Site index determination techniques for southern bottomland hardwoods
Site index is a species-specific indirect measure of forest productivity expressed as the average height of dominant and codominant trees in a stand of a specified base age. It is widely used by forest managers to make informed decisions regarding forest management practices. Unfortunately, forest managers have difficulty in determining site index for southern US bottomland hardwood stands because of a lack of available information for many tree species, outdated information for several techniques, and a lack of knowledge in the application of other techniques for specific site conditions. Techniques to determine site index in bottomland hardwood stands include species trials, site index curves, soil-site equations, soil series, and expert systems. Each technique is reviewed here, including recent advances if available, advantages, disadvantages, and application to bottomland hardwood stands.