New Caledonia

Porter P. Lowry II²⁶, Jérôme Munzinger³³, Philippe Bouchet³⁴, Hubert Géraux³⁵, Aaron Bauer³⁶, Olivier Langrand¹ and Russell A. Mittermeier¹

New Caledonia is one of the smallest of the hotspots, and has some of the highest levels of endemism, especially in plants. It lies at the southern extremity of the Melanesian Region, some 1 200 km east of Queensland, Australia and 1 700 km northeast of New Zealand. Until recently, New Caledonia was classified as a French Overseas Territory, but is now in the process of becoming an Overseas Country (“Pays d'Outre-Mer”) with substantial political autonomy that stops short of full independence.

Unlike the nearby island nations of the East Melanesian Islands Hotspot, which are of volcanic origin, the main island of New Caledonia, Grande Terre (16 595 km²), was once part of the great ancient continent of Gondwana, from which it became separated 65-80 million years ago. Of more recent origin are the 1 600-km long reef (second in the world) that encircles Grande Terre and the raised limestone Loyalty Islands to the east (Ouvéa, Lifou, Tiga, and Maré, plus a few uninhabited islands). The hotspot includes the Belep Islands to the north of Grande Terre, and the Isle of Pines, immediately south. The Chesterfield Islands further to the west, and the uninhabited volcanic islands of Matthew and Hunter to the east, are politically dependent on New Caledonia and also included here, although their value for terrestrial biodiversity conservation is limited. The total land area of New Caledonia, therefore, comes to 18 972 km².

Despite its small size, New Caledonia is biologically very diverse and, like the other hotspots that are also pieces of Gondwana (Madagascar and New Zealand), has very high levels of endemism, both at species and higher levels, especially among plants and invertebrates. Plant diversity and endemism are truly outstanding in global terms, with 3 270 vascular plant species, of which 2 432 species (74.4%) are endemic. These are in 808 genera, of which 108 (13.4%) are endemic (updated from Jaffré et al. 2001). Furthermore, there are five endemic families – Amborellaceae, Paracryphiaceae, Strasburgeriaceae, Oncothecaceae, and Phellinaceae (Morat 1993; Jaffré et al. 2001)–, a truly amazing number for such a small area and exceeded only by Madagascar and the Cape Floristic Region of South Africa. Conservative estimates suggest that as much as 5% of the vascular plants in New Caledonia remain undescribed, which would bring the total to more than 3 400 species (Lowry 1998).

The flora occurs in four main natural vegetation types, namely humid evergreen forest, sclerophyllous forest, low- to mid-altitude maquis and high-altitude maquis formations. Grassland and niaouli (Melaleuca quinquenervia) savanna today occupy more than 6 000 km² or 32% of the area, and are often mistaken by visitors and residents as the typical landscape of New Caledonia. These are, in fact, highly disturbed anthropogenic formations that are maintained by repeated fire and grazing by cattle and introduced deer; the niaouli, an invasive, non-endemic (and possibly even non-native) eucalypt, has a thick, papery bark that makes it resistant to fire.

Humid evergreen forest once covered some 70% of the territory, or more than 13 000 km², but has now been reduced to only about 4 000 km². Around 2 012 plant species are found in the rainforest, of which 82.2% are endemic, making it the richest of New Caledonia's vegetation types (Jaffré et al. 1998, 2001). Sclerophyll forest once covered about 23% of New Caledonia, or more than 4 400 km²; however, it has now been drastically reduced to just 45 km² (Bouchet et al. 1995; Jaffré et al. 1998; H. Géraux, unpubl.), making sclerophyll forest the most threatened vegetation type in the territory. Even what little remains is generally very degraded and fragmented into small patches of 20–30 ha or less (though there are a few blocks that exceed 100 ha), surrounded by agricultural land. A recent study suggests that New Caledonia's sclerophyll forest is the most threatened tropical dry forest in the world (Gillespie and Jaffré 2003). Sclerophyll forest is not as rich as humid evergreen forest or maquis, but nonetheless contains numerous endemic species; some 456 plant species have been recorded from this forest type (57.5% endemic) ((Jaffré et al. 1998, 2001).

New Caledonia's unusual maquis is a specialized edaphic formation that is now the most extensive vegetation type in the territory. High-altitude maquis is very limited, but still occupies almost all of its original extent of 100 km². Some 200 plant species occur in highaltitude maquis, of which 91% are endemic to New Caledonia. In contrast, low- to mid-altitude maquis is now the most extensive natural formation in the country. It once occupied only about 5% of the country, but has now expanded, largely as a result of fire disturbance, to cover some 4 400 km², or 23% of New Caledonia. Some 1 144 plant species occur in this kind of maquis (89% endemic) (Jaffré et al. 1998).

