ilkari Conservation Group   est.1990

Planting Local  Provenance Plants at Flinders University Lake 1996-2001

Nele Findlay, June 2003

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Ilkari undertook a campaign to improve the environmental quality of the lake in 1995 and as a result of this decided to remove the exotic plants on its surrounds and replace them with local provenance native plants. This was to be done in a gradual manner so that the lake would never look bare and that the work would be within our capabilities.

The first part of the project was to plant native macrophytes (sedges and rushes) and some other plants on the “western” bank adjoining the walkway. This planting was largely completed during 1996 and 1997.

A number of river red gums (Eucalyptus camaldulensis) and some shrubs (Bursaria spinosa) were also planted scattered in various locations around the lake.

The immediate aim of the project then focused on removing the large patches of Coolatai grass (Hyparrhenia hirta) then known as Tambookie grass. This species is a vigorous weed which is capable of invading bush land and is difficult to eradicate.

The dense patch of Coolatai at the “eastern” end of the lake was removed first and native plantings started there. A further problem in this area was the dense network of roots of the young elm trees which had developed around the lake banks from suckers arising from the large elm trees. The young trees were removed over the next few years, extending first to the north. A major planting of small native trees, shrubs and grasses was achieved during 1999. The species planted provide a colourful display when they flower in the spring. The elm removal and planting is now extending along the south side of the lake.

The next area of Coolatai to be removed was on the north western embankment.  Here we had done some planting on the shore below the Tambookie but now the weed was removed and the plantings extended. The main attraction here now is the river bottlebrush (Callistemon sieberi) along the lake shore. The plants are progeny of two old  plants, the only ones remaining on the Sturt River in Sturt Gorge Recreation Park. To the east of the stony embankment is a patch where Poa grass species predominate.

In 2000 attention extended to the last remaining patch of Coolatai, that on the south-western embankment. The planting  on this north-facing embankment concentrates on 2 species of grass which are found on the bare north-facing slopes of South Creek, the Sturt R. tributary south of the Ring Rd. These 2 species, silky blue-grass (Dichanthium sericeum) and scented grass (Cymbopogon obtectus) are native species which are related to Coolatai grass. This area of planting is still being extended and substantial amounts of Coolatai remain to be removed here. As seedlings of the Coolatai continue to appear, vigilance to prevent it seeding will be needed possibly for some years.

The choice of species for planting around the lake has aimed to include as many as possible of the native riparian (growing at the edge of lakes or streams) species which already occur on campus with the addition of others occurring on the nearby Sturt River and other smaller local streams.  Several of these are now quite rare locally as are also several of the woodland plants that are planted on the higher banks of the lake. In time the lake will provide a convenient display of the native species still to be found scattered in remnant vegetation in the vicinity of Flinders University.

The species that Ilkari, with the help of the maintenance staff, has already planted are listed in the accompanying table. Local sources of seed and plants have been used for propagation and details of these are listed in other tables in Ilkari files. Many of the plants have been propagated by Ilkari members from seed collected by them. Friends of Warriparinga have also been collecting local seed and propagating it for planting on the Sturt River at Warriparinga/Laffers Triangle and were often able to donate some plants to increase the range of species planted at Flinders University. Geoff Lloyd at the Biology School glass-house has given valuable help with propagation.