I am a Supervisory Research Ecologist at the Forest and Rangeland Ecosystem Science Center in Corvallis, OR
I am interested in forest biogeochemistry and ecosystem studies, watershed science, riparian forests, global change, nutrient cycling, forest soil fertility and stable isotopes.
Professional Experience
2001-present: Supervisory Research Ecologist, USGS Forest and Rangeland Ecosystem Science Center, Corvallis, OR
2001: Post Doctoral Position, Stanford University, Stanford, CA
Education and Certifications
Ph.D., Cornell University, Ithaca, NY (2000)
M.S., University of Washington, Seattle, WA (1994)
B.S., University of Pennsylvania, Philadelphia, PA (1990)
Science and Products
Terrestrial Ecosystems Laboratory (FRESC)
Novel multi‐scale synthesis of nitrogen fixation rates and drivers across the terrestrial biosphere
Terrestrial Ecosystems Laboratory (FRESC)
Nitrogen Deficiency and Excess in Forests: Patterns, Mechanisms and Management
Riparian Forests
Fire Effects and Forest Recovery
Ecosystem Baselines and Restoration
Climate and Ecosystem Biogeochemistry
Forecasting forest response to N deposition: integrating data from individual plant responses to soil chemistry with a continental-scale gradient analysis
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Invasive Grasses Cheatgrass and Medusahead Yield Responses to Sucrose in Experimental Plots in the Northern Great Basin, USA Dataset, 2005-2006
Data supporting the study of tree species' access to rock-derived nutrients, Tillamook State Forest, 2015
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Leaf nitrogen affects photosynthesis and water use efficiency similarly in nitrogen-fixing and non-fixing trees
Tree symbioses sustain nitrogen fixation despite excess nitrogen supply
Nitrogen-bedrock interactions regulate multi-element nutrient limitation and sustainability in forests
Symbiotic nitrogen fixation does not stimulate soil phosphatase activity under temperate and tropical trees
Exploring the role of cryptic nitrogen fixers in terrestrial ecosystems: A frontier in nitrogen cycling research
N and P constrain C in ecosystems under climate change: Role of nutrient redistribution, accumulation, and stoichiometry
Hypotheses and lessons from a native moth outbreak in a low-diversity, tropical rainforest
Climatic aridity shapes post-fire interactions between Ceanothus spp. and Douglas-fir (Pseudotsuga menziesii) across the Klamath Mountains
Early growth and ecophysiological responses of Koa (Acacia koa A. Gray) seedlings to reduced water and phosphorus
N supply mediates the radiative balance of N2O emissions and CO2 sequestration driven by N-fixing vs. non-fixing trees
A roadmap for sampling and scaling biological nitrogen fixation in terrestrial ecosystems
Climate-mediated changes to linked terrestrial and marine ecosystems across the northeast Pacific coastal temperate rainforest margin
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
Science and Products
- Science
Terrestrial Ecosystems Laboratory (FRESC)
Research in our laboratory centers on the ecology and biogeochemistry of forest ecosystems, as well as grassland and riparian systems. We examine how factors such as natural and human disturbances, climate and climate change, succession, and soil fertility shape ecosystem biogeochemistry - and the reciprocal effect of biogeochemical cycles on these and other factors.Novel multi‐scale synthesis of nitrogen fixation rates and drivers across the terrestrial biosphere
Biological nitrogen fixation (BNF) is a critical biogeochemical process that converts inert atmospheric N2 gas into biologically usable forms of the essential nutrient nitrogen. A variety of free-living and symbiotic organisms carry out BNF, and in most regions worldwide, BNF is the largest source of nitrogen that fuels terrestrial ecosystems. As a result, BNF has far reaching effects on ecosystemTerrestrial Ecosystems Laboratory (FRESC)
Research in our laboratory centers on the ecology and biogeochemistry of forest ecosystems, as well as grassland and riparian systems. We examine how factors such as natural and human disturbances, climate and climate change, succession, and soil fertility shape ecosystem biogeochemistry - and the reciprocal effect of biogeochemical cycles on these and other factors.Nitrogen Deficiency and Excess in Forests: Patterns, Mechanisms and Management
This research theme facilitates the sound management and restoration of Pacific Northwest Douglas-fir forests, as well as to refine broader-scale predictions of how temperate forests will function in an increasingly nitrogen-rich world.Riparian Forests
Riparian vegetation is an often ignored yet critical source of nutrition for riparian food webs. Many food webs are supported at their base by the breakdown and incorporation of leaf litter into fungi, insects, etc. In headwater streams, riparian leaf litter inputs provide essential subsidies that fuel in-stream productivity, in addition to subsidizing food chains of terrestrial riparian habitats...Fire Effects and Forest Recovery
This research theme examines the impacts of prescribed fire on plant productivity, soil physical, chemical, and biological characteristics, and nutrient leaching. Results from this research will enable improved decision-making of how to manage fire-prone forests to maintain long-term forest fertility and productivity, especially across wide climate gradients characteristic of the Pacific Northwest...Ecosystem Baselines and Restoration
