Radiata pine (Pinus radiata, known as Monterey pine in its place of origin, California), makes up nearly 90% of New Zealand’s plantation forest (1.6 million hectares). The pine grows much faster here than its homeland – about 7 times faster than in the US and 20 times faster than in Canada. No wonder then that New Zealand, along with Chile and Australia, are the top growers of this species worldwide. New Zealand also boasts the most extensive plantation forest, dominated by radiata pine, in the southern hemisphere (Kaingaroa Forest [click here for map]). So, how did this pine species become so integral to our landscape and economy? Radiata pine was first introduced in the late 1850s as a trial for more widespread planting. Encouraged by its excellent growth rate, seeds were imported from California in the 1870s, mainly for shelter belts and woodlots. It proved to be versatile and grew well throughout New Zealand on a variety of soil types, including coastal sands, heavy clays, gravels and volcanic ash deposits, and by the first forestry planting boom in the 1920s and 1930s, it had been adopted as the species of choice.
The first New Zealand radiata pine plantations were grown from seed collected from farm shelter belts. In its natural state it was a coarse and highly variable tree and also tended to grow many branches and a forked trunk. To improve its quality as a timber species, a genetic research programme was started in the 1950s. Trees of superior growth and form were selected and propagated by grafting. The first improved radiata pines were planted in forests in 1970 and scientists continue to work on ways to improve the quality, disease-resistance and robustness of the radiata pine in New Zealand today.
However, some view our radiata pine forests as “cloned” forests and say that a forest of genetically identical trees is more susceptible to new viruses or pests than a genetically diverse forest. New Zealand’s forestry industry is also criticised for its clear-cutting practices (as opposed to selective logging practised in many European countries) and the excessive application of herbicides and insecticides. Certainly, the commercially grown trees today bear little resemblance to the earliest known radiata pine at Mt Peel Station (photo above right).