Conclusion
Within the exciting, natural fragmentation experiment provided by Hawaiian kīpuka, we have used a powerful metabarcoding approach to study the role this fragmentation can play in simultaneously restructuring biological communities and driving interspecific differentiation. We found that Hawaiian kīpuka were characterized by simpler communities with higher proportions of non-native taxa than Hawaiian continuous forest. Kīpuka communities were more distinct from one another than communities sampled across similar distances in continuous forest, and similarly we found evidence for higher rates of genetic differentiation between kīpuka than across similar distances sampled in continuous forest. Conceivably, our results suggest that forest specialist species in these ‘islands’ might undergo more granular local adaptation in kīpuka than they would otherwise do in continuous forest habitat.