This research theme coalesces studies of old-growth temperate forests in several major thematic areas including landscape and ecosystem controls on watershed nutrient export, wildfire disturbance legacies on biogeochemical cycling, and the imprint of tree species on soil nutrients in old-growth forests.Climate and Ecosystem Biogeochemistry
This research theme advance fundamental understanding of climate-biogeochemistry interactions, with wide applicability to virtually all terrestrial ecosystems.Forecasting forest response to N deposition: integrating data from individual plant responses to soil chemistry with a continental-scale gradient analysis
Nitrogen deposition is altering forest dynamics, terrestrial carbon storage, and biodiversity. However, our ability to forecast how different tree species will respond to N deposition, especially key response thresholds, is limited by a lack of synthesis across spatial scales and research approaches. To develop our best understanding of N deposition impact on tree growth and survival, we will inte - Data
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Invasive Grasses Cheatgrass and Medusahead Yield Responses to Sucrose in Experimental Plots in the Northern Great Basin, USA Dataset, 2005-2006
Comma-separated values (.csv) files containing data related to plant biomass and seed production responses of invasive Bromus tectorum (cheatgrass) and Taeniatherum caput-medusae (medusahead) to varying sucrose treatments.Data supporting the study of tree species' access to rock-derived nutrients, Tillamook State Forest, 2015
This dataset describes foliar and soil chemistry and isotopes for six tree species in Tillamook State Forest, 2015. - Multimedia
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
- Publications
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 75Leaf nitrogen affects photosynthesis and water use efficiency similarly in nitrogen-fixing and non-fixing trees
Nitrogen (N)-fixing trees are thought to break a basic rule of leaf economics: higher leaf N concentrations do not translate into higher rates of carbon assimilation. Understanding how leaf N affects photosynthesis and water use efficiency (WUE) in this ecologically important group is critical.We grew six N-fixing and four non-fixing tree species for 4–5 years at four fertilization treatments in fAuthorsThomas A. Bytnerowicz, Jennifer L. Funk, Duncan N. L. Menge, Steven Perakis, Amelia A. WolfTree symbioses sustain nitrogen fixation despite excess nitrogen supply
Symbiotic nitrogen fixation (SNF) is a key ecological process whose impact depends on the strategy of SNF regulation—the degree to which rates of SNF change in response to limitation by N versus other resources. SNF that is obligate or exhibits incomplete downregulation can result in excess N fixation, whereas a facultative SNF strategy does not. We hypothesized that tree-based SNF strategies diffAuthorsDuncan N.L. Menge, Amelia A. Wolf, Jennifer L. Funk, Steven Perakis, Palani R. Akana, Rachel Arkebauer, Thomas A. Bytnerowicz, K. A. Carreras Pereira, Alexandra M. Huddell, Sian Kou-Giesbrecht, Sarah K. OrtizNitrogen-bedrock interactions regulate multi-element nutrient limitation and sustainability in forests
Nutrient limitation of tree growth can intensify when nutrients are lost to forest harvest, creating challenges for forest growth and sustainability. Forest harvest accelerates nutrient loss by removing nutrient-containing biomass and by increasing nutrient leaching, shaping patterns of nutrient depletion that cause long-term shifts in nutrient limitation. Nitrogen most frequently limits tree growAuthorsKaveh G. Siah, Steven Perakis, Julie C. Pett-Ridge, Gregory van der HeijdenSymbiotic nitrogen fixation does not stimulate soil phosphatase activity under temperate and tropical trees
Symbiotic nitrogen (N)-fixing plants can enrich ecosystems with N, which can alter the cycling and demand for other nutrients. Researchers have hypothesized that fixed N could be used by plants and soil microbes to produce extracellular phosphatase enzymes, which release P from organic matter. Consistent with this speculation, the presence of N-fixing plants is often associated with high phosphataAuthorsEmily Jager, Andrew Quebbeman, Amelia A. Wolf, Steven Perakis, Jennifer L. Funk, Duncan N.L. MengeExploring the role of cryptic nitrogen fixers in terrestrial ecosystems: A frontier in nitrogen cycling research
Biological nitrogen fixation represents the largest natural flux of new nitrogen (N) into terrestrial ecosystems, providing a critical N source to support net primary productivity of both natural and agricultural systems. When they are common, symbiotic associations between plants and bacteria can add more than 100 kg N ha−1 y−1 to ecosystems. Yet, these associations are uncommon in many terrestriAuthorsCory Cleveland, Carla R. G. Reis, Steven Perakis, Katherine A Dynarski, Sarah Batterman, Timothy Crews, Maga Gei, Michael Gundale, Duncan Menge, Mark Peoples, Sasha C. Reed, Verity Salmon, Fiona M. Soper, Benton Taylor, Monica Turner, Nina WurzburgerN and P constrain C in ecosystems under climate change: Role of nutrient redistribution, accumulation, and stoichiometry
