Vegetation characteristics of forested hillside seeps in eastern Maine, USA1,2

Abstract

Abstract The influence of forested hillside seeps on local biodiversity is not well known in the glaciated northeastern USA. We documented the physical and vegetative characteristics of fifteen forested seeps and adjacent uplands to determine their contribution to local biodiversity and to improve existing regional seep classification methods. We determined the uniqueness of plant species using the Indicator Value Method, a method that combines individual species' relative abundance with its relative frequency of occurrence to produce a score (0–100%) based on the ability of that species to be associated within a defined group. We used nonmetric multidimensional scaling (NMDS) to address species-site relationships. Hardwood seeps were always located on slopes from 8–12° and were between 5 and 800 m2 in area. Conifer seeps were also located on similar slopes, but were typically larger (900 to 3600 m2) and within areas of lower topography or ‘benches’ on a hillslope. Herbaceous layer diversity (H′) was high...