Forests for People

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plantation productivity and, more recently, plantation

silviculture. ACIAR’s impact assessment modelling

found that its A$1.5 million investment in plantation

productivity research in Viet Nam has delivered bene-

fits with a net present value of around A$129 million.

About two thirds of these benefits flow to consumers

via lower prices but the rest go to the producers, includ-

ing large numbers of smallholder farmers, who have

planted the better quality genetic material. On average

a farmer growing

acacia

pulpwood on a 7-year rotation

would get an extra 11 m

-1

of product to sell as a

result of this collaborative research. Smallholders can

achieve greater income and make more informed deci-

sions on whether to grow short-rotation pulpwood or

longer-rotation sawlogs.

Some smallholder plantations can be grown on short

rotations in conjunction with agricultural crops. In

PNG, farmers are growing balsa plantations on a five-

year rotation. Following a decline in productivity due

to the introduction of seed of poor genetic origin,

research is being conducted to improve the availability

of high-quality balsa germplasm. It is anticipated that

this collaborative research will increase yields by at least

75 per cent and thereby generate an additional revenue

of PGK5,900 per hectare for farmers.

Adding value to plantation-grown wood products

Viet Nam has a very substantial wood processing sector,

which includes pulp and panel mills as well as thou-

sands of small and medium-sized wood manufacturing

enterprises. Its furniture industry is now the fifth largest

contributor to exports, but the industry currently relies

inventory plots and analytical capacity, developing community-

based forest assessment and management planning capabilities with

four communities and modelling the possible financial outcomes.

The project developed innovative individual-tree growth models

that can be used in combination for forests with virtually any species

mixture or size structure. These models were used to calculate changes

in merchantable volume and carbon stocks over time in different forest

types. The research demonstrated that commercial timber resources

in most secondary forests are recovering, with above-ground woody

biomass recovering at an average sequestration of 1.12 ton C ha

-1

and that it will therefore take about 75 years to return to the pre-harvest

carbon stock. Forest scientists can now calculate the impacts of differ-

ent forest management scenarios on carbon sequestration using PNG

forest inventory data, rather than having to use default values from the

Intergovernmental Panel on Climate Change’s reports.

Another finding was that community-based small portable sawmill

operations can be profitable if they process about 1,000 m

-1

logs into sawn timber, which can be sold within 100 km of the mill

without the need to construct roads. The work undertaken to develop

forest management plans for four community forests, together with

the improved information on carbon sequestration rates and profit-

ability of small sawmill operations, provides these communities with

the ability to decide how to manage their forests sustainably.

Better returns from plantations

About half of Viet Nam’s plantations are comprised of Australian

tree species of

eucalypts

acacias

casuarinas

and

melaleucas

and

about one third of the plantations are owned by smallholder farmers.

In some areas, more than 65 per cent of the total annual income of

poorer households is derived from forestry.

Since 1989, ACIAR has supported the development of these plan-

tations through research on species selection, genetic improvement,

Australian and Vietnamese researchers carried out thinning trials on four-year-old

Acacia mangium

trees

Vietnamese researcher with one-year-old

Acacia mangium

clone

Image: Tony Bartlett