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Recent losses in the abundance and diversity of arthropods have been documented in many regions and ecosystems. In grasslands, such insect declines are largely attributed to land use, including modern machinery and mowing regimes. However, the effects of different mowing techniques on arthropods remain poorly understood. Using 11 years of data from 111 agricultural grassland plots across Germany, we analyzed the influence of various grassland management variables on the abundance and abundance‐accounted species richness of four arthropod orders: Araneae, Coleoptera, Hemiptera, and Orthoptera. The analysis focused on detailed mowing information, for example, days after mowing and mower type, and compared their effect with other aspects of grassland management, that is, rolling, leveling, fertilization, and grazing. We found strong negative effects of mowing on all four arthropod orders, with arthropod abundance being lowest directly after mowing and steadily increasing to three to seven times the abundance after 100 days post‐mowing. Likewise, Hemiptera and Coleoptera species richness was 30% higher 100 days after mowing. Mower width showed a positive effect on Orthoptera abundance, but not on the other arthropods. Arthropod abundance and Coleoptera species richness were lowest when a mulcher was used compared to rotary or bar mowers. In addition to mowing, intensive grazing negatively affected Orthoptera abundance but not the other orders. Mowing represents a highly disturbing and iterative stressor with negative effects on arthropod abundance and diversity, likely contributed by mowing‐induced mortality and habitat alteration. While modifications of mowing techniques such as mower type or mowing height and width may help to reduce the negative impact of mowing on arthropods, our results show that mowing itself has the most substantial negative effect. Based on our results, we suggest that reduced mowing frequency, omission of mowing in parts of the grassland (refuges), or extensive grazing instead of mowing have the greatest potential to promote arthropod populations. [ABSTRACT FROM AUTHOR]

The article explores how to enhance ecosystem services in urban soils, focusing on managing the microbiome of Technosols to improve soil health and biodiversity. Topics include the impact of urban development on soil quality, the potential benefits of microbial inoculation and diverse plant communities, and strategies for integrating nature-based solutions into urban landscapes.

In modified production landscapes, biodiversity faces unprecedented pressures from human actions, resulting in significant species declines of plant and animal taxa, including birds. Understanding the underlying mechanisms responsible for such declines is essential to counteract further loss and support practitioners in conserving biodiversity and associated ecosystem function. In this study, we used standardized bird monitoring data collected over 6 years in managed forest and grassland areas across different regions in Germany, Central Europe. We combined these data with morphometric, ecological, behavioral, and acoustic trait data and detailed information on local land use management practices to understand how management decisions affect species and functional diversity, as well as ecological processes shaping local species composition. Our results reveal that the ecosystem and regional context must be considered to understand how management practices affect bird diversity aspects and composition. In forests, regional management decisions related to tree species and stand age affected bird diversity, as well as community and functional composition, and indicated environmental sorting due to ecological and behavioral requirements, biotic interactions, and morphometric constraints. In grasslands, independent of local management practices, increased intensity of land use resulted in an overall loss in bird species richness and functional diversity. Predominantly, constraints due to ecological or behavioral requirements affected bird species assemblage composition. In addition, our results indicated the importance of woody vegetation near managed grasslands and of considering environmental conditions beyond the local scale to support bird diversity and associated ecosystem functions. Our results highlighted that local management decisions can support bird diversity and maintain ecological function. However, this needs a view beyond the local scale of management units. It also demands a joint effort of biologists and land managers to integrate targeted conservation actions into regional management practices and create a network of habitats within production landscapes to protect nature, guard against biotic and functional homogenization, and prevent further degradation of ecosystems in production landscapes. [ABSTRACT FROM AUTHOR]

Changing environmental conditions and land use are threatening biodiversity on a large scale, making successful conservation and restoration essential for maintaining biodiversity. Planning of such efforts profits from information about where conditions are suitable for biotopes, to evaluate how likely successful conservation or restoration is at these sites. This study uses the distribution model Maxent to identify varying levels of conservation and restoration potential for 29 different biotopes in the central European region of Bavaria, Germany, by comparing the environmentally suitable areas identified by models with the current distribution of each biotope. We identified a conservation potential when a biotope occurred under suitable environmental conditions and a restoration potential when suitable environmental conditions were present at a site where the biotope was not observed. We found that 69.57% of biotope observations occurred under suitable environmental conditions representing a large conservation potential. Also, 22 biotopes showed more restoration potential than their current distribution and both conservation and restoration potential showed a similar geographical distribution. The approach used in this study can provide valuable insights for conservation and restoration decision-making by suggesting priority areas for the conservation and restoration of multiple biotopes. Further, it could be applied in other regions globally and by incorporating future climate projections it could identify particularly resilient locations for biotope conservation or restoration. [ABSTRACT FROM AUTHOR]

