In many parts of Asia deforestation has occurred. One option to replace trees on plantations and in smallholder agroforestry systems is Australian species, notably eucalypts and acacias. Early efforts to use these tree species in parts of Asia were constrained by poor genetic stocks, resulting in low yields. ACIAR-supported research to overcome these barriers has delivered benefits in excess of A$1 billion in Asia, and fast-tracked the expansion of reforestation efforts.
The utilisation of forest resources in developing countries requires careful management, both for long-term sustainability and short-term productivity. Increasingly plantation owners and smallholders are seeking fast-growing species that also produce wood suitable for commercial use.
Commercial quality wood is used for pulp, to make high-grade writing paper and sometimes for furniture and other manufacture. Eucalypts can also be used for fuel wood, and for environmental management—protecting watersheds, stabilising soils and even for farm shelter. Acacias have similar commercial uses, as pulp, for paper and artificial fibreboard manufacture and to replace deforested areas.
In China eucalypts were first introduced in 1890 as an ornamental species then used in plantations in the 1950s. Poor genetic stock unsuited to plantation growth limited yields of eucalypts, as did management techniques and planting sites.
Vietnam’s smallholders and plantation sector have grown acacias species first introduced in the early 1960s. While several acacias have exhibited valuable traits no one species has met all the requirements of commercial millers.
A naturally occurring hybrid of two species was identified that met these requirements but was not suited to mass production and deployment, nor were propagation techniques to support this available.
ACIAR research has supported the uptake and adoption of Australian trees in these locations.
Eucalypts in China
China harvests approximately 3.5 million cubic metres of eucalypt wood annually, with an estimated gross value of A$105 million. This is only a small proportion of China’s total wood harvest, eucalypts accounting for less than 5 per cent of total forest plantation area.
Eucalypts are best suited to the warmer sub-tropical and tropical regions of the south. In southern provinces eucalypts are expanding in area planted, due in large part to ACIAR-supported research. A three-fold approach has been taken:
- introducing improved genetic species to build a suitable genetic base,
- improving the silviculture or management of plantations, including through the use of beneficial root fungi to aid in tree establishment, and
- planting those varieties best-suited to match the conditions at plantation sites.
As a result yields of eucalypts have tripled since 1985. Around 88,000 hectares have been planted to eucalypts in each of the past three years, expanding the area under eucalypts to 1.5 million hectares. Australia, through AusAID, first supported China in research to improve the use of Australian tree species, in 1981, with this investment estimated to have generated benefits of AUD1.3 billion. ACIAR’s ‘share’ of this return is around 78 per cent.
An important benefit of the research is boosting off-farm employment. This is benefiting rural households in two ways; through employment in timber processing enterprises, and, in some provinces, from companies leasing land from households, thus providing an alternative source of income.
Short-rotation eucalypts are also being used as an alternative to traditional cash-crops. A proportion of plantation revenue is being redistributed through the tax system to help fund public infrastructure development.
ACIAR is now examining improvements to eucalypt plantations in India, focusing on; nutrient status and nutrient cycling, plant physiology and water relations, tree growth and nutrient uptake, and soil process and growth modelling.
Acacias in Vietnam
Acacias have been widely planted in the warmer, southern provinces of Vietnam, where climatic conditions result in accelerated growth, since the 1960s.
Of 16 species introduced only A. auriculiformis has been widely adopted despite A. mangium having desired genetic traits that would enhance acacia production.
Naturally occurring hybrids of A. mangium and A. auriculiformis were identified that produced the best traits of each species—higher productivity and better resistance to adverse conditions.
Despite this discovery efforts to reproduce this hybrid resulted in inconsistent progeny, limiting the value of these hybrids for commercial and smallholder farmers.
ACIAR supported research in Malaysia developed stable hybrids exhibiting the desired traits. This research also developed supporting techniques for the vegetative propagation of such species, overcoming the remaining two barriers to breeding hybrids—speed and cost.
Independent economic assessment has placed the benefits of this research at AUD152 million to Vietnam. Almost a quarter of those planting acacias are smallholder farmers, for who acacias represent a valuable cash crop. Many areas where acacia’s have been planted have poverty levels above the national average of 29 per cent.
More indirect benefits are starting to flow to smallholders as demand for acacia timber rises and processors increase their prices.