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Summary of full report
Proceedings of a Blackwood Industry Group (BIG) Workshop, Victoria, 26-29 April 2006
Edited by C.L. Beadle and A.G. Brown
November 2007
RIRDC Publication No. 07/095 RIRDC Project No. WS045-08
Executive Summary
What this report is about
This proceedings contains
the research and review papers presented at a workshop on acacia utilisation
and management, held in Victoria 26–29 April 2006. Using Australian blackwood
as the key species, the workshop covered four areas: utilisation and wood
quality; marketing and investment; advances in silviculture; and Acacia
species and resource management.
This workshop is the fourth in a series that commenced in 1996. These proceedings, together with those of the second and third workshops (also published by RIRDC), provide a comprehensive view of the blackwood industry in Australia and New Zealand.
Who is the report targeted
at?
This proceedings will benefit
land managers, researchers and industry investors through providing a comprehensive
collation of current knowledge on growing and marketing blackwood and allied
acacias. Use of the information will improve efficiency of resource use
and promote continued access to a valuable material, which in due course
will benefit processors, craftspeople, retailers and the public.
Background
Australian blackwood (Acacia
melanoxylon) is the most important commercial timber of the Acacia genus
in Australia.
A number of other indigenous Acacia species are also being grown commercially for timber in multi-purpose agroforestry systems in high, medium and medium-to-low rainfall areas. These include A. mearnsii (black wattle), A. dealbata (silver wattle), A. implexa (lightwood) and a range of medium-to-low rainfall species with promising timber characteristics. More arid-land Acacia species like mulga (A. aneura) are being investigated for their timber value, and coojong (A. saligna) has a long history of use in coastal sand dune stabilisation, and mine site and landscape rehabilitation, and more recently is being investigated as a fast-growing source of biomass for energy, wood composites and charcoal.
Research on the genus has been small in scale and fragmented. Until 1996, there was little communication between research workers, growers, processors and retailers, or between these people in south-eastern Australia, Western Australia or New Zealand. This workshop held in 2006, together with its predecessors in 1996, 2000 and 2002, provided an important opportunity to maximise the value of research by collating and disseminating existing information, as well as to focus new work in areas of high priority. It was also an opportunity for the acacia growers and processors to meet and consider their sector as a whole.
The Blackwood Industry Group was also the focus of the three earlier Blackwood Workshops. The first, at Lorne in 1996, considered all aspects of blackwood as a species, while the second at Smithton in 2000 considered blackwood in its natural environment and as a potential plantation species. The third workshop, in New Zealand in 2002 (in cooperation with the AMIGO — Acacia Melanoxylon Interest Group Organisation), was the first truly international meeting, with speakers from China and South Africa, and a Chilean paper. That workshop considered the silvicultural management of blackwood in plantations.
All these workshops have been supported by funds from the Joint Venture Agroforestry Program (JVAP).
Workshop aims
The aims of the workshop
were to:
Results
The meeting attracted 55
registrants and papers from the Hawaii, Chile, New Zealand and Australia.
It gave an opportunity for growers, processors and researchers to learn
of current research, and to discuss the growing and marketing of blackwood
and allied acacias. Key points from the presented papers are given below.
The industry, utilisation
and wood quality
In Australia, some blackwood
is grown in mixed plantations with a nurse or shelter species. If mixed-species
systems are to succeed, there is little room for error in the timing of
blackwood pruning or in nurse-crop management — the focus must be on the
blackwood, not the nurse crop. It was demonstrated that attributes such
as basic density, percentage heartwood and heartwood colour from plantation-grown
samples are similar in most respects to native forest samples from trees
at a similar stage of growth. Also, increased diameter increment did not
adversely affect timber basic density or heartwood colour at the tree ages
(15–20 y) studied. More detailed study of growth, basic density, heartwood
colour and heartwood percentage in trees of similar age in New Zealand
concluded that wood properties can be influenced by site and silviculture.
The conclusion was that there is no reason to manipulate silviculture in
search of specific wood characteristics.
