Most deciduous trees in Australia are exotic species; however there are a few native deciduous trees and one of the most spectacular is the Red Cedar. Its new, spring growth appears as a beautiful flush of copper red, due to the presence of a red pigment called anthocyanin. Most plant leaves are green because of a green pigment called chlorophyll which is utilised in photosynthesis. Red pigmented leaves reduce a plant’s ability to photosynthesise, however they have other benefits – they protect from excess light and radiation, the red colour undermines insect camouflage and is apparently a colour which is not appealing to potential insect pests. Plants also have to balance their energy capture with energy consumption and dissipation, so by reddening their leaves Red Cedars reduce the rate of photosynthesis which may be an advantage at a certain seasonal developmental stage of leaf growth.
The Red Cedar is a forest tree that had wide distribution through southern Asia and Australia. Its natural habitat is subtropical rainforest and in Australia it was originally found in forests on the east coast that stretched from southern NSW to northern Queensland. In the rainforest, the Red Cedar was a giant canopy tree that could tower to over 60 metres. These huge trees were aerial ecosystems in their own right, they produced flowers and fruit and their branches were festooned with orchids, mosses, fungi, staghorns, elkhorns which provided food and shelter for a multitude of creatures.
As a timber, Red Cedar was so valuable that it was called “Red Gold”. It is very beautiful as a cabinet timber, with rich red heartwood and golden yellow sapwood. As softwood it was easy to cut and work and it was also buoyant enough to be floated along rivers to ships and sawmills. In Australia, within a few years of European settlement, Red Cedar was being felled so relentlessly that in 1795 Governor Hunter issued restrictions on cutting Red Cedar in an effort to halt its rapid devastation. However, logging of the species continued in the forests along the east coast, until practically every large millable tree was cut down.
When millable Red Cedar became commercially extinct in the forests, efforts were made to grow it as a plantation tree. This failed largely because the species is vulnerable to attack by the Cedar Tip Moth. This moth lays its eggs on the tree’s leading shoot, when the larvae hatch they burrow into the stem and cause dieback. Although the attack rarely kills the tree it stimulates the growth of secondary branches which produces a multi branched tree which has little commercial value, unlike a rainforest Red Cedar which has an enormous straight trunk. In the untouched rainforest the shade of surrounding vegetation and natural predators of the Cedar Tip Moth protect the tree from attack until it breaks through the canopy as a huge mature tree.