This indicator provides information on the areas and extent of forest ecosystem types, including successional stage, age class and the nature of tenure or ownership. The sustainability and stability of forest ecosystems may depend on their size and diversity. If these are not maintained, forest may become vulnerable to habitat degradation and loss. Tenures or ownership types may have a variety of management regimes associated with them – each with a different impact on biological diversity.
Recent satellite-based estimates put the total forested area of New Zealand at a little over 10 million hectares, composed of tall indigenous forest (6.8 million hectares), regenerating forest (1.2 million hectares) and plantation forest (2.1 million hectares). Tall indigenous and regenerating forest area has declined slightly (< 1 percent) over recent decades. Planted forests expanded steadily through to the early 2000s, but have since shown a small (about 3 percent) decline as plantations are converted to more profitable agricultural land uses, notably dairy farming. While most tall indigenous forests (76 percent) remain in public ownership, large areas of plantation forest have shifted from publicly listed companies to various forms of private ownership over the last decade.
Current estimates based on grower surveys put the net stocked area of planted forest at a little over 1.7 million hectares. Radiata pine is the predominant species grown for timber in New Zealand and, together with Douglas-fir, makes up 96 percent of the total plantings. Planted forests have an average area- weighted age of 16.8 years. Thirty percent of the planted forest estate is aged between 16 and 20 years, and only 5.6 percent is older than 30 years.
Over the last decade, the area of radiata pine forest has declined by 4.7 percent (76 700 hectares), eucalypt forests have declined by 38 percent (13 400 hectares), other exotic hardwood species by 35 percent (6800 hectares) and other exotic softwoods by 13 percent (3700 hectares). Conversely the area of Douglas-fir has increased marginally (2.4 percent), and there has been a substantial (about 70 percent) increase in cypress plantings, albeit from a low base.
The ownership of plantation forests over the last decade has changed substantially. In particular, large areas of forest previously owned by public companies have been transferred to private ownership. Private owners include private companies, partnerships, pension funds, individuals and trusts, as well as Māori trusts and incorporations. “Central government” forests are predominantly government- owned forests on Māori leasehold land that are managed by the Ministry for Primary Industries (Crown Forestry).