The forces
Ecosystems are the what. These are the why: rock, soil, water and fire taken one at a time, the four forces that build every kind of country on the coast. The rock lays down the rules; the soil translates them into something a plant can use; water and fire work over the details for the rest of time. Everything alive simply lives out the result.
It starts with what's underneath.
The stone at the bottom decides what grows at the top. Dark basalt on the range breaks down into deep red, fertile soil — rainforest ground. Poor stone and old bleached sand give you hungry country and heath. The steep blue peaks are the hardest rock of all: the burnt-out cores of ancient volcanoes, left standing while everything softer around them wore away. Learn to see the rock and you can predict the soil before you've even looked at it.
The thin skin that translates rock into life.
Soil is where rock becomes something living things can use — and its two reliable signals are colour and depth. Deep red means basalt and richness; bone-white means sand leached almost to pure poverty. At Cooloola you can read a soil's entire life, from young and fertile to ancient and starved, just by walking inland across dunes that get older as you go. Nothing else you can see from the road tells you more about what will grow: give a place deeper soil and the forest grows tall; starve it and the forest opens out, or shrinks to heath.
Less how much than how salt, how acid, how long.
Water sorts this coast as sharply as soil does, and not by rainfall alone. In the estuary, the master variable is how often the salt reaches. In the swamps, it's how many days a year the ground stays underwater. In the wallum, it's the tea-dark, acidic blackwater that seeps out of the sand — and a hidden aquifer, recharged by summer storms, holding the whole sand country together from below. Most of what lives on this coast is just following the water.
The force that draws the lines between the forests.
Fire decides where one kind of country stops and the next begins. Eucalypts are built for it: armoured to come through a burn, quick to seed once it has passed. It runs in their favour, and that is how they hold their ground. Rainforest takes the other route — a closed, damp interior that fire can't get into, and without which it couldn't exist here. Where the fire stops, gum forest gives way to rainforest. For tens of thousands of years, people have used that same tool to shape this country — a history we can tell here only as far as the published record reaches.
See how these four stack up into every ecosystem on the coast, from the reef to the range.
Explore the ecosystemsThe whole story of how these forces build the coast is in the book, which is free to download. Get the book →