Development of a New England Salt Marsh

TLDR

The Barnstable salt marsh in Massachusetts has expanded over 4,000 years, displaying all developmental stages from bare sand to mature high marsh with deep peat, shaped by halophyte tolerance, tidal regime, sedimentation, and sea‑level rise. Early development rates were measured over a 12‑year observation period, while later stages were dated using radiocarbon analysis. The study presents observations and measurements documenting the marsh’s developmental stages.

Abstract

The salt marsh at Barnstable, Massachusetts, occupies an embayment into which it has spread during the past 4,000 years. It exhibits all stages of development from the seeding of bare sand flats through the development of intertidal marsh to the formation of mature high marsh underlain by peat deposits more than 20 ft deep. Observations and measurements of the stages of its formation are presented. The geomorphology of the marsh is considered in relation to the factors which have influenced its development, i.e., the ability of halophytes to grow at limited tide levels, the tidal regime, the processes of sedimentation, and the contemporary rise in sea level. The rates at which the early stage of development takes place have been determined by observations during a period of 12 years and the time sequence of later stages by radiocarbon analyses.