Plant-Microbe Interactions and the Production of Dissolved Organic Carbon and Nitrogen

Michigan Technological University, Houghton MI

Investigators

Abstract

Abstract 00-75397 Pregitzer Plant-microbe interactions and the production of dissolved organic carbon and nitrogen Nitrogen (N) saturation of terrestrial ecosystems is one of the most important contemporary ecological issues. Researchers at Michigan Technological University and the University of Michigan are adding nitrate (NO3-) to northern hardwood forests in Michigan to learn how this common forest type responds to chronic N additions. After six years, a variety of changes indicate chronic N additions have altered ecosystem processes. These include much greater leaching losses of dissolved organic carbon, dissolved organic nitrogen and nitrate, and reduced soil respiration. Over the next three years the research team will continue the nitrate additions in order to learn the specific mechanisms behind these changes and to determine if they will persist over time or if they are only temporary responses that will fade as the ecosystems adjust to higher levels of N availability. If the changes persist or magnify, they could have profound effects on this widely-distributed forest type.