Eucalyptus regnans
Encyclopedia
Eucalyptus regnans, known variously by the common names 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 100 metres (328.1 ft) and is one of the tallest tree species in the world.
tree
, Eucalyptus regnans is the tallest of the eucalypts, growing to 70–100 m (230–330 feet), with a straight, grey trunk, smooth-barked except for the rough basal 5 –. The leaves
are falcate (sickle-shaped) to lanceolate, 9 – long and 1.5 – broad, with a long acuminate apex and smooth margin, green to grey-green with a reddish petiole
. The flower
s are produced in clusters of 9–15 together, each flower about 1 centimetre (0.393700787401575 in) diameter with a ring of numerous white stamen
s. The fruit
is a capsule 5 – long and 4 – broad.
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 30 to 40 individuals per hectare. Because it takes roughly 20 years for seedlings to reach sexual maturity
, repeated fires in the same area can cause local extinction
s. If, however, no fires regenerate an area, the trees die off after about 400 years and are replaced by other species.
s, and possibly the tallest of all plant
s, although no living specimens can make that claim. The tallest measured living specimen, named Centurion
, stands 101 metres tall in Tasmania
. Before the discovery of Centurion, the tallest known specimen was Icarus Dream, which was rediscovered in Tasmania
in January, 2005 and is 97 metres (318.2 ft) high. It was first measured by surveyors at 98.8 metres (324.1 ft) in 1962 but the documentation had been lost. 16 living trees in Tasmania have been reliably measured in excess of 90 metres (295.3 ft).
Historically, the tallest individual is claimed to be the Ferguson Tree, at 132.6 metres (435 ft), found in the Watts River
region of Victoria in 1871 or 1872. This record is often disputed as unreliable, despite first-hand documentary evidence of it being measured on the ground with surveyor's tape by a senior forestry official (see below). Widespread agreement exists, however, that an exceptionally tall individual was reliably measured at 112.8 metres (370.1 ft) by theodolite
in 1880 by a surveyor, George Cornthwaite, at Thorpdale, Victoria (the tree is known both as the Cornthwaite or Thorpdale Tree). When it was felled in 1881, Cornthwaite remeasured it on the ground by chain at 114.3 metres (375 ft). The stump was commemorated with a plaque that exists today. That tree was about 1 metre shorter than the world's current tallest living tree, a Coast Redwood, 115.55 metres (379.1 ft).
The tallest specimens of this and many other species encountered by early European settlers are now dead as a result of bushfires, logging
and advanced age
. Few living specimens exceed 90 metres (295.3 ft); old records of logged trees make varied claims of extreme heights, but these are difficult to verify today.
Most of those claims come from Victoria. Al Carder, notes that in 1888 a cash reward of 100 pounds was offered there for the discovery of any tree measuring more than 122 metres (400.3 ft). The fact that such a considerable reward was never claimed is taken as evidence that such large trees did not exist. Carder's historical research, however, revealed that the reward was offered under conditions that made it highly unlikely to be collected. First, it was made in the depths of winter and applied only for a very short time. Next, the tree had to be measured by an accredited surveyor. Since loggers had already taken the largest trees from the most accessible Victorian forests, finding very tall trees then would have demanded an arduous trek into remote wilderness and at considerable altitude. In turn, that meant that searchers also needed the services of experienced bushmen to be able to guide them and conduct an effective search. Only one expedition actually penetrated one of the strongholds of E. regnans at Mount Baw Baw but its search was rendered ineffectual by cold and snow and managed to measure only a single living tree — the New Turkey Tree: 99.4 metres (326.1 ft) — before appalling conditions forced a retreat, Carder notes.
In 1911, a previously unknown report was discovered: it was written by a licensed surveyor, G.W. Robinson, who had kept his personal forestry records from six decades earlier during the 1850s in the Dandenong Ranges, near Melbourne. Robinson had arranged with loggers to notify him when they found a very tall tree, and noted that every one he measured exceeded 91 metres (298.6 ft), the tallest being 104 metres (341.2 ft). Robinson noted that the tallest trees were felled first and had no doubt that "some of the trees felled earlier would have measured quite some 400 ft".
