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New Zealand’s natural and planted forests are valued by people, either as individuals or as a society, because they are:
• Part of our national heritage
• Essential for preserving the ecological balance of the planet
• Important in stabilising the soil and in watershed protection
• Absorbers of carbon dioxide – mitigating the greenhouse
effect
• Enjoyed for their scenic attraction and recreational resource
• Important for the tourist industry
• Habitats of many plants, animals and birds
• Locations of many historical sites
• Important for the production of timber and wood products
and for other traditional uses of forest products
Heritage and Culture
The heritage values of natural forests has been traditionally important to Maori. After a period of intense deforestation following European settlement, there is now generally strong commitment to conservation of our native forests, which are recognised as unique and distinctly different from northern hemisphere forests. Our native plants have evolved over millennia in relative isolation and the native tree species exhibit a range of form and colour that is unique to New Zealand.
Many of the timbers cut from native trees have excellent wood properties, plus unique and desirable grain and colour. However, the harvesting of natural stands is now recognised by many as being non-sustainable in the long term. There is now increased interest in renewable plantation forestry with native trees. Many native species are slow growing and not amendable to plantation forestry. However, there are exceptions such as totara (Podocarpus totara), which is now grown in plantation on a small scale. Totara is culturally very important to Maori and has superb wood properties and finish.
Some of our protected native trees have special cultural significance, such as some of the remaining large trees in our once extensive kauri (Agathis australis) forests. Kauri grows to be one of the largest tree species worldwide. Tane Mahuta, in the Waipoua Forest, has a girth of 14 m and is 51 m tall and 1,200 years old. Considerably larger kauri have been recorded.
Soil And Water Conservation
New Zealand is relatively mountainous and has a high rainfall. The potential for erosion of steep slopes during heavy rainfall is high and in many cases clearance of natural vegetation has resulted in severe slipping of hillsides. This was dramatically evident during the floods of February 2004 in the Manawatu region when large areas of pastureland were washed away and caused devastation downstream with massive deposits of soil and silt. It was also evident during cyclone Bola in 1988, particularly on the Eastern Cape.
Some areas have had to be retired from agriculture, and in severe cases, trees have been planted to help recovery from erosion. The mountain ranges along the east coast of the North Island exhibit some striking examples of eroded hill country and the dramatic recovery once trees are again established.
Where trees have been retained, they protect the soil, regulate the rate at which water is able to run off the land, clean the water as it flows through the mat of roots and vegetative litter on the forest floor, and act as a sponge – holding and slowly releasing the water for many days after the last rainfall. This is vital in helping to prevent the sudden flash floods that can be so dangerous to settlements and grazing stock.
Nutrient Cycling
Through the process of photosynthesis, trees and other vegetation use the energy of sunlight to convert carbon dioxide in the air, and water collected via the roots, into carbohydrates. These compounds are in turn combined with other elements such as phosphorus, potassium, iron and magnesium to create the basic materials of all living tissues. Other organisms, which do not have the same ability to create food from air and water, feed on plants for their own sustenance. Nutrients are passed on up the food chain and are eventually returned to the soil and air.
Because trees live for a long time and have significant ‘mass’, large quantities of carbon and other nutrients may be tied up in their structure. It is this ability to lock up vast stores of carbon in the tissues of trees that has caused them to be described as ‘carbon sinks’ – offsetting the carbon emissions resulting from the burning of fossil fuels such as oil and coal.
Year by year environmental issues became more critical and so does the knowledge that the quality of our life on earth is linked directly to the well-being of forest ecosystems.
See the Wood & Climate Change section of this site for more information.
Habitat
Forests are home to lots of smaller plants and animals that take advantage of the shelter and food supplies. Even in plantations where trees may have been planted only recently, other plants and animals quickly establish themselves and create a diverse population of both natural and introduced organisms.
Recreation and Tourism
New Zealanders love to be out of doors and the country’s forests are an important recreational resource offering scope for walking, hunting, horse riding, orienteering, white water rafting, off-roading, mountain biking as well as the gentler pursuits such as bird-watching and simply camping out in the bush.
Tourism now accounts for 15.7% of export earnings and it continues to grow. Visitors are drawn to the country by its scenery – brought to their attention in film series such as The Lord Of The Rings. Look at any tourist guide to New Zealand or a calendar of scenic views and you will see that forest landscapes feature strongly.
Commercial Uses
Since time began forests have been important as a source of wood for building, heating and cooking. Heating and cooking still account for about 50% of the use of wood.
Wood is also now the raw material for many other substances in common use including paper, fuel, chemicals, foodstuffs and pharmaceuticals. It could be said that wood is the most useful and versatile material available to man.
Other commercial values relate to products directly derived from trees such as resins, rubber, foliage and flowers. Other values are more indirect such as grazing, honey collection, hunting and trapping, and tourism. It is quite frequently the case that the net value from these sorts of activities may exceed the wood value of the forests and they may be specifically set aside for recreational use or habitat protection.
Plantations (planted forests) are usually grown for their wood, although forests may be specially created as a source of commercially important derived products such as latex rubber.
Many of the roles that were originally performed by New Zealand’s natural forests are now fulfilled by commercial plantations.
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