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Aim: To investigate the community-level impacts of woody plant invasions using Robinia pseudoacacia as a model species, affecting organisms on different trophic levels: vascular plants, nocturnal Lepidoptera and birds. Location: Czech Republic, central Europe. Methods: Nineteen plots with strong dominance of the invader were compared to 20 plots with native deciduous trees on sites with similar conditions. Species richness was compared using marginal models, species composition and the distribution of species traits by ordination analyses. Functional relationships between the three groups of organisms were investigated using a path analysis. Results: Only minor differences in species richness between invaded and uninvaded plots were detected for plants and birds, but the invaded stands hosted significantly fewer species of nocturnal Lepidoptera. On the contrary, all three groups differed in species composition and in the distribution of traits between the invaded and uninvaded stands. Nitrophilous plants, supported by human disturbances, were more represented in the invaded stands, while habitat specialist birds preferred uninvaded forest. Within noctutnal Lepidoptera, species of open habitats and the cycle preferred the invaded stands, and forest and canopy species and habitat generalists of larger sizes preferred the uninvaded stands. Path analysis showed a minor effect of R.pseudoacacia on the numbers of plants which were unrelated to species richness at nal Lepidoptera, contributing to a weak negative indirect impact on birds. Main conclusions: The impacts of R. pseudoacacia on species richness differed across the trophic levels, questioning the existence of simple cascading effects as a consequence of its invasion. Invasive plants do not always reduce the diversity of species per se, but cause shifts in species composition by replacing some of the pre-invasion biota by species with traits enabling tolerance to the invaded habitat.

Context Biodiversity in agroecosystems has experienced significant declines in species richness due to intensive agricultural practices. Historically, diverse agricultural landscapes have been replaced by nutrient-rich monocultures. To improve the situation, it is important to find out what are the attributes of these landscapes that support the highest species richness. Objectives This study investigates the relationships of farmland bird species richness to field size, diversity of crop types and landscape elements (expressing different kinds of habitat heterogeneity), areas of winter and spring crops (i.e., crops sown in the autumn and in the spring, respectively), and invertebrate food availability. The research objective is to find out which of these factors are linked to the highest richness. Methods Bird species were surveyed using point counts during the breeding season at 52 sites of varying field sizes, landscape element composition, and crop types in open agricultural landscapes in northwestern Hungary, Europe. Food availability was expressed as invertebrate abundance, diversity, and biomass, respectively. Results Bird species richness increased with landscape element diversity and invertebrate abundance, while the field size showed opposing effects depending on crop type. Smaller field sizes were more beneficial in the case of winter crops, but larger fields supported more farmland bird species in the case of spring crops. The abundance of invertebrates was particularly high in alfalfa and fallow fields. Conclusions The value of open farmland for farmland bird species richness can be improved by enhancing diversity of landscape elements (e.g. by adding small water bodies to landscape mosaic), increasing invertebrate abundance (e.g. by reducing pesticide use), reducing the size of fields covered by winter crops and supporting the spring crops.

The landscape matrix is suggested to influence the effect of habitat fragmentation on species richness, but the generality of this prediction has not been tested. Here, we used data from 10 independent studies on butterfly species richness, where the matrix surrounding grassland patches was dominated by either forest or arable land to test if matrix land use influenced the response of species richness to patch area and connectivity. To account for the possibility that some of the observed species use the matrix as their main or complementary habitat, we analysed the effects on total species richness and on the richness of grassland specialist and non-specialist (generalists and specialists on other habitat types) butterflies separately. Specialists and non-specialists were defined separately for each dataset. Total species richness and the richness of grassland specialist butterflies were positively related to patch area and forest cover in the matrix, and negatively to patch isolation. The strength of the species-area relationship was modified by matrix land use and had a slope that decreased with increasing forest cover in the matrix. Potential mechanisms for the weaker effect of grassland fragmentation in forest-dominated landscapes are (1) that the forest matrix is more heterogeneous and contains more resources, (2) that small grassland patches in a matrix dominated by arable land suffer more from negative edge effects or (3) that the arable matrix constitutes a stronger barrier to dispersal between populations. Regardless of the mechanisms, our results show that there are general effects of matrix land use across landscapes and regions, and that landscape management that increases matrix quality can be a complement to habitat restoration and re-creation in fragmented landscapes.