Marketing and investment
Blackwood is a well known
and respected species in Australia, and worldwide is one of the best cabinet
timbers. Its market turnover is about 14 000 m3 y–1 of logs and 4000 m3
y–1 of sawn timber. Although Victoria has a history of blackwood production,
the declaration of the Otway National Park means that most Australian blackwood
now originates from Tasmania. In New Zealand, the market consists of about
85 m3 y–1 of sawn timber.
The market considers colour as the most important wood characteristic, and the supply of logs and timber the most important current issue. In Australia, blackwood has a greater acceptance in the domestic market than in New Zealand, but as the supply comes from native forests, timber supply has political ramifications. Australian blackwood also sells into an immature timber market that does not recognise the true value of premium timber or the quality of products that are made from it, its low value hindering further investment in growing blackwood. As domestic demand has declined, Australia has responded to, and developed, offshore markets, especially in China. In New Zealand, logs from plantations are fetching higher prices than logs from native forest in Tasmania, leading to a greater interest in and a better understanding of plantation management in New Zealand. Both countries have a similar price for clear grades and lack any consistent use of knotty-grade boards.
The greatest new opportunity is to develop a range of flooring products. A broader base is therefore required to secure the future of the industry, but this must be at the right price in niche markets that leads to increased returns for the grower, processor, manufacturer and retailer. Promotion of the attributes of blackwood in these markets and the production of first quality, clear-grade wood of good colour have to be part of this strategy. Entirely new markets could be created through sawn timber or by value-adding.
Competitive stumpage tendering rather than the traditional graded-log sale is one option for increasing returns to the grower, as it shifts risks from the forest owner to the buyer. The stand used by way of illustration was successfully sold, but as the bidder was unfamiliar with competitive stumpage tendering and the qualities of the wood were unknown, the process followed did not provide a perfect solution for establishing a fair market price for blackwood. Competitive stumpage tendering should provide an option for the future when better-managed stands come onto the market.
Tropical ‘Australian’ acacias now form part of a rapidly expanding plantation estate, particularly in Southeast Asia, some of which is being managed for solid-wood products. The timber is competitively priced and is being converted into ‘acacia’ furniture that is sold in western as well as domestic markets. The intense price competition that countries like Indonesia and Vietnam can mount in lower-cost segments of western markets confirms that blackwood growers and processors should target their products towards high-value niche markets.
An example of a strong, high-value local market is that for highly figured material used for guitar making. Blackwood is now taken seriously as a tonewood in guitar making.
Private forestry (non industrial private forestry, generally on farmers’ lands) has never been mainstream in Australia, basically because of the dominance of the public sector, the lack of market transparency and the fragmented nature of the private forest resource. Four main problems for private growers are:
It is a responsibility
for all members of the industry to improve coordination of marketing and
supply, and to ensure the environmental benefits of forests are understood
and accepted by the community.
The keys to successful long-term forestry investments are:
In Australia, blackwood
currently rates poorly against all these criteria, except stable markets.
The conundrum remains how to grow straight tall specimens in planted
systems in its native country! In an economic comparison with shining gum,
blackwood had 24% higher establishment costs and 18% higher management
costs. Blackwood logs would need to achieve a stumpage of $580 m–3 at current
prices to compete with shining gum on the same site.
Advances in silviculture
Blackwood is an exotic crop
in New Zealand. In Australia it is currently harvested only from native
forest, although it has been established in plantations. The silvicultural
objective for growing blackwood in plantations must be to produce a high-quality
log that will sustain a blackwood industry. The directions taken have differed.
Australia is still considering growing blackwood in mixtures, whereas New
Zealand concentrates on pure plantations with intensive silviculture, especially
form pruning and thinning-to-waste, that has led to a large number of small-scale,
well-managed stands being established. In Australia, the focus on commercial
nurse crops has resulted in very few examples of wellmanaged pure-species
stands. A series of regime trials and active permanent-sample-plot measurements
in New Zealand are providing a strong data base.
