Plant zonation in an Alaskan salt marsh. 1. Distribution, abundance and environmental factors

Patterns of plant species distribution, plant abundance, and environmental factors on Susitna Flats, an Alaskan subarctic salt marsh, are described. Eight vegetation zones were recognized along a transect from the Cook Inlet shore to the inland shrub boundary. Although there was little topographic relief and soil texture was similar throughout the flats, the vegetation zones differed with respect to flooding frequency, rate of siltation, soil organic content, moisture content, redox potential, and salinity. In particular, combinations of soil salinity and waterlogging segregated most of the vegetation zones. One cannot conclude from these correlations that edaphic factors determine plant zonation.