Centurion tree – the tallest eucalyptus

Forests in Tasmania contain some of the highest, mightiest and also oldest trees of the world.

Discovery of the tallest eucalyptus tree

Any tree in the Tasmanian state forest, which exceeds the fantastic 85-meter height and/ or 280 cubic meters of volume, has to be registered and protected (5.).

These rules are implemented by the government agency “Sustainable Timber Tasmania” which earlier was named “Forestry Tasmania”. Like most of the world’s state forestries, Sustainable Timber Tasmania has to act as a protector of the forest and at the same time: get profit out of the forest.

In August 2008 Forestry Tasmania staff were using their state-of-the-art airborne equipment for the mapping and assessment of the values of commercial forests in the Arve River basin. This was a comparatively early use of LiDAR laser equipment (light detection and ranging) for 3D mapping of the land surface. When mapping a forest, LiDAR shows both the surface of trees and land level thus helping to assess the amount of wood in between.

Later, when looking through the data collected by LiDAR, employees Mayo Kajitani and David Mannes noticed two previously unknown very tall trees standing close together. Both trees exceeded the height of 85 meters and one was even some 99 meters high. As LiDAR tends to underestimate tree height, foresters thought that the tree might be even 101 meters high.

This was a sensation: nowadays only coast redwoods (Sequoia sempervirens), Sitka spruce (Picea sitchensis) in California, as well as yellow meranti in Sabah (Malaysia) (discovered in 2019) exceed 100-meter height. One more tree species – coast Douglas fir has a very similar height – 99.75 m.

Australia’s historical record trees

Many reports tell about taller eucalypts from earlier times in Victoria. Some even claim heights that exceed 150 meters but most of these reports are not credible enough.

Genus of eucalypts include approximately 700 species and eucalypts belong to the largest trees of planet in any respect – girth of largest trees might exceed 20 metres and the volume of trunk – 350 m³.

Still, specialists consider that eucalypts theoretically can exceed even 110-meter height. Maximum historical heights of trees in Tasmania are less impressive: two blue gums (E.globulus) in 1906 were 101 meters high.

Before the discovery of 2008 the tallest eucalyptus tree and the tallest tree in Australia was swamp gum (Eucalyptus regnans) “Icarus Dream” in Andromeda Reserve, Tasmania. The measured height of this tree in 2005 was the fantastic 97 m. This tree has a dead top and, most likely, is less tall by now.

Ground measurements of Centurion tree

Soon after foresters inspected both trees from the ground with laser rangefinders. Both of them turned out to be swamp gums (Eucalyptus regnans).

The top of the highest tree was hidden in the canopy and only approximate measurements were possible. They assumed that the tree is at least 101 meters high, its age is around 400 years, (4.) the diameter was 4.05 meters (5.).

David Mannes later explained that he was saving the name “Centurion” for the 100th giant tree of Tasmania but he never expected that the hundredth tree would also exceed 100 meters in height. This name has a root "centum" meaning in Latin "hundred".

The other giant tree was named Triarius, 86.5 meters tall and with a diameter of 3.90 m (1.).

Later tree climbers Greenwood and Mifsud (1.) made more exact measurements. The results caused some disappointment: Centurion tree was below the 100-meter height: 99.6 meters. Later measurements slightly increased the height of the tree – 99.8 m and in 2016 again a bit less – 99.67 m. Then in March 2017, the next measurement gave a height of 99.82 m (8.).

Tree climbers also reported that the crown is healthy and is resprouting from the broken top, thus some time ago it was some 103 meters high.

One more measurement (in fact, 300 measurements) with a laser rangefinder in December 2018 (The Tree Projects and Giant Tree Expeditions) gave a result of 100.5. In April 2019 Mr. Brett Mifsud made additional measurements with laser equipment from the ground and his results gave an estimated height of 101 m! (10.)

But… official registration of this record needs a measurement with tape. Wondermondo is waiting for the news…

Troubled forest

Discovered forest giants were located in a non-protected state forest but immediately were included in the list of protected trees.

This is a lucky coincidence that Centurion has survived. Wildfires in 1934 spared just a few older trees in this area and passed on the west side. In 1950 there was logging nearby and at that time this giant tree would not be spared. In 1966 and 1967 the forest close nearby was deliberately burned for later regeneration, in 1967 this turned into furious, devastating fires. This time fire passed the tree on the east side (5.).

These fires were a reason why the forest around the giants was not old-growth and thus – not protected. It was not expected to find any tall trees in this area.

Unfortunately, the beautiful forest has been cut close to the tree – there is a clear-cut some 200 m from the Centurion.

The tree was in great danger once more in January 2019, during a great forest fire. It suffered burns but seems to live. (9.)

References

1. Giant Trees. Tasmania’s world class giants.
2. New series of Going Bush screens Sundays at 5.30pm Forestry Tasmania. Accessed 03.01.10.
3. The world’s tallest hardwood tree. Australian Forest Grower, winter 2009. Accessed 03.01.10.
4. Technology aids in record-breaking tree discovery. International Forest Industries, August 2009. Accessed 03.01.10.
5. Welcome to the Centurion! Forestry Tasmania, 10 Oct 2008. Accessed 03.01.10.
6. New series of Going Bush screens Sundays at 5.30pm Forestry Tasmania. Accessed 03.01.10.
7. Facebook report from The Tree Projects, 10.12.2018. Accessed 09.05.19.
8. Australia’s Champion Trees, National Register of Big Trees. Accessed on 4th July 2019.
9. Centurion still standing tall, press release by Sustainable Timber Tasmania, 22.02.2019. Accessed on 3rd December 2019.
10. native Tree Society BBS Forum. Accessed on 4th December 2019.

Centurion tree is included in the following articles and lists: