Abstract
Background Evaluation of carbon (C), nitrogen (N) and phosphorus (P) ratios in aquatic and terrestrial ecosystems can advance our understanding of biological processes, nutrient cycling and the fate of organic matter (OM). Eutrophication of aquatic ecosystems can upset the accumulation and decomposition of OM which serves as the base of the aquatic food web. This study investigated nutrient stoichiometry within and between wetland ecosystem compartments of two treatment flow-ways (FWs) in the Everglades Stormwater Treatment Areas located in south Florida (USA). These FWs include an emergent aquatic vegetation FW dominated by Typha spp.(cattail) and a submerged aquatic vegetation FW composed of species such as Chara spp. (muskgrass) and Potamogeton spp. (pondweed).
Results This study demonstrates that C, N, and P stoichiometry can be highly variable within and between wetland ecosystem compartments influenced largely by biota. Generally, total P declined along the length of each treatment FW in all ecosystem compartments, whereas trends in total N and C trends were more variable. These changes in C and nutrient concentrations results in variable nutrient stoichiometry along treatment FWs signaling potential changes in nutrient availability and biogeochemical processes.
Conclusions Assessment of wetland nutrient stoichiometry between and within ecosystem compartments suggest decoupling of OM decomposition from nutrient mineralization which may have considerable influence on nutrient removal rates and contrasting dominate vegetation communities. Moreover, based on these OM dynamics and nutrient stoichiometric relationships differences food webs structure and composition could vary between systems resulting in variable feedback cycles related to nutrient cycling. Therefore, this information could be used to further understand water treatment performance and adaptively manage these constructed wetlands.