Tasmanian Eucalyptus (Eucalyptus regnans) known variously by the common names giant ash, mountain ash, Victorian ash, swamp gum, Tasmanian oak or stringy gum, is a species of Eucalyptus native to southeastern Australia, in Tasmania and Victoria. Historically, it has been known to attain heights over 374 ft making it one of the tallest tree species in the world and the tallest flowering plant.
It occurs in cool, deep soiled, mostly mountainous areas to 3,300 ft altitude with high rainfall of over 47 in per year. They grow very quickly, at more than 3 ft a year, and can reach 213 ft in 50 years, with an average life-span of 400 years. The fallen logs continue supporting a rich variety of life for centuries more on the forest floor.
Unusually for a eucalyptus, it tends not to recover by re-shooting after fire, and regenerates only from seed. The seeds are released from their woody capsules (gumnuts) by heat and for successful germination the seedlings require a high level of light, much more than reaches the forest floor when there is a mature tree canopy. Severe fires can kill all the trees in a forest, prompting a massive release of seed to take advantage of the nutrients in the ash bed. Seedling densities of up to 2.5 million per hectare have been recorded after a major fire. Competition and natural thinning eventually reduces the mature tree density to about 15 to 20 individuals per acre. Because it takes roughly 20 years for seedlings to reach sexual maturity, repeated fires in the same area can cause local extinctions. If, however, no fires regenerate an area, the trees die off after about 400 years and are replaced by other species.
In the late 1960's the Germans (leaders in scientific approaches to forestry) had published research showing that 40% of the progeny of two curly trees would be curly. (If it was a dominant gene all the progeny would be curly.) That is why when you find a curly tree in the woods you should look at all the other maples in the immediate neighborhood. They all came from the same parent stock so curly trees do occur together– and that has probably lead to the myth that where the tree grows causes it to be curly.
The heredity is a lot like the gene that causes curly hair on people. Anything from a slight wave to real kinky. Note that not all the hair on a person has the same amount of curl, likewise, wood in different parts of the same tree have different amounts of curl! Some of the extremely curly trees are curly all the way up into the limbs but most are not.
In wood curl shows up as some form of wave pattern to the fibers. The wave can vary in amplitude (height) and frequency (spacing). The higher the amplitude the more the curl will show as a stripe when stained or even just finished. Curl can also run in different directions. Peel the bark on a curly tree and the curl can be like a washboard with the waves going in and out on the radius (toward the heart of the tree) OR it can be a wave that is 90 degrees to the radius or in the plane of a tangent (much more subtle because you have to look at the fibers of the wood to see them waving back and forth) . Most curl has some of both components.
There are also two kinds of curl that are not hereditary. The “crotch grain” wood occurs (naturally) in the crotch where a tree forks or a big limb comes off. It is caused by wrinkling of the wood fibers as the two limbs both increase in diameter. Each year a new annual ring tries to squeeze into the remaining space. The correct term for this kind of curl in compression wood. The same thing happens at the swell where the trunk flows in to the roots. If you look at a smooth barked tree you can see wrinkles on the outside of the stump swell where the wood is being compressed.
It occurs in cool, deep soiled, mostly mountainous areas to 3,300 ft altitude with high rainfall of over 47 in per year. They grow very quickly, at more than 3 ft a year, and can reach 213 ft in 50 years, with an average life-span of 400 years. The fallen logs continue supporting a rich variety of life for centuries more on the forest floor.
Unusually for a eucalyptus, it tends not to recover by re-shooting after fire, and regenerates only from seed. The seeds are released from their woody capsules (gumnuts) by heat and for successful germination the seedlings require a high level of light, much more than reaches the forest floor when there is a mature tree canopy. Severe fires can kill all the trees in a forest, prompting a massive release of seed to take advantage of the nutrients in the ash bed. Seedling densities of up to 2.5 million per hectare have been recorded after a major fire. Competition and natural thinning eventually reduces the mature tree density to about 15 to 20 individuals per acre. Because it takes roughly 20 years for seedlings to reach sexual maturity, repeated fires in the same area can cause local extinctions. If, however, no fires regenerate an area, the trees die off after about 400 years and are replaced by other species.
In the late 1960's the Germans (leaders in scientific approaches to forestry) had published research showing that 40% of the progeny of two curly trees would be curly. (If it was a dominant gene all the progeny would be curly.) That is why when you find a curly tree in the woods you should look at all the other maples in the immediate neighborhood. They all came from the same parent stock so curly trees do occur together– and that has probably lead to the myth that where the tree grows causes it to be curly.
The heredity is a lot like the gene that causes curly hair on people. Anything from a slight wave to real kinky. Note that not all the hair on a person has the same amount of curl, likewise, wood in different parts of the same tree have different amounts of curl! Some of the extremely curly trees are curly all the way up into the limbs but most are not.
In wood curl shows up as some form of wave pattern to the fibers. The wave can vary in amplitude (height) and frequency (spacing). The higher the amplitude the more the curl will show as a stripe when stained or even just finished. Curl can also run in different directions. Peel the bark on a curly tree and the curl can be like a washboard with the waves going in and out on the radius (toward the heart of the tree) OR it can be a wave that is 90 degrees to the radius or in the plane of a tangent (much more subtle because you have to look at the fibers of the wood to see them waving back and forth) . Most curl has some of both components.
There are also two kinds of curl that are not hereditary. The “crotch grain” wood occurs (naturally) in the crotch where a tree forks or a big limb comes off. It is caused by wrinkling of the wood fibers as the two limbs both increase in diameter. Each year a new annual ring tries to squeeze into the remaining space. The correct term for this kind of curl in compression wood. The same thing happens at the swell where the trunk flows in to the roots. If you look at a smooth barked tree you can see wrinkles on the outside of the stump swell where the wood is being compressed.