In the summer of 2024, a study was conducted on Terceira Island in the Azores Archipelago, Portugal, aiming to characterise the vertical diversity and spatial distribution patterns of arthropods within native and exotic forest ecosystems. This study forms part of a broader research initiative designed to investigate how alterations in habitat structure influence the complexity and stability of arthropod food webs in Azorean forest habitats. By systematically sampling arthropods across multiple vertical strata —from forest floor to canopy the study aimed to generate detailed insights into the ecological dynamics governing biodiversity patterns and species interactions. Results from this monitoring will contribute significantly to understanding the ecological impacts of forest composition and management strategies, ultimately providing information for conservation planning and habitat restoration efforts aimed at preserving arthropod diversity and ecological resilience in island ecosystems.<br> The current dataset comprises identified terrestrial arthropods collected using SLAM (Sea, Land and Air Malaise) traps and Pitfall traps across diverse forest strata. A total of 32,797 specimens were collected from the Arachnida, Diplopoda, Chilopoda and Insecta classes. A total of 18,372 (56%) were identified at the species or subspecies level, including 12,745 adults and 5,627 juveniles for taxa, such as Araneae and Hemiptera due to the availability of reliable identification methods. The resulting dataset encompasses 150 species and 11 subspecies, distributed across 21 orders, 81 families and 148 genera.<br> Hemiptera emerged as the most abundant identified order, with a total of 7,697 recorded specimens and Coleoptera stood as the most taxonomically diverse, encompassing 19 distinct families and 50 species and sub-species. The ten most abundant species comprise predominantly endemic and native non-endemic species, with two exotic species detected amongst them.<br> This comprehensive dataset serves as a significant augmentation of the existing baseline knowledge concerning the diversity of Azorean arthropods, thereby facilitating the formulation of future long-term ecological comparisons. It offers valuable insights into the vertical distribution of species abundance within both native and exotic forests of the Azores.
