Soil/Landscape Relationships in a Mesotidal Maine Estuary

Abstract

Submerged sediments represent an important component of near‐shore coastal systems. Soil scientists have begun to study subaqueous soils from a pedological perspective, and conceptualize these soils as organic or mineral materials, having the ability to support rooted plants, which are submerged by estuarine, marine, or lacustrine water for a period of time such that their pedogenesis reflects an environment dominated by submergence. The objective of this study was to describe and classify subaqueous soils of a shallow, mesotidal, Maine estuary and identify the relationship between soil properties and landscape position. A detailed bathymetric map was created for the study site using a fathometer, Global Positioning System (GPS), tide gauges, surveying equipment, and Geographic Information System (GIS) software. The bathymetric map was used to identify the slope for each landscape unit and the mean water depth above each landscape unit. Slopes in the study range from 1 to >25%. Water depths above the soil surfaces are between 0.1 and 21.0 m at mean sea level (MSL). Soil samples were collected to depths between 1.0 and 5.5 m below the soil surface using a bucket auger, McCauley peat auger, or vibracoring device. Seven soil landscape units and 10 soil map units were differentiated from one another according slope class, geomorphic position, depositional environment, and soil characteristics. Most of the soil parent materials in the estuary are fine‐textured sediments. This work is the first estuary soil survey completed in Northern New England.