There are four dominant tree species through the Western Australia’s
South West region – Jarrah, Karri, Marri and Black Butt.
All are unique to Western Australia and support a diverse range of fauna and other flora species in their associated forests.
The diverse ecosystem of the Jarrah forest is so named after the dominant tree species ‘Jarrah’ or Eucalyptus Marginata. The Jarrah tree grows up to 40 metres in height (130 feet) and can live to up to 1,000 years old. They are only found in the south west corner of Western Australia.
Jarrah forests include other tree species such as Marri, a eucalypt which grows up to 60 metres. Jarrah trees are prized for their rich red timber which has seen them extensively logged. Excellent examples of Jarrah forest can be found through the Collie River Valley and around the town of Nannup.
The Southern Forests area of Australia’s South West is well known for its majestic Karri forests. Growing up to 90 metres tall the smooth barked Karri tree (Eucalyptus Diversicolor) is the tallest tree in Western Australia and one of the world’s tallest hardwood trees. They are typically found between Manjimup and Denmark but outlying populations are found as far west as Margaret River, in the Boranup forest, and as far east as the Porongurup National Park.
Black Butt (Western Australian variety, also known as the Yarri, WA Black Butt, or Swan River Black Butt) is one of the taller eucalypts, growing up to 40-45 meters high. It is one of the least flammable eucalypts and usually survives moderate forest fires, although the base of the tree becomes blackened, giving the tree its name.
The Black Butt tree itself resembles the Jarrah, but is relatively scarce as it was a favourite timber for farmers, railway wagons, bridge building, and flooring due to its durability and fire resistant properties. Large portions of the remaining Black Butt trees are contained in reserves and its plants are highly regarded as honey trees.
The timber of this tree looks good, and has more of an even colour than other species. Plantation Black Butt is a light yellow colour and even-grained, while native regrowth Black Butt has much more variation.
Jarrah is a large sized hardwood found only in the South West of Western Australia. It is Western Australia’s principal tree in terms of both the extent of forest and in the versatility of its timber. The bark is rough, covering the whole trunk to the smallest branches and is similar to that of the Stringybark.
Jarrah heartwood varies from rich reds to deep browns, with sapwood being a clearly distinguished pale yellow. The texture is course and generally straight grained although some interlocked grain may feature.
The heartwood is durable (Class 2), allowing a wide range of applications. The material works well and has been widely used in a variety of applications including flooring, joinery, paneling, sleepers, poles and piles, heavy construction and domestic structural framing.
Karri is known as the giant tree of Western Australia, with examples in excess of 50 metres in height. It has quite rapid growth, and can attain enormous dimensions.
It is found in the higher rainfall areas in the South West of Western Australia, favouring light loamy soils of good depth. The heartwood varies from rich reddish browns through to pale pinks with the sapwood being a clearly distinguishable light yellow.
The texture is course and considerable interlocked grain may be a feature. The heartwood is moderately durable (Class 3), with some restriction on the timbers use in exposed structural applications. The material is not easily worked, in part due to the interlocking grain and high density.
It is used in a variety of applications including flooring, joinery, paneling, veneer, sleepers, shipbuilding, heavy construction and domestic structural framing.
Wood from the Marri tree is incredibly hard and durable. The wood itself has a lustrous, golden glow and honey coloured hue with fascinating grain patterns. The natural colours of Marri exotic wood blanks are quite breathtaking and there is no need to stain the lumber. This creamy coloured, exotic wood with contrasting black gum veins and streaks has now become a highly sought after and fashionable lumber.