Intraspecific variation of specialized metabolites in plants, such as terpenoids, are used to determine chemotypes. Tansy Tanacetum vulgare exhibits diverse terpenoid profiles that affect insect communities. However, it is not fully known whether patterns of their chemical composition and associated insects vary beyond the community scale. Here, we investigated the geographic distribution of mono‐ and sesquiterpenoid chemotypes in tansy leaves and their relationships with specific insect communities across Germany. We sampled tansy leaves from ten plants with and five plants without aphids in each of 26 sites along a north–south and west–east transect in Germany. Hexane‐extracted metabolites from leaf tissues were analyzed by gas chromatography‐mass spectrometry (GC‐MS). Plant morphological traits, aphid occurrence and abundance, and occurrence of ants were recorded locally. The effect of plant chemotype, plant morphological parameters, and abiotic site parameters such as soil types, temperature and precipitation on insect occurrences were analyzed. Plants clustered into four monoterpenoid and four sesquiterpenoid chemotype classes. Monoterpene classes differed in their latitudinal distribution, whereas sesquiterpenes were more evenly distributed across the transect. Aphid and ant occurrence was influenced by monoterpenoids. Plants of monoterpenoid class 1 were colonized by aphids and ants significantly more often than expected by chance, whereas in other classes there were no significant differences. Aphid abundance was affected by soil type, and average annual temperature positively correlated with the occurrence of ants. We found significant geographic patterns in the distribution of tansy chemodiversity and show that monoterpenoids affect aphid and ant occurrence, while the soil type can influence aphid abundance. We show that geographic variation in plant chemistry influences insect community assembly on tansy plants. [ABSTRACT FROM AUTHOR]

Forest birds respond to a diverse set of environmental factors, including those altered by forest management intensity, such as resource and habitat availability in the form of food or nesting sites. Although resource/habitat availability and bird traits likely mediate responses of bird diversity to global change drivers, no study has assessed the direct and indirect effects of changes in forest management and traits on bird assemblages jointly at large spatial scales. In this context the questions remain whether (1) the birds' response to forest management changes through alterations in structural properties and/or food availability, or (2) if birds' eco-morphological traits act as environmental filters in response to environmental factors. We audio-visually recorded birds at 150 forest plots in three regions of Germany and assessed the forest structure (LiDAR) as well as the diversity of the herbaceous layer and diversity and biomass of arthropods. We further assessed eco-morphological traits of the birds and tested if effects on bird assemblages are mediated by changes in eco-morphological traits' composition. We found that abundance and species numbers of birds are explained best by models including the major environmental factors, forest structure, plants, and arthropods. Eco-morphological traits only increased model fit for indirect effects on abundance of birds. We found minor differences between the three regions in Germany, indicating spatial congruency of the processes at the local and regional scale. Our results suggest that most birds are not specialized on a particular food type, but that the size, diversity and species composition of arthropods are important. Our findings question the general view that bird traits adapt to the resources available. [ABSTRACT FROM AUTHOR]

Copyright of Functional Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plants of the same species can strongly differ in their specialized metabolite profiles, which can affect insect presence and abundance in the field. However, how specialized chemistry shapes plant attractiveness to herbivorous insects is not fully understood. Here, we used common tansy Tanacetum vulgare, Asteraceae) – a perennial plant that is highly diverse in terpenoid composition and is known to have variable chemotypes – to test whether 1) plants with different chemotype profiles differ in attractiveness to two specialist aphid species, Macrosiphoniella tanacetaria and Uroleucon tanaceti, in pairwise choice assays; 2) the diversity of the terpenoid blend affects plant attractiveness to aphids; 3) how plant chemical traits relate to plant morphological traits and which traits best explain aphid preference. We found that M. tanacetaria preferred two out of five chemotypes, dominated by α‐thujone/β‐thujone and β‐trans‐chrysanthenyl acetate, while avoiding a chemotype dominated by α‐pinene/sabinene. Uroleucon tanaceti showed no clear preference towards chemotypes, but when given a choice between chemotypes dominated by α‐thujone/β‐thujone and by α‐pinene/sabinene, they preferred the former. Importantly, plant attractiveness to aphids was marginally negatively correlated with chemodiversity, i.e. the number of terpenoid compounds, in M. tanacetaria, but not in U. tanaceti. Interestingly, the relative concentration and number of terpenoids were generally higher in larger and bushier plants. Hence, we did not observe a tradeoff between plant growth and defence. We conclude that plant chemical composition affects plant attractiveness to aphids and hence may contribute to variation in natural aphid colonization patterns on plants of the same species. [ABSTRACT FROM AUTHOR]

Population growth, urbanization, and climate change have significantly contributed to environmental degradation, posing severe consequences for humans and other species. By integrating ecological objectives with human-centric goals, a path towards a sustainable, multi-species future is possible. Current sustainable design principles have shown positive environmental impacts by addressing human-centric objectives such as enhancing green infrastructure, energy efficiency, thermal comfort, and more. However, the incorporation of multi-species design criteria remains unresolved. This paper proposes a conceptual framework in which human-centric and ecological design objectives are defined and associated through the selection of key performance indicators (KPIs) represented by numerical thresholds. But, while the objective-KPI relationship is an established path in architectural design, the same does not apply for preserving and promoting biodiversity. The proposed conceptual framework identifies, defines, and associates the relevant objective-KPI relationships for all stakeholders and becomes the basis for evaluating the project computationally. Such an approach is currently lacking. [ABSTRACT FROM AUTHOR]

