International Day for Biological Diversity

by Bronwyn Mitchell, Editor, Queensland Museum

This year on the International Day for Biological Diversity, discover the Eungella rainforests, a biodiversity hotspot and one of Queensland’s most stunning natural environments.

Even with all the technology available in our modern world, humanity will always depend on healthy and vibrant ecosystems for our continued existence, particularly for food, water, fuel, energy, shelter, medicines and clothing.

Biological diversity — biodiversity — is an important factor in the health of an ecosystem, and therefore any loss of biodiversity represents a threat to human survival.

The biologically rich forests of Eungella are dominated by a diverse set of canopy trees of many different evolutionary lineages. Image: Gary Cranitch

Biodiversity – what is it, and why is it important?

Biodiversity encompasses the wide variety of plants, animals and microorganisms living on our planet, but it also includes genetic differences within each species, and the variety of ecosystems (such as forests, lakes, deserts and agricultural landscapes) where all these elements interact.

Biodiversity is particularly relevant for human health, since biodiversity loss is closely linked to an increase in zoonoses — diseases that are transmitted from animals to humans.

The United Nations International Day for Biological Diversity, observed annually on 22 May, calls on the global community to re-examine our relationship with the natural world. ‘Biological diversity resources are the pillars upon which we build civilizations’ — ‘when biodiversity has a problem, humanity has a problem.’

The Eungella rainforests from above. Image: Gary Cranitch

Queensland’s biodiversity

Queensland is a biodiversity hotspot, recognised internationally not only for places of incredible natural beauty, and our many unique and important species, but also for scientific and conservation research.

One of Queensland’s largest national parks, and an area of especially high biodiversity, is Eungella National Park, in the hinterland of Mackay. Eungella lies within the longest continuous stretch of rainforest in Australia outside the Wet Tropics. These rainforests are perhaps less well-known to tourists than rainforests further north (such as the Daintree, near Cairns), but Eungella has long been fascinating to scientists for its biodiversity and endemic species.

(Note: Eungella is pronounced young-ga-la. There are a few unusual place names in the area — check out this list so you can blend in with the locals on your next visit to central Queensland!)

The eastern escarpment of the Clarke Range, with cloud blanketing the Eungella plateau (view from Peases Lookout, Dalrymple Rd). Image: Gary Cranitch

Eungella — the ‘land of clouds’

Eungella’s climate is subtropical, but one factor contributing to its unique ecology is a process known as ‘cloud stripping’. Moist easterly trade winds encounter the escarpment of the Clarke Range and are forced to rise, blanketing the plateau in heavy cloud and generating ‘orographic’ rainfall, delivering additional water to forests and streams.

As a result, Eungella is an intriguing mix of tropical and subtropical elements, with many Wet Tropics species — particularly among the plant life — reaching the southern limits of their distribution at Eungella. Some species more commonly found in south-east Queensland are at their northern limits at Eungella.

A forthcoming book by Queensland Museum, Eungella: Land of Clouds, published in partnership with Mackay Regional Council, celebrates the landscape, flora, fauna and human history of this stunning part of Queensland. More than 30 authors — experts in their respective fields of botany, zoology, geology, geography, ecology, history and anthropology — have contributed their research to broaden our understanding of what makes Eungella unique.

The sweeping views of the Pioneer Valley from Eungella township. Image: Gary Cranitch

William Francis was one of the first scientists to visit the Eungella region. (Extract from Eungella: Land of Clouds)

Scientific research in the Eungella rainforests

William Douglas Francis (1889–1959), who later became State Botanist at the Queensland Herbarium in the early 1950s, was one of the first scientists to visit Eungella. (A specimen of Corduroy Laurel (Cryptocarya corrugata) that he collected in October 1922 is held in the collection of the Royal Botanic Gardens Victoria.)

In the second half of the 20th century, researchers began to identify various endemic species in the region. Most of the Eungella endemics are invertebrates (most notably dragonflies, stoneflies, beetles, true bugs, crayfish and snails). But there are also several endemic vertebrates, including three endemic rainforest frogs (all of which are now either critically endangered or thought to be extinct), a number of skinks, and the Eungella Honeyeater, which has the smallest core range of any Australian bird.

From 2012 to 2014, a team of international and interdisciplinary researchers conducted the Eungella Biodiversity Survey, the most extensive study of Eungella to date. The study had a particular focus on dragonflies and damselflies (Odonata), land snails, rainforest ants, moths, frogs and birds.

The endemic Northern Gastric-brooding Frog (Rheobatrachus vitellinus). Thought to be common in its local habitat when first discovered in 1984, it disappeared abruptly, and was last seen alive less than a year later. Image: Bruce Cowell

The endemic Orange-speckled Forest Skink (Magmellia luteilateralis), found above 900 metres. Such narrowly endemic, high-altitude species are most at risk from climate change. Image: Gary Cranitch

The Eungella Honeyeater (Bolemoreus hindwoodi) has the smallest core range of any Australian bird. (Extract from Eungella: Land of Clouds)

Dragonflies and damselflies photographed during the Eungella Biodiversity Survey by Dr Chris Burwell, Senior Curator (Entomology), Queensland Museum. (Extract from Eungella: Land of Clouds)

Preserving Eungella’s biodiversity

Eungella’s complex and fragile rainforest ecosystem is vulnerable in our changing climate, especially from natural disasters such as cyclones and fire. Cyclones not only cause catastrophic destruction to the rainforests themselves but also create more understorey fuel, worsening the threat and impact of bushfires. Parts of the Eungella rainforests, especially those adjacent to eucalypt-dominated sclerophyll forest, were badly burnt by fire in November 2018. According to ecologists, fire-damaged areas of rainforest may take centuries to fully recover.

The rainforests of Eungella are vulnerable in our changing climate. (Extract from Eungella: Land of Clouds)

The survival of this biodiverse region depends greatly on continued research and conservation efforts. Botanic gardens around the country have an especially important role to play in preserving species found in Eungella’s cloud forests, future-proofing Australia’s unique flora through seed banks and living collections.

Learn more about Eungella and its biodiversity in this richly illustrated publication, featuring more than 400 full-colour photographs. You’ll be planning your next Queensland holiday well before the International Day for Biological Diversity rolls around next year!