Threatened Species - Recovery of the Monarto Mintbush - Between a Rock and a Hard Place
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Monarto Mintbush in flower
(Photo: M Jusaitis) |
Monarto Mintbush Prostanthera eurybioides is listed
as endangered under both national and state legislation. It
is endemic to South Australia and is known from only two
locations: the Monarto area near Murray Bridge and Mt Monster
near Keith in the South East. It is found on granite outcrops
with mallee and/or broombush and wattles.
There are only about 750 known plants and these are found at
17 sites. The table below shows plant numbers for land tenure
and locations.
| Location in South Australia |
Monarto
|
Mount Monster |
Total Known
Plants |
| Roadside or Council Reserves |
very few |
~ 30 |
> 30 |
| Private land |
~ 50 |
~ 30 |
~ 80 |
| Heritage Agreements |
> 250 |
0 |
> 250 |
| NPWSA
Reserves |
0 |
~ 390 |
~ 390 |
| Total |
> 300 |
> 450 |
~ 750 |
|
Seeds germinated in the laboratory
(Photo: M Jusaitis) |
- At both locations very few young plants are present, natural
recruitment is poor
- Mature plants in Mount Monster Conservation Park have died
in recent years. But in Spring 2000, after good winter and
spring rains, over 100 young plants were observed, many of
which have now survived their first summer.
- Plants on road reserves are under threat from accidental
clearance and disturbance
- Many sites are degraded and introduced plants such as Bridal
Creeper, Periennial Veldt Grass and African Boxthorn are competing
with the native vegetation
- Rabbits graze the plants heavily and are present at all
sites. Grazing by stock, kangaroos and hares is also a threat
To ensure that the Monarto Mintbush does not become extinct,
a recovery program, which began in the early 1990s is continuing
to be implemented. Recovery has been coordinated jointly by
the Plant Biodiversity Centre and Biodiversity Conservation
Program, Department for Environment and Heritage
South Australia. Community groups also play a large part in
implementing many of the recovery actions.
|
Volunteer assisting with
Bridal Creeper control on a Heritage Agreement at Monarto.
(Photo: B Sorensen)
|
- many sites at Monarto have been placed under Heritage Agreement
- isolated plants have been fenced
- seed has been collected for long term storage
- rabbit proof fencing has been erected
- weed control
- rabbit control
- maintaining seed in long term storage
- studying effects of fire and soil disturbance on regeneration
- planting seedlings in existing populations (seedlings are
planted at the site that seed was sourced from)
|
Monarto Mintbush grazed by rabbits
(Photo: M Jusaitis) |
- reintroduce plants to suitable sites where they previously
occurred
Wendy Stubbs,
Ecologist, Threatened Flora, Department for Environment and Heritage
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