Ecosystem management aims at providing many ecosystem services simultaneously. Such ecosystem service multifunctionality can be limited by tradeoffs and increased by synergies among the underlying ecosystem functions (EF), which need to be understood to develop targeted management. Previous studies found differences in the correlation between EFs. We hypothesised that correlations between EFs are variable even under the controlled conditions of a field experiment and that seasonal and annual variation, plant species richness, and plot identity (identity effects of plots, such as the presence and proportion of functional groups) are drivers of these correlations. We used data on 31 EFs related to plants, consumers, and physical soil properties that were measured over 5 to 19 years, up to three times per year, in a temperate grassland experiment with 80 different plots, constituting six sown plant species richness levels (1, 2, 4, 8, 16, 60 species). We found that correlations between pairs of EFs were variable, and correlations between two particular EFs could range from weak to strong or negative to positive correlations among the repeated measurements. To determine the drivers of pairwise EF correlations, the covariance between EFs was partitioned into contributions from species richness, plot identity, and time (including years and seasons). We found that most of the covariance for synergies was explained by species richness (26.5%), whereas for tradeoffs, most covariance was explained by plot identity (29.5%). Additionally, some EF pairs were more affected by differences among years and seasons, showing a higher temporal variation. Therefore, correlations between two EFs from single measurements are insufficient to draw conclusions on tradeoffs and synergies. Consequently, pairs of EFs need to be measured repeatedly under different conditions to describe their relationships with more certainty and be able to derive recommendations for the management of grasslands. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) threatens natural ecosystems globally. While ALAN research is increasing, little is known about how ALAN affects plants and interactions with other organisms. We explored the effects of ALAN on plant defence and plant–insect interactions using barley (Hordeum vulgare) and the English grain aphid (Sitobion avenae). Plants were exposed to 'full' or 'part' nights of 15–20 lux ALAN, or no ALAN 'control' nights, to test the effects of ALAN on plant growth and defence. Although plant growth was only minimally affected by ALAN, aphid colony growth and aphid maturation were reduced significantly by ALAN treatments. Importantly, we found strong differences between full-night and part-night ALAN treatments. Contrary to our expectations, part ALAN had stronger negative effects on aphid colony growth than full ALAN. Defence-associated gene expression was affected in some cases by ALAN, but also positively correlated with aphid colony size, suggesting that the effects of ALAN on plant defences are indirect, and regulated via direct disruption of aphid colonies rather than via ALAN-induced upregulation of defences. Mitigating ecological side effects of ALAN is a complex problem, as reducing exposure to ALAN increased its negative impact on insect herbivores. This article is part of the theme issue 'Light pollution in complex ecological systems'. [ABSTRACT FROM AUTHOR]

Background: Agricultural yields have increased continuously over the last few decades. However, a focus solely on production can harm the environment. Diversification of agriculture has been suggested to increase production and sustainability. Biodiversity experiments showed positive effects on ecosystems and productivity. However, application of these results to intensively managed grasslands has been questioned due to differences in plant species and management regimes. Research on whether diversity can benefit multifunctionality, that is, an integrated index of multiple ecosystem functions, under intensive management, is still scarce. Methods: To address this, we manipulated plant species richness from one to six species spanning three functional groups (legumes, herbs, and grasses) in intensively managed multispecies grassland leys and examined seven ecosystem functions. Results: We found that multifunctionality increased with functional group and species richness. Legume+herb mixtures showed high multifunctionality, while grass monocultures and mixtures with high proportions of grasses had low multifunctionality. Different plant species and plant communities drove different ecosystem functions. Legumes and herbs improved productivity and water availability, while grasses enhanced invasion resistance. These results indicate that multifunctionality and individual ecosystem functions can be promoted through targeted combinations of plants with complementary ecological traits. Conclusions: Plant diversity can improve multifunctionality also under intensive management, potentially benefitting agroeconomics and sustainability. [ABSTRACT FROM AUTHOR]

Floral plantings adjacent to crops fields can recruit populations of natural enemies by providing flower nectar and non‐crop prey to increase natural pest regulation. Observed variation in success rates might be due to changes in the unseen community of endosymbionts hosted by many herbivorous insects, of which some can confer resistance to natural enemies, for example, parasitoid wasps. Reduced insect control may occur if highly protective symbiont combinations increase in frequency via selection effects, and this is expected to be stronger in lower diversity systems.We used a large‐scale field trial to analyse the bacterial endosymbiont communities hosted by cereal aphids Sitobion avenae collected along transects into strip plots of barley plants managed by either conventional or integrated (including floral field margins and reduced inputs) methods. In addition, we conducted an outdoor pot experiment to analyse endosymbionts in S. avenae aphids collected on barley plants that were either grown alone or alongside one of three flowering plants, across three time points.In the field, aphids hosted up to four symbionts. The abundance of aphids and parasitoid wasps was reduced towards the middle of all fields while aphid symbiont species richness and diversity decreased into the field in conventional, but not integrated, field‐strips. The proportion of aphids hosting different symbiont combinations varied across cropping systems, with distances into the fields, and were correlated with parasitoid wasp abundances.In the pot experiment, aphids hosted up to six symbionts. Flower presence increased natural enemy abundance and diversity, and decreased aphid abundance. The proportion of aphids hosting different symbiont combinations varied across the flower treatment and time, and were correlated with varying abundances of the different specialist parasitoid wasp species recruited by different flowers.Synthesis and applications. Floral plantings and flower identity had community‐wide impacts on the combinations of bacterial endosymbionts hosted by herbivorous insects, which correlated with natural enemy diversity and abundance. We recommend that integrated management practices incorporate floral resources within field areas to support a more functionally diverse and resilient natural enemy community to mitigate selection for symbiont‐mediated pest resistance throughout the cropping area. [ABSTRACT FROM AUTHOR]

