baumzaehlen - Primeval Forests & Their Trees

Styx Tall Trees Forest Reserve, Tasmania, Australia

This small (3 km ² ) reserve – also called Andromeda Reserve – is located in Tasmania’s Styx Valley at an elevation of about 400 metres. In 2013, it was added to the Tasmanian Wilderness World Heritage Site.  It is not untouched - some stumps can be seen. However, it is the tallest broadleaf forest in the world, with 12 Eucalyptus regnans (mountain ash) individuals of at least 90 metres, the tallest reaching 97 metres. The only taller specimen is a single isolated individual reaching 99.8 m found to the south of Hobart, Tasmania. ¹ However, the Andromeda stand is senescing and most of the tallest mighty trees already have dead tops. The stand mostly regenerated in about 1710 after a wildfire which burned the whole former forest apart from two trees, which are still 150 years older ² . E. regnans forests have the highest fire intensities of any vegetation type in Australia ³ , but species regeneration is dependent on these infrequent stand-replacing wildfires ⁴ , which kill the trees and undergrowth but also release seeds from the woody capsules in the E. regnans canopy, to initiate a new generation ⁵ . Unlike most Eucalyptus species, E. regnans cannot regenerate vegetatively, which allows it to grow more rapidly because it does not invest in protective bark and storage organs ⁶ . The photosynthetic bark of E. regnans may also contribute to the extremely rapid growth ⁷ .

In addition to E. regnans the canopy layer also has E. delegatensis (alpine ash). The canopy is very open so the understory is dense and difficult for walking. There are no trails. Tree identification is fairly easy.

References:

1 http://gianttrees.com.au/

2 Hickey, Kostoglou & Sargison (2000): Tasmania ’s tallest trees. Tasforests Vol. 12.

3 McCarthy, M. A., Gill, A. M. & Lindenmayer , D. B. (1999): Fire regimes in mountain ash forest: evidence from forest age structure, extinction models and wildlife habitat. Forest Ecology and Management 124 : 193–203.

4 Jackson , W. D. & Brown, M. J. (2005): Pattern and Process in the Vegetation. In Reid, B., Hill, R., Brown, M. & Hovenden, M. (eds.): Vegetation of Tasmania , pp. 11–38. Australian Government, Canberra.

5 Gill, A. M. (1997): Eucalypts and fires: interdependent or independent? In Williams, J. & Woinarski, J. (eds.): Eucalypt ecology, Individuals to ecosystems , pp. 151-167. Cambridge University Press.

6 Tng, D. Y. P., Williamson, G. J., Jordan, G. J. & Bowman, D. M. J. S. (2012): Giant eucalypts – globally unique fire-adapted rain-forest trees? New Phytologist 196 : 1001–14.

7 Sillett, Van Pelt, Koch, Ambrose, Carroll, Antoine & Mifsud (2010): Increasing wood production through old age in tall trees. Forest Ecology and Management 259 : 976–994.