Microbes

Plant growth contributes to the sequestration of nutrients in natural and constructed wetlands alike but unless harvested the plant only have a minor roll in nutrient remediation because as plants die back or drop there leaves they reintroduce most of the nutrients that had taken up. Even when plants are harvested it is the action of microbial respiration that performs the bulk of the nutrient and toxin remediation that occurs in any wastewater treatment system.

Microbes such as Bacteria and Archaea can utilize many different electron donators and electron acceptors to respire utilizing the charge differential between donor and the acceptor to power the formation of ATP. This ability to use electron energy gradients for metabolic and catabolic functions allows microbes to alter the redox species of many nutrients, and pollutants that are pumped in to a constructed wetland system to help sequester or remediate their toxic effects. Some of the more important biogeochemical cycles in wetlands (natural, and constructed) are Nitrogen, Sulfur, and the Carbon Cycle.