Forests canopy gaps play an important role in forest ecology by driving the forest mosaic cycle and creating conditions for rapid plant reproduction and growth. The availability of young plants, which represent resources for herbivores, and modified environmental conditions with greater availability of light and higher temperatures, promote the colonization of animals. Remarkably, the role of gaps on insect communities has received little attention and the source of insects colonizing gaps has not been studied comprehensively. Using a replicated full-factorial forest experiment (treatments: Gap; Gap + Deadwood; Deadwood; Control), we show that following gap creation, there is a rapid change in the true bug (Heteroptera) community structure, with an increase in species that are mainly recruited from open lands. Compared with closed-canopy treatments (Deadwood and Control), open canopy treatments (Gap and Gap + Deadwood) promoted an overall increase in species (+ 59.4%, estimated as number of species per plot) and individuals (+ 76.3%) of true bugs, mainly herbivores and species associated to herbaceous vegetation. Community composition also differed among treatments, and all 17 significant indicator species (out of 117 species in total) were associated with the open canopy treatments. Based on insect data collected in grasslands and forests over an 11-year period, we found that the species colonizing experimental gaps had greater body size and a greater preference for open vegetation. Our results indicate that animal communities that assemble following gap creation contain a high proportion of habitat generalists that not occurred in closed forests, contributing significantly to overall diversity in forest mosaics. [ABSTRACT FROM AUTHOR]

Invertebrate herbivory is a crucial process contributing to the cycling of nutrients and energy in terrestrial ecosystems. While the function of herbivory can decrease with land‐use intensification, the underlying mechanisms remain unclear. We hypothesize that land‐use intensification impacts invertebrate leaf herbivory rates mainly through changes in characteristics of plants and insect herbivores. We investigated herbivory rates (i.e., damaged leaf area) on the most abundant plant species in forests and grasslands and along land‐use intensity gradients on 297 plots in three regions of Germany. To evaluate the contribution of shifts in plant community composition, we quantified herbivory rates at plant species level and aggregated at plant community level. We analyzed pathways linking land‐use intensity, plant and insect herbivore characteristics, and herbivory rates. Herbivory rates at plant species and community level decreased with increasing land‐use intensity in forests and grasslands. Path analysis revealed strong direct links between land‐use intensity and herbivory rates. Particularly at the plant community level, differences in plant and herbivore composition also contributed to changes in herbivory rates along land‐use intensity gradients. In forests, high land‐use intensity was characterized by a larger proportion of coniferous trees, which was linked to reduced herbivory rates. In grasslands, changes in the proportion of grasses, plant fiber content, as well as the taxonomic composition of herbivore assemblages contributed to reduced herbivory rates. Our study highlights the potential of land‐use intensification to impair ecosystem functioning across ecosystems via shifts in plant and herbivore characteristics. De‐intensifying land use in grasslands and reducing the share of coniferous trees in temperate forests can help to restore ecosystem functionality in these systems. [ABSTRACT FROM AUTHOR]

The patterns of successional change of decomposer communities is unique in that resource availability predictably decreases as decomposition proceeds. Saproxylic (i.e. deadwood‐dependent) beetles are a highly diverse and functionally important decomposer group, and their community composition is affected by both deadwood characteristics and other environmental factors. Understanding how communities change with faunal succession through the decomposition process is important as this process influences terrestrial carbon dynamics.Here, we evaluate how beta‐diversity of saproxylic beetle communities change with succession, as well as the effects of different major drivers of beta‐diversity, such as deadwood tree species, spatial distance between locations, climate and forest structure.We studied spatial beta‐diversity (i.e. dissimilarity of species composition between deadwood logs in the same year) of saproxylic beetle communities over 8 years of wood decomposition. Our study included 379 experimental deadwood logs comprising 13 different tree species in 30 forest stands in Germany. We hypothesized that the effects of tree species dissimilarity, measured by phylogenetic distance, and climate on beta‐diversity decrease over time, while the effects of spatial distance between logs and forest structure increase.Observed beta‐diversity of saproxylic beetle communities increased over time, whereas standardized effects sizes (SES; based on null models) of beta‐diversity decreased indicating higher beta‐diversity than expected during early years. Beta‐diversity increased with increasing phylogenetic distance between tree species and spatial distance among regions, and to a lesser extent with spatial distance within regions and differences in climate and forest structure. Whereas effects of space, climate and forest structure were constant over time, the effect of phylogenetic distance decreased.Our results show that the strength of the different drivers of saproxylic beetle community beta‐diversity changes along deadwood succession. Beta‐diversity of early decay communities was strongly associated with differences among tree species. Although this effect decreased over time, beta‐diversity remained high throughout succession. Possible explanations for this pattern include differences in decomposition rates and fungal communities between logs or the priority effect of early successional communities. Our results suggest that saproxylic beetle diversity can be enhanced by promoting forests with diverse tree communities and structures. [ABSTRACT FROM AUTHOR]

