Collaborative research on below-ground ecosystem function: merging climate monitoring with soil, root, and foodweb dynamics to understand mechanisms regulating carbon and nitrogen transformations in Olympic National Park


Principal Investigator:


Kurt Pregitzer
School of Forest Resources & Environmental Science
Michigan Technological University
1400 Townsend Dr., Houghton MI 49931-1295
Phone: (906) 487-2396


Paul Rygiewicz, US EPA, NHEERL/WED
Robert Stottlemyer, USGS
Sarah Green, Michigan Technological University
Jiquan Chen, Michigan Technological University
Andrew Burton, Michigan Technological University
Erik Hobbie, US EPA-NRCA

Park: Olympic National Park


Project Summary:

        The overall objective of this program of research and intensive monitoring is to provide a mechanistic understanding of soil foodweb dynamics related to changes in below ground indicators of ecosystem integrity, specifically the production of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON). We believe changes in the quantity and quality of root and mycorrhizal carbon can be used to predict changes in soil biota - the gatekeepers of nitrogen (N) availability. Soil biota, intimately linked to plant roots, regulate C and N transformations and provide a critical linkage at the landscape level to aquatic environments through their role in the production of DOC and DON. We will link variation in below ground processes to spatial and temporal environmental gradients that control the export of DOC and DON from terrestrial environments to streams and lakes.

        A nested, hierarchical sampling strategy will be used to assess the effects of climatic variation and N addition on DOC and DON production and transport in Olympic National Park. This will consist of 1.) measurements of vegetation, temperature, soil moisture, and soil solution DOC and DON at a network of sites covering dominant vegetation types along elevation and precipitation gradients, and 2.) intensively studied soil processes within major vegetation types on a subset of plots located along the broad moisture and temperature gradients. Plot level studies will be used to quantify how temporal soil climatic variation and N addition alter soil C inputs, food web C transformations, and the production of various DOC and DON precursors and fractions. Existing and newly established weather monitoring stations will be used in conjunction with vegetation, elevation, aspect, and soil temperature and moisture information to predict DOC and DON export at the landscape scale.

        This study addresses all three PRIMENet objectives. The research emphasizes spatial and temporal variation in ecological response to stress, especially from atmospheric N deposition and climate change. The research is proposed for a national park with an existing long-term monitoring and research program. This will help place the study in a broader ecosystem context. Soil biota are intimately linked to plant roots and they regulate C and N transformations. Through the production of DOC/DON, soil biota provide a critical connection with aquatic environments at the landscape level.

FINAL REPORT: Collaborative research on below-ground ecosystem function: Merging long-term climate monitoring with soil, root, and foodweb dynamics to understand mechanisms regulating C and N transformations in Olympic National Park

Summary of Project Results

2002 Olympic PRIMENet Meeting Presentation

Distributions of Airborne Agricultural Contaminants Relative to Amphibian Populations in the Southern Sierra Nevada, California Research Plan

Trudell et al., 2004. Patterns of nitrogen and carbon stable isotope ratios in macrofungi, plants and soils in two old-growth conifer forests. New Phytologist 164:317-335.


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