Taxonomic and Geographic Distributions of Native Angiosperms in the Islands of French Polynesia (South Pacific): An Analysis Based on the Nadeaud Botanical Database1

Herbarium databases can play a crucial role in the study of botany, ecology, and biogeography. With 22,717 specimens, the Nadeaud botanical database of the herbarium of French Polynesia represents a significant resource for the study and preservation of the unique and diverse flora of French Polynesia. This study aims to describe the taxonomic and geographic distributions as well as the ecology of native and endemic vascular plants included in the database. We focused our analysis on native angiosperms representing more than 14,000 specimens, 416 endemic taxa, and 190 non-endemic native taxa. First, the distribution of native angiosperms and the rate of endemism for French Polynesia, for each archipelago and for 60 islands were characterized. The environmental variables associated with each specimen were extracted, which enabled us to document the ecology of the various taxa present in the different archipelagos and islands. We found high rates of endemism in the high-elevation islands, such as the Marquesas and the Society archipelagos, compared to low-lying atolls of the Tuamotu. Environmental correlates enabled us to group them according to their archipelago and/or island endemism, revealing the relevance of the variables chosen for the biogeographical study. The limited geographical distribution of some endemic taxa underlines their vulnerability in relation to certain threatened ecosystems within islands. The taxonomic and geographical distribution of native angiosperms highlights the disparate distribution of taxa among the French Polynesia. This study is an important step toward a better planning of projects related to the preservation of the flora of French Polynesia.