Forestry
Forestry is the planting, managing and caring for a forest or woodlot (planting of less than 1 hectare).
Silviculture is the art and science of controlling the establishment, growth, composition, health, and quality of forests to meet diverse needs and values of the many landowners.
Pruning, as a silvicultural practice, refers to the removal of the lower branches of the young trees so clear knot free wood can subsequently grow over the branch stubs. Clear knot-free lumbar has a higher value. Pruning has been extensively carried out in the Radiata pine plantations of New Zealand.
Radiata Pine
Radiata Pine is particularly vigorous in the New Zealand climate, being able to grow well on a wide range of sites. Many special purpose timber species will also grow well but are more demanding in their site requirements.
Radiata Pine (Pinus Radiata) accounts for 90 percent of New Zealand's currently plantation forest estate. It is the most versatile species available. Radiata Pine is also the most robust species for forest growing investment in milder climatic zones, providing the highest yeilds, the shortest rotations and the lowest risk of crop failure. Radiata is better able to cope with weed competition than any other species because of its early strong growth and canopy closure.
Radiata Pine has the ability to tolerate a wide range of sites from the coastal lowlands to high altitude sites. Optimum growth occurs on sheltered sites with deep free-draining ash soils of moderate fertility. Young radiata seedlings are susceptible to damage by heavy frosts, and the risk of snow damage will often set it's upper planting limits.
Radiata Pine does not do well on very wet sites where growth will be characterised by thin crowns, die-back and symptoms of nutrient stress. Poor root development on weaterlogged soils is the cause of these problems.
Markets for ratiata pine lumber, wood fibre, panel products and pulp and paper are well developed in NZ and the Pacific Rim, with demand expected to increase in the long term. The stability of radiata pine for a wide range of end-uses helps to ensure its future marketability and value.