Victoria's early State botanist, Ferdinand von Mueller
, claimed to have personally measured one tree near the headwaters of the Yarra River at 122 metres (400.3 ft). A government surveyor, David Boyle, claimed in 1862 to have measured a fallen tree in a deep gully in the Dandenongs at 119.5 metres (392.1 ft), and with a diameter at its broken tip that indicated it might have lost another eight metres of trunk when it broke, for 128 metres (419.9 ft).
Von Mueller's early records also mention two trees on the nearby Black Spur Range, one alive and measuring 128 metres (419.9 ft) and another fallen tree said to measure 146 metres (479 ft), but these were either based on hearsay or uncertain reliability. David Boyle also reported that a tree at Cape Otway measured 160 metres (524.9 ft), but this too was based on hearsay.
Many prominent botanists and tree enthusiasts have long been sceptical of such claims because they lacked first-hand evidence from a credible source. But Carder notes that nor can all the claims be considered imaginary: "The frequency, the persistence, and the wide occurrence of the reports leads to the belief that there was some basis of fact for the statements made."
None, however, had been verified by direct documentation until 1982 when Ken Simpendorfer, a Special Projects Officer for the Forests Commission, Victoria, directed a search of official Victorian archives. It unearthed a forgotten report from more than a century earlier, one that had not been referred to in other accounts of the species up to that time. It was written on 21 February 1872, by the Inspector of State Forests, William Ferguson, and was addressed to the Assistant Commissioner of Lands and Surveys, Clement Hodgkinson. Ferguson had been instructed to explore and inspect the watershed of the Watts River and reported trees in great number and exceptional size in areas where loggers had not yet reached. He wrote: "In one instance I measured with a tape line one huge specimen that lay prostrate across a tributary of the Watts, and found it to be 435 ft [133 metres] from its root to the top of its trunk. At 5 feet from the ground it measures 18 feet in diameter, and at the extreme end where it has broken in its fall, it is 3 feet in diameter. This tree has been much burnt by fire, and I fully believe that before it fell it must have been more than 500 ft [150 metres] high. As it now lies, it forms a complete bridge across a deep ravine."
Carder concludes that the height limit for E. regnans is "not greatly over 300 feet now, but there is sound evidence that trees very much taller did indeed at one time stand,".
It is also possible that individual trees will again attain such heights. Author Bob Beale has recorded that the tallest trees in the Black Spur Range now measure about 85 metres (278.9 ft) but — due to major bushfires in the 1920s and 30s — are less than 80 years old and have been growing consistently at the rate of about one metre a year.
near Dunedin
, New Zealand
(where E. regnans is an introduced species
) contains that country's tallest measured tree.
, and has been harvested in very large quantities. Primary uses are sawlogging and woodchipping
. It was a major source of newsprint
in the 20th century. Much of the present woodchip harvest is exported to Japan. While the area of natural stands with large old trees is rapidly decreasing, substantial areas of regrowth exist and it is increasingly grown in plantation
s, the long, straight, fast growing trunks being much more commercially valuable than the old growth timber.
It is a medium weight timber (about 680 kg/m³) and rather coarse (stringy) in texture. Gum veins are common. The wood is easy to work and the grain is straight with long, clear sections without knots. The wood works reasonably well for steam-bending.
Primary uses for sawn wood are furniture, flooring (where its very pale blonde colour is highly prized), panelling, veneer, plywood, window frames, general construction. The wood has sometimes been used for wood wool and cooperage. However, the wood needs steam reconditioning for high value applications, due to a tendency to collapse on drying. This wood is highly regarded by builders, furniture makers and architects.
s in provides essential habitat
to important birds and mammals (notably the Wedge tailed eagle, the Lyrebird
and the endangered Victorian state animal emblem Leadbeater's Possum
). In a land of vast, arid plain
s and desert
, the contrasting lush fertility of mountain-ash forest
is particularly dear to nature lovers.
Although its status as a species is secure, old-growth forests of Eucalyptus regnans are particularly susceptible to destruction by forestry. For this reason stands of very old and very tall trees exist only in pockets. Very few such stands of trees fall within those areas that have been listed as National Park or World Heritage environments. Most lie within areas controlled by state forestry management authorities and their heritage value is balanced against the commercial value of harvesting and then planting fast-growing and more productive monoculture timber crops on these comparatively well-watered and fertile areas.
In Tasmania
, of the 10,000 hectares of tall-eucalypt forest logged between 1996 an 2006, E. regnans made up more than 1,100 hectares. The trees continue to be logged, most notably by Gunns
, a major forestry enterprise.
