Edge effects constraint endemic but not introduced arthropod species in a pristine forest on Terceira (Azores, Portugal)

•Edge effects constraint the abundance and composition of endemic species but not of introduced ones.•Both biogeographical categories and temporal dynamics play a role in forming assemblage patterns.•Endemics are the most abundant but richness is similar for all biogeographic categories.•The edge can affect the abundance of indigenous species up to100 m into the forest interior.