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As a consequence of agricultural intensification and habitat fragmentation since the mid-20th century, biological diversity has declined considerably throughout the world, particularly in Europe. We assessed how habitat and landscape-scale heterogeneity, such as variation in fragment size (small vs. large) and landscape configuration (measured as connectivity index), affect plant and arthropod diversity. We focused on arthropods with different feeding behaviour and mobility, spiders (predators, moderate dispersal), true bugs (mainly herbivores and omnivores with moderate dispersal), wild bees (pollinators with good dispersal abilities), and wasps (pollinators, omnivores with good dispersal abilities). We studied 60 dry grassland fragments in the same region (Hungarian Great Plain); 30 fragments were represented by the grassland component of forest-steppe stands, and 30 were situated on burial mounds (kurgans). Forest-steppes are mosaics of dry grasslands with small forests in a matrix of plantation forests. Kurgans are ancient burial mounds with moderately disturbed grasslands surrounded by agricultural fields. The size of fragments ranged between 0.16–6.88 ha (small: 0.16–0.48 ha, large: 0.93–6.88 ha) for forest-steppes and 0.01–0.44 ha (small: 0.01–0.10 ha and large: 0.20–0.44 ha) for kurgans. Fragments also represented an isolation gradient from almost cleared and homogenous landscapes, to landscapes with relatively high compositional heterogeneity. Fragment size, connectivity, and their interaction affected specialist and generalist species abundances of forest-steppes and kurgans. Large fragments had higher species richness of ground-dwelling spiders, and the effect of connectivity was more strongly positive for specialist arthropods and more strongly negative for generalists in large than in small fragments. However, we also found a strong positive impact of connectivity for generalist plants in small kurgans in contrast to larger ones. We conclude that besides the well-known effect of enhancing habitat quality, increasing connectivity between fragments by restoring natural and semi-natural habitat patches would help to maintain grassland biodiversity. [ABSTRACT FROM AUTHOR]

Drainage canals are widespread components of agricultural landscapes. Although canals have greatly contributed to biodiversity loss by desiccating wetlands, they have recently attracted conservation attention due to their potential to function as refugia for native species in intensively managed landscapes. However, their conservation role in complex landscapes composed of agricultural fields and desiccated but otherwise untransformed, semi‐natural habitats, on which canals still pose a heavy burden, is unknown. Improved understanding of drainage canals and related biodiversity in these landscapes could help unlock their potential and support synergistic land management for nature conservation and water resource management.We applied a multi‐taxon approach, including plants, butterflies, true bugs, spiders and birds, to (a) assess the conservation value of drainage canals with temporary water cover in a heavily drained European lowland region, (b) to test landscape‐level and local canal parameters for aiding prioritization among canals and (c) to propose a reconciliation‐based management framework that suits the interest of all stakeholders.We found that drainage canals and their banks concentrate more species across most taxa than semi‐natural, mostly grassland habitats, possibly due to micro‐environmental heterogeneity and the absence of low‐intensity annual management compared to grasslands. Canals traversing semi‐natural grasslands concentrate particularly high numbers of native species, but agricultural canals also support remarkable species richness. However, agricultural canals are important dispersal corridors for non‐native invasive plants, which may negatively affect native biodiversity. Canal size has little effect on biodiversity, but habitat stress is an important determinant. The higher the stress (due to sandiness and salinity), the higher the added value of canals to landscape‐wide biodiversity.Synthesis and applications. We show that drainage canals can harbour high biodiversity and should therefore be recognized as important novel ecosystems with high conservation value, even when cutting through semi‐natural grassland habitats. Canals have previously been considered detrimental to nature conservation due to their association with loss of wetlands. However, by reducing water loss with reversible obstructions, controlling invasive species and applying specific conservation measures, they may be turned into conservation allies without compromising long‐term interests of water management and agricultural land use. [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]

The majority of natural forest steppes in Central-Europe were converted to forest plantations, a significant part of plantations are composed of exotic pine trees. This brings dramatic changes in habitat structure. The formerly open-canopy forest patches and grasslands became closed-canopy forests and key habitat factors were altered, such as microhabitat diversity, plant species composition, microclimate, and amount of dead organic matter. Here we studied the difference in spider species richness, assemblage composition, and functional diversity of native forest steppes, exotic pine plantations, their edges, and adjacent grasslands. We selected 10 native forest patches and 10 pine plantations in commercial maturity, all plantations had direct interface with extensive forest steppe areas. We sampled spiders in forests, forest edges, and adjacent steppe grasslands, resulting in 60 sampling plots. We found different species composition in natural forest patches and pine plantations; however forest edges and grasslands near forest edges did not differ significantly. Spiders with preferences for shaded and humid habitats were associated with forests. Web builders were associated with pine plantations and their edges, large vegetation dwelling spiders had preferences for grasslands and native forest edge, and ballooning spiders were associated with grasslands and edges. Pine forest belts around natural forest steppe patches, besides being low quality secondary habitats for forest steppe spiders, also hamper effective dispersal; the high density of trees and the lower wind speed may act as barriers for effective ballooning. Contrary to our expectations, we found lower functional diversity at natural sites than at pine plantations. The hot and dry microclimate of natural forest steppes favours some trait states (e.g., drought-tolerant, preferences for open habitats), and this may lead to convergence in trait values and a lower functional diversity of forest steppe spider assemblages than the that of assemblages in pine plantations. [ABSTRACT FROM AUTHOR]

