Norfolkian Araucaria Forest

These forests, dominated by the endemic Araucaria heterophylla (Araucariaceae), are thought to have originally covered all of the islands of this BioProvince. Usually seen emerging from the canopy, Araucaria is a giant of a tree reaching heights of up to 60 m. Associated trees included endemic species like Dysoxylum patersonianum (Meliaceae), Meryta angustifolia (Araliaceae), the Norfolk palm Rhopalostylis baureri (Arecaceae) and two giant tree ferns Cyathea brownii and C. austalis subsp. norfolkensis (Cyatheaceae), while the smaller trees and shrubs included endemics such as Alyxia gynopogon (Apocynaceae), Boehmeria australis (Urticaceae) and Coprosma pilosa (Rubiaceae). Among the lianas and climbers the endemic Capparis nobilis (Capparidaceae), Freycinetia baueriana (Pandanaceae) and Melodinus baueri (Araliaceae) frequently occur in the upper branches, while the many epiphytic species included the ancient endemic pteridophyte Tmesipteris forsteri (Tmesipteridaceae), which only grows on the trunks of tree ferns, and several endemic orchids such as Bulbophyllum argyropus, Dendrobium brachypus and Phreatia limenophylax (Orchidaceae). The ground flora is particularly rich in ferns including the magnificent king fern Marrattia salicina and various endemic species such as Asplenium dimorphum (Aspleniaceae) and Blechnum norfolkianum (Blechnaceae). However, today only remnants of these forests can found mainly in the Norfolk Island National Park in the Mount Pitt area. On the volcanic, Philip Island, Araucaria once dominated the lower slopes, but today it is reduced to a few scattered trees, while other remaining trees include the endemic Myoporum obscurum (Myoporaceae). Two other woody species, the spinose Hibiscus insularis (Malvaceae) and the pinnately leaved vine Streblorrhiza speciosa (Fabaceae) are unique to this island, but the latter has not been seen for over a century. On the limestone island of Nepean, the forests were decimated primarily by the introduction of domestic stock, but there remain a few prostrated stands of white oak (Lagunaria), while other associated species include the endemic Senecio evansianus (Asteraceae).

 

Norfolkian Coastal Vegetation

Phornium tenax (New Zealand flax) still dominates some of the exposed coastal slopes as seen by Captain Cook when he first discovered the island in 1774. Other native species found on these slopes include the herb Lobelia anceps and several endemic species such as the liliaceous tree Cordyline objecta (Liliaceae) and the shrub Euphorbia norfolkiana (Euphorbiaceae). On the sandy beachs of the south coast (Hunter’s Point) fleshy, creeping herbs of the family Aizoaceae, such as Tetragonia implexicoma, predominate, together with woody plants like the ground-appressed Lagunaria patersonia. Lord Howe Island also shows this preponderance of beach dwelling Aizoaceae. This is different from the beach vegetation of most tropical Pacific islands, which typically support species of Ipomoea, Scaevola and Tournefortia.

Further information required.

 

References

Adam, P. 1992. Australian Rainforests. Clarendon Press, Oxford.

Balgooy, Van. M. M. J. 1960. Preliminary plant geographical analysis of the Pacific. Blumea, 10: 385-430.

Balgooy, Van. M. M. J. 1969. A study of the diversity of island floras. Blumea, 17: 139-178.

Green, P. S. 1979. Observations on the phytogeography of New Hebrides, Lord Howe Island and Norfolk Island. In: Plants and Islands. Ed. D. Bramwell. Academic Press.

Lange, P. J. de., Gardner, R. O., Sykes, W. R., Crowcroft, G. M., Cameron, E. K., Stalker, F., M. L. & Braggins, J. E. 2005. Vascular flora of Norfolk Island: some additions and taxonomic notes. New Zealand Journal of Botany, 43: 563-596.

Mueller-Dombois, D. & Fosberg, F. R. 1998. Vegetation of the Tropical Pacific Islands. Springer.

Turner, A. J., Smithers, C. N. & Hoogland, R. D. 1975. The conservation of Norfolk Island. Australian Conservation Foundation, Inc. Victoria. Special Publication No. 1.