Plantation Thinning and Re-establishment Equipment

Plantation work with excavator attachments sits around the edges of commercial harvesting rather than in the middle of it. Production thinning and clearfall in a mature softwood or hardwood estate belong to purpose-built harvesters, feller bunchers and forwarders on secure tonnage contracts. The attachment market is everything else: non-commercial thinning of young or failed stands, tidying compartment edges along roads and firebreaks, felling windthrow and small woodlots on farm forestry blocks, managing the residue and stumps left after harvest, converting a plantation to another land use, and preparing ground for the next rotation. This work is priced per hectare, per hour or as a lump sum per compartment, and it is usually won by a contractor whose excavator does other things for the rest of the year.

The commercial test is asset utilisation. A feller buncher makes sense where annual felling hours are high and the extraction system can keep up; an excavator with a shear, a mulcher, a stump tool and an auger makes sense where the work is project-based, compartment-sized and interleaved with roading, drainage and civil work on the same estate. Tree shear versus feller buncher sets that decision out in full.

The work sequence

A re-establishment job runs through most of the chain below. A thinning or edge job uses only the felling, grapple and pruning stages, and stops before stump treatment because the residual crop stays in the ground.

1. Mark the residual crop and the compartment boundary
2. Prune edge limbs and lift canopyCS300 or CS400
3. Fell selected or failed stemsWL shear with accumulator, or WR20
4. Bunch and extract to the landingEX36 or EX40 grapple
5. Mulch residue and regrowthVM-60SR, VM-65SV or HM-90SV
6. Treat stumps in the planting linesSC850 Pro or WE15
7. Rake and rip roots across the siteTerragrip
8. Drill planting holes on steep groundTRV auger

Broad-area ripping, mounding and mechanical planting across hundreds of hectares still call for specialist forestry tillers and planters; the attachments here support the parts of the workflow an excavator does well. The clearing workflow guide covers sequencing and changeover.

Which attachments do the heavy lifting

Tree shears for thinning and small-stem felling

Non-commercial thinning is a high stem count of small diameters in a narrow row with a residual crop on either side, which is exactly the job an accumulating shear was designed for. The Trevi Benne WL Series spans 2.5 to 21 tonne carriers across three models with an optional upper accumulator, so the operator gathers several stems before slewing to the row edge, which is the single biggest productivity lever in dense young stands. The optional oscillation or twin slewing cylinders help place a stem between rows without touching the crop. For conversion and windthrow with mature hardwood, the WR20 (indicatively 23 to 30 tonne carriers, around 550 mm nominal cut) with a twin-blade system and fork tower handles large stems, and the WR15 does the same on 17 to 22 tonne machines. A very heavy shear is counterproductive in thinning because it damages the residual crop and slows manoeuvring, so size to the median stem; maximum diameter versus production diameter explains why.

Mulchers for residue and regrowth

After harvest the site is a mat of slash, broken tops and regrowth that has to be reduced before planting lines can be prepared, and on a conversion the whole understorey goes. Slash is a different proposition from standing regrowth: it is loose, it hides stone and stumps, and it packs the rotor, which is why the 40 cm target diameter of the Shearex VM-60SR (20 to 25 tonne, 149 cm width, 130 hp minimum) matters more than its width on a plantation floor. The VM-65SV is the step up where a conversion leaves mature stems rather than tops. Both reach over drains and across slope that a front-mount cannot manage; on traversable ground a dedicated carrier with an HM-90SV covers more hectares per hour and is usually the cheaper way to buy them. Mulching destroys the stem, so the value of recoverable pulp or biomass should be calculated before a whole stand is mulched; mulcher versus tree shear covers that decision.

Stump tools for the planting lines

Re-establishment can usually leave stumps between rows, but stumps in the planting line, in a new road or in a drain are a problem, and a conversion to cropping or grazing may require them out altogether. The Dipperfox SC850 Pro (13 to 30 tonne, 850 mm stump, 900 mm depth, 43,000 Nm first-gear torque) processes a high count of large stumps in place with a contained footprint, which is the production choice for forestry blocks. Where the root mass must leave the ground, the Trevi Benne WE15 (20 to 28 tonne, 1,400 mm jaw) and WE10 (11.5 to 18 tonne, 980 mm jaw) cut roots, extract and split the stump for stockpiling or biomass. Extracted plantation stumps carry soil and stone, so the biomass outlet must be one that tolerates contamination. Stump grinder versus stump cutter explains which outcome each delivers.