Aim Landscape simplification and the spread of invasive species are considered beyond the main threats to global biodiversity. It is well recognized that non‐crop habitats bring complexity to farmland and provide refuge for a wide range of organisms, including arthropods. However, knowledge about the effects of invasive trees on arthropods in non‐crop habitats in intensive agricultural landscapes is still weak. Therefore, we examined differences in the arthropod assemblages between woodlots formed by the invasive black locust (Robinia pseudoacacia L.) and by native deciduous tree species in the intensive agricultural landscape. Location Czech Republic, Central Europe. Methods We used a multi‐taxonomic approach to record arthropod assemblages using various sampling methods. The impacts of woodlot habitat structure were investigated across 13 arthropod taxa from different trophic levels. Results Total abundance and species richness of all arthropods and the majority of the herbivore taxa were lower in R. pseudoacacia woodlots, likely due to losses of the forest canopy specialists. The forest specialists were associated with the native woodlots with more developed canopy and shrub layers. The impoverished diversity of the forest specialists and canopy herbivores in the R. pseudoacacia woodlots was partly compensated by the higher presence of species exploiting a well developed herb layer and open‐habitat specialists, including threatened species. Main conclusions Native woodlots and those formed by R. pseudoacacia differ in vegetation structure and host different assemblages of arthropods. Therefore, parallel presence of both types of woodlots supports arthropod diversity in otherwise simplified agricultural landscapes through creating more complex mosaic of habitats.

Cities contain only a low representation of natural and semi-natural habitats, existing in fragments surrounded by built-up areas. In 2003-2004, we surveyed butterflies and Zygaenidae moths in 21 reserves and 4 parks within the city of Prague, Czech Republic, situated from the periphery to city centre. A total of 85 species (47% of the Czech fauna of the study groups) was detected, 22 of them being of conservation concern. Ordination analyses of the local assemblages revealed that the richest sites were large, situated far from the city centre, on alkaline bedrocks, south- to southwest oriented, and hosting high numbers of vegetation types and vascular plant species. We then used generalised linear models to fit responses of individual species to the main ordination gradient, corresponding to increasing urbanisation. Out of 60 species that met criteria for the modelling, none responded positively to urbanisation. Twenty displayed negative linear response; these urban avoiders contained a surplus of mesophilous species presumably preferring rural landscapes. Further 29 species (suburban adaptable) responded in domed manners, peaking at the city periphery. Prevailing among them were xerophilous specialists inhabiting large grassland reserves at the Prague outskirts. Finally, eleven urban tolerant species did not respond to urbanisation at all, containing three highly mobile species, three xerothermophilous specialists, and five species utilising shrubs or trees and finding suitable conditions even in urban parks. Suburban adaptable butterflies apparently benefit from such suburban environments as gardens, road or railway verges, collectively increasing the connectivity of remnants of seminatural habitats. The fact that arboreal species persist even in urban parks, whereas common grassland species are absent there, implies that the quality of urban habitats might be increased by a more sensitive management of urban green spaces, such as leaving aside small temporary fallows or adapting lawns mowing schemes. [PUBLICATION ABSTRACT]

Urbanization and its urban‐heat‐island effect (UHI) have expanding footprints worldwide. The UHI means that urban habitats experience a higher mean and more frequent extreme high temperatures than rural habitats, impacting the ontogeny and resilience of urban biodiversity. However, many organisms occupy different microhabitats during different life stages and thus may experience the UHI differently across their development. While evolutionary changes in heat tolerance in line with the UHI have been demonstrated, it is unknown whether such evolutionary responses can vary across development. Here, using common‐garden‐reared Chiasmia clathrata moths from urban and rural populations from three European countries, we tested for urban evolution of heat shock tolerance in two life stages: larvae and adults. Our results indicate widespread urban evolution of increased heat tolerance in the adult stage only, suggesting that the UHI may be a stronger selective agent in adults. We also found that the difference in heat tolerance between urban and rural populations was similar to the difference between Mid‐ and North‐European regions, suggesting similarity between adaptation to the UHI and natural, latitudinal temperature variation. Our observations incentivize further research to quantify the impact of these UHI adaptations on fitness during urbanization and climate change, and to check whether life‐stage‐specific adaptations in heat tolerance are typical of other ectothermic species that manage to survive in urbanized settings.

Temporal patterns in butterfly behavior should reflect diurnal, seasonal and population-level changes in mate availability. Investment into mating should peak at times when potential mates are at a maximum; at other times, individuals should save energy and focus on maintenance activities. To explore these assumptions, we re-analyzed mark-recapture data containing records of behavior for each handled individual: 15 species, 21 separate datasets, total of 20,828 activity records (13,223 males and 7605 females). We used ordination analysis, with activity categories as response variables and controls for dataset identity and weather effects. Across species, basking and nectaring were prevailing morning activities, while mating peaked at afternoons. With the progressing season, males switched from maintenance behavior to mating activities, whereas opposite trend applied to females. Density predictors (sex ratio, daily population size) revealed that mating concentrated to high densities of the opposite sex and that female oviposition, resting and nectaring increased under low density of males. Exploring mark-recapture data for studying behavioral patterns proved to be fruitful but cannot replace focused observations or experiments.

