Influence of Inundation Depth on Typha domingensis and its Implication for Phosphorus Removal in the Everglades Stormwater Treatment Area

The influence of inundation depth on phytomass, shoot density, photosynthesis, elongation, and nutrients of Typha domingensis in Stormwater Treatment Area-1East (STA-1East) was examined and results were evaluated relative to phosphorus (P) treatment from 2006 to 2011. Biomass and nutrient concentrations of T. domingensis were not related to inundation depth. Necromass and belowground/leaf biomass ratio increased with increasing inundation depth from 30 to 80 cm. Shoot density, photosynthesis, and elongation decreased with inundation depth. The contents of necromass nutrients and phytomass nitrogen increased with inundation depth. Annual total P (TP) concentration increase (−) or decrease (+) from inflow to outflow was −21 %, −3 %, +8 %, −54 %, +41 %, and +29 % in 2006–2011, respectively. Decreases in soluble reactive P (SRP), total dissolved P (TDP), dissolved organic P (DOP), and/or particulate P (PP) from inflow to outflow were low or did not occur annually. Prolonged inundation damaged T. domingensis community and thus adversely impacted the capacity of the system to treat P. Inundation depths in the STAs can be categorized into optimal, subtle stress, and lethal stress zones. This study stressed the importance in maintaining vegetation within an optimal zone of inundation for a sustainable system.