BER Research Highlights

Search Date: August 16, 2017

5 Records match the search term(s):


December 27, 2004

Long-term Ecosystem Research Highlights Fate of Nitrogen in Rainfall

Department of Energy studies on Walker Branch Watershed in the Departments Oak Ridge (Tennessee) National Environmental Research Park showed that stream ecosystems can help prevent nitrogen pollutants from reaching downstream lakes, estuaries, and the ocean. Fossil fuel use is increasing the amount of nitrogen in rainfall in many parts of the United States, and inputs of this nitrogen to aquatic ecosystems can result in harmful algal blooms and drinking water contamination. Combining computer simulation and data from 12 years of field measurements, scientists at Oak Ridge National Laboratory found that biological organisms in streams removed about 20% of the nitrate nitrogen entering the stream from the watershed, thus reducing the concentration of nitrate exported downstream. The removal of nitrate nitrogen was highly seasonal; it was greatest in autumn (due to uptake by bacteria and fungi growing on newly fallen leaves trapped in the stream) and in early spring (due to high rates of uptake by algae before the stream becomes heavily shaded by new leaves in the deciduous forest overhead). These results are consistent with studies at the Hubbard Brook Experimental Forest (New Hampshire) and elsewhere showing that streams can reduce the downstream transport of nitrate nitrogen, and demonstrate the important role of streams in preventing high nitrate export and the eutrophication of downstream aquatic ecosystems. This study was recently documented in the journal Biogeochemistry.

Contact: Jeff Amthor, SC-74, (301) 903-2507
Topic Areas:

Division: SC-23.1 Climate and Environmental Sciences Division, BER
      (formerly SC-74 Environmental Sciences Division, OBER)


September 20, 2004

World's First Whole-Forest Warming Experiment, Open House

In the summer of 2002, Department of Energy (DOE) initiated construction of the first whole-forest warming (soil and air) experimental facility in a field setting. The project is being conducted by University of Wisconsin scientists, along with outside collaborators from the United States and Canada. The purpose is to study effects of (potential) global warming on the structure and functioning of a boreal black spruce forest in northern Manitoba, Canada. The experimental facility (involving large chambers and sophisticated underground temperature control) is now fully functional, with ecological responses to the warming (5 degrees Celsius above ambient) already apparent, including what appears to be significantly increased production of spruce cones (i.e., tree reproductive potential) in the warmed plots. To commemorate the successful operation of the experimental facility, which is expected to continue for several years, the project held an open house September 11, 2004, at the facility. The open house was attended by several dozen interested persons, including Manitoba Hydro's Environmental Education Specialist, Manitoba's Minister of Conservation, and Assistant Deputy Ministers of the Manitoba government.

Contact: Jeff Amthor, SC-74, (301) 903-2507
Topic Areas:

Division: SC-23.1 Climate and Environmental Sciences Division, BER
      (formerly SC-74 Environmental Sciences Division, OBER)


September 13, 2004

BER-Funded Scientist Receives Presidential Early Career Scientist Award

Dr. Margaret Torn of Lawrence Berkeley National Laboratory was given an "early career scientist award" at a September 9 Forrestal Ceremony that saluted seven exemplary investigators from DOE National Laboratories and collaborating universities. Under Secretary David Garman (representing Secretary Abraham) and Dr. Raymond L. Orbach, Director of the Office of Science, presented the awards. Recipients were also recognized for their achievements at the White House by Dr. John Marberger, the President's Science Advisor. Dr. Torn was specifically recognized for her research on the biogeochemistry and sequestration of carbon in soil. Her results are providing new insights for modeling the carbon cycle and carbon sequestration of terrestrial ecosystems. The unique feature of her research is the use of isotopic carbon and oxygen tracers to identify and understand mechanisms and quantities of carbon transformed from plant material to organic matter storage in soil, which is important information for modeling both the carbon cycle and for determining the fate of excess carbon dioxide from energy emissions. One important finding from the tracer research is that fine roots of pine trees live five times longer than previously thought and the roots decompose slowly, which leads to relatively long residence times of carbon that is sequestered by terrestrial ecosystems. Dr. Torn actively engages other scientists in her field investigations of carbon, and one location of the experiments is the DOE Atmospheric Radiation Measurement (ARM) site in Oklahoma.

Contact: Roger C. Dahlman, SC-74, (301) 903-4951
Topic Areas:

Division: SC-23.1 Climate and Environmental Sciences Division, BER
      (formerly SC-74 Environmental Sciences Division, OBER)


August 16, 2004

DOE Ecological Research Facility Tests Ecosystem Models

A paper to be published in the August issue of Ecological Monographs, authored by nine DOE/Office of Science researchers and 10 of their collaborators from a total of 13 institutions, presents a comprehensive test of the ability of 13 ecosystem models to simulate exchanges of carbon and water between a forest and the atmosphere. The model testing used eight years (1993-2000) of data from DOE's Throughfall Displacement Experiment at the Oak Ridge National Laboratory (an Office of Science ecosystem research facility) and other data collected on the DOE Oak Ridge National Environmental Research Park; this represents the longest experimental dataset used to test the largest number of ecosystem models ever. Models that included more detailed energy balance and carbon metabolism calculations provided consistently better predictions, indicating that the level of detail in the models is important. Most of the models were able to predict carbon and water exchanges relatively well when growing conditions were favorable, but many models failed during periods of drought, which occurred during several years of the study period. The loss of model accuracy with drought indicates that considerable uncertainty may exist with respect to present predictions of ecological effects of climatic change on forest ecosystems. Although a single model was not the best predictor of all important ecological variables, the mean of all model outputs was a robust predictor of the observations, even under drought. This result indicates that multiple models, rather than a single "best" model, may be needed to reliably predict effects of environmental changes on ecosystem carbon and water balances.

Contact: Jeff Amthor, SC-74, (301) 903-2507
Topic Areas:

Division: SC-23.1 Climate and Environmental Sciences Division, BER
      (formerly SC-74 Environmental Sciences Division, OBER)


July 12, 2004

BER-Funded Scientists Receive 2004 Norbert-Gerbier Mumm International Award From the World Meteorological Organization for "Most Outstanding Original Publication of the Year"

Dr. Beverly E. Law from Oregon State University and co-authors funded by BER's Carbon Cycle Research program and/or the European Union's CarboEurope Research Program, received the award for a synthesis paper titled Environmental Controls over Carbon Dioxide and Water Vapor Exchange of Terrestrial Vegetation. Dr. Law received the award on behalf of 33 co-authors at a ceremony at WMO Headquarters in Geneva Switzerland on June 16 that was attended by the Secretary-General of the WMO and the Ambassador of the United States. The scientific paper was recognized as the most outstanding original publication of the year on the influence of meteorology on the physical, natural, or human sciences. The paper is based on a synthesis of data from the application of a micrometeorological method used to measure the flux of energy, water, and trace gases, such as carbon dioxide, between the atmosphere and terrestrial ecosystems. The data synthesis, which resulted from application of the method at 37 different locations in North America and Europe with different vegetation types, demonstrated a robust relationship between carbon uptake and water vapor exchange across all of the vegetation and ecosystem types where fluxes were measured. Dr. Law is the science team leader of the U.S. AmeriFlux Network that is about 60% funded by DOE's Office of Science.

Contact: Roger C. Dahlman, SC-74, (301) 903-4951
Topic Areas:

Division: SC-23.1 Climate and Environmental Sciences Division, BER
      (formerly SC-74 Environmental Sciences Division, OBER)