Native blackwood-eucalypt forests in north-western Tasmania are managed for blackwood. These are based on silvicultural systems that use ground-stored blackwood seed, large-scale disturbances to stimulate germination of this seed, and whole-coupe fencing to protect the seedlings. Good blackwood stem form is encouraged by very high densities of naturally-occurring understorey species such as Pomaderris apetala. These regrowth forests also carry a young Eucalyptus obliqua overstorey. Understanding and managing the light competition between the eucalypt overstorey, the blackwood understorey and the dense co-dominant Pomaderris vegetation through thinning is the key for producing both blackwood and eucalypt sawlogs from these forests. An analysis showed that effective self-pruning in the lower bole of blackwood is achieved only through a marked reduction in direct and diffuse sunlight incident on the lower crown, a result that has implications for the improved design of mixed-species plantation nurse systems using functionally-similar species.
Australian blackwood is arguably one of the most challenging tree species to grow for high-quality sawlogs. Inherent genetic variability in stem form and its susceptibility to exposure suggests that growers should consider high initial stocking rates from which to select trees of good form and vigour for pruning. Once established the species does not self-thin well; without intervention stands can become overstocked, resulting in very little diameter increment. Reinekestyle stand density diagrams are proposed as an aid to designing appropriate management regimes that reflect growers’ particular interests. The ratio of tree diameter to stand basal area provides a simple, practical, yet effective tool for guiding the thinning of blackwood plantations.
Understanding the competition for light and other resources remains critical for successfully managing blackwood in nurse-crop systems. The growth of many nurse-crop species used to date often outstrips that of the blackwood, leading to suppressed blackwood growth because of excessive shade and competition for water. Black wattle (Acacia mearnsii) displays rapid early growth but quickly reaches its maximum height and therefore has potential as an alternative nurse crop for blackwood. In a mixed planting of black wattle and blackwood, there was a trend towards decreasing blackwood volume with increasing nurse-crop density.
Recoverable yields from blackwood plantations are not well documented. MARVL (Method of Assessing Recoverable Volume by Log type) and Atlas Cruiser were used to assess recoverable yields from 24 plots of 18-y-old tended blackwood across four sites. When the data were ‘grown forward’ to simulate expected tree sizes at clearfelling, the sawlog component was reduced to two-thirds. This supports published figures that suggest a mature stand of blackwood will have 55–60%, or about 300 m3 ha–1, of sawlog material. The study showed that pruned stands produce around 40% of high-quality pruned butt log, as well as 20–30% of branched sawlog. This refutes the perception that blackwood is a butt log species only. Blackwood with a dbhob of about 60 cm and 38 m tall will produce recoverable sawlog having a range of qualities.
Acacia species and resource
management
In the AcaciaSearch project,
almost 500 native species of Acacia which occur in the southern Australian
agricultural zone (250–650 mm rainfall zone) were assessed for their suitability
as new woody crops for large-scale planting, primarily as a means of salinity
control in recharge areas. Emphasis was given to fast-growing species with
potential for producing large amounts of wood biomass that may find uses
in solid and reconstituted wood products, and for bioenergy, and which
may yield commercially attractive by-products. Thirty-five species were
identified as having some potential, and all were ranked as to how well
they met selection criteria that indicated their ability to deliver anticipated
end products. Species ranked most highly included A. decurrens, A. lasiocalyx,
A. leucoclada subsp. leucoclada, A. linearifolia, A. mearnsii, A. microbotrya,
A. pycnantha, A. retinodes, A. salicina and A. saligna.
Together with the partners in the FloraSearch project, the Western Australian Department of Conservation and Land Management is evaluating A. saligna for domestication and biomass production on farmland affected by dryland salinity.