Political opposition to the logging of forests by the process known as clearfelling
has grown very strong in recent years (particularly in the case of woodchipping), and the extent of future harvesting remains uncertain.
It has long been believed that while many species of eucalyptus successfully survived severe bushfires, forests of Eucalyptus regnans are highly susceptible to destruction by fire. While the process of recovery of most eucalyptus forests is rapid, so that trees that are devoid of leaves may be fully foliaged within two years, in the case of Eucalyptus regnans, the recovery of a forest after a severe fire might require the total regrowth from seed of the devastated area, taking perhaps 200 years or more.
It has been suggested that fire is necessary for the germination of Eucalyptus regnans, and that young Eucalyptus regnans trees flourish best where there is open space, allowing sunlight to penetrate. Prior to European intervention, indigenous land management practices involved controlled burning in order to maintain grassland. This resulted in cleared areas in forests, around the peripheries of which young trees could germinate and grow. It is probable that these indigenous practices were used within forests of Eucalyptus regnans. Cleared spaces also occur naturally in tall forests when an old tree falls, or dies and loses its foliage. These very tall trees do not survive independently of each other, as single trees are more subject to lightning strikes and wind damage.
The natural habitat of the Eucalyptus regnans is in general the areas of Australia with the highest and most reliable precipitation. These areas are less prone to catastrophic fires than other forested areas. Research has indicated that a stand of Mountain Ash in Victoria is actually a multi-age stand due to fire, having experienced seven fires since the 15th century, whereas, since European settlement, many of Australia's Eucalyptus forests have suffered severe fires as often as every 20 years.
Studies conducted in the 20th by T. M. Cunningham and David H. Ashton suggest that the re-growth habit of Eucalyptus regnans requires open space, and an ash layer. For this reason clearfelling (as opposed to selective logging methods) are justified by the timber industry by claiming it is required for the successful germination and growth of seedlings, despite such intense burns not occurring naturally and the cleared land requiring reseeding from seed collected elsewhere. The clearfell process can lead to spectacular and uniform regrowth of commercially viable timber, if managed properly. Those who support clearfelling see it as an ideal method of land management but critics point to the impact of such activities on stream health, water yield of catchments, impacts on threatened forest fauna and flora, long term soil healthy and viability, and the loss of all biodiversity to the harvested area.
In addition to this, opponents of clearfelling point out that the forests survived for centuries without clearfelling and that it takes perhaps 300 years to replace a giant tree, commercially valuable only as woodchip, and therefore designated as "waste" by the harvesters. Opponents of clearfelling point out that the clearfell process was unavailable until the arrival of European settlers (indigenous people practised a mosaic burn system that kept the forest open but didn't remove large amounts of timber).
Half of Victoria's forested water catchment areas, which provides water requiring little treatment, are composed of E. regnans forest. Yields from these catchments fall significantly for 20 to 40 years after disturbance. These areas have an increased risk of bushfire due to smaller trees being more flammable, the risk increasing further with climate change.
which identified that mountain ash forests in Victoria’s Central Highlands as the best in the world at locking up carbon.
Victorian Ash
Victorian Ash can refer to the wood of either of the trees Eucalyptus regnans or Eucalyptus delegatensis, when it is sourced from the Australian state of Victoria. The same wood sourced from Tasmania is called Tasmanian Oak....
, Swamp Gum, Tasmanian Oak
Tasmanian Oak
Tasmanian Oak refers to the hardwood produced by three trees: Eucalyptus regnans, Eucalyptus obliqua or Eucalyptus delegatensis, when it is sourced from the Australian state of Tasmania....
or Stringy Gum, is a species of Eucalyptus
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
native to southeastern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, in Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
and Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
. Historically, it has been known to attain heights over 100 metres (328.1 ft) and is one of the tallest tree species in the world.
Description
An evergreenEvergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
, Eucalyptus regnans is the tallest of the eucalypts, growing to 70–100 m (230–330 feet), with a straight, grey trunk, smooth-barked except for the rough basal 5 –. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are falcate (sickle-shaped) to lanceolate, 9 – long and 1.5 – broad, with a long acuminate apex and smooth margin, green to grey-green with a reddish petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are produced in clusters of 9–15 together, each flower about 1 centimetre (0.393700787401575 in) diameter with a ring of numerous white stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a capsule 5 – long and 4 – broad.
