XVI International Botanical Congess

Constructed wetland systems (CWS) are being promoted as an effective, low-cost method of improving the quality of effluent from a range of agricultural waste streams. However, many questions remain unanswered regarding the roles of macrophytes in facilitating the treatment process. Our studies have shown 1) the presence of macrophytes in CWS improves treatment ability, 2) there are differences between macrophyte species in their impact on treatment, 3) in general, a mixture out performs monocultures. It has long been hypothesized that it is through the release of oxygen from their roots that macrophytes impact treatment by allowing aerobic microbial processes to proceed. This study compares the levels of release of oxygen among Appalachian wetland macrophytes with reference to root age, size and depth.