Community and aerial photograph analyses of salt marsh vegetation within the southern Gulf of St. Lawrence

Abstract

<p>A classification of salt marsh communities for barrier environments within the southern Gulf of St. Lawrence is presented. Communities are described in terms of their species composition, frequency and cover, phenology, and habitat requirements. An idealized marsh profile outlining typical marsh communities, species frequencies and tide relations is constructed from surveyed transect and vegetation data. Its applicability to other sites within the study area is evaluated through aerial photo interpretation.</p> <p>The tide is identified as one of the controlling factors in community distribution or zonation across the marsh profile. Indicator communities, whose occurrence is indicative of specific tide levels are identified for mean sea level, mean high water and higher high water levels.</p> <p>Photo communities are compared to floristic communities. An evaluation of aerial photo interpretation for marsh community identification and delineation is carried out. The optimal film type, scale and season combination for maximum community discrimination is determined.</p> <p>Interpretation of marsh communities from aerial photographs is extended through space and time. Community-environment relationships and responses, identified from present data are shown to be consistent.</p> <p>With the detailed background knowledge provided by the floristic analysis, the aeiral photo interpretation of marsh communities was enhanced.</p>