Wildlife Australia - Spring 2017

(Dana P.) #1

IMPERILLED


BUT RESILIENT


RED HOT LIST: FLAGSHIP 4


T


he suburbs of Melbourne are expanding at an unbelievable
rate. The 100-km stretch to Ballarat is dotted with new
subdivisions, big brick boxes popping up on the newly-
flattened ground and signs promoting convenience, contentment
and lifestyle. It’s a shock when, amid the bustling human endeavour,
the first volcano appears on the horizon. Not so long ago, in
geological terms, these rounded, mostly treeless domes spewed
forth lava that slowly spread across the landscape towards the Great
Dividing Range to the north. This geological activity created the
fertile rolling land now known as the Victorian Volcanic Plain.
Early explorers waxed lyrical about the grasslands and open
woodlands, inspiring a great grass rush in the 1840s. One of
the volcanoes, Mt Elephant, became known as the Stockman’s
Lighthouse – a prominent navigational landmark in an otherwise
featureless expanse. The first white settlers traversed a land
of sweeping, herb-rich kangaroo grasslands (Themeda triandra)
bounded by distant blue ranges and dotted with occasional
groves of silver banksia (Banksia marginata) and, in the west,
open ‘parklands’ of huge, sprawling river red gums (Eucalyptus
camaldulensis). They brought their sheep, and later their ploughs.
The destruction of grassland ecosystems continued well into
the 1980s. Today, less than 1% of these grasslands remain and
only a couple of hundred hectares, mostly restricted to tiny
linear roadside and rail reserves, retain the species-rich pre-
native flora. These reserves are under constant pressure; most
occur in areas earmarked for urban expansion or road widening,
at the whims of hostile or oblivious landholders, and susceptible
to weed invasion (particularly from annual grasses) or crop spray
drift. Others are more secure, being situated on quieter roads or
wider reserves – accidents of land-use history and geography.
Unsurprisingly, 29 plant species of the volcanic plain are
listed as Endangered or Critically Endangered at a national and/
or state level, including 19 ground orchids and six perennial
herbs. Seventy percent of these are known from less than ten
populations, and nearly all are severely fragmented. Many would
have been naturally restricted to the edges of swamps, low
stony rises or small bare areas, but all have undergone massive
declines in abundance and distribution. Most have complex
disturbance ecology and fluctuate seasonally in abundance,
making it difficult to ascertain their long-term trends. At least
half are known or suspected to be declining, and ecologists have
watched numerous populations become extinct in just decades.
Drier winters are predicted under future climate scenarios
and may already be inhibiting recruitment of some species. This


VOLCANIC PLAINS FLORA


Eugene Von Guerard’s 1857 artwork depicts a wall of flames threatening
the vast grasslands of Victoria’s volcanic plains between Mt Elephant and
Timboon. Image: Eugene Von Guerard


HANGING ON


Geranium sp.
Photo: Neville Walsh

Rough eyebright
Photo: John Eichler

In the Spring 2016 issue of Wildlife Australia, we introduced
a project called Red Hot Red List: No Surprises, No Regrets,
which aims to highlight the plight of Australia’s most
imperilled plant species, identify and prioritise conservation
actions, and alert community groups, scientists and
landholders. To be eligible for the Red Hot list, a species
must be both rare and declining from threats that we can
feasibly overcome. Flagship species can be used to leverage
conservation effort for a group of plants that occur in the
same region or that suffer from the same threats.

drying trend may be driving the decline of the tiny annual herb
known as southern shepherd’s purse (Ballantinia antipoda). This
species used to occur across grasslands and grassy woodlands
of Victoria and Tasmania, but is now restricted to a few small
patches on permanently moist seeps on Mt Alexander, near
Bendigo. It requires committed, long-term funding for recovery
efforts and was an obvious choice for the Red Hot List.
Among the ecological desolation are small tales of hope.
An undescribed Geranium species, last collected in 1903, was
recently discovered on a rail reserve in suburban Melbourne
by a La Trobe University student. It is now known from six
small populations. Similarly, the dwarf spider-orchid (Caladenia
pumila) was considered extinct between 1926 and 2009, when
two plants were found in grassy woodland. It is now listed as
Critically Endangered under the EPBC Act. Adamson’s blown
grass (Lachnagrostis adamsonii) was not seen since the 1850s
type collection, but surveys conducted in the late 1980s revealed
it to be relatively widespread – although all populations are
threatened by weed invasion and altered hydrology.
Rough eyebright (Euphrasia scabra) is perhaps the flagship
species. It once occurred in grasslands throughout southern
Australia but is now only known from a handful of populations.
Unfortunately, it is now considered Extinct on the volcanic plain.
An annual species with large population variations, its decline
seems to be ongoing and is particularly mysterious in areas
where its habitat has not been heavily modified.
These species, chosen to represent the Victorian Volcanic
Plain on the Red Hot List, highlight not only the perilous plight
and enigmatic nature of inter-tussock grassland species, but
also their remarkable resilience. They are stories echoed across
grasslands on fertile soils across Australia.

DR JEN SILCOCK is a post-doctoral research fellow with the University
of Queensland’s Threatened Species Hub.

10 | Wildlife Australia | SPRING 2017

Free download pdf