U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Declining Soil Nitrogen in a Free Air CO2-Enrichment Experiment (FACE)
Published: April 28, 2011
Posted: June 17, 2011

The sustainability of higher ecosystem production under elevated atmospheric carbon dioxide (CO,2) is unknown. Nitrogen (N) is often limited in ecosystems as a result of N incorporation into long-lived biomass and soil organic matter. As a result, N limitation could eventually limit or nullify increasing forest productivity under elevated CO2 (i.e., “Progressive N Limitation”). In the first six years of the Oak Ridge National Laboratory (ORNL) FACE experiment, there was no apparent evidence that N limitation was exacerbated by elevated CO2 or that N limitation reduced sweetgum tree growth. However, the CO2 stimulation of sweetgum tree growth has more recently declined and was tentatively attributed to N limitation. Using stable N isotopes, temporal trends in sweetgum leaf litterfall 15N abundance provided strong evidence that N availability in the ORNL FACE plots has in fact declined over time, and declined faster in plots exposed to elevated CO2, providing evidence for progressive N limitation. Although these results cannot be generalized for other FACE sites, examination of leaf litterfall d15N may provide an accurate indicator of soil N availability and progressive N limitation.

References: Garten Jr., C. T., C. M. Iversen, and R. J. Norby. 2011. “Litterfall 15N Abundance Indicates Declining Soil Nitrogen Availability in a Free Air CO2 Enrichment Experiment,” Ecology 92, 133–39 [doi:10.1890/10-0293.1].

Contact: Mike Kuperberg, SC-23.1, (301) 903-3281, Daniel Stover, SC-23.1, (301) 903-0289
Topic Areas:

  • Research Area: Terrestrial Ecosystem Science
  • Research Area: Free Air CO2 Enrichment (FACE)

Division: SC-23.1 Climate and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)