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Disentangling the effects of different landscape and local attributes on the biota of habitat patches is often challenging. In Central European forest‐steppe ecosystems the high number of forest fragments and the relatively homogenous matrix between them offer the opportunity to disentangle the effects of habitat size and landscape structure (both landscape composition and landscape configuration) on plant and arthropod biodiversity. We selected 40 forest fragments: 20 forest fragments in extensive, dry, sandy forest‐steppe region and 20 fragments in a mesic forest‐steppe region of Hungary. We classified the detected plant and arthropod species according to their habitat association as forest specialist species or open habitat species. We then tested the effect of fragment size, landscape composition, and landscape configuration on their species richness and abundances. We found that increasing forest fragment size, forest habitat amount, and forest edge length had in general positive effects on forest spider abundance, but negative on open‐habitat arthropod abundances and plant species richness, varying a little among the studied taxa. Most interestingly, the effects of fragment size were often moderated by both landscape composition and landscape configuration, as well as habitat association of species. The fragment size effect was more pronounced in landscapes with low forest habitat amount having positive effects on forest spiders and negative effects on open‐habitat plants. An effective conservation strategy should take into account not only the presence of forest fragments, but also the size and configuration as well as the connectivity of forest fragments, to maximize diversity benefits of forest patches. [ABSTRACT FROM AUTHOR]

Fragmented natural habitats within human-transformed landscapes play a key role in preserving biodiversity. Ants as keystone species are essential elements of terrestrial ecosystems; thus, it is important to understand the factors influencing their presence. In a large-scale multi-site study, we surveyed ant assemblages using sweep netting and D-vac sampling on 158 ancient burial mounds preserving grassland habitats in agricultural landscapes in East-Hungary. We asked the following questions: (1) How do habitat factors and landscape composition affect species richness and functional diversity of ants? (2) Which ant traits are affected by habitat factors and landscape composition? Despite their small sizes, mounds as permanent and relatively undisturbed landscape elements could provide safe havens for diverse ant assemblages even in transformed agricultural landscapes. The complex habitat structure of wooded mounds supported high species and functional diversity of ant assemblages. Ant species on wooded mounds had small or medium-sized colonies, enabling the co-existence of more species. The effect of landscape composition on ant assemblages was mediated by habitat factors: steep slopes buffered the negative effect of the cropland matrix and enabled higher ant diversity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Livestock grazing is one of the most common management practices for grasslands and can greatly affect their biodiversity. However, arthropod diversity response patterns to grazing regimes are difficult to predict. We conducted a short-term grazing exclusion experiment in traditionally managed alkali grasslands in Hungary to investigate differences between grazed and ungrazed vegetation for different arthropod groups. The experiment was laid out in a full factorial design, with twelve 50 × 100 m short-term grazing exclosures in vegetation types with high (alkali wet meadow) and low productivity (alkali steppe). We sampled ground beetles and spiders with pitfall traps and true hoppers by sweep netting. We used vegetation type (wet meadow vs dry steppe), management (grazed vs ungrazed) and their interaction as fixed effects in mixed models. We found higher species richness and activity density of spiders and ground beetles in the more productive wet meadow vegetation, where the community structure of each arthropod group also shifted toward hygrophilous species. Significant interactions between vegetation type and management indicated a dependence of management effects on vegetation types: arthropod community structure shifted towards hygrophilous species in ungrazed meadows, but not in ungrazed steppe sites. True hopper abundance was higher in grazed meadow sites, but lower in grazed steppe sites, compared to ungrazed sites. True hopper community structure shifted toward generalist herbivores in ungrazed sites, regardless of vegetation type. We concluded that vegetation types determine arthropod communities and modulate the effects of grazing on arthropods. Our results suggest that moderate disturbance from low-intensity grazing has a positive or neutral effect in wetter, more productive vegetation, but a negative or neutral effect in drier, less productive vegetation, depending on the arthropod group. Herbivorous insects that dwell on plants are particularly affected by management because they are more susceptible to direct impacts, such as unintentional predation by grazing cattle, and because of asymmetrical competition between mammalian and insect herbivores. • Interacting effect of vegetation type and grazing influenced arthropod communities. • Grazing exclusion had more positive effects in dry, less productive vegetation. • Low-intensity grazing had more positive effects in wet, more productive vegetation. • Different taxonomical and functional arthropod groups reacted differently to grazing. [ABSTRACT FROM AUTHOR]

For adequate conservation planning, ecologists need to understand the driving factors of the species richness and composition patterns of arthropod assemblages. The present study scrutinizes how the vegetation, the surrounding matrix and the process of fragmentation affects the diversity and the composition of arthropod assemblages in dune slack meadow remnants of an agricultural landscape in southern Hungary. Spiders, orthopterans and true bugs were sampled with sweep netting in a total of 25 sand steppe, mesotrophic wet meadow and alkaline meadow patches. Our general findings showed that the structure and species composition of arthropod assemblages depended primarily on the vegetation type. From among the size and shape of the patches, their extent of isolation and the types of the surrounding landscapes only the latter one could be shown to have a significant effect, though this was also restricted to the group of spiders. Therefore, the structure and composition of spider assemblages may be used as indicators for the adjacent agricultural activities. Unlike its effect on species composition, the effect of vegetation type was not consistent on the species richness of the arthropod assemblages and functional groups. The influence of vegetation type was greater on the species richness of herbivores (specialist and generalist true bugs and grasshoppers) than on that of the carnivores (spiders, bush crickets and carnivorous true bugs). Based on the fact that neither patch size nor the extent of isolation, i.e. the measures of fragmentation, influenced the species richness of the majority of the arthropod groups significantly, we conclude that fragmentation was not the main threat for the studied arthropod fauna. Furthermore, the present study calls attention to the limited efficiency of Island Biogeography Theory in the case of relatively large, traditionally managed grasslands embedded in extensive agricultural landscapes, like the general landscape pattern of the Great Hungarian Plain. [ABSTRACT FROM AUTHOR]

A decrease in habitat amount and connectivity causes immediate or delayed species extinctions in transformed landscapes due to reduced functional connections among populations and altered environmental conditions. We assessed the effects of present and historical grassland amount and connectivity as well as local habitat factors typical of the present landscape on the current species richness of grassland specialist and generalist plants and arthropods in grassland fragments. We surveyed herbaceous plants, ants, orthopterans, true bugs and rove beetles in 60 dry grassland fragments in Hungary. We recorded the area of the focal grassland, the slope and the cover of woody vegetation. By using habitat maps of the present and historical landscape, we calculated grassland amount and connectivity for four time periods covering 158 years (1858–2016). We found evidence for an unpaid extinction debt in specialist plants, suggesting that they have not come to equilibrium with the grassland amount and connectivity of the present landscape yet. This localised and typically long-lived group responded slowly to the landscape changes. Specialist arthropod taxa with short generation times responded much faster to habitat loss than plants and did not show an extinction debt. Generalist plants and animals adapted to a wide range of habitats were affected by the landscape-scale decline of grassland habitats. Despite decreased habitat connectivity, grassland fragments with dry environmental conditions and high environmental heterogeneity can sustain specialist plants in transformed landscapes. Unpaid extinction debt should be considered an early warning signal: Restoration of grassland connectivity is necessary to halt ongoing extinction processes. [ABSTRACT FROM AUTHOR]