See also below...
The Australian Obsession with Exotic Plantation Timbers,
Softwood and Hardwood Plantations
'Hardwood' & 'Softwood' Defined
The most readily available plantation timbers in Australia are softwoods such as Hoop Pine, Radiata Pine and Slash Pine, the two latter of which are introduced species.
Regrettably, there is an undersupply of plantation-grown Eucalypt and other hardwood species on the Australian market. Many eucalypt plantations growing in NSW - apart from mainly bluegum and blackbutt - are generally not yet mature, or their trees are not currently being processed as sawlogs. Until truly sustainably harvested timbers are identified and become readily available, please use recycled timber or plantation softwoods wherever possible. The efficient use of plantation pine, where suitable, is essential in order to reduce native forest logging 1.
Pine plantations are often criticised - and rightly so - as ecologically-unsustainable (due to the resulting environmental ravages caused by poor management techniques, monoculturing, use of chemicals, clearfelling, erosion, etc). In many cases, biodiversity has been radically reduced through the establishment of plantations on once-cleared native forest.
The present (ie, dominant) methodology of plantation management also results in soil and fertility loss. Plantation owners and/or managers are rightly criticised for polluting soil, groundwater, waterways and eventually, the ocean. This is because of their systemic use of herbicides, pesticides and fungicides - many of which are bioaccumulative and persist in the environment. All monocultures are vulnerable to disease and pests and soil degradation 2. All human managers and the surrounding populace are likewise vulnerable to disease and suffering.
Please avoid using any plantation pine (except maybe Hoop pine), in external building applications. This will obviate the need to use timber preservatives. Hoop pine HEARTWOOD, when it is used in the drier regions of the state, such as West of the Great Divide, may not need preservative treatment.
The Guide does not presume to suggest that exotic Pine plantations - rather than mixed, native-species plantations or other options - should be the way of the future for the Australian timber industry. The intention is only to locate and promote the most ethically acceptable timbers that are currently readily available. At this point in time, native, then exotic, plantation Pine species rate as ethically more acceptable options than imported tropical or temperate species, or Australian old growth timbers.
Pine can be used for almost all building applications and indeed often is. We suggest, however, that you do not use it in locations exposed to the weather. Even pine used in internal building applications is generally treated with Borax, but this substance's environmental impact is relatively minimal when compared with other treatments, especially when painted or sealed. ('Durable' native pines include Cypress, Huon, King William and Brown or Plum pine. Unfortunately none of these is grown in substantial commercial quantities 4.)
In Australia's one million-plus hectares of softwood plantations, the most common species is Radiata pine. It was erroneously believed for decades that radiata was the only commercially viable species that could be cultivated here.
Now Australia faces the situation of seeing its own indigenous species being successfully and profitably cultivated all over the world but not at home. Plantations of our native species exist in South Africa, Spain, Portugal, Chile, Brazil and Hawaii, mainland USA, and throughout Southeast Asia.
Australian foresters probably know more about radiata than anyone else, yet other countries may surpass our expertise in the commercial cultivation of many of our own valuable natives, due to our reluctance to embrace our own native species.
Australia has about one million hectares of softwood plantations established (mostly Radiata pine). We have only about 100,000 hectares of hardwoods in plantations so far - much of which is still immature. About 70 percent of the softwood timber we consume in Australia is domestically grown.
Softwood plantations are currently seen as the major factor in the hoped-for future shift of the timber industry out of native forest logging altogether. Unofficial reports indicate, however, that (treated) sewage-fed hardwood species can equal the rapid growth rates of Radiata Pine. Australian hardwood plantation timbers are mainly used for low-value applications such as pulp and paper products, their fibre being considered superior to that from native forest trees. The only regular commercial processer of native plantation hardwood for timber is a small radial sawmilling company, Radcon 5, in Victoria. Radcon's equipment and technology allows them to process logs from plantations at much smaller diameters (and with minimal warpage) than if they were to be processed with conventional milling techniques. Most other hardwood trees from plantations ends up at the woodchip mills.
Farm foresters 6 are steadily contributing to the future hardwood sawlog resource-base, their product being suitable for value added, employment-creating applications rather than those of lower value.
The essential structural difference between the two timber types 7 is that Hardwoods have vessels or pores when seen magnified in cross-section, and Softwoods do not. The two types are sometimes termed "pored" and "non-pored".
Normally a magnifying glass is required to see the vessels in the end-grain of hardwood - they will then be seen to be visibly larger than the surrounding tissue. These vessels are arranged in different patterns, depending on the species group; they make hardwood species-differentiation much easier than for softwoods.
The main visual elements of softwoods, tracheids, are very similar in appearance, making softwood species differentiation much harder, even with the aid of a microscope. Resin canals in softwoods may be confused with vessels. Fibre (including the tracheids) makes up about 90% of the wood volume of softwoods. Hardwoods have much less fibre: about 10 to 20% is represented by vessels.
In general, the term 'hardwood' applies to woods from deciduous and evergreen, broad-leaved trees, or dicotyledons. It does not mean 'hardness' in the normal sense, but is a botanical classification. Usually, the timber from broad-leaved trees is harder and heavier than that from needle-leaved trees (conifers), but there are plenty of exceptions to the rule. For example, the lightest-known woods are termed 'hardwoods'.
Hardwoods are more complex, being of more recent evolution. They occur in all climate types where trees grow. They bear seed-containing fruit and come from the botanical group called Angiosperms.
Softwoods generally come from coniferous or needle-leaved trees. They are simpler in structure and more ancient than hardwoods. They grow mainly in temperate and cool climates and comprise about 600 species. They are non-porous and come from the botanical group called Gymnosperms.
1. The Wilderness Society, Australian Conservation Foundation, Colong Foundation, Rainforest Conservation Society, Friends of the Earth Sydney and other groups are campaigning now to end all native forest logging immediately.
2. From The Plantation Effect, by Grant Rosoman - Greenpeace NZ.
3. Clark et al.
4. See the article What We Need to Grow are Durable Native Softwoods.
5. See the article Radial Timber Milling, and Radial Sawmilling, in the Directory.
6. See Agroforestry Groups - Non Profit, Agroforestry Groups - Commerical, and Ecoforestry Projects, in the Directory.
7. For further info, consult Wood in Australia, by Keith Bootle - see Books, Timber Species, in the Directory