Ground preparation and drainage are vital for successful forest establishment. Their main function is to provide an ideal planting environment and encourage strong tree growth.
When a new forest is being planned, it is important that consideration is given to how the site will be harvested in the years to come. The choice of ground preparation and location of drains and other site infrastructure can have a huge positive (or negative) impact on future harvesting operations. At forest design stage and without compromising early development where possible the general site layout and development should both encourage forest establishment but also facilitate and optimise the effectiveness of future harvesting operations.
Soil type is the most important factor when deciding the method of ground preparation. The inappropriate choice of ground preparation and unnecessary drainage can have cost implications at planting and reduce the efficiency of future harvesting operations.
Particularly effective on poorly draining heavy mineral and peat sites, mechanical mounding is the most popular form of ground preparation. It involves an excavator digging drains at regular intervals and heaping the soil in mounds. The trees are then planted into the mounds which provides an elevated vegetation free zone.
Ripping is primarily used on more fertile mineral soils sites where drainage is impeded by a compacted layer such as an iron pan or cultivation pan, beneath the surface. A bull-dozer pulls a tine behind it to a depth of 45 cm, shattering the pan layer. The trees are planted approximately 10 cm from the centre of the rip channel.
Only suitable for good soils that do not need cultivation and/or drainage, the trees are placed into a trench opened by a tractor mounted plough. This system may be used for planting conifers or broadleaves and generally results in very high survival rates and good subsequent growth. As with ripping at time of harvesting little stump is left on the ground after harvesting.