Insects are declining, but the underlying drivers and differences in responses between species are still largely unclear. Despite the importance of forests, insect trends therein have received little attention. Using 10 years of standardized data (120,996 individuals; 1,805 species) from 140 sites in Germany, we show that declines occurred in most sites and species across trophic groups. In particular, declines (quantified as the correlation between year and the respective community response) were more consistent in sites with many non-native trees or a large amount of timber harvested before the onset of sampling. Correlations at the species level depended on species' life-history. Larger species, more abundant species, and species of higher trophic level declined most, while herbivores increased. This suggests potential shifts in food webs possibly affecting ecosystem functioning. A targeted management, including promoting more natural tree species composition and partially reduced harvesting, can contribute to mitigating declines. Species richness and biomass of insects has declined on average across 140 forest sites sampled over a decade in Germany, with larger, more abundant, and carnivorous species found to be more susceptible to decline. [ABSTRACT FROM AUTHOR]

Aim: Environmental conditions define the suitability of an area for biotopes, and any area can be suitable for several biotopes. However, most previous studies modelled the distribution of single biotopes ignoring the potential co‐occurrence of biotopes in one area, which limits the usefulness of such models for conservation and restoration planning. In this study, we described the potential biotope composition of an area in response to environmental conditions. Location: Bavaria, Federal State of Germany. Methods: Based on the Bavarian biotope mapping data, we modelled the distribution of 29 terrestrial biotopes based on six climate variables and six chemical and four physical soil properties using the species distribution modelling algorithm Maxent. Results: For most biotopes, we found that climate variables were more important than soil variables for the biotope distribution and that the area of the predicted biotope distribution was larger than the observed distribution. The potential biotope composition illustrated that while 8% of the area in Bavaria was not sufficiently suitable for any analysed biotope, 92% of the modelled area in Bavaria was suitable for at least one biotope, 84% for two and 77% for at least three biotopes. The difference in suitability between the most suitable biotopes in composition was minor. Further, over one‐quarter of the modelled area was suitable for 6–8 different biotopes. Main Conclusions: Our study showed that considering a composition of potentially suitable biotopes in a raster cell, instead of only the most suitable biotope, provides valuable information to identify conservation priorities and restoration opportunities. [ABSTRACT FROM AUTHOR]

Simple Summary: People in cities have varying opinions about the animals around them, but there is rather little knowledge on how attitudes towards different urban animals compare with each other and how that relates to how familiar they are with them. Using self-reporting questionnaires, we found that students thought themselves familiar with most animals, and that the animals were not equally liked. While the more familiar animals were not also the better liked ones, we did find that attitudes towards familiar animals were more extreme on both the positive and negative sides. We suggest that more research in which drivers of attitudes towards many different animals can be compared is needed to reduce conflict between animal and human urban inhabitants. While there is growing consensus that nature should be promoted in cities, it is less clear what kind of nature this should be. One hypothesis is that humans show greater liking for those parts of nature that they know better. Using questionnaires, we studied the familiarity of 475 students with 91 urban animal species and the relationship between familiarity and attitudes towards the species. Students declared that they were familiar with most animals, but not all animals were equally liked. Better-known species were not generally the better-liked ones. The more familiar animal species were the more extreme attitudes became towards them, both positively and negatively. Our research shows that familiarity and attitude are not two sides of the same coin. It also emphasizes that there are parts of nature that are not liked by many humans and that this dislike is not necessarily correlated with insufficient knowledge. Detailed studies of what components of nature humans like and reasons underlying this are necessary to successfully increase nature in cities. [ABSTRACT FROM AUTHOR]

Copyright of People & Nature is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Numerous studies have demonstrated that biodiversity drives ecosystem functioning, yet how biodiversity loss alters ecosystems functioning and stability in the long-term lacks experimental evidence. We report temporal effects of species richness on community productivity, stability, species asynchrony, and complementarity, and how the relationships among them change over 17 years in a grassland biodiversity experiment. Productivity declined more rapidly in less diverse communities resulting in temporally strengthening positive effects of richness on productivity, complementarity, and stability. In later years asynchrony played a more important role in increasing community stability as the negative effect of richness on population stability diminished. Only during later years did species complementarity relate to species asynchrony. These results show that species complementarity and asynchrony can take more than a decade to develop strong stabilizing effects on ecosystem functioning in diverse plant communities. Thus, the mechanisms stabilizing ecosystem functioning change with community age. Biodiversity-ecosystem functioning relationships may change over time. Here, Wagg et al. show that richness-productivity and richness stability relationships grow stronger over time in an experimental grassland community, and shed light on the ecological mechanisms. [ABSTRACT FROM AUTHOR]