We use the Multiple Element Limitation (MEL) model to examine responses of twelve ecosystems to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in precipitation. Ecosystems respond synergistically to elevated CO2, warming, and decreased precipitation combined because higher water-use efficiency with elevated CO2 and higher fertility with warming compensate for responses to dAuthorsEd Rastetter, Bonnie Kwiatkowski, David Kicklighter, Audrey Barker Plotkin, Helene Genet, Jesse Nippert, Kimberly O’Keefe, Steven Perakis, Stephen Porder, Sarah Roley, Roger W. Ruess, Jonathan R. Thompson, William Wieder, Kevin WIlcox, Ruth YanaiHypotheses and lessons from a native moth outbreak in a low-diversity, tropical rainforest
Outbreaks of defoliating insects in low-diversity tropical forests occur infrequently but provide valuable insights about outbreak ecology in temperate environments and in general. We investigated an extensive outbreak of the endemic koa moth (Scotorythra paludicola), which defoliated endemic koa trees (Acacia koa) over a third of their range on Hawai‘i Island during 2013 and 2014. At Hakalau ForeAuthorsPaul C. Banko, Robert W. Peck, Stephanie G. Yelenik, Eben H. Paxton, Frank Bonaccorso, Kristina Montoya-Aiona, R. Flint Hughes, Steven PerakisClimatic aridity shapes post-fire interactions between Ceanothus spp. and Douglas-fir (Pseudotsuga menziesii) across the Klamath Mountains
Climate change is leading to increased drought intensity and fire frequency, creating early-successional landscapes with novel disturbance–recovery dynamics. In the Klamath Mountains of northwestern California and southwestern Oregon, early-successional interactions between nitrogen (N)-fixing shrubs (Ceanothus spp.) and long-lived conifers (Douglas-fir) are especially important determinants of foAuthorsDamla Cinoglu, Howard E Epstein, Alan J. Tepley, Kristina J. Anderson-Teixeira, Jonathan R. Thompson, Steven PerakisEarly growth and ecophysiological responses of Koa (Acacia koa A. Gray) seedlings to reduced water and phosphorus
Sites in need of restoration typically have one or more environmental factors that limit seedling establishment. Identifying ecophysiological responses to environmental stressors can provide important insights into mitigating measures that would allow seedlings to overcome such constraints to survival. Koa (Acacia koa A. Gray) is a nitrogen-fixing tree species endemic to Hawaiʻi that is highly valAuthorsKaitlin Gerber, Amy Ross-Davis, Steven Perakis, Anthony S. DavisN supply mediates the radiative balance of N2O emissions and CO2 sequestration driven by N-fixing vs. non-fixing trees
Forests are a significant CO2 sink. However, CO2 sequestration in forests is radiatively offset by emissions of nitrous oxide (N2O), a potent greenhouse gas, from forest soils. Reforestation, an important strategy for mitigating climate change, has focused on maximizing CO2 sequestration in plant biomass without integrating N2O emissions from soils. Although nitrogen (N)-fixing trees are often recAuthorsSian Kou-Giesbrecht, Jennifer L. Funk, Steven Perakis, Amelia A. Wolf, Duncan MengeA roadmap for sampling and scaling biological nitrogen fixation in terrestrial ecosystems
Accurately quantifying rates and patterns of biological nitrogen fixation (BNF) in terrestrial ecosystems is essential to characterize ecological and biogeochemical interactions, identify mechanistic controls, improve BNF representation in conceptual and numerical modelling, and forecast nitrogen limitation constraints on future carbon (C) cycling.While many resources address the technical advantaAuthorsFiona M. Soper, Benton Taylor, Joy Winbourne, Michelle Wong, Katherine A Dynarski, Carla R. G. Reis, Mark Peoples, Cory Cleveland, Sasha C. Reed, Duncan Menge, Steven PerakisClimate-mediated changes to linked terrestrial and marine ecosystems across the northeast Pacific coastal temperate rainforest margin
Coastal margins are important areas of materials flux that link terrestrial and marine ecosystems. Consequently, climate-mediated changes to coastal terrestrial ecosystems and hydrologic regimes have high potential to influence nearshore ocean chemistry and food web dynamics. Research from tightly coupled, high-flux coastal ecosystems can advance understanding of terrestrial–marine links and climaAuthorsAllison L. Bidlack, Sarah Bisbing, Brian Buma, Heida Diefenderfer, Jason Fellman, William Floyd, Ian Giesbrecht, Amritpal Lally, Ken Lertzman, Steven Perakis, David Butman, David D'Amore, Sean W. Fleming, Eran W. Hood, Brianna K. Hunt, Peter Kiffney, Gavin McNicol, Brian Menounos, Suzanne E. TankNon-USGS Publications**
Perakis, S.S., Hedin, L.O., 2002, Response to commentary on "Nitrogen loss from unpolluted South American forests mainly via dissolved organic compounds": Nature, v. 418, p. 665-665.Perakis, S.S., Welch, E.B., Jacoby, J.M., 1996, Sediment-to-water blue-green algal recruitment in response to alum and environmental factors: Hydrobiologia, v. 318, no. 3, p. 165-177.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- News
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
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