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| Rural Industries |
Objectives
Background
Establishment of at least 100,000 hectares of plantations
will be required to provide resources for a proposed world scale
pulp mill in the south west of Western Australia.
Currently the State (Department of Conservation and
Land Management) controls 8,152 hectares and Bunnings Treefarms
9000 hectares of E. globulus plantations of ex-farmland.
Bunnings Treefarms has planted 4600 hectares in 1993 and expects
to maintain new planting at about this level for the next ten
years. The Albany Plantation Company of Australia Pty Ltd, a venture
company formed by Oji, Japan's largest pulp and paper manufacturer,
and Itochu, Japan's biggest trading house, plants to establish
20,000 hectares of E. globulus plantations over ten years.
Prospects are excellent for a commercially viable plantation industry integrated with current farming enterprises and the WA state government has called for expressions of interest in construction of a pulp mill within seven years.
Research
A physiologically based model of tree growth (BIOMASS)
has been adapted to simulate growth of Eucalyptus globulus
and applied to study effects of factors which determine growth
rates at five sites in the south-west of Western Australia.
Major factors considered were climatic variation
and soil physical conditions. Soil characteristics at these sites
differed widely, but as the plantations were established on farmland
where fertilisers had been applied over a number of years, soil
fertility was moderate to high.
Thus, availability of soil nutrients, which is known to affect growth rates, is not a major factor determining differences in growth rates among these plantations.
Outcome
Simulations were moderately successful in explaining
differences in growth rates among the various plantations and
in relating these differences to soil and climatic factors. Major
constraints on use of simulation to predict production rates are
the uncertainties in defining root depths and allocation of photosynthates
to biomass components.
Simulations of seasonal variation in soil moisture
contents gave results which agreed well with measured values where
the plant-available soil moisture and depth of root penetration
could be estimated reliably.
However, at sites where the depth of root penetration
is difficult to estimate or where watertables may be accessible
to roots, agreement between simulated and measured moisture contents
of the top 3m of soil was less satisfactory. In the drier period
of the year simulated patterns of soil water variation gave values
that were lower than was measured. A probable explanation for
this difference is that soil water was extracted from greater
depth than 3 m.
RIRDC Project No: CSF-41A
RESEARCHER: F J Hingston
ORGANISATION: CSIRO Division of Forestry
WA Forest Research Group Private Bag, PO WEMBLEY WA 6014PHONE: 09 387 0792
FAX: 09 387 6046
Last updated: 10 October 1996
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