Identification and characterization of floristic groups in dry forests relicts of a West Coast region of New Caledonia

Abstract

We describe the floristic composition of dry forest relicts on the west coast of New Caledonia. Using multivariate techniques, four floristic groups were defined from 71 floristic samples. The large proportion of species with rain forest affinities in all floristic groups shows similarities with the ?dry? rainforest of Australia. The two more open and disturbed groups have the highest proportion of species associated with dry areas, the strongest level of endemism and more ?most threatened? species. The two more closed groups have the highest proportion of rain forest species, but are slightly less original and have fewer threatened species. This raises the question of the exact relation of the dry forest still present in the study area to mesic forest, which has not yet been studied separately from dense humid forest in New Caledonia. The influence of the local micro-climatic conditions on the distribution of floristic groups appears critical. A good knowledge of these conditions is necessary for a sound delimitation of new protected areas, and for the implementation of protective and restorative measures appropriate to each vegetation category.