Numerous studies have demonstrated that biodiversity drives ecosystem functioning, yet how biodiversity loss alters ecosystems functioning and stability in the long-term lacks experimental evidence. We report temporal effects of species richness on community productivity, stability, species asynchrony, and complementarity, and how the relationships among them change over 17 years in a grassland biodiversity experiment. Productivity declined more rapidly in less diverse communities resulting in temporally strengthening positive effects of richness on productivity, complementarity, and stability. In later years asynchrony played a more important role in increasing community stability as the negative effect of richness on population stability diminished. Only during later years did species complementarity relate to species asynchrony. These results show that species complementarity and asynchrony can take more than a decade to develop strong stabilizing effects on ecosystem functioning in diverse plant communities. Thus, the mechanisms stabilizing ecosystem functioning change with community age. Biodiversity-ecosystem functioning relationships may change over time. Here, Wagg et al. show that richness-productivity and richness stability relationships grow stronger over time in an experimental grassland community, and shed light on the ecological mechanisms. [ABSTRACT FROM AUTHOR]

Copyright of Functional Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ecosystem functioning may directly or indirectly—via change in biodiversity—respond to land use. Dung removal is an important ecosystem function central for the decomposition of mammal faeces, including secondary seed dispersal and improved soil quality. Removal usually increases with dung beetle diversity and biomass. In forests, dung removal can vary with structural variables that are, however, often interrelated, making experiments necessary to understand the role of single variables on ecosystem functions. How gaps and deadwood, two main outcomes of forest management influence dung removal, is unknown.We tested if dung removal responds to gap creation and deadwood provisioning or if treatment effects are mediated via responses of dung beetles. We expected lower removal rates in gaps due to lower dung beetle biomass and diversity.We sampled dung beetles and measured dung removal in a highly‐replicated full‐factorial forest experiment established at 29 sites in three regions of Germany (treatments: Gap, Gap + Deadwood, Deadwood, Control). All gaps were experimentally created and had a diameter of around 30 m.Dung beetle diversity, biomass and dung removal were each lower in gaps than in controls. Dung removal decreased from 61.9% in controls to 48.5% in gaps, irrespective of whether or not the gap had deadwood. This treatment effect was primarily driven by dung beetle biomass but not diversity. Furthermore, dung removal was reduced to 56.9% in the deadwood treatment.Our findings are not consistent with complementarity effects of different dung beetle species linked to biodiversity‐ecosystem functioning relationships that have been shown in several ecosystems. In contrast, identity effects can be pronounced: gaps reduced the abundance of a large‐bodied key forest species (Anoplotrupes stercorosus), without compensatory recruitment of open land species. While gaps and deadwood are important for many forest organisms, dung beetles and dung removal respond negatively. Our results exemplify how experiments can contribute to test hypotheses on the interrelation between land use, biodiversity and ecosystem functioning. [ABSTRACT FROM AUTHOR]

Increasing plant species richness has been shown to positively affect the diversity of a range of other organisms, both above‐ and belowground. Although ants have a multitude of interactions with other organisms through their role as predators and mutualists, ants are a taxon that has rarely been investigated in studies of biodiversity effects. Ants are known to respond to changes in microclimatic conditions such as temperature and humidity, and these microclimatic conditions are known to be affected by vegetation characteristics such as standing biomass, which in turn can be affected by plant diversity. We investigated the effects of plant species richness (1–60), the number of plant functional groups (FGs; 1–4), and the presence of particular FGs on the occurrence and activity of ants, in the context of a grassland biodiversity experiment. Ant abundance, estimated as the mean number of workers in pitfall traps, and the number of colonies within plots, but not ant species richness, were negatively affected by plant species richness, and also by the identity of plant FGs, particularly legumes (negative effects) and grasses (positive effects). Statistical approaches showed that these effects were largely mediated by biotic (aboveground plant biomass: negative effect) and abiotic variables (soil temperature: positive effect). Notably, ant activity, measured as the mean number of workers foraging on baits and with a disproportionate dominance of a single species (Lasius niger), showed a more complex pattern, where plant species richness and number of FGs interacted to explain differential attractiveness to different resources (represented by sugar and tuna baits), likely representing current nutritional requirements for ants. Similarly, increasing soil temperature increased the level of ant activity, indicating that abiotic factors might impose thermal constraints on ectotherms inhabiting temperate grasslands. Our results indicate that a higher number of plant species and higher plant biomass had a negative effect on ants in experimental grasslands. Understanding the responses of an ecologically important group such as ants will allow us to infer the effects that biodiversity loss could have on animal‐mediated ecosystem processes. [ABSTRACT FROM AUTHOR]