The Tisza River Basin is an important area as it is a green corridor in which there are highly endangered habitats and a high level of biodiversity. The patterns in the species richness of invertebrates and the environmental conditions affecting these patterns are poorly studied in the grassy habitats in the lower reaches of the Tisza River Basin. The present study focuses on the effects of flooding, habitat and landscape features on the species richness of orthopterans at 24 grassland sites in two different landscapes. The relations between the explanatory variables and the pattern of diversity of orthopterans with different life-history traits were studied, using ordination and Generalized Linear Mixed Models. Although the influential factors for the different trait groups differed, we suggest that landscape features are the most important in shaping orthopteran assemblages, whereas habitat characteristics and flooding have comparatively little effect. Habitat characteristics affected only the non-xerophilous and Ensifera species and only the species richness of non-xerophilous orthopterans in flooded and non-flooded sites differed. We emphasize that even in countries where there are still considerable areas of high value natural grasslands, such as Hungary, non-protected meadows, linear grassy habitats (dikes, ditch banks, road verges, etc.) need more attention and should be given higher priority in the conservation of invertebrates. [ABSTRACT FROM AUTHOR]

Floodplain forests are among the most threatened habitats in Europe and contain a highly diverse and characteristic fauna. We tested the effect of landscape and habitat attributes on the structure of spider assemblages of river islands and floodplain forests along the Mures River, Western Romania. The fieldwork was carried out in seven islands and seven riverbank forest sites. Spiders were collected with pitfall traps. We found significant association between habitat structure and rarefaction diversity and species composition of spider assemblages. The type of the sites (i.e. island vs. riverbank) also influenced the composition of the spider assemblages. However, there was no relationship between the landscape attributes and the spider assemblages, presumably due to the presence of large non-flooded forests in the study area, which may serve as overwintering habitat for the floodplain fauna. The present study emphasizes the importance of protecting river islands and floodplain forests for preservation of the regional species richness. [ABSTRACT FROM AUTHOR]

Intensive management causes significant changes to the habitat structure of forest stands and threatens forest specialist insect species. To assess and counteract the effect of periodic intensive forestry interventions, such as clear-cutting and reforestation, it is important to adequately quantify the recovery rate and composition of the native biota. We aimed to characterize the above parameters for ant assemblages in forests with different structure and age., Epigeic ant assemblages were studied using pitfall traps in young (6-10 years old), middle-aged (23-26 years old) and mature (35-37 years old) poplar forest plantations in the Kiskunság region of Hungary., Species richness of ant assemblages and the abundance of nonforest ants did not differ among the age classes. The abundance of forest specialist ants was, however, higher in middle-aged and mature stands compared with young plantations. The assemblage composition of ants significantly correlated with habitat structure and forest age., We conclude that nonforest ant species can persist throughout the entire forestry cycle in poplar plantations with moderate tree density. The present study suggests that forest age and habitat structure together shape the ant assemblages of lowland poplar plantations. [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]

River basins are among the most threatened ecosystems. The species diversity of several European river basins decreased seriously during the last decade due to loss of habitats and increasing land use pressure on the remaining habitats. We studied true bug assemblages in various land use types of grassland fragments and dikes as linear grassland habitats in the agricultural landscape of the lower reach of the Tisza River Basin. We tested the effects of the recorded variables of habitat quality, surrounding landscape and land use type on the abundance, species richness and composition of true bugs. Altogether, 5,389 adult Heteroptera individuals representing 149 species in 13 families were collected. The factors which influenced significantly the species richness of different trophic levels (i.e. herbivors, predators) and degrees of food specialization (i.e. generalist and specialist herbivors) were concordant. Contrary to this, the factors which influenced the abundance of the different feeding groups varied strongly. We emphasise the vegetation and land use types as primarily influential factors for insects. Excluding the grass-feeding species, the number of both generalist, specialist herbivorous and predaceous species were lower in agricultural swards, i.e. hay-meadows and pastures than in old field and dike habitats and their number increased with increasing vegetation diversity. Due to the high species richness and abundance observed in dike and old field habitats compared to agricultural swards, we emphasise their importance for conservation of insect diversity and we stress the negative effects of agricultural intensification on the remaining grasslands of the lower reach of the Tisza River Basin. [ABSTRACT FROM AUTHOR]