Scientists & Staff

Speaking to visitors at the Marcell Experimental Forest

Stephen Sebestyen

Research Hydrologist
1831 Hwy 169 East
Grand Rapids, MN, 55744-3399
Phone: 218-326-7108

Contact Stephen Sebestyen

Current Research

I study how water, nutrients, and pollutants solutes flow through the landscape and affect streams, lakes, or wetlands.

As a research hydrologist with the USDA Forest Service in Grand Rapids, MN. I devote portions of my time to research at the Marcell Experimental Forest (MEF) and national-scale syntheses of data from multiple catchment studies. At the MEF, I co-lead research planning and research on hydrological and biogeochemical research. I have developed a research program that builds upon the 55-year legacy of research at this site. The MEF was established to study the ecology and hydrology of peatlands and uplands along the southern fringe of the boreal zone. I pursue research on the effects of nitrogen pollution on ecosystem functions, carbon cycling in peatlands, understanding effects of climate variability, interactions of dissolved organic matter with mercury and other trace metals, and quantifying effects of landscape disturbance on water and solutes yields. I am an investigator in the SPRUCE Experiment (Spruce and Peatland Response Under Climatic and Environmental change), a large-scale, experiment in which above- and below-ground temperatures are being manipulated in a black spruce-Sphagnum bog at the MEF.

While much of my research is based at the MEF, I continue to study lakes, streams, and wetlands elsewhere in Minnesota and on various catchment studies, whether in the USA or abroad. Some of these studies synthesize information from many sites and are intended to broaden understanding to national and global scales. My other research is focused on particular sites and particular environmental issues.  At the Sleepers River Research Watershed in northeastern Vermont, I explore how sources of stream nitrate and dissolved organic matter (DOM) vary over time and space. My research elsewhere in the northeastern USA includes studies of nitrate sources and DOM dynamics. Since the start of my graduate research, a portion of my work has been focused on how groundwater seepage influences biogeochemical cycles in lakes and wetlands. In several studies, I collaborate on research to quantify effects of groundwater seepage on lake trophic status.

I collaborate with a broad range of research scientists, graduate students, and undergraduate students. My position as a Forest Service scientist and being adjunct faculty at the University of Minnesota and Michigan Tech allow me to be highly involved with graduate and postdoctoral researchers.

Research Interests

I pursue research that:
  • Quantifies rates of terrestrial and aquatic biogeochemical transformations to definitively pinpoint the landscape processes that affect water chemistry.
  • Determines how sources, transformations, and transport processes interact to control nutrient and pollutant concentrations within ecosystems.
  • Quantifies how short-term processes that occur at discrete locations and times (the hotspots and hot moments of biogeochemical processes) are important when considered at the ecosystem level.
  • Synthesizes understanding of hydrological and biogeochemical processes from various studies and locations to gain a general understanding of reference conditions and the effects of management decisions on water, air, and soil resources.
  • Establishes monitoring and experimental (manipulative) studies to identify how the timing, release, and cycling of solutes in catchments is affected by climatic and land use / land cover changes.

Why This Research is Important

  1. The flow of water transfers energy and matter from the atmosphere and land to lakes, streams, wetlands, and coastal zones. My scientific interests center on understanding how water and chemicals are transported and transformed in the environment. With an emphasis on catchment science, I study hydrological and biogeochemical cycles to identify ways to effectively maintain water quality and ecosystem productivity. I use multiple approaches (hydrologic, biologic, geochemical, biogeochemical, and isotopic) across range of temporal, spatial, climatic, and ecological settings to study such issues as atmospheric pollutant deposition, forest health, ecosystem acidification, nutrient enrichment of surface waters, and ecosystem responses to climate change.
  2. The variation of stream nutrient concentrations over time and space reflects complex processes that affect ecosystem functions, but more fundamentally, relates to the availability of biologically-essential substances that fuel life cycles on land and in water.
  3. In landscapes where human activities enrich nutrient availability and affect land use / land cover, my work highlights the need to consider how water and nutrient cycles affect surface water chemistry. Understanding linkages among the atmosphere, land, and water helps to inform scientists, land managers, and policy makers who seek to protect valuable natural resources.

Professional Organizations

  • American Association for the Advancement of Science
  • American Geophysical Union
  • International Association of Hydrological Sciences

Awards & Recognition

  • Forest Service Award for Applying Knowledge Globally, 2017 Awarded by the National Forest System Eastern Region of the USDA Forest Service for the project, "Long Term Benefits of Research in the Northwoods: A Partnership with Northern Research Station and the Chippewa National Forest."
  • Publication in Biogeochemistry recognized as being highly cited, 2016 Taking the pulse of snowmelt: In situ sensors reveal seasonal, event and diurnal patterns of nitrate and dissolved organic matter ..."(Pellerin et al., 2012) was recognized as one of the "Top Cited Papers for 2012 and 2013," in Biogeochemistry
  • Northern Research Station Director's Early Career Scientist Award, 2013 In recognition of exemplary contributions to the fields of biogeochemistry and hydrology across the US, and locally at the Marcell Experimental Forest. Your research on nitrogen and dissolved organic matter identifying sources, chemical transformations,
  • Forest Service award for contributions to a strategic focus document on the Clean Air, 2008 Forest Service award for contributions to a strategic focus document on the Clean Air

Featured Publications & Products

Publications & Products

Research Datasets

  • 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.
  • 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.
  • Sebestyen, Stephen D. ; Kyllander, Richard . 2018. Event runoff volume data and daily runoff data for the S2 and S6 catchments at the Marcell Experimental Forest . Fort Collins, CO: Forest Service Research Data Archive.

National Research Highlights

Phenocam and Antenna on top of the pierce laboratory at the Hubbard Brook Experimental Forest, NH. USDA Forest Service

“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.

Last modified: Wednesday, July 11, 2018