FRESC Terrestrial Ecosystems Laboratory

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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.

We are particularly interested in how activities within ecosystems shape nutrient inputs, losses, and whole-system nutrient balances, and in linkages between terrestrial and aquatic ecosystems.

Our studies occur primarily in Pacific Northwest forests, with a strong focus on cycles of carbon and major nutrients through soils, plants, water, and air. Nitrogen is especially important in this work - both as a control on local ecosystem structure and function - and as a broker between ecosystem properties, land management and global change. Interest in the causes and consequences of nutrient limitation on land extends our studies into other regions and types of ecosystems, as well as into simulation modeling. Our interest in watersheds also compels us to understand how streams work in a landscape context.

Post-Doctoral Alumni

  • Chev Kellogg (2002-2004): Nutrient limitation in oak woodland/grasslands of Sequoia-Kings Canyon National Park
  • Stephanie Yelenik (2008-2010): Post-fire nitrogen fixation along a climate-productivity gradient in the Klamath-Siskiyou Mountains

Graduate Student Alumni

  • Emily Scott (MS 2004): Use of δ15N and δ13C to analyze food webs and identify source-sink relationships in riparian canopy vegetation of the Oregon Coast Range
  • Tom Giesen (MS 2006): Four centuries of soil carbon and nitrogen change after severe fire in a western Cascades forest landscape
  • Stephanie Hart (MS 2006): Riparian litter inputs to streams in the central Oregon Coast Range
  • Alison Cross (MS 2006): Tree species-soils relationships in old-growth forests of the Oregon Coast Range
  • Emily Sinkhorn (MS 2007): Non-linear nitrogen dynamics and calcium depletion along a temperate forest soil nitrogen gradient
  • Aaron Thiel (MS 2008): Nitrogen dynamics across silvicultural canopy gaps in young forests of western Oregon
  • Joselin Matkins (MS 2009): Decomposition of red alder and Douglas-fir leaf litter in Oregon Coast Range riparian forests
  • Tiffany van Huysen (PhD 2009): Nitrogen and phosphorus dynamics during decomposition of multiple litter types in temperate coniferous forests
  • Carlos Sierra (PhD 2009): Environmental variability and system heterogeneity in terrestrial biogeochemical models
  • Jenny Dauer (PhD 2012): Calcium-oxalate in sites of contrasting nutrient status in the Oregon Coast Range
  • Justin Hynicka (MS 2014): Interactions between ecosystem nitrogen and bedrock control long-term calcium sources in Oregon Coast Range forests
  • Giovanny M. Mosquera (MS 2015): Addressing emerging issues in tropical ecohydrology: A combined hydrometric and isotopic approach to evaluate the origin and age of water in a high-elevation tropical ecosystem