The COVID‐19 pandemic has led to temporary changes in human–animal interactions due to changes in human activities. Here, we report on a surge in hedgehog observations during the first COVID‐19 lockdown in Germany in 2020, on the citizen science Web portal "Igel in Bayern" (Hedgehogs in Bavaria) in Germany. This increase in comparison with previous years was attributed to an increase in the number of people reporting hedgehog observations, rather than an increase in the number of hedgehog observations made by each observer. Additionally, in contrast to other studies on the effects of a COVID‐19 lockdown on observations recorded by citizen science projects, the share of observations made in more urbanized areas during the lockdown time was not higher than the change observed in less urbanized areas. This is possibly a result of the differences in COVID‐19 measures between Germany and other countries where preceding studies were carried out, in particular the lack of measures limiting traveling outdoor activities for citizens. [ABSTRACT FROM AUTHOR]

Deadwood is an important component of the global carbon cycle, and its decomposition releases carbon dioxide (CO2) and methane (CH4) into the atmosphere. However, the main drivers of these greenhouse gas emissions from deadwood are not well understood. We investigated drivers that govern the CO2 and CH4 emission rates of 793 deadwood specimens from 13 different tree species, which were exposed on 27 forest and 38 grassland plots at Schorfheide‐Chorin (Germany) for one year. Tree species identity was an important driver for emissions of both gases, whereas habitat type and management intensity were only important for CO2 emission rate. CO2 emission rates were positively linked to mass loss and were one‐third higher in forest compared to grassland habitats. The wood traits organic extractives, lignin, and sulfur content were negatively associated with CO2 emission rates, whereas carbon, nitrogen, and magnesium content showed the opposite effect. Among climate variables, air humidity in forest and soil moisture in grassland habitats positively affected CO2 emission rates. CH4 emission rates showed a negative relationship with increasing wood density exposed in both habitat types but were positively related to tree species with higher sulfur contents. Taken together, CO2 emission rates from deadwood were well predicted by wood traits, management intensity and climatic variables, whereas CH4 emission rates were less well predictable and were influenced only by wood traits that differed from those of CO2 emissions. Our results provide a deeper insight into the mineralization processes of deadwood and should be considered in further carbon cycle assessments. Plain Language Summary: Living trees are an essential reservoir for carbon storage. While the process of photosynthesis describes the ability of plants to fix atmospheric carbon, the decomposition of deadwood is the first stage of recycling this nutrient. Aerobic decomposition of deadwood is mainly carried out by specialized fungi that release carbon into the atmosphere during their respiration processes. Most microorganisms require oxygen to utilize deadwood and form carbon dioxide during respiration. In addition, archaea can respire carbon dioxide in the absence of oxygen, which leads to methane production. In our study, we determined the gas emission rates of carbon dioxide and methane for 13 tree species and investigated the influence of regional climate and habitat conditions and types (grassland and forest). The emission rates of carbon dioxide and methane largely differed among tree species, which probably depended on their wood traits. Both gas emission rates were higher under humidity, while higher temperatures increased only carbon dioxide emission rates. Methane emission rates were independent of habitat conditions, while carbon dioxide in forest habitats were higher and influenced by naturally existing tree species. Our results improve future assessment of the impact of deadwood on the global carbon cycle. Key Points: Tree species identity is an important driver of CO2 and CH4 emission ratesCO2 emission is two‐thirds higher in forest compared to grassland habitatsForest management intensity decreased CO2 emission rates, whereas CH4 was only affected by single management components [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Key message: TLS scans of three surveys before, during and after gypsy moth gradation, allowed high-resolution tracking of defoliation and subsequent inter-annual growth losses on an individual tree level. Foliation strongly determines all tree growth processes but can be reduced by various stress factors. Insect defoliation starts at variable times and is one stress factor that may affect photosynthetic processes and cause immediate reactions like refoliation, which are difficult to detect by surveys repeated at 1-year intervals. This study used a large-scale field experiment in German oak/mixed forests affected by gypsy moths (Lymantria dispar) to test the use of terrestrial laser scanning (TLS) for detecting inter-annual foliation and growth losses at the individual tree level caused by the gypsy moth. The experiment comprised two levels of gypsy moth defoliation risk, high (H) and low (L), as well as two pest control treatment levels: spraying with the insecticide Mimic (M) or unsprayed control (C). The factorial design consisted of four treatment combinations (HC, HM, LC, and LM), applied to 11 spatial blocks with a total of 44 plots. The TLS approach detected the defoliation caused by the gypsy moth, estimated as leaf area and crown perforation parameters. For the first time, TLS-derived tree foliation was evaluated based on inter-annual stem growth. Leaf area and crown perforation showed a correlation of + 0.6 and – 0.35, respectively, with basal area increments. Furthermore, this study revealed subsequent growth losses in the same year due to defoliation. Our results show that TLS can offer new opportunities to develop new indicators that monitor foliation at the individual tree level. The crown perforation can describe defoliation or the tree's vitality based on one scanning campaign, whereas the leaf area needed at least two. [ABSTRACT FROM AUTHOR]

