Semi-natural linear landscape elements such as road verges, hedgerows and field margins are important in maintaining the connectivity between habitat fragments of highly modified landscapes. Preservation of habitat specialist fauna requires conservation of the remaining natural habitat patches and connectivity of fragments. Our study focuses on the spider, ant and true bug fauna and functional diversity (FD) of fragmented forest steppe patches, moderately grazed pastures and road verges embedded in a matrix of forest plantations in Hungary, Central Europe. We established total 30 sampling sites, 10 in each, the grassland component of forest-steppes (F), pastures (P) and road verges (R) near pine forests. We collected arthropods with pitfall and sweep-net techniques. We calculated FD and species composition of arthropods using linear mixed models. We observed higher species richness in road verges for spiders and ants. We also found higher FD values for spiders and different trait composition for all taxa in road verges when compared with forest steppes and pastures. Species composition suggests that road verges do not serve as habitat for several forest-steppe and grassland species, in spite of the fact that numerous specialist species were found in the road verges. We show that forest steppes have higher species richness of spiders than pastures, and there are differences in species assemblage composition of the two habitat types for all taxa.Our results indicate that road verges should be considered as an important refuge for grassland specialist arthropods, as road verges provide secondary linear habitats for many arthropod species, and we would suggest the maintenance of these grassy strips in order to preserve arthropod biodiversity.

Plantations of non-native trees for commercial use are common practice in Europe. They are known to have severe ecological impacts on arthropod fauna by altering microclimatic conditions and reducing microhabitat diversity. However, the effect of plantation tree species on winter-active fauna is relatively unknown. Spiders are a diverse predatory arthropod taxon with strong effect on their prey populations. The composition of spider communities sensitively indicates changes in habitat structure. We established 40 sampling sites in five non-native pine and five native poplar plantations and collected spiders with pitfall traps for two winters in the Southern part of Hungary. We assessed the average height of vegetation and percentage cover of leaf litter, mosses, herbaceous vegetation, and shrubs to characterize habitat structure. We found species richness and activity density of spiders in the non-native compared to the native plantations, presumably due to the more temperate microclimate in pine than in poplar plantations. However, there was no significant effect of habitat structure and its interaction with forest type on species richness and activity density of spiders. Species composition of non-native and native plantation forests differed significantly. Furthermore, we identified six characteristic spider species of non-native plantations with preference for relatively moist habitat conditions. The single characteristic species, (Agroeca cuprea Menge, 1873) for the native plantations preferred dry and partly shaded habitats. We conclude that the effect of microclimatic differences and prey availability presumably overrides the effect of habitat structure on winter-active spiders.

Non‐native tree plantations constitute a large part of forestation worldwide. Plantations are prone to invasion by exotic herbaceous plant species due to habitat properties, including understory vegetation structure. We established 40 sampling sites in 10 plantation forests. Sites were selected according to tree species (native poplar forests and exotic pine plantations) and common milkweed (Asclepias syriaca) density (invaded and non‐invaded sites) in a full factorial design. We collected spiders with pitfall traps. We found a significant effect of A. syriaca invasion on spider functional diversity (Rao's quadratic entropy), with invaded sites having a lower functional diversity than non‐invaded sites. A larger effect of invasion with A. syriaca on the RaoQ of spiders was observed in pine compared to poplar plantations. Spider species were larger, and web‐building spiders were more frequent in poplar forests than in pine plantations. We found no effect of A. syriaca invasion on species richness or abundance of spiders. Species composition of spider assemblages in the two forest types was clearly separated according to non‐metric multidimensional scaling. We identified seven species associated with pine plantations and six species associated with poplar plantations. The similar species richness and the higher functional diversity of non‐invaded sites suggested that these trait states were less similar than invaded sites and that functionally different species were present. In contrast, the invaded sites had lower functional diversities and thus more uniform trait state compositions, suggesting that environmental filtering played an important role in species sorting, making invaded plantations low‐quality secondary habitats for the original spider fauna.