EGAN, TODD P.* AND IRWIN A. UNGAR. Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, 53201. - Similarity between seed banks and aboveground vegetation along a salinity gradient.
Zonation of aboveground vegetation often occurs in salt marshes along
salinity and moisture gradients. The aboveground vegetation and seed
bank in four physiognomically different vegetation zones in a salt
marsh were compared to determine their level of similarity using
percent similarity as a distance measure. Ten meter transects were
established along a salinity gradient through four different zones, a
Salicornia zone, a Salicornia-Atriplex zone, an
Atriplex zone, and an Atriplex-Hordeum zone. A
UPGMA cluster analysis demostrated that the aboveground vegetation
usually was not highly correlated with the seed bank composition of
zonal communities. Since seeds of these annual salt marsh species
occurred in all zones, the levels of salt stress may be the main
factor determining which species were found in the aboveground
vegetation.
Key words: Atriplex prostrata, community, halophyte, Salicornia europaea, salt marsh, seed bank