The Ecology and Management of Wood in World Rivers

Modeling the Dynamics of Wood in Streams and Rivers

Stan V. Gregory, Mark A. Meleason, and Daniel J. Sobota


Abstract.—Extensive research over the last 30 years has documented the abundance and ecological functions of wood in streams and rivers. Most studies have focused on amounts and distributions of wood in streams, and a small number of studies have explored critical processes that determine quantities and patterns of wood in streams—riparian tree mortality, input, breakage, decomposition, mechanical breakdown, and transport. Empirical studies describe the outcomes of the stand dynamics, disturbance history, and human management at a site, but questions about long-term dynamics or landscape patterns and distributions are difficult to answer based on empirical observation alone. General properties of simulation models that have been developed recently to explore long-term or large-scale implications of wood dynamics are reviewed. Most existing models are not stochastic, and those that incorporate variation and unpredictable change do not incorporate interactions between processes. Models consistently indicate that forest age directly influences abundance of wood in streams, and sensitivity analysis demonstrates that most models of wood dynamics are most sensitive to estimates of decomposition rates and rates of input.