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.
Click here to return to FRESC Terrestrial Ecosystems Laboratory.
Below are other science projects associated with this project.
Terrestrial Ecosystems Laboratory (FRESC)
Below are data or web applications associated with this project.
Data supporting the study of tree species' access to rock-derived nutrients, Tillamook State Forest, 2015
Below are publications associated with this project.
Decadal-scale decoupling of soil phosphorus and molybdenum cycles by temperate nitrogen-fixing trees
A spatially explicit, empirical estimate of tree-based biological nitrogen fixation in forests of the United States
Riparian soil nitrogen cycling and isotopic enrichment in response to a long-term salmon carcass manipulation experiment
Growth and survival relationships of 71 tree species with nitrogen and sulfur deposition across the conterminous U.S.
Centennial-scale reductions in nitrogen availability in temperate forests of the United States
Nutrient feedbacks to soil heterotrophic nitrogen fixation in forests
Mechanisms of nitrogen deposition effects on temperate forest lichens and trees
Nitrogen enrichment regulates calcium sources in forests
Disturbance and topography shape nitrogen availability and δ15 N over long-term forest succession
Effects and empirical critical loads of Nitrogen for ecoregions of the United States
Convergence of soil nitrogen isotopes across global climate gradients
Nitrate in watersheds: straight from soils to streams?
- Overview
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.
Click here to return to FRESC Terrestrial Ecosystems Laboratory.
- Science
Below are other science projects associated with this project.
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. - Data
Below are data or web applications associated with this project.
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. - Publications
Below are publications associated with this project.
Filter Total Items: 14Decadal-scale decoupling of soil phosphorus and molybdenum cycles by temperate nitrogen-fixing trees
Symbiotic nitrogen- (N) fixing trees can influence multiple biogeochemical cycles by fixing atmospheric N, which drives net primary productivity and soil carbon (C) and N accumulation, as well as by mobilizing soil phosphorus (P) and other nutrients to support growth and metabolism. The soil micronutrient molybdenum (Mo) is essential to N-fixation, yet surprisingly little is known of whether N-fixAuthorsKatherine A Dynarski, Julie C. Pett-Ridge, Steven PerakisA spatially explicit, empirical estimate of tree-based biological nitrogen fixation in forests of the United States
Quantifying human impacts on the nitrogen (N) cycle and investigating natural ecosystem N cycling depend on the magnitude of inputs from natural biological nitrogen fixation (BNF). Here, we present two bottom‐up approaches to quantify tree‐based symbiotic BNF based on forest inventory data across the coterminous United States and SE Alaska. For all major N‐fixing tree genera, we quantify BNF inputAuthorsAnika Staccone, Wenying Liao, Steven Perakis, Jana Compton, Christopher L. Clark, Duncan MengeRiparian soil nitrogen cycling and isotopic enrichment in response to a long-term salmon carcass manipulation experiment
Pacific salmon acquire most of their biomass in the ocean before returning to spawn and die in coastal streams and lakes, thus providing subsidies of marine‐derived nitrogen (MDN) to freshwater and terrestrial ecosystems. Recent declines in salmon abundance have raised questions of whether managers should mitigate for losses of salmon MDN subsidies. To test the long‐term importance of salmon subsiAuthorsMegan Feddern, Gordon W. Holtgrieve, Steven Perakis, Julia A. Hart, Hyejoo Ro, Tom QuinnGrowth and survival relationships of 71 tree species with nitrogen and sulfur deposition across the conterminous U.S.