Habitat
It occurs in cool, deep soiled, mostly mountainous areas to 1000 metres (3,280.8 ft) altitude with high rainfall of over 1200 millimetres (47.2 in) per year. They grow very quickly, at more than a metre a year, and can reach 65 metres (213.3 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
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
, 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 30 to 40 individuals per hectare. Because it takes roughly 20 years for seedlings to reach sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
, repeated fires in the same area can cause local extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
s. If, however, no fires regenerate an area, the trees die off after about 400 years and are replaced by other species.
Tallest specimens
Eucalyptus regnans is the tallest of all flowering plantFlowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s, and possibly the tallest of all plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s, although no living specimens can make that claim. The tallest measured living specimen, named Centurion
Centurion (tree)
The Centurion is the tallest Swamp Gum tree in the world, thus making Eucalyptus regnans the second highest tree species in the world after Coast Redwood and the highest angiosperm in world...
, stands 101 metres tall in Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
. Before the discovery of Centurion, the tallest known specimen was Icarus Dream, which was rediscovered in Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
in January, 2005 and is 97 metres (318.2 ft) high. It was first measured by surveyors at 98.8 metres (324.1 ft) in 1962 but the documentation had been lost. 16 living trees in Tasmania have been reliably measured in excess of 90 metres (295.3 ft).
Historically, the tallest individual is claimed to be the Ferguson Tree, at 132.6 metres (435 ft), found in the Watts River
Watts River
The Watts River is a tributary of the Yarra River. It rises on the southern slopes of the Great Dividing Range, north east of Healesville, Victoria, Australia and joins the Yarra River near Healesville...
region of Victoria in 1871 or 1872. This record is often disputed as unreliable, despite first-hand documentary evidence of it being measured on the ground with surveyor's tape by a senior forestry official (see below). Widespread agreement exists, however, that an exceptionally tall individual was reliably measured at 112.8 metres (370.1 ft) by theodolite
Theodolite
A theodolite is a precision instrument for measuring angles in the horizontal and vertical planes. Theodolites are mainly used for surveying applications, and have been adapted for specialized purposes in fields like metrology and rocket launch technology...
in 1880 by a surveyor, George Cornthwaite, at Thorpdale, Victoria (the tree is known both as the Cornthwaite or Thorpdale Tree). When it was felled in 1881, Cornthwaite remeasured it on the ground by chain at 114.3 metres (375 ft). The stump was commemorated with a plaque that exists today. That tree was about 1 metre shorter than the world's current tallest living tree, a Coast Redwood, 115.55 metres (379.1 ft).
The tallest specimens of this and many other species encountered by early European settlers are now dead as a result of bushfires, logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
and advanced age
Senescence
Senescence or biological aging is the change in the biology of an organism as it ages after its maturity. Such changes range from those affecting its cells and their function to those affecting the whole organism...
. Few living specimens exceed 90 metres (295.3 ft); old records of logged trees make varied claims of extreme heights, but these are difficult to verify today.
Most of those claims come from Victoria. Al Carder, notes that in 1888 a cash reward of 100 pounds was offered there for the discovery of any tree measuring more than 122 metres (400.3 ft). The fact that such a considerable reward was never claimed is taken as evidence that such large trees did not exist. Carder's historical research, however, revealed that the reward was offered under conditions that made it highly unlikely to be collected. First, it was made in the depths of winter and applied only for a very short time. Next, the tree had to be measured by an accredited surveyor. Since loggers had already taken the largest trees from the most accessible Victorian forests, finding very tall trees then would have demanded an arduous trek into remote wilderness and at considerable altitude. In turn, that meant that searchers also needed the services of experienced bushmen to be able to guide them and conduct an effective search. Only one expedition actually penetrated one of the strongholds of E. regnans at Mount Baw Baw but its search was rendered ineffectual by cold and snow and managed to measure only a single living tree — the New Turkey Tree: 99.4 metres (326.1 ft) — before appalling conditions forced a retreat, Carder notes.
In 1911, a previously unknown report was discovered: it was written by a licensed surveyor, G.W. Robinson, who had kept his personal forestry records from six decades earlier during the 1850s in the Dandenong Ranges, near Melbourne. Robinson had arranged with loggers to notify him when they found a very tall tree, and noted that every one he measured exceeded 91 metres (298.6 ft), the tallest being 104 metres (341.2 ft). Robinson noted that the tallest trees were felled first and had no doubt that "some of the trees felled earlier would have measured quite some 400 ft".
