A tree that needs to be removed can sometimes be felled in one with cuts at the base. A selection of felling cuts and calculations are made to direct the whole tree into a designated drop zone where it will then be sectioned and removed. Whilst this method is quick, it is not always possible, due to lack of space or obstructions. In this case the tree would need to be dismantled, see references to 'Section Felling' and 'Lowering' below.
When a tree cannot be felled in one due to a lack of space or unsuitable terrain, for example a prestine lawn, a block paved driveway, proximity to buildings or overhead cables, it may be possible to identify a drop zone where sections of tree can be dropped. In this case manageable sections of tree are removed by climbing around the tree using ropes and harness. The removed sections are dropped into the designated drop zone in a precise and controlled manner.
When a tree cannot be felled in one due to a lack of space or unsuitable terrain, for example a pristine lawn, a block paved driveway, proximity to buildings or overhead cables and it is not possible to identify a drop zone where sections of tree can be dropped, the tree would need to be dismantled in manageable sections that are lowered to the ground using ropes and pulleys.
This is where the lower branches are removed to allow more light under the canopy, to improve vehicle or pedestrian access or prevent obstruction to buildings. Where trees overhang public footpaths or roads, there is a legal requirement for the owner to maintain overhead clearance of 2.1 metres and 5.2 metres respectively.
This term has been removed from the BS3998 2010 Tree Work Recommendations documentation but is still used as a description of work to remove crossing and rubbing branches. Where branches rub together this can break the bark and create an entrance point for pests and disease. Split, diseased, dying and dead wood will also be removed from the canopy. Where there is a Tree Preservation Order (TPO) or the tree is in a Conservation Area, removal of dead wood only can be carried out without consent or giving notice.
Where a tree has an extremely dense canopy, a percentage of it's inner canopy is removed, taking out poor or tight unions, secondary limbs and epicormic growth to reduce the canopy sail area and create a more open canopy and dappled light.
The crown of the tree is made smaller by shortening leading branches back to secondary branches without leaving stumps. This practice is often used to reduce the volume of a tree where it has outgrown it's urban environment. Other than in exceptional circumstances, no more than 30% of the canopy should be removed in one year.
An industrial stump grinder with a spinning head is hydraulically driven across the stump until the main rootball is either ground completely away or to a depth of 28 inches.
Often when a tree with a Tree Protection Order (TPO) is removed, the local planning department will insist a replacement tree is planted. All trees are planted with top grade mulch and staked to support the tree while it establishes it's root system.
The annual regrowth is trimmed off of the face of the hedge or shrub to maintain a formal shape and desirable height. Where a hedge has become undesirably high a height reduction may be made using a chainsaw.
Fruit trees are pruned in early spring or mid-summer by thinning and cutting back to leave a minimum of two auxiliary buds allowing space for fruit to develop. Pruning in early spring or mid-summer avoids infection, especially from silver leaf which is a fungal disease that causes a silvering of the leaves followed by death of the branch.
On occasions, instead of climbing with ropes and harnesses, cranes or mobile elevated work platforms (MEWPs) are needed. Example situations may be where an extremely large tree needs to be dismantled or a tree has died and is deemed unsafe to climb. Cranes and MEWPs are hired in when required and although these can be expensive they create a safe environment and usually reduce the man hours required offsetting the costs.
When power lines are within five metres of a climber, unless fully insulated, the power should be isolated by the electricity board. Whilst there is no extra cost for this, they will require four weeks notice to organise turning the power off.