Development of a salt marsh microecosystem

Abstract

Four replicate outdoor microecosystems were constructed, utilizing “ sodded” Spartina alterniflora salt marsh plots (with attendant fauna and flora) contained within polyvinylchloride (PVC) metabolism chambers which were open to the atmosphere. This study was designed to demonstrate replicability of salt marsh microecosystem units and to observe how closely the structural and functional processes within the microecosystems “tracked” those of the natural marsh site. This paper describes an approach to the design of the units and provides a rationale for measuring selected community structure and functional processes within the units. Each unit consisted of 6 m² plots of salt marsh with substrate intact to a depth 18 cm and was provided with a flow‐through sea water system to simulate the following characteristics of the tides at the natural site: (1) sheet flow, (2) real time synchrony with the natural tides, (3) depth of inundation, and (4) duration of inundation. In addition, each unit had flow measurement devices and water sampling ports to budget water entering and exiting the units. Samples were taken for determining the water borne fluxes of various forms of nitrogen and phosphorus for a selected tide. In addition, each unit is complete with flow‐through air sampling devices. Samples for primary productivity determinations were made. Benthic faunal surveys of the macro and meiobenthos indicate these communities are essentially identical to the communities at the natural site.