A limited bottomland hardwood forest (approximately 400 acres) is present on the refuge, primarily in the riparian areas along the Mermentau River and Lacassine Bayou. Additional woody vegetation is present on canal and stream banks, and on a series of ring levees in Lacassine Pool that are associated with former oil and gas exploration sites. Chinese tallow, an invasive exotic plant species, is a dominant woody species on the ring levees. Refuge staff have worked to eliminate tallow from some levees, and to replant native species, such as bald cypress, tupelo gum, black gum, red maple, common persimmon, sugarberry, live oak, Nuttall oak, swamp dogwood, red mulberry, wax myrtle, and buttonbush. The staff is monitoring the use of treated ring levees as compared to control sites on other untreated levees, which remain dominated by Chinese tallow trees.