Forests of Palau: a long-term perspective

The Republic of Palau is an archipelago of the Caroline Islands (latitudes 8˚12' to 2˚48' and longitudes 131˚07' to 134˚44') with over 802 native plants of which 18.7% are endemic. Forest vegetation growth ranged from 0.04% to 0.22% yr -1 in three decades. Forest patches in Babeldaob showed differential growth rates with an overall rate of expansion of 38 m 2 yr -1 . Nine patches expanded at an average rate of 608 m 2 yr -1 , three patches decreased at a rate of 1267 m 2 yr -1 and 34 patches showed no change. Uncommon endemic species occurred in stable, wet and inaccessible areas of Babeldaob including Parkia parvifoliola and Terminalia crassipes. Dominant trees include Campnosperma brevipetiolata, Horsfieldia spp., Maranthes corymbosa and Alphitonia carolinensis. One large limestone island had a higher percentage of endemic trees (16.4%) than ten smaller limestone islands (11%). Within the island cluster, the larger islands had more species (mean = 26.8) than the smaller islands (mean = 7.8). A 2001 survey of 90 homes indicated that Areca catechu, Cocos nucifera and Mangifera indica were the most common trees. Year round and synchronous spring and fall flowering and fruiting was observed for dominant tree species. Endemic trees tend to have smaller fruits. Broad reproductive periods, easily dispersed seeds, seeds with thick exocarps and dwarfism are adaptations that may help trees survive climate change and human disturbance on small islands. The invasive trees, Falcataria moluccana and Adenanthera pavonina are considered threats to native forests. National land use and forest policies are needed to ensure that Palau's forests remain intact into the next century.