Saltmarsh vegetation thrives in the saltpan areas where the occasional exposure to king and spring tides creates a high saline area. These herbaceous plants are adapted to coping with high salt levels as well as long periods of drought.
Casuarina and marine couch are also found on the terrestrial side of saltmarsh as they can cope with higher levels of salinity than other terrestrial forest systems. Melaleuca (paperbark) can cope with fresh water inundation and so tend to dominate the lower lying freshwater habitats. Coastal Eucalypt needs higher elevations where water and salinity are not an issue.
A good example in Clontarf shows a small area with varying levels (caused by a drainage channel). You can stand at one point and look on to mangroves (along a channel and also a low lying area) as well as look onto a small area of saltmarsh vegetation lined with Casuarina and Melaleuca. Literally 20 meters away the land is elevated slightly and you see massive mature Eucalypts. The difference in elevation is a matter of one or two meters.
It makes you realise how dynamic this system is and how specialised some of our vegetation is in terms of colonising wetland areas. The variety of vegetation types in such close proximity makes the Clontarf eco-site a hotspot for biodiversity with many animals also adapted to utilise particular plant types.