Victoria's early State botanist, Ferdinand von Mueller
Ferdinand von Mueller
Baron Sir Ferdinand Jacob Heinrich von Mueller, KCMG was a German-Australian physician, geographer, and most notably, a botanist.-Early life:...
, claimed to have personally measured one tree near the headwaters of the Yarra River at 122 metres (400.3 ft). A government surveyor, David Boyle, claimed in 1862 to have measured a fallen tree in a deep gully in the Dandenongs at 119.5 metres (392.1 ft), and with a diameter at its broken tip that indicated it might have lost another eight metres of trunk when it broke, for 128 metres (419.9 ft).
Von Mueller's early records also mention two trees on the nearby Black Spur Range, one alive and measuring 128 metres (419.9 ft) and another fallen tree said to measure 146 metres (479 ft), but these were either based on hearsay or uncertain reliability. David Boyle also reported that a tree at Cape Otway measured 160 metres (524.9 ft), but this too was based on hearsay.
Many prominent botanists and tree enthusiasts have long been sceptical of such claims because they lacked first-hand evidence from a credible source. But Carder notes that nor can all the claims be considered imaginary: "The frequency, the persistence, and the wide occurrence of the reports leads to the belief that there was some basis of fact for the statements made."
None, however, had been verified by direct documentation until 1982 when Ken Simpendorfer, a Special Projects Officer for the Forests Commission, Victoria, directed a search of official Victorian archives. It unearthed a forgotten report from more than a century earlier, one that had not been referred to in other accounts of the species up to that time. It was written on 21 February 1872, by the Inspector of State Forests, William Ferguson, and was addressed to the Assistant Commissioner of Lands and Surveys, Clement Hodgkinson. Ferguson had been instructed to explore and inspect the watershed of the Watts River and reported trees in great number and exceptional size in areas where loggers had not yet reached. He wrote: "In one instance I measured with a tape line one huge specimen that lay prostrate across a tributary of the Watts, and found it to be 435 ft [133 metres] from its root to the top of its trunk. At 5 feet from the ground it measures 18 feet in diameter, and at the extreme end where it has broken in its fall, it is 3 feet in diameter. This tree has been much burnt by fire, and I fully believe that before it fell it must have been more than 500 ft [150 metres] high. As it now lies, it forms a complete bridge across a deep ravine."
Carder concludes that the height limit for E. regnans is "not greatly over 300 feet now, but there is sound evidence that trees very much taller did indeed at one time stand,".
It is also possible that individual trees will again attain such heights. Author Bob Beale has recorded that the tallest trees in the Black Spur Range now measure about 85 metres (278.9 ft) but — due to major bushfires in the 1920s and 30s — are less than 80 years old and have been growing consistently at the rate of about one metre a year.
In New Zealand
A Eucalyptus regnans stand in the Orokonui EcosanctuaryOrokonui Ecosanctuary
Orokonui Ecosanctuary, called Te Korowai o Mihiwaka in Māori, is an ecological island wildlife reserve being developed by the Otago Natural History Trust in the Orokonui Valley near Waitati, New Zealand, 20 km to the north of central Dunedin....
near Dunedin
Dunedin
Dunedin is the second-largest city in the South Island of New Zealand, and the principal city of the Otago Region. It is considered to be one of the four main urban centres of New Zealand for historic, cultural, and geographic reasons. Dunedin was the largest city by territorial land area until...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
(where E. regnans is an introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
) contains that country's tallest measured tree.
Uses
Eucalyptus regnans is valued for its timberTimber
Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...
, and has been harvested in very large quantities. Primary uses are sawlogging and woodchipping
Woodchipping
Woodchipping is the act and industry of chipping wood for pulp, processed wood products, and mulch.-Papermaking:Timber is converted to woodchips and sold, primarily, for pulp production used in paper manufacture...
. It was a major source of newsprint
Newsprint
Newsprint is a low-cost, non-archival paper most commonly used to print newspapers, and other publications and advertising material. It usually has an off-white cast and distinctive feel. It is designed for use in printing presses that employ a long web of paper rather than individual sheets of...
in the 20th century. Much of the present woodchip harvest is exported to Japan. While the area of natural stands with large old trees is rapidly decreasing, substantial areas of regrowth exist and it is increasingly grown in plantation
Plantation
A plantation is a long artificially established forest, farm or estate, where crops are grown for sale, often in distant markets rather than for local on-site consumption...
s, the long, straight, fast growing trunks being much more commercially valuable than the old growth timber.
