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Maintenance should start on all sites once the trees are planted. Key tasks include operations such as weed control, replacing tree losses and ensuring that the crop remains healthy and vigorous. All young plantations should be maintained so that:
• Stocking levels are satisfactory and to specification
• The site is kept in good health and nutrition
• The site is kept stock and trespass free
• Adequate growth levels are achieved.
Proper forest maintenance will be required in order to pass the inspection for the Second Installment of the Grant. This inspection is carried out by the Forest Service approximately four years after planting.
Adequate Stocking Levels are important
During the first few years, losses may occur in plantations for any of the following reasons:
• Poor planting technique,
• Poor quality plants,
• Drought or waterlogged sites,
• Weed and scrub competition
• Frost,
• Trespass by stock,
• Damage by wild animals (eg. deer, rabbits, or bank vole),
• Other e.g. insect, fungal.
If failures occur, identify the cause and eliminate if possible prior to replanting. If frost was the problem it may be advisable to change species or origin of plant . Replant early in the season and ensure that good quality plants are used. Avoid planting into frozen ground. Remember that all replanted sites will require vegetation control for longer. In the first two years a number of sample plots for assessing stocking levels should be laid down throughout the site. At year 4 stocking should be at least 90% of the original levels.
Count the number of live trees in an 8m-radius circle. Full stocking (100 %) requires the following numbers of trees per circular plot:
Lodgepole pine 62
All other conifers 50
All Oak or all Beech 132
Other broadleaves 66
Vegetation Control
Weeds and grasses compete with young trees for light, moisture and nutrients so good vegetation control is vital for establishment of the forest. In conifer crops, weed control is required until the leading shoot is well above the level of surrounding vegetation. Broadleaves normally require chemical weed control for longer. Vegetation normally starts growing from March/April onwards and can be normally classified into three main types: grass/broadleaf weeds, woody weeds and bracken. Control can be either manual or chemical or a combination of both.
Manual cleaning is slow and may be suitable in small areas or in the autumn period when weeds are dying back to prevent smothering of the young trees. Manual cleaning may also be required during long periods of wet inclement weather when chemical application is not possible.
Chemical control is by far the most cost effective and gives the best results as the trees become more vigorous due to less competition for moisture and nutrients. Conifers may require chemical control for 2 to 3 years and broadleaves for up to 3 to 4 years.
When using chemicals always follow the manufacturers label in relation to timing, application rates, weather conditions, safety precautions, disposal and the effects that chemicals may have on the trees and the environment.
The Glyphosate-based herbicides (e.g. Roundup, Pride, Gallup) are the most widely used and safest herbicides in forestry at present. These chemicals give good control against grasses and most broadleaf weeds and should be applied when the vegetation is actively growing in spring. Glyphosate-based herbicides may also be applied in the mid to late autumn and will provide adequate control into the following spring and early summer. It is sufficient to treat a circular area around the base of each tree (1 to 1.2 metres in diameter) usually with the aid of a spray shield to avoid any drift. Glyphosate is also available in premixed systems such as Nomix and Greenaway.
Atrazine is a useful herbicide for controlling grass/rush vegetation in conifer forests. It must be applied only during the dormant season and on suitable soils. It is a cheap herbicide and is residual in nature.
Triclopyr-based chemicals (e.g. Garlon, Timbrel, Brushwood Killer) are plant growth regulators. They are absorbed through foliage, stem and roots and are very effective against woody weeds. Woody weeds such as briar and furze can invade sites after 2 to 3 years. Triclopyr-type herbicides can be used in Sitka spruce, Norway spruce and Douglas fir plantations when trees have hardened off in autumn and while the woody weeds are still actively growing. Pines and larches are particularly sensitive to these sprays.
Asulox is an effective herbicide in the control of bracken. It should be applied during July and August when bracken is in full bloom. Best results are achieved if applied to the site in the summer prior to planting.
Crop Protection
It is important that the site is protected at all times and walked through regularly.
• check fences and stiles,
• watch out for animal trespass,
• ensure that the site is stock proof and
• check for rabbit and hare damage.
Constant supervision is necessary to ensure that the crop is adequately protected, that drainage, plant health and nutrition are adequate and that all access routes and existing fire lines are kept clear.
Drainage
Adequate drainage is vital for the long-term stability of the crop therefore
• ensure that the drainage system is working properly and that all silt traps are clear,
• clear any blocked drains particularly after heavy rainfall,
• ensure that all large silt traps and reservoirs are properly fenced off.
Access
Access is essential to facilitate ongoing maintenance operations. Access routes should be left unplanted at establishment and kept clear at all times.
Fire Protection
Fire protection is important in areas of high risk.
• Fire-lines must be regularly maintained and kept clear of vegetation
• Screefing and/or spraying of vegetation may be used
• March, April and May are high-risk months for fires
• Take stock of the fire risk in your plantation
• Insurance is recommended, particularly in high-risk areas.
• A plan should be in place in case of fire
It is important to note that the ultimate responsibility for all plantations rests with you the landowner. It is essential that all young forests get the attention that they require. If you detect a problem you should contact your Teagasc forestry adviser or approved forester immediately and try and remedy the situation. It is also a good habit to walk your plantation regularly and at least once a year with your forester during this maintenance period. Owners of sites over 10 ha must submit to the Forest Service a Management Plan prepared by an approved forester. You should retain a copy of this plan which covers any operations which may be necessary up to year 10. In general, the more interest that you take, the better the plantation will be in the long run.
Teagasc and the Forest Service regularly run courses and field days on the management of young plantations. These are a must for all landowners with a farm forest enterprise. Use these events to build up knowledge on the way your forest should be growing. |
