A biodiversity hotspot

on 13 Jun 2017 

At first sight, the dry landscape of the Tasmanian Midlands seems an unlikely contender for the title of ‘National Biodiversity Hotspot’. There are only 15 of these hotspots in Australia; areas with high concentrations of species that are endemic (unique) to each region, and which are threatened with destruction.

What makes the Midlands one of them?

Map of the Tasmanian Midlands.Located in the shadow of mountains, parts of the Midlands receive just 450mm of rainfall each year, on average. The combination of this dry climate and fertile dolerite soils (a relic of the landscape’s volcanic past) allows for a complex mosaic of ecosystems to thrive.

In turn, these ecosystems support a range of endemic species. The lowland native grasslands, in particular, support a rich variety of lilies, orchids, daisies and other herbs in between patches of Wallaby Grass, Kangaroo Grass and other native tussocks.

These grasslands, and the surrounding woodlands and forests, are also home to threatened animals like the Eastern Bettong and Eastern Barred Bandicoot.

Biodiversity (noun): The variety of species of plants, animals and microorganisms, their genes, and the ecosystems they form. Biodiversity is often used to describe the complexity of life in a certain area. If any single species in that area disappears, it will impact upon the other species in that same area.

Tasmanian Wedge-tailed Eagle

A Wedge-tailed EagleThese enormous birds evolved into their own subspecies after being separated from their mainland counterparts for thousands of years. Wedge-tailed Eagles will often desert their nests if disturbed by human activities.

Almost half of Tasmania’s entire Wedge-tailed Eagle population is based in the Midlands and surrounding mountains, so it’s vital their Midlands nesting habitat is protected.

Eastern Bettong

An Eastern BettongThe Eastern Bettong became extinct on the mainland in the early 20th century, largely due to predation by feral cats and land clearance.

Today, these nocturnal marsupials are only found in Eastern Tasmania, in dry open woodlands and grassy woodlands such as those in the Tasmanian Midlands. Their habitat there is threatened by land clearing and over grazing.

Black-tipped Spider-orchid

A Black-tipped Spider OrchidEcologists often use orchids as an indicator of an ecosystem’s health because they're sensitive to disturbances such as ploughing and fertiliser use.

There are six orchid species found only in the Midlands that are endangered or critically endangered. Their continued survival will depend on the preservation native grasslands and woodlands.

Eastern Barred Bandicoot

An Eastern Barred BandicootThe Eastern Barred Bandicoot is functionally extinct in the wild on mainland Australia. Although Tasmania’s population hasn't suffered the same dramatic declines, it's steadily falling.

Historically, the Tasmanian Midlands have been a stronghold, but agricultural practises have destroyed much of the habitat they rely on, and they’ve now all but disappeared from the region.

Kangaroo Grass

Kangaroo GrassLowland Themeda triandra (Kangaroo Grass) Grassland is one of two sub-types of the critically endangered Lowland Native Grasslands of Tasmania ecological community – one of Tasmania’s most depleted and threatened ecosystems.

Themeda triandra Grassland mostly occurs in the Midlands, and is host to an incredibly diverse array of native grasses and herbs.

Eastern Quoll

An Eastern QuollThese nocturnal creatures spend their days sleeping, coming out at night to hunt and scavenge. They remain common in Tasmania, but are now considered extinct on the mainland, where the last confirmed sighting occurred in the early 1960s.

Eastern Quolls seem to prefer networks of dry grasslands and forests, just like the habitat found in the Tasmanian Midlands.