By Hans van Veluwen  

All too often we only hear bad news about the state of the worlds tropical rainforests. Statements like, "there goes the lungs of the planet". Well, here in North Queensland the news is actually good, our tropical rainforests are actually expanding and not contracting at all.

Until about ten years ago our sugar cane farmers had been burning their sugar cane crops annually  prior to harvesting for many years. Those fires often escaped up the hill sides and over many years gradually burnt and forced the rainforests back into the moist deep gullies where the forests could still survive in what are known as refugal areas.

When the rainforests retreated the vegetation then changed to more firefast forests mainly made up of eucalyptus, melaleucas, acacias and cycads, etc. These forests could not only withstand the regular fires but actually needed them to overcome dormancy factors in their seeds.

So after many years the firefast forests gradually replaced the  rainforest and became the predominant vegetation type covering the hillsides adjacent to many sugar cane farms.

Over the last ten years most of the fires stopped because of changing agricultural procedures  and the rainforests escaped out of their refugial sanctuaries and started competing with the firefast forests for space, light, water and nutrients. Given the right conditions  rainforest by its very nature can be very aggressive or fast growing and are now starting to reclaim many of the hill sides.

Without regular fires the the firefast forests wont be able to regnerate efficiently and so given another fifty to sixty years all the hillsides between the Daintree River and Ingham , about four hundred kilometres as the crow flies, will once again be covered under a type of tropical rainforest. That will re create rainforest corridors and green belts for endangered tropical rainforest wildlife species like the endangered cassowaries.

Driving between Port Douglas and Mossman in the hills opposite the Skysafari landing strip is a great example of this rainforest transition. If you are astute you will notice two distinct types of vegetation, the light green forest covering most of the hills is the firefast Eucalypt forests and the dark green in the gullies and starting to encroach on the ridge lines is the re emerging Tropical rainforests.

Here one can clearly see the white trunks of the Eucalyptus trees in a sea of regenerating Tropical rainforests. The accompanying photo shows the two types of forest merging on these very hills.

In many areas National Park land managers actually use fires to maintain habitat types where rainforest is encroaching on delicate and fragile buffer zone forests.

For more details visit Hans van Veluwen on www.C3D.net.au