1998
- Kolka, Randall K.; Trettin, Carl C.; Nelson, E.A. 1998. Development of an Assessment Framework for Restored Forested Wetlands. Proceedings of Ecosystems Restoration & Creation, May 14-15, 1998, Tampa, Florida
- Kolka, Randall K.; Trettin, Carl C.; Nelson, E.A.; Conner, W.H. 1998. Tree Seedlings Establishment Across a Hydrologic Gradient in a Bottomland Restoration. Proceedings of The Twenty Fifth Annual Conference on Ecosystems Restoration and Creation, May 1998, Patrick J. Cannizzaro (ed.)
- Kolka, Randall K.; Wolf, Ann T. 1998. Estimating actual evapotranspiration for forested sites: modifications to the Thornthwaite Model. Res. Note SRS-6. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 7p.
- Leary, Rolfe A.; Nimerfro, Kevin; Holdaway, Margaret; Brand, Gary ; Burk, Tom; Kolka, Randall; Wolf, Ann. 1997. Height growth modeling using second order differential equations and the importance of intial height growth. Forest Ecology and Management
- Kolka, Randy K.; Grigal, D.F.; Nater, E.A. 1996. Forest soil mineral weathering rates: use of multiple approaches. Geoderma. Vol. 73 no. 1.:p. 1-21. (1996)
Research Datasets
- Verry, Elon S.; Elling, Arthur E.; Sebestyen, Stephen D.; Kolka, Randall K.; Kyllander, Richard. 2018. Marcell Experimental Forest daily streamflow data. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2018-0009.
- Verry, Elon S.; Elling, Arthur E.; Sebestyen, Stephen D.; Kolka, Randall K.; Kyllander, Richard. 2018. Marcell Experimental Forest peatland and upland water table elevations. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2018-0002.
National Research Highlights
Warming Peatlands Emit Carbon Faster than Previously Known
Year: 2020
Peatlands occupy just 3 %of the planet but store about 30 %of the soil carbon in terrestrial landscapes. A team of scientists is exploring whether climate change could transform peatlands from a carbon sink to a carbon source and, if so, how quickly.
Incorporating ecosystem services into Midwest agriculture
Year: 2017
Science-based Trials of Rowcrops Integrated with Prairie Strips (STRIPS) is transforming the way farmers conduct agriculture in the Midwest. STRIPS strategically integrates small strips of native prairie into rowcrop agriculture to achieve a greater number of benefits, including reduced soil erosion and better habitat for birds, pollinators, and other insects.
Scaling Up Ecosystem Impacts of the Pagami Creek Fire in Northern Minnesota
Year: 2016
Quantifying fire severity is critical to understanding the ecosystem impacts of wildfire. Forest Service research demonstrates the magnitude of ecosystem impacts from large wildfires, the challenges of relating those impacts to repeatable and scalable fire severity indices, and the application of remote sensing to help scale severity and ecosystem impacts of large wildfires.
Sustainable Northern Conifer Forest Management Stores More Carbon than Exploitative Harvesting
Year: 2016
An important part of climate change mitigation is carbon storage in forests and wood products. Yet managers are often uncertain about which management approaches maximize carbon storage. New findings from long-term research in northern conifers in Maine reveal that sustainable forest management results in greater carbon storage than exploitative harvesting.
Largest Climate Change Experiment on the Planet: SPRUCE
Year: 2016
The Spruce and Peatland Responses Under Climatic and Environmental Change Experiment (SPRUCE) is stretching scientists’ ability to manipulate ecosystems to assess the effects of climate change (elevated temperature and carbon dioxide levels) in a high-carbon peatland in northern Minnesota. Because of the massive amount of carbon northern peatlands store, they will have dramatic feedbacks on global greenhouse gas emissions. Research at SPRUCE aims to understand climate change processes affecting both carbon and organisms, which will improve data used in global circulation models and allow scientists to better predict climate in the future.
“Smart Forests” Digital Environmental Sensors and Telecommunications Take Research to New Levels
Year: 2015
Scientific breakthroughs of the 21st century will be powered by tools that help researchers collect and manipulate massive datasets, visualize that data, and offer new ways of understanding the scientific processes behind that information. Forest Service scientists are taking a lead in developing a national Experimental Forests and Ranges “Smart Forests” Network. This network of wired forests uses digital environmental sensors, wireless communications, and new data visualization programs to create a powerful integrated research and monitoring program for the nation’s air, water, forest and rangeland resources.
Prairie Strips Lead to Better Environmental Health and Greater Socioeconomic Vitality
Year: 2012
Forest Service scientists help Midwestern farming communities understand how to transform strategic portions of the agricultural landscape into perennial plant communities