It is a medium weight timber (about 680 kg/m³) and rather coarse (stringy) in texture. Gum veins are common. The wood is easy to work and the grain is straight with long, clear sections without knots. The wood works reasonably well for steam-bending.
Primary uses for sawn wood are furniture, flooring (where its very pale blonde colour is highly prized), panelling, veneer, plywood, window frames, general construction. The wood has sometimes been used for wood wool and cooperage. However, the wood needs steam reconditioning for high value applications, due to a tendency to collapse on drying. This wood is highly regarded by builders, furniture makers and architects.
Conservation
Great controversy surrounds the logging of old-growth Eucalyptus regnans in its natural range in both Victoria and Tasmania. Aside from its symbolic significance as the largest eucalypt of all, Eucalyptus regnans has value to conservationistConservationist
Conservationists are proponents or advocates of conservation. They advocate for the protection of all the species in an ecosystem with a strong focus on the natural environment...
s in provides essential habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
to important birds and mammals (notably the Wedge tailed eagle, the Lyrebird
Lyrebird
A Lyrebird is either of two species of ground-dwelling Australian birds, that form the genus, Menura, and the family Menuridae. They are most notable for their superb ability to mimic natural and artificial sounds from their environment. Lyrebirds have unique plumes of neutral coloured...
and the endangered Victorian state animal emblem Leadbeater's Possum
Leadbeater's Possum
Leadbeater's Possum is an endangered possum restricted to small pockets of remaining old growth mountain ash forests in the central highlands of Victoria north-east of Melbourne...
). In a land of vast, arid plain
Plain
In geography, a plain is land with relatively low relief, that is flat or gently rolling. Prairies and steppes are types of plains, and the archetype for a plain is often thought of as a grassland, but plains in their natural state may also be covered in shrublands, woodland and forest, or...
s and desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
, the contrasting lush fertility of mountain-ash forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
is particularly dear to nature lovers.
Although its status as a species is secure, old-growth forests of Eucalyptus regnans are particularly susceptible to destruction by forestry. For this reason stands of very old and very tall trees exist only in pockets. Very few such stands of trees fall within those areas that have been listed as National Park or World Heritage environments. Most lie within areas controlled by state forestry management authorities and their heritage value is balanced against the commercial value of harvesting and then planting fast-growing and more productive monoculture timber crops on these comparatively well-watered and fertile areas.
In Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
, of the 10,000 hectares of tall-eucalypt forest logged between 1996 an 2006, E. regnans made up more than 1,100 hectares. The trees continue to be logged, most notably by Gunns
Gunns
Gunns Limited is a major forestry enterprise located in Tasmania, Australia. Founded in 1875 by brothers John and Thomas Gunn, it is one of Australia's oldest companies. It has over 900 square kilometres of plantations, mainly eucalyptus trees. It is Tasmania’s largest private land-owner...
, a major forestry enterprise.
Political opposition to the logging of forests by the process known as clearfelling
Clearcutting
Clearcutting, or clearfelling, is a controversial forestry/logging practice in which most or all trees in an area are uniformly cut down. Clearcutting, along with shelterwood and seed tree harvests, is used by foresters to create certain types of forest ecosystems and to promote select species that...
has grown very strong in recent years (particularly in the case of woodchipping), and the extent of future harvesting remains uncertain.
It has long been believed that while many species of eucalyptus successfully survived severe bushfires, forests of Eucalyptus regnans are highly susceptible to destruction by fire. While the process of recovery of most eucalyptus forests is rapid, so that trees that are devoid of leaves may be fully foliaged within two years, in the case of Eucalyptus regnans, the recovery of a forest after a severe fire might require the total regrowth from seed of the devastated area, taking perhaps 200 years or more.
It has been suggested that fire is necessary for the germination of Eucalyptus regnans, and that young Eucalyptus regnans trees flourish best where there is open space, allowing sunlight to penetrate. Prior to European intervention, indigenous land management practices involved controlled burning in order to maintain grassland. This resulted in cleared areas in forests, around the peripheries of which young trees could germinate and grow. It is probable that these indigenous practices were used within forests of Eucalyptus regnans. Cleared spaces also occur naturally in tall forests when an old tree falls, or dies and loses its foliage. These very tall trees do not survive independently of each other, as single trees are more subject to lightning strikes and wind damage.
