How Rainforests Grow in the Sand on K'gari (Fraser Island)
The ancient rainforests of K'gari (Fraser Island) are a rare and beautiful sight that draws many visitors to this island paradise. Picture giant leafy ferns, Kauri pines, brush box, hoop pines and towering thousand-year-old satinay trees with girths of up to four metres stretching towards the light and all growing in… sand? But how?
How Do Rainforests Grow in the Sand on K'gari (Fraser Island)?
K'gari is the only known sand island in the world where rainforest has not only survived but thrived for thousands of years. What makes this so unusual is that sand is notoriously low on nutrients and rainforests need these nutrients in order to survive. The key to K'gari’s rainforest success lies in the rainforest’s location and the fungi that are able to grow on the forest floor under the thick forest canopies formed over many hundreds of years.
Dune plants on K'gari: how do they survive?
Plants growing on the dunes of K'gari can only obtain their nutrients from two sources - rain and sand. As luck would have it, K'gari’s rainforests are situated on the middle, high dunes which are the most protected from the harsh salty winds, have the highest rainfall and have the deepest accessible soil from which to take their nutrients. This is the ideal location in which to grow.
However, as we know, the nutrients in the sand are minimal and once they are absorbed over time only shrubs and smaller plants can survive. So, what makes K'gari’s sand so unique? How can this bare sand sustain the high nutrient needs of this ancient rainforest?
Fungi in K'gari Rainforests
Fungi. Yes, that’s right, the fungi and lichen which grows on the rotting vegetation on the forest floor is the hero in this story. As it consumes the decaying plants, the fungi returns the life-sustaining nutrients and minerals to the ground. Over time, the minerals become re-concentrated in the sand and as each successive sand dune forms, a deeper nutrient level is developed and the sand is able to sustain a more complex forest.
Now you know how K'gari’s magnificent rainforest still exists today, take a moment to appreciate the brightly coloured fungi by your feet next time you stroll through the forest - these little plants are a lifesaver!
Check out our top K'gari tours if you want to experience the beauty of the island yourself!
