The Development of Salt Pans on Tidal Marshes, with Particular Reference to South-Eastern Australia

Evidence is provided in support of Pethick's hypothesis that salt pans may develop on tidal salt marshes by suppression of surface vegetation (Pethick 1974). Such pans have formed in Spartina townsendii (s.l.) marshland in Australia as a result of localized waterlogging, Spartina failure in the shade cast by mangroves, and the deposition of tidal wrack. Some pans have developed into pond holes, characterized by near vertical or undercut sides. The evidence suggests that the majority of pans and pond holes formed at an early stage of marsh development will persist throughout the sequence of marsh maturation. As additional pans can be expected to form during this period, pan density is likely to increase with marsh age.