Tidal energy subsidy and standing crop production of Spartina alterniflora

Abstract

Standing crop biomass of the intertidal graminoid Spartina alterniflora, as determined by clip harvest, has a strong positive linear correlation with tidal range along the Connecticut coastline of Long Island Sound. These findings support the hypothesis that tides provide an ‘energy subsidy’ which accounts for much of the observed variation in the productivity of the salt marsh ecosystem. Although the physiological basis for this phenomenon will demand further research, it is suggested that increased nitrogen availability may be important.