Arthropod data
Arthropods were collected with suction sampling, using a modified leaf
blower (Stihl™ BG85), for 45-60 seconds. In each site, three suction
samples, less than 1 m apart, were taken in the central pixel. Before
each sampling, a plastic ring (Ø = 45 cm) was haphazardly placed in the
central pixel to delimit the suction area. Arthropods were collected in
a cotton bag mounted at the front of the suction device and this bag was
emptied into a plastic container. All specimens were transferred to
Eppendorf tubes filled with 75% ethanol. In the laboratory, we sorted
and counted spiders and beetles. All specimens were sorted to family,
and partly identified to genus or species (spiders – all families,
beetles – only Staphylinidae and Carabidae) by ourselves or experts. In
some cases, mainly juvenile spiders, specimens could not be identified
to lower taxonomic levels. Those individuals were included in total
density estimates but only in species counts if no individuals of that
genus were identified to a lower taxonomic level. We thereafter rarefied
species number for each site using the alpha-command in BAT (Cardoso, et
al. 2015).
For further community analyses, we scored traits; main habitat
preference (beetles and spiders), feeding guild (beetles) and hunting
guild (spiders). Habitat preference was obtained from artfakta.se, based
on expert assessment, using the approach of Åhlén et al. (2024). In
short, species are scored as wetland specialists if indicated habitat
preferences mainly include wetland habitat types, as terrestrial
specialist is preferences mainly include terrestrial habitat types, and
as habitat generalist when the preference include both wetland and
terrestrial habitat types. Beetle feeding guilds (carnivore, herbivore,
other feeders) were based on artfakta.se and spider hunting guilds
(ambush hunter, ground hunter, orb web weaver, sheet web weaver and
space web weaver) were based on Cardoso et al. (2011). For lists of
traits and species classifications, see Appendix 1.