Tuesday, November 14, 2006 - 8:00 AM

Do We Know Enough about Fine Root Dynamics of Woody Plants to Predict their Response to Natural and Anthropogenic Stresses?.

Mark G. Johnson, Paul T. Rygiewicz, David T. Tingey, Christian P. Andersen, and Donald L. Phillips. U.S. Environmental Protection Agency, 200 S.W. 35th Street, Corvallis, OR 97333

Understanding the effects of natural and anthropogenic stresses on root dynamics is needed to predict how the belowground part of ecosystems will respond to regional and global environmental stresses.  While many long-term studies have been conducted on the effects of elevated CO2, elevated temperature, and N deposition on woody plants, the effects on fine root production, mortality and lifespan are often unexpected.  Given this situation, is it possible to reliably predict how tree fine roots will respond to anthropogenic stressors and environmental change?  In this presentation we will enumerate the current governing concepts of fine root behavior (e.g., production, mortality and lifespan) and assess their efficacy using published research.  The goal of this presentation is to evaluate whether or not sufficient information is known to reliably predict the response of fine root dynamics to various stressors, and when shortfalls in information impede our predictive capabilities, to identify what additional information is needed to improve our understanding of the factors affecting or controlling root dynamics and ultimately our ability to predict fine root responses to stress.