Tuesday, 26 July 2016

What Beach Vegetation was like 30 Years Ago

Back in the mid-1980’s when I first visited the beaches of the Barron River Delta near Cairns in tropical Australia, they had coastal vegetation consisting of open woodland with scattered large old trees, small thickets of saplings and wide open grassy areas.  As the beach was rapidly retreating due to sand mining in the Barron River, the face of the beach was completely covered in fallen woodland trees.  Today beach almond and casuarina trees dominate the foredune and these were planted by revegetation groups in the mid-1990’s.  What was once open and sunny is now heavily shaded forest with an understorey of mainly Singapore daisy.  Coconut palms, which were entirely absent along the uninhabited stretches of beach,  have been planted all over the place by people who think that all beaches need them.

Holloways Beach as it is in 2016 - a vista of Casuarinas and coconut palms
Much of the strand forest is beach almond, which create shady forests
Usually a blanket of Singapore Daisy covers the forest floor
There are some vestiges of old style coastline near Cardwell and along the coastline near Yarrabah, to the east of Cairns and these provide the photos in this post.  Small vestiges also occur on Taylor Point and inaccessible areas of the Cook Highway coastline on the way to Port Douglas.

Holloways and Machans had scattered trees in tall grass (this is Edmund Kennedy NP)
Tall paperbarks occurred in the swales between dunes and made up many of the fallen trees when the beach retreated
Dry rainforest trees occurred in pockets on the edges of the dunes.
Savanna was present on the sandy flats bordering mangroves (Redden Island)
I suspect that I arrived at a particular time when indigenous burning had been suppressed and the vegetation was in the process of change.  Without fire or attempts to graze the land, the vegetation rapidly thickened.  Vegetation thickening is when too many tree saplings become established and they fill up all the space between the larger trees forming what looks a bit like dry rainforest. 

Before thickening the forest had large trees with an understorey of shrubs and blady grass
After thickening, spindly saplings form most of the forest and the understorey plants are virtually eliminated
Since 1994, non-eucalypt bushland trees have replaced the previously grassy understorey and the tall trees have since died
To someone who has seen the bush before thickening, today’s thickened bushland is painful to look at.  When I first saw the north Queensland woodlands they were full of well-formed trees and shrubs that were very healthy and which had attractive dense foliage.  I now suspect this was the first generation of trees growing up in the reduced fire regime and was transitional to the thickened forest that we see today.  Younger people probably think that the forest remnants they see are representative of what once existed, however this is not the case.

South of Yarrabah had seaside eucalypt woodlands in 2016
The tip of Taylor Point has a tall and thriving sward of giant spear grass
For wildlife, I think that the beach vegetation of eucalypt/paperbark woodland with pockets of dry rainforest was more productive for animals other than black cockatoos which eat beach almonds.  In thickened vegetation the bulk of the saplings struggle to survive and barely fruit or flower.  In contrast the understorey shrubs in the grassy woodlands have more space and can thrive and produce much more food for animals.  Finches and wrens love the grass.  On the beach with the blady grass, every metre of beach had wildlife footprints, including water rat, bandicoots, wallabies, goannas, and even crocodile.  It is amazing how much wildlife these area can support in there natural state.

Wallaby and joey footprints on the beach


  1. Nice post Andrew. Even on remote beaches up past Cape Trip, where there aren't too many people to plant coconuts or anything else, many of the beaches are fringed with dense coconut stands. Nothing much can grow in the coconut root mats.
    Coconuts are basically designed to make long sea voyages before washing up on a nice beach and germinating. I suspect that many of the thick stands have been established through natural dispersal, but have attained unnatural densities through lack of harvesting etc. Casuarina fringes up there are still burnt from time to time, even when they're surrounded by wet rainforest, and this probably makes a nice bed for the coconuts.

    1. Hi Rowdy, I think coconuts are an introduced species. Captain Cook did not record any coconuts on his travel up the east coast and he certainly knew what they were and would have stocked up on them if they were present. Also many of these coconut thickets have only developed in the last 30 years. There were no coconuts near the mouth of the Daintree River back then, now there are lots.

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  3. Andrew, this was really interesting, especially the vegetation thickening. It's always fascinating to learn how things were in the past. You can learn a lot from doing that. http://www.ecohort.com/home/page/bush-regeneration