Insidious Island Invasion: An exploration of Falcataria moluccana stand ecology

Mo’orea, French Polynesia of the Society Islands archipelago is a highly isolated volcanic Pacific Island. It is vulnerable to invasion by introduced species due to this isolation in conjunction with its small size and disharmonic native biota. Falcataria moluccana is one such invader; since its introduction in the 1960s to reforest burned and eroded ridges it has established monodominant stands throughout the island. I studied the effects of this species on vegetation ecology, specifically native and non-native understory diversity, tree community dynamics, and species spread potential. Contrary to expectations, I found that native understory was able to persist despite ecosystem modifications caused by F. moluccana. However, the majority of native species present were post-disturbance taxa. Tree community analysis revealed that F. moluccana trees are able to grow to large sizes where other trees cannot, which suggests either niche differentiation or resource monopolization. Seedling count results indicate that this species may be enabling its spread through ecosystem modification, specifically the infusion of nitrogen into the environment via leaf litter. Future studies on long-term dynamics of F. moluccana stands combined with germination studies, soil chemistry analyses, and resource availability surveys would be beneficial to future conservation efforts on Mo’orea