Nature, culture and history
World Heritage listing
Parts of Herberton Range Conservation Park and National Park are within the Wet Tropics World Heritage Area (WTWHA). Proclaimed in 1988, the WTWHA extends for about 450km between Cooktown and Townsville. Consisting of nearly 900,000ha, vegetation is made up of tropical rainforest, open eucalypt forest, wetlands and mangrove forests. The WTWHA meets all four natural criteria for World Heritage listing. These criteria recognise the area's exceptional natural beauty and the importance of its biological diversity and evolutionary history, including habitats for numerous threatened species. The WTWHA also has cultural significance for Aboriginal people who have traditional links with the area and its surrounds.
Find out more at the Wet Tropics Management Authority.
Rocks, volcanoes and soil
About 420 million years ago, when Australia was still a part of the ancient continent of Gondwana, the east coast was 20–150km inland of the present coastline. Over time, rivers running off the continent carried bits of land into the sea in the form of gravel, sand and clay. This material accumulated in an undersea basin known as the Hodgkinson Basin over the next 60 million years.
About 360 million years ago these sediments were caught in a squeeze and were compressed, folded and lifted far above the sea, creating a series of mountain ranges that would rival today’s Andes or Himalayas in height. Sand, mud and gravel formed these mountain ranges, which were transformed into metamorphic rocks by immense pressure and heat. These are the rocks which form much of the landscape we see in the Wet Tropics today.
From 310 to 260 million years ago, other events deep in the Earth’s crust caused further changes in the landscape. Large pools of molten rock (magma) pushed up into the crust. In many places it did not make it to the surface, instead slowly cooling and solidifying to form bodies of granite deep underground.
For over 100 million years there were no dramatic geological changes in the Wet Tropics’ region. Instead, it was a long, stable period where mountains continued to rise, but were also subjected to the persistent processes of erosion. Gradually the granite, once deep below the surface, was exposed, and the covering rocks were weathered. It was during this time the Herberton Range became apparent.
The vegetation types throughout these parks, forest and reserve are dictated by altitude and rainfall. Higher elevation ridgelines, hilltops and gullies are cloaked in rainforest and surrounded by wet sclerophyll forest. As altitude decreases, the forests become drier and more open. Species composition within these forest types is influenced by rainfall—the northern part of the area receives less than that of the south.
Wet, high-altitude rainforest cloaks the peaks and ridges, becoming more widespread as you move south. Above 900m these areas are known as cloud forests, so named because it is often shrouded in cloud, mist and fog. The high moisture level and cool year-round temperatures foster plant communities rich in mosses, ferns and epiphytes.
Cloud forests harvest water directly from clouds, fog, mist and rain. This, and the fact that they use comparatively little water, means they contribute a much higher volume of water to catchments than lower altitude rainforest. Like giant sponges, they capture large volumes of water and release it slowly throughout the year. For this reason, cloud forests are believed to be of great importance to the maintenance of stream flows throughout the dry season.
Even though cloud forests only cover a small area of the Wet Tropics, their world-wide ecological importance is evident. In some countries, cloud forests are under threat from development and agriculture. One potential threat from global warming, which predicts an increase of one to two degrees in temperature over 50 years, is that it may cause the cloud base to rise in altitude. In the Wet Tropics, this would result in a predicted loss of about 75 per cent (70,000ha) of Queensland’s cloud forests.
Endangered wet sclerophyll forests surround the rainforest, forming a transitional zone between it and the drier more open forests. Wet sclerophyll is fairly abundant in south-east Australia but in the north is restricted to wetter areas above 600m. In the wet tropics it is limited to a narrow, broken strip, 400km long, bordering the western edge of the rainforest. Wet sclerophyll is a dynamic community containing many species typical of forests in southern Queensland. This forest is an important habitat for threatened species like yellow-bellied gliders, tropical bettongs and northern quolls.
In these parks, forest and reserve, the wet sclerophyll contains rose gum Eucalyptus grandis, red mahogany E. resinifera, turpentine Syncarpia glomulifera, yellow messmate E. acmenoides, pink bloodwood Corymbia intermedia, Gympie messmate E. cloeziana, stringybark pine Callitris macleayana and Bakers oak Allocasuarina torulosa.
As altitude drops and the vegetation becomes drier and more open, turpentines still remain part of the landscape and are joined by range bloodwood C. abergiana, white mahogany E. portuensis, black she-oak Allocasuarina littoralis and grasstrees Xanthorrhoea johnsonii. A unique open forest of Gympie messmate E. cloeziana and forest red gum E. tereticornis occurs on the western slope of the conservation park.
The transition between vegetation types on the Herberton Range supports a wide range of animal life. Many of these animals are only found in the Wet Tropics.
In the rainforest look for Lumholtz’s tree-kangaroos Dendrolagus lumholtzi and golden bowerbirds Amblyornis newtonianu. The near threatened (rare) Lumholtz’s tree-kangaroo has distinct body characteristics to enable them to live in trees. An exceptionally long, pendulous tail helps with balance while strong forelimbs and short, broad hind feet help with balancing, gripping and climbing. Curved claws and spongy soles and palm also help with gripping and climbing. The Lumholtz's tree-kangaroo eats mostly leaves but also fruit and flowers from quite a wide variety of native trees and some weeds.
Golden bowerbirds are only found in mist-draped rainforest above 900m altitude in north-east Queensland and they are Australia’s only representative of a group of maypole-building bowerbirds found also in New Guinea. Rich, golden-yellow and olive-brown, the males of this species live in loose clans, with as many as 10 to 15 birds in 40 to 50 hectares. Bowers are display areas built by male bowerbirds to attract females for mating. The male golden bowerbird keeps his bower site, year after year, defending, tending, refurbishing and extending the bower through most months. The two towers of the bower are made from twigs, glued with saliva and adorned with moss, grey-green lichens, pale flowers and fruit. From one to 3m high, the towers are built around two saplings, about a metre apart. These towers are bridged by a low branch or buttress, from which the male displays.
An unnamed northern subspecies of yellow-bellied gliders Petaurus australis, like so many animals found in wet sclerophyll, have close relatives in similar habitat further south but have been isolated from the main population long enough to become a subspecies. The southern subspecies feed on sap from over 20 different tree species but the ones in the north eat sap only from red mahogany E. resinifera trees. Their diet also includes arthropods and pollen and nectar from a wide range of rainforest and open forest trees and shrubs. Also known as the fluffy glider, yellow-bellied gliders are known for their particularly long, bushy tail. They use this tail to carry leaves to line their communal den inside tree hollows. In most cases these trees are rose gum E. grandis but they do occasionally use other species.
A flash of brilliant blue and a shrill ‘peeee peeee’ signals the flight of an azure kingfishers Ceyx azureus. Spending most of their time perched just above the water surface, azure kingfishers stare intently into the water, waiting to pounce on fish, crustaceans and water insects. Azure kingfishers nest in stream banks where they dig a tunnel to an enlarged nesting chamber. The chamber is loosely lined with fish bones, scales and remains of crustaceans.
Red-bellied black snakes Pseudechis porphyriacus are often found near water where they feed on aquatic animals and small reptiles. They are quick to retreat and, if cornered, tend to make bluff attacks, so as not to waste venom. Although their venom is toxic, there have been very few adult fatalities. Look for them sunning in clearings and on rocks and road.