Pine Plantations

APM Forests commenced thinning its 12-year-old pine plantations in 1962. The total annual pine wood input to Maryvale Mill was approximately 50,000m³ being supplied mainly from State plantations at a considerable distance from the mill. Input doubled the next year and redoubled in 1970. However, this young wood from the company plantations was not particularly attractive to Maryvale. The discovery of Sirex made the large-scale thinning of the plantations an urgent matter. As an outlet for this young wood a particle board factory was established at Rosedale, jointly owned by CSR and APM Forests. Production commenced in 1964 and wood intake increased to 50,000m³ per year. Because of its small size the factory became unprofitable and was closed at the end of 1978. Later, biological control of Sirex was developed.

During this period, the plantations were intensively managed with thinning commencing at age 10/11 and repeated at 2- to 3-year intervals. Demand was in excess of supply necessitating the purchase of wood from external sources at high cost. This intensive thinning minimised losses from Sirex attack in this period prior to biological control. Wood from second and subsequent thinnings from age 14 on was suitable for pulp mill requirements.

Although the plantations were planned to be pulpwood only, by the mid 1970s when the oldest plantings were 25 years old, the suitability of the pine resource for sawn timber production was investigated. The outcome was the establishment of a large sawmill at Morwell. Log intake commenced in 1976 with that from the company plantations increasing from an initial level of 50,000m³ to 100,000m³ in 1988 with further increases thereafter.

A major new pine Kraft pulp mill on the existing Maryvale site was planned for commencement around 1978. The minimum economic size for such a mill was then considered to be approximately 150,000 tonnes of pulp per year. To meet this project demand, planting rates were increased considerably in 1973. The new mill eventually commenced operation in 1985 with a capacity of 160,000 tonnes of pulp per year.

In the 1990s output from the plantations was 650-700,000m³/yr of pulpwood, sawlogs and peeler logs for external sales.

Planting rates averaged 1300ha/yr with clear-felling averaging 1000ha/yr.

By the 1990s growth was in excess of pulpwood demand. A less intensive silvicultural regime evolved with three thinnings. (First thinning at age 14-15 years with subsequent thinnings at 4 year intervals and clear-felling at age 26 to 28 years.)

Eucalypt Plantations

Some native forests were purchased from the start of APMF operations including some natural regeneration on partially cleared farmland. Various thinning, timber stand improvement and other treatments were applied in the 1950s and 1960s but results were generally disappointing in terms of wood production.

Small trial plantings of several species of eucalypts commenced from 1952, but remained on a small scale until the commencement of the Strzelecki Project (Heartbreak Hills) for the future supply of additional eucalypt pulpwood in 1960. Successful establishment on this very steep topography was not readily achievable until the control of browsing animals was available through the introduction of myxomatosis and the use of 1080 poisoning.

Plantings were mainly of E. regnans with some E. globulus.  In the 1960s plantings averaged about 200ha/yr and in the 1970s approximately 500ha/yr until the leasehold areas were completed. Then, because of increased availability of residual roundwood from State Forests, in the next seven years a total of only 370ha were planted.

In the early 1980s, APM decided to expand significantly into the business papers segment of the paper market, requiring a major rebuild of a paper machine and expansion of bleached eucalypt pulp output, requiring an increasing input of eucalypt wood.

The eucalypt plantation program was reactivated in 1986. Planting rates commenced at 100ha/yr rising to 800ha/yr in 1989. It was envisaged that the rotation age for E. regnans plantations would be about 30 years. For other eucalypt species shorter rotation ages were envisaged.

Plantation eucalypt research was greatly expanded with the establishment of a eucalypt seed orchard, eucalypt harvesting thinning operations in both plantation and natural regeneration areas and a comprehensive program of wood and pulping quality investigations.

 

 

Jeeralang Tree Farm - E.regnans planted in 1961
1991
Photo: R McCarthy

Jeeralang Tree Farm - E.regnans planted in 1961
1991
Photo: R McCarthy

In assessing areas for plantation development, the following criteria applied:

• Rainfall should not be less than 800mm/yr.
• Within 100km of a processing plant and preferably within 50km.
• Preferably with slopes of less than 12 degrees and no more than 20 degrees.
• Individual blocks should be 100ha and reasonably compact in shape.
• At least 16m³/ha/yr MAI at age 20.
• Soils to exhibit load carrying capacity in winter.
• Year-round access for extraction of forest produce.
• Appropriate for perpetual forestry activities.
• Free of noxious weeds/pests and diseases.
• Access to inexpensive roading materials.
• Size and vegetation cover such that the new plantation crop could be economically protected from fire.
• Reasonably well drained.

Size

Each compartment of the plantation estate was approximately 40ha, but this varied according to plantable area and geographic features.

Buffer Zones

Water courses and depressions were protected by a buffer zone of undisturbed vegetation. For minor depressions which drain short and gentle slopes, a total buffer of 20m was generally adequate. On well-defined water courses, a minimum buffer of 20m was allowed. Earthworks and vehicular activity were excluded from the buffer zones.

Roads

As far as practicable roads were located adjacent to each compartment of planted trees.
All internal access roads were trafficable throughout the fire season. In hilly country, internal ridge tracks (to a maximum grade of 1 in 10) were maintained.
The main road network was trafficable to all vehicles and maintained in this state by appropriate methods such as grading and slashing.
No roads were allowed to dead-end for reasons of fire safety.

Firebreaks

• External firebreaks of 7-20m width were established on the upwind boundaries (usually on the northern, southern and western boundaries) of the block, where the land was accessible by machine. A vehicular track was placed on these firebreaks where practicable.
• Firebreaks were maintained in a vegetation-free condition by appropriate methods such as disc ploughing (to prevent erosion), grading, grazing and tractor slashing.
• In hilly country, where mechanical cultivation of firebreaks was not possible, the external boundaries were manually cleared of vegetation, as necessary.
• There was an all-weather track within 400m of any point of the plantation.
• All tracks were negotiable by a four-wheel-drive fire tanker in summer conditions.
• If a track became impassable to a four-wheel-drive tanker it was signposted as such at the nearest track junction at which the fire tanker could turn.
• Wherever possible, dead end tracks were avoided on firebreaks

 

Cat 528 skidder with disc plough on firebreaks
1993
Photo: R McCarthy

Water Supply

• Where the soils would hold water, fire dams were established for each 100ha of plantation.
• Fire dams were greater than 100,000 litres capacity.
• Fire dams were to be accessible by helicopter and fire tanker and to be located alongside all-weather roads.
• Maximum distance to any water point was no more than 2km.

APMF placed environmental and safety considerations high on its management agenda. Operations were undertaken in conformance with Victoria's Code of Forest Practices for Timber Production. Professional forest scientists were employed to ensure that soil, hydrology, flora and fauna, aesthetic values, diseases and weed problems were considered in plantation operations.

• Since 1978, soil cultivation was carried out on the contour leaving a double furrow surrounding undisturbed soil between each ridge.
• APMF recognised early the importance of avoiding windrowing and burning of slash on second rotation sites to avoid second rotation decline. APMF quickly developed appropriate slash incorporation techniques using chopper rolling and stump-jump ploughs that retain and incorporate organic matter and nutrients in the logging slash.