New Caledonia — Refuge for the last dinosaurs on earth
by Mirco Berenbrinker
On the 18th of August 2000, one Kew Diploma student set out on a journey that would take more than a month to complete — the destination being the Pacific islands of New Caledonia.
Located about 1500km off the Australian east coast, this small archipelago lies just north of the Tropic of Capricorn. New Caledonia encompasses five islands: the main island “Calliou” or Grande Terre, the Isle of Pines, and the three Loyalty Islands of Lifou, Mare and Ouvéa. A number of small, uninhabited coral islets form part of the archipelago. They belong to the great coral reef that surrounds the whole of the main island at distances of 5 to 20km from the coast. New Caledonia’s Great Reef (Grande Récif) is second in size only to the Great Barrier Reef of Eastern Australia, and I had one day of snorkelling in the lagoon to view and photograph the marine flora as part of the original Travel Scholarship proposal. Grande Terre, at a length of 400 km and a maximum width of 50 km, is quite reminiscent of Israel I size and shape. New Caledonia is a French overseas territory, hence the national language is French. The capital is Nouméa, which is located in the southwestern part of the main island.
Grande Terre itself and also the small Isle of Pines at its southern tip, are of major interest for plant life, due to their ultramafic soils derived from peridotite oceanic crust. These soils are red, with high iron levels and also contain high amounts of nickel and chrome. During the Earth’s history, large parts of New Caledonia were submerged for certain periods and only the schist mountaintops of the northern mountains remained exposed. Most of the vegetation survived there. After the retreat of the ocean, plants from the north re-colonised the peridotite soils. They had to develop a large variety of adaptations to cope with the extreme soil conditions, as well as with drought and high winds up in the mountains. The plant communities that have evolved on the peridotite were the main targets of the Travel Scholarship. Plants include many endemic species that often only occur on a single mountain. The major plant groups are the gymnosperms, the orchids, the palms, and the mosses and ferns. The plant families of Cunnoniaceae and Epacridaceae are quite predominant.
Botanists identify some of the mountain habitats of New Caledonia as most reminiscent of the Earth’s flora as its existed during the Cretaceous Era, 65-144 million years ago. Indeed, the moist and often foggy conifer communities explored by the recipient seem like time capsules that transfer the visitor back to a time long gone. Dense moss and fern covers on the spongy ground and on tree trunks further add to this effect.
The original focus of the Travel Scholarship was on gymnosperms, especially on the Araucariaceae, the monkey-puzzle family. The family includes the genera Araucaria, `Agathis‘ and the recently discovered Australian genus Wollemia. Sixteen of the ten known species of Araucaria grow on New Caledonia, 13 of which are endemic! All of those 13 species were viewed and basically described by the author at the herbarium of the Institut de Recherche pour le Development (IRD) in Nouméa. The author’s contact there was Dr. Tanguy Jaffré, Head of the Botany Department, who was extremely helpful and co-operative in giving advice and organising the necessary permits to visit certain nature reserves.
Accommodation and subsistence were generously provided by a nurseryman in the village of Palta, 12 kilometres north of Noumea. The connection was made through the Palmengarten in Frankfurt, Germany. Main field trips undertaken by the author are listed below. As described above, the main target areas for field trips were in the south of the archipelago, especially in the mountains: Mount Mou; Mount Dzumac; Mount Humbolt; Territorial Park of the Riviere Bleue (Blue River); Plaine des Lacs (Plain of Lakes) and Madeleine River, Montagne des Source (Mountains of Springs); and Isle of Pines.
Apart from a few exceptions, all the plants that I aimed to find and study were actually discovered and photographed. These plants include:
Parasitaxus ustus (Podocarpaceae), the only known (semi)parasitic conifer on Earth.
Xeronema moorei (Liliaceae), `New Caledonia Poor Knight’s Lily’, a plant with iris-like foliage and a bright red, horizontal “toothbrush” flower.
Dacrydium guillauminii (Podocarpaceae), named as the rarest conifer on Earth by Dr. Stephen Schneckenburger, Darmstadt Botanical Garden (ex Frankfurt).
Neocallitropsis pancheri (Podocarpaceae), a conifer that is equally rare, growing in the Plain of Lakes.
Actinokentia divaricata (Arecaceae), a palm that produces the most outstanding juvenile foliage which shines bright red amongst dense rainforest vegetation.
Blechnum franckii (Blechnaceae), unfortunately not seen in its wild habitat, but a dried herbarium specimen at the IRD made up for the loss.