The relationship between mangrove and saltmarsh communities in the Sydney region.

Abstract

Coastal saltmarshes around the world are characterised by belts of vegetation parallel to the shore. The species and communities which define the zones vary geographically such that it is claimed that a particular zonation pattern is a feature of a broad geographical region (Chapman 1974). It has been suggested that the zonation pattern repeats in space the course of succession over time. The most seaward zone occupies the lowest elevation on the shore and is vegetated by pioneer species. As sediment accretes the marsh surface is raised, and thus experiences fewer tidal inundations. The changed physical environment is conducive to the invasion of species which replace the pioneers. However, conditions to seaward are now appropriate for colonisation so that the pioneer species move seaward. With further sedimentation the pioneer zone continues to migrate seaward (Se fig. 1) until a balance between accretion and erosive forces is reached and extension ceases.