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Giant eucalypts found in ... Europe!

Dean Nicolle
Currency Creek Arboretum
europes-giant-trees
Ever since seeing the inspiring red tingle (Eucalyptus jacksonii) trees in the far south-west of Western Australia as an eight-year old, I have been fascinated by the biggest and tallest trees of different species. And like all eucalypt-obsessed Australians (I assume there are many!), I like to claim that the tallest tree ever was a 130+ metre mountain ash (E. regnans) felled in Victoria sometime in the 1800s, even if the actual evidence for such a giant is scant.

But even if the tallest contemporary tree species is a non-eucalypt - the redwoods (Sequoia sempervirens; a non-flowering softwood up to 115 m tall) of the west coast of North America, we gum nuts can still brag about having the tallest ‘hardwood’ species, the tallest ‘flowering plant’, and the tallest tree in Australia (all applicable to the 99 m “Centurion" E. regnans in Tasmania - visit Tasmania's giant tree register). But that’s not enough for me…

While visiting my partner Annett in Germany in November 2010, I thought we should take the opportunity to see some eucalypts in southern Europe. There are ample data on big trees (‘big’ being variously defined) but few data on tall trees. Web-based searching led me to the web pages of Gustavo Iglesias (Eucalyptologics & GIT Forestry), where two potentially tall trees were highlighted – the ‘Grandfather Tree’ in Spain and the ‘Karri Knight’ in Portugal. What followed was a rapid-fire five day field trip with Gustavo, chasing eucalypts along the Atlantic coast of these two countries.

The five days with Gustavo were at times chaotic (in a Spanish sort of way!) but highly productive. We recorded over 40 different eucalypt species, including a number of species which are either naturally rare or poorly known in cultivation in Australia. But the highlights were the tall eucalypts (see Table 1), including:

1) The opportunistic find (following on from earlier research by Gustavo) of a massive E. regnans (mountain ash) in Portugal measuring about 65 metres tall and 2.66 metres diameter at breast height;

2) Stands of E. globulus (Tasmanian blue gum) near Viveiro in Spain with trees at least 68 metres tall, and including the ‘Grandfather Tree’;

3) The Vale de Canas (near Coimbra in Portugal) where, despite being devastated by fire a couple of years ago, there were several eucalypt species greater than 65 metres tall, including the ‘Karri Knight’, a lone Eucalyptus diversicolor (karri) in a forest of other eucalypt species.

Using a laser hypsometer, we made about 50 measurements of the ‘Karri Knight’, using different methods and from different positions. A height of 72 metres (accurate to within 0.5 m) was established, making this tree the tallest measured tree in Europe west of the Caucasus Mountains.

Interestingly, immediately adjacent to the Karri Knight was a planted Araucaria bidwillii (Bunya pine), with a height of 50 metres, making it taller than any measured indigenous Bunya pines from Queensland, Australia.

So it now appears that the tallest measured tree in each of Australia, Europe and Africa are eucalypts (and each a different species – E. regnans, E. diversicolor and E. saligna respectively; see Table 2). Tall-tree height data are virtually unknown in South America, and are poorly verified in Asia proper (see Table 3), so it remains to be seen if we can add eucalypts as tallest trees for these continents also.

Note:
On a more local level, a National Register of Big Trees in Australia has recently been established by Derek McIntosh of Sydney (see http://nationalregisterofbigtrees.com.au/). While this web-based database aims to document ‘big’ rather than tall trees, many of Australia’s tallest trees can be found listed on the database. With the aid of the laser hypsometer that Derek has kindly lent me, I have nominated and measured many big and tall trees; however, as the project is in its infancy, there is still a paucity of data in many regions and for many species. In particular, there are very few data on tall trees in Queensland and the Northern Territory (see Table 2).

I would be most pleased to receive any nominations of potentially big or tall trees (for any species), which I would endeavour to measure and document, with due acknowledgement to the nominator. If you know of a tree that potentially is taller than those listed in Tables 2 and 3, drop me an email at dn@dn.com.au.


Images, from top to bottom:

1. The white-trunked tree at the Vale de Cana near Coimbra in Portugal is the tallest measured tree in Europe – a Eucalyptus diversicolor (karri) known as “Karri Knight”, with a height of 72 metres measured using a laser hypsometre. Immediately adjacent is a tall Araucaria bidwillii (Bunya pine) with a height of 50 metres. Surrounding these trees are other tall specimens of E. viminalis, E. globulus, E. obliqua and E. regnans, representatives of each measuring over 60 metres tall. All these species are naturally indigenous to Australia.

2.  The measurement team are (left to right) Paulo Ferreira (University of Coimbra), Gustavo Iglesias (GIT Forestry), Dean Nicolle, Annett Börner (Max Plank Institute for Biogeochemistry), Yolanda Fernandez (Ence) and Miguel Cogolludo (Ence).

3. Our Spanish Eucalyptologist (gum nut) colleague and local guide Gustavo Iglesias relaxes at the base of the 72 m tall karri (tallest measured tree in Europe). The small diameter of the tree relative to its height, is indicative of its relative youth (about 120 years old).

4. Dean Nicolle and Gustavo Iglesias identify other potentially tall trees in the Vale de Cana near Coimbra in Portugal.

5. Annett Börner appears gnome-like when standing between the “King Regnans” and twin redwoods at Bussaco, near Luso in Portugal. The “King Regnans”, a Eucalyptus regnans named as such following its serendipitous discovery by Gustavo Iglesias on this field trip, is 64.5 (+/- 1) metres tall , while the tallest of the twin redwoods in the background (also exotic to the region) is 52 metres tall.

6. Dean Nicolle and Annett Börner measure the diameter of the “King Regnans”. Diameter at breast height is 2.66 m. This tree had the greatest diameter of the eucalypts we measured in Spain and Portugal. Note the autumnal oak leaves littering the ground at the base of the tree.

7. Annett Börner stands next to twin Eucalyptus cornuta (yate) trees on the Vilagarcia foreshore in Spain. (Height, 31.5 metres; diameter at breast height, 1.24 metres.) This species is native to south-western Western Australia, where it rarely reaches such proportions. This public park also contained a number of other eucalypt species including Corymbia calophylla (marri), C. variegata (northern spotted gum), E. amplifolia (cabbage gum), E. melliodora (yellow box), E. rudis (flooded gum) and E. tenuramis (silver peppermint).


Figure 8. “El Abuelo” (“Grandfather Tree”), a 65 metre-tall Eucalyptus globulus adjacent to El Landro (river), near Viveiro in Spain. Certainly the most famous eucalypt in Spain, where it grows in a forest of younger trees of the same species, some of which are taller. Note the indigenous Abies (fir) and Quercus (oak) growing under the towering eucalypts.

Figure 9. A typical forest-grown Eucalyptus viminalis in Pontevedra, Spain. Rapid growth rates and branch-free cylindrical trunks are typical of plantation eucalypts in Spain and Portugal.

 Biobuzz issue fourteen, May 2011