Wonderful Use of Weed Tree Timber (WUWTT)
In 2012 SOWN received $10,000 from the Energex Sustainability Fund to explore the sustainable use of weed tree timber for hobby and commercial use. This project was celebrated with SOWN’s first ‘Weeds to Woodcraft’ Expo on June 9 2013.
Weed trees in Australia
During the colonization of Australia forested areas around settlements like Brisbane were intensively cleared for agricultural use. Soon after this it became common practice to plant street and park trees from abroad for shade and beauty.
Having no natural competitors, these trees thrived in the new environment. Over time, some species were found to threaten native habitat due to their invasive nature – they became ‘weed trees’. However the affection locals sometimes feel for these older ‘historic’ trees brings emotions in to play that can make removing mature trees a difficult issue for land & catchment care groups.
The ultimate aim of the WUWTT project is to raise awareness about the threat weed trees pose to natural areas and engage local residents in positive actions to remove them. Some weed trees produce useful and beautiful timbers and need not go to waste when harvested. These have been the main focus of this research.
The trouble with weed trees
‘Weed trees’ once established, are often costly and difficult to remove due to their huge size. Camphor Laurel Cinnamomum camphora is a prime example. This tough customer is known to aggressively take over disturbed areas. Camphors have dense, shallow root systems that prevent native seedlings from growing. They also destabilize stream banks, push over fences and disrupt power facilities.
The impact toxins in Camphor berries & leaves have on native fish & birds is still debated. At least one study shows leaves and berries falling in water kill native rainbow fish. On the other hand, although a host of online articles claim that berries are toxic to many native birds, scientific reviews indicate that there is not enough data for the evidence to be conclusive. In fact in some cases native birds have become reliant on the weed berries due to loss of their habitat and usual food sources. Birds feeding on the fruit of Camphor and other weed trees do assist in further distributing the seeds. With a mature Camphor able to produce up to 100,000 berries each season it’s now listed as one of Brisbane’s 10 worst weeds.
Some people argue that, besides being attractive, the provision of food and shelter for wildlife is good enough reason to leave mature trees alone. However healthy habitat needs biodiversity, which weed trees do not provide. To put this into perspective, over 91,000 hectares are said to contain Camphor in NSW alone (and growing). So it is unlikely such trees will ever be totally removed from the environment. As weed trees do provide benefits in the absence of natives, staged removal of mature trees is supported as best practice to allow for areas to regenerate gradually or to be planted with locally native species.
While removing any mature tree can be distressing, the harmful effects of leaving weeds to spread in the environment, far outweigh the short-term benefits of leaving them be.
Weed trees in the city
As suburban areas expand and are largely cleared for development, protecting and rehabilitating remaining natural pockets and corridors for wildlife is vital. Brisbane’s Enoggera catchment adjoins D’Aguilar National Park, one of the most valuable biodiversity reserves in Australia. This protected parkland totaling almost 26,000 hectares acts as a buffer between urban areas and the D’Aguilar Ranges.
Native animals like the Platypus which were common in Brisbane creeks as late as the 60s have become increasingly rare. By rehabilitating the headwaters of catchments like Enoggera first and replacing invasive weed species with locally native habitat plants, the spread of weed seeds downstream can be limited. If the effects of healthy ecosystems are able to flow down, the suburbs may see a return to valuable habitat for endangered or protected species.
Support and strategies for weed tree removal
Community and landholder participation in weed management is supported by initiatives such as Land for Wildlife, Habitat Brisbane, Landcare and community bush care groups like SOWN.
Partnerships between different groups and individuals are ideal. These are assisted by various grants available through the State and Federal Government, Brisbane City Council and companies that support environmental initiatives through sustainability funds.
During on-ground projects, some large trees can be poisoned but left to provide nesting hollows for birds. Others can be mulched on the spot to provide a natural weed-mat and food for native seedlings. In cases where trees are removed, planting projects aim to replace them with beneficial and beautiful locally native plants to provide food and habitat for native wildlife.
Involving both the younger generations through School programs and sharing the skills and wisdom of experienced community members is important. The challenge is not just to find funding for projects, but also how to involve people who are not personally interested, or physically able to participate in bush care activities.
Finding ways to use the timber from weed trees creatively is one way to help to build links between groups and make the process collaborative & fun. Some projects may have a financial return but the social benefits of bringing people together are priceless.
Weed Tree Timber – how useful is it?
Local festivals like the Maleny Wood Expo showcase both native and weed tree timbers already being used by local communities commercially and in hobby work.
SOWN took the concept one step further by organizing Brisbane’s first ‘Weeds to Woodcraft’ Timber Expo in June 2013. Local woodworkers demonstrated carving and turning alongside artists & musicians who use weed vines or reclaimed timbers in their craft.
The timber SOWN focused during this project was Camphor Laurel, a favourite among wood turners and carvers throughout Australia.
While researching the project, SOWN wondered ‘is a commercial operation to remove weed trees viable? And ‘was it possible to use trees salvaged from restorations and ‘donate’ them to local community groups?’
The answer is not straightforward. One issue that came up was the huge expense of removing weed trees individually and that ‘snicking’ trees out of restoration areas was not viable for a commercial operation hoping to make a profit. In fact one local timber merchant commented that they had ‘more timber than they needed’ as is and could not get rid of it fast enough. The other consideration was how to provide sufficient workplace health and safety hand-over processes when considering salvage works on public land. Adding to this the various stages of sourcing, milling and drying timber the process becomes a lot longer than “here’s a tree – use it”.
Some community groups, like the Sunshine Coast Camphor Laurel Timber Initiative, have been successful after dedicated efforts, so it can be done.
Timber sourced from existing arborists, tree-lopping operations, private land or ‘offcuts’ from commercial operations currently seem to be a simpler and more popular sources of timber for hobby workers.
In conclusion, while timbers like Camphor are certainly valued, it is likely that any weed tree removal operations would need to be well-organised labors of love. Social interaction and skill-sharing being the main goals, with financial reward a welcome bonus rather than the main incentive.