Certain plant groups in New Caledonia are particularly exceptional: of 44 gymnosperm species, 43 are endemic, including 13 endemic species of Araucaria, an ancient group of Gondwanaland gymnosperms, of which there are only 19 worldwide (Setoguchi et al. 1998) and the world's only parasitic gymnosperm, Parasitaxus ustus. The territory also has 31 endemic species of palms, representing 15 endemic genera out of a total of 16 (Hodel and Pintaud 1998). Furthermore, New Caledonia is home to the endemic, monotypic family Amborellaceae, which comprises a single species, Amborella trichopoda, recently shown to represent the basal-most branch in the evolutionary tree of the flowering plants (see, for example, Mathews and Donoghue 1999; Qui et al. 1999). Given the uniqueness and age of New Caledonia's flora, the region has been classified as a distinct phytogeographic province (Morat et al. 1984), or placed in its own floristic entity, the Neocaledonian Subkingdom, by Takhtajan (1986).

In terms of animals, New Caledonia only has nine native land mammal species, all of them bats, six of which are endemic to the island, including a new species of long-eared bat (Nyctophilus nebulosus) recently described from Nouméa (Parnaby 2002). Native amphibians are entirely absent. However, what the territory lacks in these groups, it makes up for in birds, lizards, and invertebrates. Twenty-three of the 105 native species of birds that occur regularly in the New Caledonia region are endemic, and New Caledonia is considered an Endemic Bird Area by BirdLife International (Stattersfield et al. 1998). The native species are grouped in some 65 genera, of which three are endemic. Two are endemic monotypic genera (Rhynochetos and Drepanoptila), with the kagu (Rhynochetos jubatus, EN) being the only representative of an endemic family, Rhynochetidae; the third endemic genus (Eunymphicus) is represented by only two species.

The reptile fauna of New Caledonia is exceptionally rich at the species level, but only moderately diverse at the family level: there are a total of 70 terrestrial species (with at least 42 more as yet undescribed), nearly all of them lizards in two families of geckos and one family of skinks; the only native terrestrial snakes are a blind burrowing species (Ramphotyphlops willeyi) of the family Typhlopidae and the Pacific boa (Candoia bibroni), both restricted to the Loyalty Islands (Bauer and Sadlier 2000; Sadlier et al. 2002). Sixty-two species (or 89% of the terrestrial reptile fauna) and 11 of the 23 genera are endemic. Most New Caledonian reptiles exhibit patterns of micro-endemism and are restricted to small geographic ranges. The lizards include the largest extant species of gecko in the world, Rhacodactylus leachianus. In the marine habitats surrounding New Caledonia at least 14 sea snakes and three sea turtles occur.

The hotspot has a small inland fish fauna consisting of 85 species (only nine endemic) in 49 genera. The fauna is dominated by euryhaline species that commonly occur in marine, brackish or freshwater habitats and are generally widely distributed among islands of the tropical Western Pacific. The most notable element is perhaps the endemic galaxiid Galaxias neocaledonicus, the northernmost representative of a group that is mostly restricted to the southern tips of New Zealand, Australia, South America, and Africa. A single genus is endemic, Protogobius. Among the freshwater crabs and shrimps, 10 of the 33 native species are also endemic (and four more await description). The lake system on the Plaine des Lacs (Grand Lac and Lac en Huit) in the south of the main island has endemic genera of fishes, snails, and crustaceans.

The New Caledonian invertebrate fauna, like that of most Pacific islands, has many land snails, including an exceptional number of endemics. There are currently approximately 200 described native species (although there may be as many as 400–600 species), all of which are endemic, with many endemic genera as well. The genus Placostylus, locally known as bulime, is among the largest land snails in the South Pacific, and shows an interesting disjunct distribution with Lord Howe Island, northern New Zealand, and Fiji.

Some 4 000 insect species have been catalogued to date, and again these show high endemism at the species and genus levels (Chazeau 1993); with new species constantly being added to the inventory (e.g., Najt and Grandcolas 2002), the total insect fauna is projected to be between 8 000 and 20 000 species (J. Chazeau, pers. comm.). There are more than 70 native species of butterflies, of which at least 11 species and two genera are endemic (Holloway and Peters 1976), along with more than 300 species of moths (A. Renevier, pers. comm.), and there are 16 species of tiger beetles, 15 of which are endemic (D. Pearson, pers. comm.). Among the true spiders, 194 species have so far been recognized (Platnick 1993); New Caledonia has the only family of spiders endemic to a single island, the Bradystichidae.