Non-native invasive plants are among the main threats to global biodiversity, including insects, and it is thus important to understand the mechanisms of how invasive plants impact native species. The community composition of nocturnal Lepidoptera was studied in the Czech Republic (Central Europe) in stands of native deciduous trees and in stands dominated by the invasive tree Robinia pseudoacacia, using automatic portable light traps together with an assessment of habitat characteristics. Native stands had more closed canopies and poorly developed understories. Conversely, R. pseudoacacia stands were more open and heterogeneous, with sparse canopies, well-developed shrub layers and a higher cover of taller herbs. Moth species richness, abundance and biomass were lower in R. pseudoacacia, likely due to the low richness of canopy herbivores not adapted to feed on the exotic host. However, feeding guilds associated with the understorey were more represented in stands of R. pseudoacacia, likely due to the more heterogeneous habitat structure. The Lepidopteran communities observed in stands of R. pseudoacacia resembled communities of open-forests or forest-steppe habitats. In contrast, native stands were dominated by Lepidoptera associated with trees, including forest specialists but also habitat generalists. From a conservation perspective, it appears that the invasive R. pseudoacacia created structurally more heterogeneous environment and more Lepidopteran open-forest guilds were associated with this habitat. However, further spread of R. pseudoacacia should be prevented because it reduces the species richness of Lepidoptera. Simultaneously, we recommend increasing the habitat heterogeneity of native forests to support functionally more diverse Lepidopteran communities.

The harlequin ladybird, Harmonia axyridis, is considered to be one of the most invasive insect species worldwide. Its invasion success and extreme speed of range expansion has been partially attributed to weak control of its populations by natural enemies. Previously published data on emergence rates of the hymenopteran parasitoid Dinocampus coccinellae support the enemy release hypothesis: H. axyridis has been consistently less successfully parasitized compared to native ladybird species. In this study, we show that since 2016, i.e., 10 years after its arrival in Central Europe, several populations of H. axyridis in the Czech Republic have a very high prevalence of D. coccinellae parasitism. D. coccinellae emerged from 46% of H. axyridis individuals in the most parasitized population. Moreover, H. axyridis was more parasitized than the native Coccinella septempunctata in seven of nine investigated co-occurring populations. The meta-analytically pooled estimate of D. coccinellae emergence rate from H. axyridis across the Czech populations (this study) is thirteen times higher than the pooled estimate for invasive populations of this beetle elsewhere (historical data up to 2016). We hypothesize that some Central European populations of D. coccinellae have evolved to overcome the immune system of H. axyridis, which was previously thought to be responsible for the high larval mortality of D. coccinellae. As parasitism rates are highly variable in time and space, we encourage future research investigating the determinants of parasitoid prevalence in H. axyridis and other large ladybird species on a continental scale.

Introduction: Abandoned military training areas are biodiversity strongholds, and this is particularly true for open-habitat and threatened species in Central Europe. Such species benefited from a specific disturbance regime created by military activities that maintained small-grained environmental heterogeneity. However, the disturbance regime no longer occurs after abandonment and the biodiversity is at risk due to forest and shrub encroachment if the areas are left unmanaged. To combat these adverse changes, several management options are used. As these options are not always applied for conservation purposes and substantially differ in their implementation, it is essential to assess their impacts on biodiversity. Methods: We performed repeated standardized surveys (first in 2009–2010, second in 2020–2022) of vascular plants, grasshoppers, butterflies and birds in 42 abandoned military training areas in Czechia, a Central European country. We calculated changes of species richness and abundance between periods for each taxon and related these changes to six different management types (woody plant cutting, mowing for conservation, mowing for agriculture, grazing for conservation, grazing for agriculture, vehicle movement) performed in these areas between periods. Results: Vascular plants and grasshoppers showed generally positive changes, whereas the reverse was true for butterflies, and birds experienced mixed changes. Although beta-diversity increased between periods in plants, grasshoppers and butterflies, this increase was driven by extirpation of common species. Management impacts greatly different between respective types and between taxa. Woody plant cutting showed solely positive impacts (on plants and grasshoppers), while the impacts of both types of grazing were mixed (positive on plants and birds, negative on butterflies, mixed on grasshoppers). Mowing for agriculture supported plants and birds but had negative effects on grasshoppers. Mowing for conservation and vehicle movement were linked solely to negative biodiversity changes (former in plants, latter in butterflies). Discussion: Some components of biodiversity, i.e. plants and grasshoppers, indicate that abandoned military training areas still serve as their strongholds and the management most likely contributes to this favourable state. In contrast, the pattern found for butterflies is worrying since the management performed up to now apparently does not meet their requirements, likely because they are based on smaller-scale habitat mosaic than currently occurs in the areas. Our results may serve as a guide for future prioritization of environmental management, and we urge for development of more nuanced approaches to save the butterflies.