Forestry grapples and the Terragrip for bunching and clean-up

A shear leaves stems where they fall; a grapple gets them to the landing or the chipper. The Powerhand EX36 forestry grapple (16 to 25 tonne, 0.36 m², 1,928 mm opening) suits larger bundles on the mid-size carrier, and the EX40 (20 to 30 tonne, 0.40 m², 2,137 mm opening, 1,091 kg with rotator) handles high-volume log and biomass work at the landing. The Terragrip (around 14 to 25 tonne) is a re-establishment tool in its own right, because its fixed rake leg rips roots and rakes slash while the gripping leg moves brash, all without a changeover.

Pruners and augers at the edges

Compartment edges along roads, firebreaks and neighbours need canopy lifting and limb removal, which the OMEF CS300 (6 to 10 tonne, 300 mm cut) and CS400 (10 to 24 tonne, 400 or 420 mm cut) do with 360-degree rotation and no holding grapple, so the fall zone has to be clear. On steep or rocky re-establishment ground where a mechanical planter cannot work, an excavator-mounted OMEF TRV auger drive drills planting holes from a stable platform, and the same drive does fence and gate posts on the boundary.

Carrier size and fleet composition

Thinning and edge work favour a nimble carrier, because row spacing and the residual crop, not the timber, set the size: a 5 to 10 tonne or 10 to 16 tonne excavator with a WL shear and accumulator fits between rows and floats on a simple combination. Residue, stump and conversion work is the opposite problem and moves to the 16 to 25 tonne class, or to 25 to 40 tonne where mature hardwood has to be felled and extracted rather than reduced. Hectare-rate mulching on traversable ground is usually cheaper on a dedicated front-mount carrier running an HM head than on any excavator. A common estate fleet is one small thinning carrier and one 20 tonne class machine with four heads; the hire versus buy guide is the one to read for the heads that only work one compartment a year.

Site and commercial factors that change the equipment choice

Slope decides more than anything else. Steep plantation ground limits front-mount carriers, pushes mulching onto excavator heads and makes the optional steep-slope pedestal on a WR shear and the oscillating auger mount worth specifying. Residual crop protection in thinning rules out heavy heads and rewards accumulation and precise placement. A eucalypt estate cuts like native hardwood rather than like the softwood most heads are rated on, which the Australian hardwood guide covers.

Fire season is the dominant constraint on residue work. Whether dry slash may be mulched on a given day is set by the estate’s own fire rules and the relevant state fire authority, and on a plantation those rules are usually stricter than the general restriction, so the program has to be built around them; the carrier housekeeping in fire risk in clearing operations is not optional either. Plantation compartments are remote, so the parts strategy has to be carried on the float. Converting a plantation to another land use, or clearing native regrowth inside a plantation boundary, can require approvals that ordinary silvicultural operations do not: confirm with the estate manager and the relevant state agency before a machine is booked, using native vegetation approvals as the question list. Finally, decide whether thinnings and residue are recovered for pulp, biomass or firewood or mulched in place, because the answer changes the attachment list, the landing layout and the truck count.

Measuring and pricing production

Run a trial in a representative row or compartment and record, per productive hour: stems felled with a diameter distribution and the number of accumulator bundles, hectares of residue mulched by pass, stumps processed by diameter and species class, and holes drilled per hour on the actual soil. Record damage to the residual crop as a percentage of stems, because a thinning contract can be lost on that number even when production is good.

As an illustration only, assume a 12 tonne excavator with a WL shear at an internal cost of $180 per hour, a trial rate of 90 stems per productive hour single-stem and 130 stems per hour with the accumulator in a dense young stand. At 1,000 stems per hectare to be removed, the single-stem cost is about $2,000 per hectare and the accumulator cost about $1,385 per hectare before mobilisation, grapple work and margin. That gap is what the accumulator option costs against over a season. The building a tender rate guide and the cost per unit calculator take the numbers through wear parts and utilisation.

Before you tender or buy for this work

• Obtain the thinning prescription or re-establishment specification, including residual stocking, stump treatment and finish.
• Walk the compartment and record a stem diameter distribution and row spacing, not just the largest tree.
• Confirm whether thinnings and residue are recovered for pulp or biomass or mulched in place, and where the landing is.
• Confirm which stumps must be extracted and which may be processed in place, and what the biomass outlet will tolerate.
• Check the carrier lift chart at working radius for the heaviest head plus rotator plus hitch on the slopes involved.
• Confirm continuous auxiliary flow, pressure, case drain and cooling for a mulcher working slash all day.
• Ask what the estate's fire-danger stop conditions are and whether native vegetation approvals apply to any conversion.
• Price blade, tooth, chain and centre-screw consumables for hardwood and carry spares for a remote compartment.
• Establish exclusion zones and WHS procedures for felling and pruning near other crews and public roads.

Frequently asked questions