The geological history that resulted in such an unusual array of organisms also created one of the world's largest known deposits of nickel. Mining for nickel forms the foundation of New Caledonia's economy, the industry representing some 90% of the territory's foreign exchange. The mining is open-cast, and until recently was largely unregulated, which resulted in an exceptionally high degree of erosion that has devastated large areas. Today, open-cast mining, while still destructive, is better managed and more localized, and more serious threats to the biodiversity include bush fires, conversion to agriculture, and the introduction of alien species.

There are now 772 exotic plant species established in New Caledonia, many of which compete with the local flora. In addition, faunal species have been introduced and are now widespread on the island, constituting a real threat to the local fauna and flora. These include 24 gastropod species, 400 insect species, six freshwater fish species, one amphibian species, two reptile species, 13 bird species, and 12 mammal species (Gargominy 2003). The most serious of these introductions, with regard to environmental impact, are probably the Indonesian deer (Cervus timorensis) and the fire ant (Wasmannia auropunctata). Hunting (New Caledonian imperial pigeons, flying foxes) and selective illegal collecting of animals (reptiles, parrots) and plants (palms, orchids) represent additional threats.

Logging is less of a threat today than in times past, but about 3%-5% of the area of humid evergreen forest was cleared in the 1970s and 1980s (Morat et al. 1995) and several new logging concessions have recently been awarded in the Northern Province. The remaining humid forest is mainly on public land, whereas for sclerophyllous forest, 44% is in private holdings and 2% in indigenous tribal areas, with only 54% on public land. Remaining terrestrial habitat in more or less pristine condition includes about 3 900 km² of humid evergreen forest, only 45 km² of sclerophyll forest, ca. 100 km² of high-altitude maquis (nearly its full original extent), and about 1 000 km² of pristine to lightly impacted low- to mid-altitude maquis, for a total of ca. 5 050 km², or 27% of New Caledonia's land area.

At present, the World Database on Protected Areas includes for this hotspot a protected area network covering 22% of its land area, although, remarkably, the 24 reserves classed in IUCN categories I to IV cover only 3% of the hotspot. Regional information suggests that officially, New Caledonia has a protected area network of 46 reserves covering 1 070 km² (5.6% of the land area) in IUCN categories I to IV, and an additional two in categories V and VI, as well as three parks now being established in the Southern Province that will include a further 570 km². However, a review of the effectiveness of these reserves in protecting New Caledonia's amazing plant diversity (Jaffré et al. 1998), in particular the 25% of endemic plants that are considered to be at risk, indicated that 83% of the threatened species did not occur in any protected areas and that only 11% had their conservation status improved by these reserves (most of which lack staff and an adequate management plan).

Procuring the necessary resources to carry out biodiversity conservation is hampered by the fact that multilateral and bilateral funding agencies will not support programs in New Caledonia because it is a political dependency of a wealthy country. While the French Government in Paris is solely responsible for international relations (including conventions and treaties such as the Convention on Biological Diversity), natural resource management lies exclusively with the provincial governments. Because of this divided responsibility, the French Government has not regarded New Caledonia as a high priority for action, although it is currently developing a National Biodiversity Strategy and Action Plan in which New Caledonia is considered as a top priority. The local governments have focused their attention primarily on environmental policy, with some efforts being made recently in the area of biodiversity protection.

Aside from local government initiatives, a small number of New Caledonian residents have recognized the conservation imperative. The Nouméa-based ASNNC (Association pour la Sauvegarde de la Nature Neo-Calédonienne, or Association for the Protection of New Caledonian Nature), the oldest group in the territory, has spent three decades promoting conservation in New Caledonia, with particular emphasis on environmental education and studies of flagship species such as the kagu and sea turtles. More recently, international NGOs have also become involved in New Caledonia. WWF has worked since 1997 with local partners to implement a sclerophyllous forest conservation program. Conservation International has supported the Maruia Society's effort to implement local conservation in the Mt. Panié massif, and BirdLife International is starting a two-year IBA assessment. Clearly, as is the case for several other hotspots, an immediate priority is the establishment of additional, carefully selected protected areas to provide adequate coverage for New Caledonia's unique biodiversity, and thereby prevent not only the loss of individual species, but also of the island's numerous endemic genera and families.

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