A COMPARISON OF METHODS FOR ESTIMATING FOREST FINE-ROOT PRODUCTION WITH RESPECT TO SOURCES OF ERROR

A simulation model approach was used to assess the performance of several methods for calculating fine root production under various conditions that could lead to errors in production estimates. The models included two methods that utilize periodic data on live only or live and dead fine root biomass, plus one method (the compartment-flow model) that also incorporates root decomposition rates. Potential sources of error included long sampling intervals, random sampling error, use of an incorrect decay constant, and sample processing errors (undermeasurement of fine root biomass and inaccuracy in identifying live and dead roots). The compartment-flow method was the most accurate and overcomes the problems of underestimation of production to which the biomass-only methods are subject. The sensitivity of the method to processing errors varies according to the method used to determine decay rates. The measurement of true decay rates is the biggest obstacle to accurate estimation of fine root production when using the compartment-flow method.