Key Words: Minimal disturbance, bush regeneration, Eucalyptus fasciculosa, volunteer, Bush For Life.
The Site: In June 1996 Trees For Life (TFL), a community based not-for-profit organisation, established a volunteer bush regeneration site (known as a Bush For Life site) on a 1.4km long, one chain wide roadside remnant on Research Road about 6km south of Strathalbyn, SA. At this stage the road was still being used as a vehicle track. The vegetation was a very diverse Pink Gum (Eucalyptus fasciculosa) Open woodland with occasional mallee eucalypts, a shrub understorey, sedge and herbaceous groundcover and native grasses with many locally rare and vulnerable species including the nationally vulnerable Silver Daisy-bush (Olearia pannosa ssp. pannosa ). The largest weed problem was Bridal Creeper (Asparagus asparagoides) which blanketed the site in the cooler, wetter months. Other threats to the understorey diversity included broadleaf weeds typical of the dry, agricultural landscapes of the lower Murray Plains. These weeds included Pincushion(Scabiosa atropurpurea), Wild Sage (Salvia verbenaca) and Horehound (Marrubium vulgare ).
Diverse grassy understorey found on the site
Works: Volunteers worked on a section of the 1,400m long, one chain wide road reserve, using minimal disturbance techniques. The regenerators very carefully removed Bridal Creeper, broad leaf weeds and weed grasses; but they had to contend with the continual degradation of the remaining area. It was really only a heavily rutted, two-wheel track suitable for dry weather use only, but was subjected to indiscriminate and illegal use through all seasons, including rubbish dumping, firewood collection and “bush-bashing”.
The Alexandrina Council closed the road to motor vehicles in September 2008 and it has been allowed to recover now for 4 years. After the road closure, discussions between Council and TFL centred on whether to leave the vehicle track to regenerate by itself or to “rip” the track to fill in the ruts and promote germination. As ripping the track was predicted to have have promoted prolific broadleaf and grassy weed establishment, particularly given the close proximity of weedy agricultural land adjacent to the linear reserve, the BFL principle of minimal disturbance prevailed and the track was left to regenerate without other intervention.
Before road closure
Results: Today there is a proliferation of native species germinating on the track, with native regeneration on the track itself far outweighing the weed regeneration.
The ruts have filled with leaf litter and have encouraged the germination of spear grasses Austrostipa sp.) and wallaby grasses(Austrodanthonia sp.). As the volunteers discover new seedlings they protected them with branches; but regeneration has become so significant that this is no longer practical. .
Many Mallee Honey-myrtle (Melaleuca acuminata) and Dryland Tea-tree (Melaleuca lanceolata) seedlings have germinated and are thriving in bare patches. Many other species are also germinating, including: Golden Wattle (Acacia pycnantha), Hakea Wattle (Acacia hakeoides,) Sweet Bursaria (Bursaria spinosa), eucalypts (Eucalyptus spp.), Ruby Saltbush (Enchylaena tomentosa), Climbing Saltbush ( Einadia nutans ssp. nutans), Old Man’s Beard (Clematis microphylla var. microphylla), Australian Bindweed (Convolvulus sp., and New Holland Daisy (Vittadinia sp.). Black-anther Flax-lily (Dianella revoluta, Mallee Blue-flower (Halgania cyanea,), Rosemary Dampiera (Dampiera rosmarinifolia ) and Quandong ( Santalum acuminatum) are spreading from the sides onto the track. Areas where once a vehicle could drive have now been reduced to a narrow walking track between seedlings.
Native grasses regenerating on the road after closure
Treatment with Bridal Creeper rust (Puccinia myrsiphylli) began in 2004/2005 with wider and more intense applications applied every year from 2008. In the last couple of years rust has established itself over a large proportion of the site with very little flowering and fruiting detected during 2011. Volunteers carefully treat plants at both ends of the site by ‘tonging’ with glyphosate (i.e. using tongs with sponge tips as herbicide applicators) which has been very successful. Through careful and consistent work, most of the broad-leaved weeds have been virtually removed from site, with only isolated germinations being detected and removed. One other weed – : Soursob (Oxalis pes-caprae – is prolific on site; and has yet to be targeted for control.
Rabbits re-entered the site early in 2006 and by mid-2008 had bred up to occupy 15 locations on site. They caused significant damage to the native vegetation until controlled by baiting in March 2010. The increase in native grasses in the areas treated has been significant.
Lessons learned: Four significant events have had the greatest effect on this turnaround: the road closure, the control of rabbits, the establishment of Bridal Creeper rust and most significantly the consistent hard work of the site’s Bush For Life volunteers.
Acknowledgements: This site is owned by the Alexandrina Council and is managed in partnership with Trees For Life who train and support volunteers through its Bush For Life program.
Contact: Sue Bradstreet. Regional Coordinator, Trees For Life sueb@treesforlife.org.au
Volunteers Maggie Hincks and Dean Mortimer assisting the regeneration
EMR Project Summaries 