Break trees / Perimeter trees / Edge trees:
Perimeter trees
These trees, which are heavily limbed because they are on the perimeter of the plantation, need to be considered by the harvesting contractor. Ideally their removal should start at first thinning and aim to have most of them removed by the second thinning if they have poor form and/or have not been pruned. If they are left until the third thinning or clear fell, they will more than likely be too big for the harvesting machinery resulting in them being left behind and adding to clean up and reestablishment costs.
Future wind stability needs to be considered when removing break trees. It may be prudent to leave a “hedge” of break trees as wind protection for an exposed plantation, or a plantation that is adjacent to older trees that will be clear felled midway through your rotation. “Feathering” the thinning intensity up to the exposed edge will help to reinforce stand stability. This should be discussed when preparing prescriptions for selecting trees.
Tree selection for thinning:
There are two options for selecting trees for thinning - tree marking or operator selfselected. Tree marking is completed prior to harvesting by tree marking personal (tree markers), who walk along rows spraying paint onto those trees to be removed to identify them for the harvesting operator. It is important that the correct number of unmarked trees remain to leave the plantation at the desired stocking (ie. number of trees/hectare). Blue paint should be used as red paint is not advisable due to the relatively high rate of red – green colour blindness in the Australian population. If a purchaser is assisting with your harvesting operation, they may offer to mark the trees for a negotiated price. Operator self-selected is when the harvesting machine operator selects the trees to be harvested without any tree marking. However, poor tree selection can ruin a good forest. Removing too many trees will reduce future harvest volumes and under thinning increases harvesting costs and another thinning will be required sooner. It is recommended to use experienced operators and supervise tree selection standards.
Fire Protection:
Fire trees
To minimise the risk of fires starting from harvesting some practices and protocols should be adhered to. Some examples include:
- Machinery should have exhaust temperature restrictions of less than 240°C and be kept clean of debris.
- On extreme fire danger or total fire ban days contractors machinery should be prohibiting from working.
- Contractors should be required to have a fire unit with water and fire fighting equipment on site as well extinguishers fitted to each machine.
If you have any concerns regarding operating during periods of very high to extreme fire danger contact the purchaser or contractor.
Future Management of the site The condition that a site is left in after clear felling can affect options in the second rotation. Consideration should be given to the future use of the site after harvesting; whether a plantation will be re-established or the site returned to pasture or some other land use. This will influence the extent to which the site needs to be cleaned up. Lower slash levels are advisable to reduce the intensity of slash
Full utilisation where as much product as possible is harvested from the forest is desirable because it results in:
Better utilisation of log products:
- Maximising your return;
- Lower cost site treatments because of a reduced need for heaping and burning and the ability to chopper-roll or plough for reestablishment.
However, there needs to be a market for all log products for full utilisation. Therefore a purchaser that markets and harvests a full range of products will be more likely to leave a site with minimal slash residues.
Sell the plantation rather than clear fell?
Do not rule out selling your plantation as an alternative to clear felling it. There may be several advantages, including tax, and land value considerations that make this a treatment required.
