Vegetation
From Beachapedia
This article discusses vegetation in reference to its importance in helping to create and build dunes, stabilize the beach, and reduce coastal erosion. It was written by a class of grade school students in Australia.
Vegetation on dunes is vital for their stability thus the resilience of the coastal dune ecosystem.
The term 'vegetation', as used here, encompasses all the different plant species that grow from the high waterline to the back of the beach through the dunes.
Through the process of vegetation succession, the different climatic and environmental conditions in different areas of the dune, affect the species growing in different regions of the dune ecosystem.
Primary species
The species which occupy the area closest to the beach (pioneer zone) are highly specialised ones which can survive the harsh conditions of strong winds and salt spray. With features such as waxy and hairy layers on their leaves and stems, plants such as Marram, Sand Spinnifex and the Bitou Bush grow close to the ground to reduce their exposure to the strong winds and moving sands. With a strong root system, they are able to spread rapidly and survive on the lack of nutrients which sand has to offer. The role of these primary species is to provide the rapid stabilisation of the sand dunes after storms and strong winds, rather than preventing the movement of sand from the dune.
Secondary species
Species on the foredune are more complex than those in the pioneer zone as the presence of more nutrients means that such plants are able to be supported. Secondary species in this region are generally semi-permanent shrubbery and small trees such as the Coastal Wattle, Coastal Banksia and Shea Oak.
Tertiary species
The hind dune is occupied by more complex and developed vegetation such as trees and forests. Protected by the strong winds and salt spray experienced closer to the beach, this area is more protected, making it easier for less hardy and specialised trees to survive. The more complex species in this area result in more humus and organic matter produced, thus providing sufficient nutrients for more species. Eventually plant communities are established in this region, further contributing to the nutrients of the area.