Sampling description

A total of 45 passive flight interception SLAM traps (Sea, Land and Air Malaise traps) were used to sample the plots in the four study Islands, with one trap being set up at each plot. Trap size is of approximately 110 x 110 x 110 cm. The trap functions on the basis of intercepting arthropods that crawl up the mesh and then fall inside the sampling recipient, which is filled with propylene glycol (pure 1,2-propanodiol) (Borges et al. 2017). A total of 19 SLAM traps were deployed in exotic forest areas, eight on native forest patches and 18 on mixed forests. The trap samples were collected every three months in Flores and Corvo and six months in Terceira and Santa Maria. In Corvo Island, one trap was available in a mixed forest (Fig. ​(Fig.3;3; Table ​Table1).1). In Flores Island, five traps were available in both exotic forests and native forests (Fig. ​(Fig.4;4; Table ​Table1).1). In Santa Maria Island, a total of 16 traps were available with only three located in disturbed native forest patches (Fig. ​(Fig.5;5; Table ​Table1).1). Finally, in Terceira Island, 23 traps were available with only four in disturbed native forest patches (Fig. ​(Fig.6;6; Table ​Table11).

Map with the location of the sampling sites in Corvo Island, Azores. Codes of sites as in Table ​Table11 (Land-use data extracted from Cruz et al. 2007) (Credit: Enésima Pereira, Azorean Biodiversity Group).

Map with the location of the sampling sites in Flores Island, Azores. Codes of sites as in Table ​Table11 (Land-use data extracted from Cruz et al. 2007) (Credit: Enésima Pereira, Azorean Biodiversity Group).

Map with the location of the sampling sites in Santa Maria Island, Azores. Codes of sites as in Table ​Table11 (Land-use data extracted from Cruz et al. 2007) (Credit: Enésima Pereira, Azorean Biodiversity Group).

Map with the location of the sampling sites in Terceira Island, Azores. Codes of sites as in Table ​Table11 (Land-use data extracted from Cruz et al. 2007) (Credit: Enésima Pereira, Azorean Biodiversity Group).