© 1991 Heron Publishing—Victoria, Canada
Application of a nutrient cycling model (NuCM) to a northern mixed hardwood and a southern coniferous forest
Sally Liu (1), Ronald Munson (1), Dale Johnson (2), Steven Gherini (1), Karen Summers (1), Robert Hudson (1), Kenneth Wilkinson (1) and Louis Pitelka (3)
1. Tetra Tech, Inc., Research and Development, Lafayette, CA 94549, USA / 2. Desert Research Institute, University of Nevada, Reno, NV 89512, USA / 3. Electric Power Research Institute, Palo Alto, CA 94303, USA /
Summary
The nutrient cycling model, NuCM, which incorporates state-of-the-art understanding of the biogeochemical and transport processes
controlling nutrient cycles, simulates vegetation growth, litterfall and decay, soil biogeochemical processes, and movement
of water. Output of the model includes the available nutrients in soil strata and vegetation pools and the fluxes between
pools on a weekly, monthly or annual basis. Solution and adsorbed concentrations in the various soil layers can be plotted
versus time. The model has been used to simulate effects of acidic deposition on nutrient status at two sites: Huntington
Forest, New York and Smokies Tower, Tennessee. Model results show only minor changes in nutrient status at the sites over
the next 65 years at current rates of acidic deposition. The results also show only small differences in soil nutrient status
between two alternative scenarios for reduction of SOx emissions. Neither “threshold effects” nor abrupt changes in nutrient pool sizes occurred in either of the simulations.
