Rainbow Forest Experimental Rehabilitation Site
The Rainbow Forest Experimental Rehabilitation Site on Cubberla Creek at Indooroopilly began in September 1995. The site is about 2 km from where the creek enters the Brisbane River and is situated on the bank of the creek, just inside Rainbow Forest. This is a remnant, littoral rainforest with a wealth of native plant species but also with many weeds, particularly Cinnamomum camphora (Camphor Laurel) and Celtis sinensis (Chinese Elm). We included 'Experimental' in the name as, at that time, there was no model for rehabilitating this sort of forest on a flood plain in the Brisbane area. We have experimented, sometimes with success and sometimes with remarkable failure, but we have learned.
The inspiration for starting the rehabilitation came from the late Alan Murray of the SGAP Western Suburbs Branch. Barely able to distinguish native plants from weeds, I brought specimen after specimen from Rainbow Forest near my home to meetings of the Western Suburbs Branch. Either to stop me or encourage me, the group decided on an excursion to Rainbow Forest. In May 1994 the group fossicked through the forest, up and down creek banks, the odd wet shoe notwithstanding and totaled up an impressive list of 83 plant species for the day. There was also an impressive weed list of 31. During a post-mortem, Alan told me that the Brisbane City Council (BCC) supported bush regeneration by members of the public. I made contact with the BCC and was amazed at what they offered.
Despite department amalgamations, splits and name changes, in our experience there has been a consistent stream of support for community bushcare groups from the BCC. Habitat Brisbane is currently the relevant entity. In the beginning, we received generous advice and proactive assistance in formulating our original application. This included the setting up of a public meeting at which BCC staff officers spoke in favour of a small, experimental bushland regeneration project against a background of strongly expressed, public opposition to anything that would threaten the Camphor Laurels! Members of the SGAP Western Suburbs Branch also attended and spoke in favour of the project. A vote by a show of hands supported the project by a large majority. This was an early political lesson that the opposition can be numerically small but loud. Support from Council Officers has continued unfalteringly with the supply of training, advice, tools, chemicals, plants and mulch.
In the last few years, Greening Australia has been serving a role as liaison officers between bushcare groups and the BCC and as area (catchment) co-ordination officers. This system has also worked seamlessly in our experience. The enthusiasm and dedication of all the young people who have helped us in their official capacities from Council and Greening Australia has impressed us and often refreshed us in our endeavours. In the Cubberla Creek catchment we are fortunate to have a network of bushcare groups and it is the greatest pleasure to meet others with similar interests at occasional functions and gatherings.
A bushland care approval is effectively a grant but we do not handle any money. The costs of goods and services are handled by the responsible BCC department.
The original site was quite small, approximately 27 meters by 27 meters. It was by far the smallest bushland care site in Brisbane. This was done deliberately as I did not know what level of practical support would be forthcoming. In a stroke of remarkable good fortune, an old friend who was doing a horticultural course at TAFE was immediately attracted to the project. Another member was attracted to the site through her university studies and remained to weed, plant and mulch. Our number of participants per working bee averages about three. It feels quite crowded when we get to five and even six! We work on the site for two hours a month. Ideally we do maintenance weeding for the first hour and give ourselves a little reward for the second hour. This might be mulching and planting in a newly weeded area or killing a few woody weeds. It is very satisfying to 'liberate' native plants.
Our original site was very thickly vegetated. It was bordered on two adjacent sides by a path and the creek. The other two sides were a no-man's-land of mostly weeds. Two enormous Eucalyptus tereticornis (Queensland Blue Gum) 18 meters apart are the dominant feature of the site. A five meter Streblus brunonianus (Whalebone Tree) and a clump of rainforest saplings and vines clung to the bank of the stream. Some other good sized plants on the site included Aphananthe philippinensis (Native Elm), Ficus coronata (Creek Sandpaper Fig), Cryptocarya triplinervis, Mallotus claoxyloides (Odour Bush) and Jagera pseudorhus (Foam Bark) . These were obvious amongst the thick growth of large Cinnamomum camphora and Celtis sinensis and the undergrowth of largely Lantana camara and Ochna serrulata. Below knee-level was a vigorous crop of Rivina humilis (Coral Berry) but with Pseuderanthemum variabile (Love Flower) and several species of native grass to make us feel better. We had to face three issues immediately. The Ochna serrulata was flowering and beginning to fruit, the Lantana was denying us access and the woody weeds had to come out.
We trimmed the flowers and fruit from every Ochna serrulata on the site and took them home in a bag. We charged up our battery drills and poisoned dozens of woody weeds from as thick as a thumb to more than 60 cm diameter. We enlisted the help of the local park committee and the SGAP Western Suburbs Branch and spent a morning demolishing the Lantana camara. It was quite astonishing to see large patches of Lantana 'rolled up'. At this point we made our first big experimental 'mistake'. We decided not to mulch in order to see what the resident seed bank would produce. We were also concerned with the possibility of having any mulch wash into the creek in the expected summer flooding. Although we removed the extant Rivina humilis, it regrew and dominated the vegetation layer below 1 meter in height. After a year of watching the effects of our 'no mulching' decision we had to dedicate many working bees to removing the Rivina humilis and mulching.
Care has been taken to remove weeds from the site if they have the potential to cause a problem. In practice, this means that several of our group take them home and either mulch them, bin them or 'cook' them in a black bag for several days, depending on their virulence as weeds. Some weeds can be left on the ground, such as small seedlings and Guinea Grass; and some are hung up to dry on a platform of branches.
As suitable areas were cleared of weeds we planted. According to the current best practice, we planted species already in the local area. This was no hardship as Rainbow Forest is rich in species. Supply has never been an issue thanks to the various individuals and institutions propagating local species. Being beside a creek has made watering a simple matter of carrying buckets. Most plantings have been successful.
Record keeping is an essential part of bushland regeneration. Participants sign on at each working-bee. Immediately following each working-bee I make notes on what was done and suggestions for the following working-bee. These records are sent to the relevant BCC department twice a year. There is also an annual audit of equipment. Photographs are taken at regular intervals using at least one fixed photo point. We have plant records for native and weed species on the site before we started. This incomplete list was thoroughly augmented in February 1996 when the SGAP Western Suburbs Branch did a detailed survey of the site. Recording of planting and natural regeneration has been ongoing, including the creation of highly detailed spreadsheets by one of our members.
The site has been used as a study subject by students from primary to tertiary level. This has ranged from a single interview, to a full semester subject, to the subject of a thesis.
At the end of 1998 the site was increased in size. Large woody weeds were removed from part of the site extension by the Brisbane City Council enabling us to 'roll back at the edges'. We are proceeding in this way rather than by the mosaic method. The original site is very small, and the whole, expanded site is within the range of a single, mosaic block in other places. Multiple blocks within a given area also mean multiple edges to deal with and we are mindful of keeping the maintenance within our abilities.
In a recent development our site has been made an official recovery site for the endangered plant, Austromyrtus gonoclada (Angle-stemmed Myrtle). Specimens planted are tagged with information on the location of their parent, whether seedling or cutting and the year. Each specimen has a record sheet for planting and growth information. Plant dimensions are recorded six monthly.
There are many reasons for what we do. We are improving the faunal habitat, preserving local plant species and learning about native plants. Picture an early morning in the forest beside a bubbling stream with bird calls all around, in the finest company of fellow weeders and planters. We have all this and the satisfaction of recreating a living treasure.