Koa (Acacia koa) provides a highly figured wood and is endemic to the Hawaiian Islands, and in Hawaii is the most ecologically and economically important forest tree. The wood colour varies greatly, ranging from pale blonde to dark chocolate. Koa timber is of medium density, easy to work and is the preferred species in the Hawaiian specialty hardwood market. It is used for producing fine furniture, veneers, musical instruments and crafts. The current annual harvest is about 250 000 bd ft or 600 m3. Standing koa timber is now priced at $1000–1300 US m–3. Koa lumber ranges from $4.50 to over $65.00 US per bd ft at retail, depending on colour and figure. The forest industry in Hawaii was valued at $30.7 million US in 2001 and derived at least 90% of its value from koa. Providing an adequate supply is a major concern, and there is extensive interest from land owners and land managers to re-establish koa on many underutilised lands.
There has been insufficient analysis of genetic improvement of blackwood. Over 60 progeny trials have been established since the mid-1970s in both Australia and overseas, but there are few published reports of results from these trials, although it is clear that blackwood is a species with large within-provenance and family variation as well as significant provenance variation for many characteristics. In Chile, research has been undertaken to provide a basis for exploiting the adaptability of blackwood to local environments and to explore its potential as an alternative forest species for wood production. Although blackwood has been sawn in Chile since the 1980s, and is deemed suitable for particle board and veneer as well as solid wood, the lack of a reliable wood supply and a formal market have meant that its contribution to industrial wood production remains very small.
Concern has been expressed about the potential weediness of blackwood in New Zealand, as regeneration is often noted in or adjacent to planted stands. A study of weediness found no invasion of native forest had occurred on any of the sites visited. The study reinforced an earlier view that blackwood can regenerate well in open, disturbed conditions, but no significant spread is likely to occur in shaded, undisturbed conditions within indigenous forest. Preliminary tests showed that in the North Island up to 50% of seed can be damaged by the insect Storeus albocignatus. Seed predation appears relatively absent in the South Island. There is no confirmed evidence of bird dispersal, but there are seed predators. The weediness score for blackwood in New Zealand is 27, the same as for radiata pine. Blackwood plantings can root sucker and germinate from ground-stored seed. If no longer wanted on such sites, it may be considered a weed problem. It remains prudent to continue monitoring regeneration.
Conclusions and implications
for stakeholders
Conclusions from the discussions
are that, in Victoria, supplies of blackwood logs are at a very low level
following the transfer of production forest to reserves. The expectation
that reduced log supplies from native forests in Tasmania might be offset
by blackwood from mixed-species plantations is unlikely to be realised.
There is, however, an opportunity, currently largely neglected, to better
manage and utilise natural regeneration in corporately-managed forests
and on farmland in Tasmania and Victoria to sustain supply. Silvicultural
techniques are available to improve the returns from natural regeneration.
In New Zealand, there is a lot of enthusiasm among farmers for blackwood, and the plantation area already established probably has a potential yield exceeding the present harvest in Australia. Blackwood logs in New Zealand have attracted prices higher than those in Australia, and interest among potential processors is strong. The essential feature of the market for blackwood is that logs must be of high quality.
Among other acacias, A. saligna is of particular interest because of its potential role in combating salinity over very large areas of agricultural land in southern Australia; the genetic variation in this species is a significant asset.
Understanding of silviculture has improved as a result of research in Australia and New Zealand, and this knowledge needs to be disseminated to current and potential growers. Lack of improved genetic material for future plantations remains a constraint to productivity.
In 1989, the Acacia Melanoxylon Interest Group Organisation (AMIGO) was formed under the umbrella of the New Zealand Farm Forestry Association (NZFFA). The equivalent group in Australia is the Blackwood Industry Group (BIG). Participants felt that this had been a very successful workshop, but it remains a concern that BIG is no way near AMIGO in its capacity to effectively coordinate the interest of blackwood growers in Australia ten years after its inception.
Recommendations
There is an established
market for blackwood and other acacias, but with a shortage of supply in
Australia and competition from Asian sources, it is important to develop
the high value end of the market, and to increase supply from sustainably-managed
regrowth stands in Tasmania and Victoria and plantations there and elsewhere.
Future priorities are:
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