Channel Migration and Regeneration of Bald Cypress in Western Tennessee

Bald cypress (Taxodium distichum) regeneration was examined in the bottomland forest of the lower Hatchie River in western Tennessee. Bald cypress is found mostly in abandoned meanders. Its absence along the active channel indicates that colonization begins after the meander cuts off, creating an oxbow lake. Analysis of the size, the age, and the spatial structure of the stands indicates that the individuals first establish along the margins of the lake, and then colonize the interior as the lake fills in and new surfaces are exposed. Bald cypress will dominate abandoned meanders for several centuries. However, it will not regenerate in stands with a well-developed forest canopy. Bald cypress is eventually replaced by shade tolerant species and, therefore, only rarely occurs on older surfaces. Channel migration and the subsequent creation of oxbows will maintain bald cypress as a major component of bottomland forests. However, many of the major streams in the lower Mississippi River alluvial valley have been channelized. Maintenance of a straightened channel will exclude the creation of oxbows. Therefore, a primary regeneration opportunity for bald cypress disappears in many areas. [Key words: channel migration, exact probabilities, floodplain forest, oxbow lakes, Taxodium distichum, Tennessee.]