Atmospheric deposition of nitrogen (N) influences forest demographics and carbon (C) uptake through multiple mechanisms that vary among tree species. Prior studies have estimated the effects of atmospheric N deposition on temperate forests by leveraging forest inventory measurements across regional gradients in deposition. However, in the United States (U.S.), these previous studies were limited iAuthorsKevin J Horn, R. Quinn Thomas, Christopher M. Clark, Linda H Pardo, Mark E. Fenn, Gregory B. Lawrence, Steven Perakis, Erica A.H. Smithwick, Doug Baldwin, Sabine Braun, Annika Nordin, Charles H. Perry, Jennifer N Phelan, Paul G. Schaberg, Samuel B St Clair, Richard Warby, Shaun A. WatmoughCentennial-scale reductions in nitrogen availability in temperate forests of the United States
Forests cover 30% of the terrestrial Earth surface and are a major component of the global carbon (C) cycle. Humans have doubled the amount of global reactive nitrogen (N), increasing deposition of N onto forests worldwide. However, other global changes—especially climate change and elevated atmospheric carbon dioxide concentrations—are increasing demand for N, the element limiting primary productAuthorsKendra K. McLauchlan, Laci M. Gerhart, John J. Battles, Joseph M. Craine, Andrew J. Elmore, Phil E. Higuera, Michelle M Mack, Brendan E. McNeil, David M. Nelson, Neil Pederson, Steven PerakisNutrient feedbacks to soil heterotrophic nitrogen fixation in forests
Multiple nutrient cycles regulate biological nitrogen (N) fixation in forests, yet long-term feedbacks between N-fixation and coupled element cycles remain largely unexplored. We examined soil nutrients and heterotrophic N-fixation across a gradient of 24 temperate conifer forests shaped by legacies of symbiotic N-fixing trees. We observed positive relationships among mineral soil pools of N, carbAuthorsSteven Perakis, Julie C. Pett-Ridge, Christina E. CatricalaMechanisms of nitrogen deposition effects on temperate forest lichens and trees
We review the mechanisms of deleterious nitrogen (N) deposition impacts on temperate forests, with a particular focus on trees and lichens. Elevated anthropogenic N deposition to forests has varied effects on individual organisms depending on characteristics both of the N inputs (form, timing, amount) and of the organisms (ecology, physiology) involved. Improved mechanistic knowledge of these effeAuthorsTherese S. Carter, Christopher L. Clark, Mark E. Fenn, Sarah E. Jovan, Steven Perakis, Jennifer Riddell, Paul G. Schaberg, Tara Greaver, Meredith HastingsNitrogen enrichment regulates calcium sources in forests
Nitrogen (N) is a key nutrient that shapes cycles of other essential elements in forests, including calcium (Ca). When N availability exceeds ecosystem demands, excess N can stimulate Ca leaching and deplete Ca from soils. Over the long term, these processes may alter the proportion of available Ca that is derived from atmospheric deposition vs. bedrock weathering, which has fundamental consequencAuthorsJustin D. Hynicka, Julie C. Pett-Ridge, Steven PerakisDisturbance and topography shape nitrogen availability and δ15 N over long-term forest succession
Forest disturbance and long-term succession towards old-growth are thought to increase nitrogen (N) availability and N loss, which should increase soil δ15N values. We examined soil and foliar patterns in N and δ15N, and soil N mineralization, across 800 years of forest succession in a topographically complex montane landscape influenced by human logging and wildfire. In contrast to expectations,AuthorsSteven Perakis, Alan J. Tepley, Jana ComptonEffects and empirical critical loads of Nitrogen for ecoregions of the United States
Human activity in the last century has increased nitrogen (N) deposition to a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. We synthesized current research relating atmospheric N deposition to effects on terrestrial and freshwater ecosystems in the United States, and estimated associated empirical critical loads oAuthorsLinda H. Pardo, Molly J. Robin-Abbott, Mark E. Fenn, Christine L. Goodale, Linda H. Geiser, Charles T. Driscoll, Edith B. Allen, Jill Baron, Roland Bobbink, William D. Bowman, C M Clark, B. Emmett, Frank S Gilliam, Tara L. Greaver, Sharon J Hall, Erik A. Lilleskov, Lingli Liu, Jason A. Lynch, Knute J Nadelhoffer, Steven Perakis, John L Stoddard, Kathleen C. Weathers, Robin L. DennisConvergence of soil nitrogen isotopes across global climate gradients
Quantifying global patterns of terrestrial nitrogen (N) cycling is central to predicting future patterns of primary productivity, carbon sequestration, nutrient fluxes to aquatic systems, and climate forcing. With limited direct measures of soil N cycling at the global scale, syntheses of the 15 N: 14 N ratio of soil organic matter across climate gradients provide key insights into understanding gAuthorsJoseph M. Craine, Andrew J. Elmore, Lixin Wang, Laurent Augusto, W. Troy Baisden, E. N. J. Brookshire, Michael D. Cramer, Niles J. Hasselquist, Erik A. Hobbie, Ansgar Kahmen, Keisuke Koba, J. Marty Kranabetter, Michelle C. Mack, Erika Marin-Spiotta, Jordan R. Mayor, Kendra K. McLauchlan, Anders Michelsen, Gabriela B. Nardoto, Rafael S. Oliveira, Steven S. Perakis, Pablo L. Peri, Carlos A. Quesada, Andreas Richter, Louis A. Schipper, Bryan A. Stevenson, Benjamin L. Turner, Ricardo A. G. Viani, Wolfgang Wanek, Bernd ZellerNitrate in watersheds: straight from soils to streams?
Human activities are rapidly increasing the global supply of reactive N and substantially altering the structure and hydrologic connectivity of managed ecosystems. There is long-standing recognition that N must be removed along hydrologic flowpaths from uplands to streams, yet it has proven difficult to assess the generality of this removal across ecosystem types, and whether these patterns are inAuthorsElizabeth B. Sudduth, Steven S. Perakis, Emily S. Bernhardt