The natural habitat of the Eucalyptus regnans is in general the areas of Australia with the highest and most reliable precipitation. These areas are less prone to catastrophic fires than other forested areas. Research has indicated that a stand of Mountain Ash in Victoria is actually a multi-age stand due to fire, having experienced seven fires since the 15th century, whereas, since European settlement, many of Australia's Eucalyptus forests have suffered severe fires as often as every 20 years.
Studies conducted in the 20th by T. M. Cunningham and David H. Ashton suggest that the re-growth habit of Eucalyptus regnans requires open space, and an ash layer. For this reason clearfelling (as opposed to selective logging methods) are justified by the timber industry by claiming it is required for the successful germination and growth of seedlings, despite such intense burns not occurring naturally and the cleared land requiring reseeding from seed collected elsewhere. The clearfell process can lead to spectacular and uniform regrowth of commercially viable timber, if managed properly. Those who support clearfelling see it as an ideal method of land management but critics point to the impact of such activities on stream health, water yield of catchments, impacts on threatened forest fauna and flora, long term soil healthy and viability, and the loss of all biodiversity to the harvested area.
In addition to this, opponents of clearfelling point out that the forests survived for centuries without clearfelling and that it takes perhaps 300 years to replace a giant tree, commercially valuable only as woodchip, and therefore designated as "waste" by the harvesters. Opponents of clearfelling point out that the clearfell process was unavailable until the arrival of European settlers (indigenous people practised a mosaic burn system that kept the forest open but didn't remove large amounts of timber).
Half of Victoria's forested water catchment areas, which provides water requiring little treatment, are composed of E. regnans forest. Yields from these catchments fall significantly for 20 to 40 years after disturbance. These areas have an increased risk of bushfire due to smaller trees being more flammable, the risk increasing further with climate change.
Impact on the environment
ABC News reported on 17 June 2009 that a study has been carried out by environmental scientist Professor Brendan Mackey of the Australian National UniversityAustralian National University
The Australian National University is a teaching and research university located in the Australian capital, Canberra.As of 2009, the ANU employs 3,945 administrative staff who teach approximately 10,000 undergraduates, and 7,500 postgraduate students...
which identified that mountain ash forests in Victoria’s Central Highlands as the best in the world at locking up carbon.
Mackey and colleagues found the highest amount of carbon was contained in a forest located in Victoria’s Central Highlands, which held 1900 tonnes of carbon per hectare.
This most “carbon-dense” forest was a stand of unlogged mountain ash over 100 years old. Mountain ash live for at least 350 years, according to Mackey.
See also
- Eucalyptus delegatensisEucalyptus delegatensisEucalyptus delegatensis, commonly known as Alpine Ash or Gum-topped stringybark or White-top, is a sub-alpine or temperate tree of southeastern Australia. A straight, grey-trunked tree, it reaches heights of over 90 metres in suitable conditions. The tallest currently known specimen is located in...
- Eucalyptus globulusEucalyptus globulusThe Tasmanian Blue Gum, Southern Blue Gum or Blue Gum, is an evergreen tree, one of the most widely cultivated trees native to Australia. They typically grow from 30 to 55 m tall. The tallest currently known specimen in Tasmania is 90.7 m tall...
- Manna GumManna GumEucalyptus viminalis, Manna Gum, also known as White Gum, Ribbon Gum or Viminalis is an Australian eucalypt.It is a straight erect tree, often around 40 metres tall, with rough bark on the trunk and base of larger branches, its upper bark peels away in long "ribbons" which can collect on the...
- For other trees named Mountain Ash, see Mountain ashMountain AshMountain Ash is a name used for several trees, none of immediate relation. It may refer to:* Eucalyptus regnans, the tallest of all flowering plants and other floral species* Fraxinus texensis, an ash tree species in Texas...
External links
- Prof Stephen Sillett's webpage with photos taken during canopy researchCanopy researchCanopy research is the field of scientific research based upon data collected in the canopy of trees.-Objects:* Description of plant and animal species residing in the tree-summits. Mainly ancient forests and tropical forests are studied....
. - Website dedicated to Eucalyptus regnans