Context: Current diversity and species composition of ecological communities can often not exclusively be explained by present land use and landscape structure. Historical land use may have considerably influenced ecosystems and their properties for decades and centuries. Objectives: We analysed the effects of present and historical landscape structure on plant and arthropod species richness in temperate grasslands, using data from comprehensive plant and arthropod assessments across three regions in Germany and maps of current and historical land cover from three time periods between 1820 and 2016. Methods: We calculated local, grassland class and landscape scale metrics for 150 grassland plots. Class and landscape scale metrics were calculated in buffer zones of 100 to 2000 m around the plots. We considered effects on total species richness as well as on the richness of species subsets determined by taxonomy and functional traits related to habitat use, dispersal and feeding. Results: Overall, models containing a combination of present and historical landscape metrics showed the best fit for several functional groups. Comparing three historical time periods, data from the 1820/50s was among the most frequent significant time periods in our models (29.7% of all significant variables). Conclusions: Our results suggest that the historical landscape structure is an important predictor of current species richness across different taxa and functional groups. This needs to be considered to better identify priority sites for conservation and to design biodiversity-friendly land use practices that will affect landscape structure in the future. [ABSTRACT FROM AUTHOR]

Quantifying tree defoliation by insects over large areas is a major challenge in forest management, but it is essential in ecosystem assessments of disturbance and resistance against herbivory. However, the trajectory from leaf‐flush to insect defoliation to refoliation in broadleaf trees is highly variable. Its tracking requires high temporal‐ and spatial‐resolution data, particularly in fragmented forests.In a unique replicated field experiment manipulating gypsy moth Lymantria dispar densities in mixed‐oak forests, we examined the utility of publicly accessible satellite‐borne radar (Sentinel‐1) to track the fine‐scale temporal trajectory of defoliation. The ratio of backscatter intensity between two polarizations from radar data of the growing season constituted a canopy development index (CDI) and a normalized CDI (NCDI), which were validated by optical (Sentinel‐2) and terrestrial laser scanning (TLS) data as well by intensive caterpillar sampling from canopy fogging.The CDI and NCDI strongly correlated with optical and TLS data (Spearman's ρ = 0.79 and 0.84, respectively). The ΔNCDIDefoliation(A‐C) significantly explained caterpillar abundance (R2 = 0.52). The NCDI at critical timesteps and ΔNCDI related to defoliation and refoliation well discriminated between heavily and lightly defoliated forests.We demonstrate that the high spatial and temporal resolution and the cloud independence of Sentinel‐1 radar potentially enable spatially unrestricted measurements of the highly dynamic canopy herbivory. This can help monitor insect pests, improve the prediction of outbreaks and facilitate the monitoring of forest disturbance, one of the high priority Essential Biodiversity Variables, in the near future. [ABSTRACT FROM AUTHOR]

Cities have been shown to be biodiverse, but it is unclear what fraction of a regional species pool can live within city borders and how this differs between taxa. Among animals, most research has focused on a few well-studied taxa, such as birds or butterflies. For other species, progress is limited by the paucity of data. We used species occurrence data for 11 taxa and 23 German cities from the Global Biodiversity Information Facility (GBIF) and the different German states, in a 50-km buffer around the city centre, to investigate what proportion of species of the regional species pools also occur in cities. While data could be obtained for all cities from GBIF, state databases only provided data for a subset of cities. Sample coverage of data from GBIF was higher across all taxa than of the state databases. For each database and taxon, we analysed (i) all cities where the number of occurrences of a taxon was >50 and (ii) only those cities where additionally sample coverage was >0.85. Across all taxa studied on average, 44.9 ± 7.2% (GBIF) and 40.8 ± 9.6% (German states) of the species of the regional species pool were also found in cities. When all cities were considered together, more than 76% of all species occurred within city borders. Our results show that German cities harbour a large part of the regional diversity of different taxa when city borders rather than the city centre is considered. This opens up ample opportunities for conservation and for fostering human–nature relationships. [ABSTRACT FROM AUTHOR]

Floral plantings are often used in agriculture to attract pollinator communities, but they also play an important role in recruiting and establishing natural communities for natural pest control. Inconsistent effects of floral plantings for pest control may be a result of an absence of mechanistic insights and a reliance on the idea that simply increasing flower diversity will benefit these services. A more tailored set of flower species may be needed to benefit the natural enemies through provision of nectar and alternative prey. We used an outside pot experiment to investigate the effect of three flower plants (Fagopyrum esculentum, Vicia faba, and Trifolium pratense) on reducing aphid pests on four different plant cultivars of barley (Hordeum vulgare), over two years. We grew the four cultivars of barley alone, next to a single flower or next to a mixture of flowers, and observed aphid and natural enemy colonization across the growing season. Aphid population sizes were reduced on all barley cultivars grown next to a flower with stronger pest suppression when all flowers were present. Each flower species recruited a different community of non‐barley aphids that, in turn, varied in their ability to establish the natural enemy populations and subsequently the ability to reduce barley aphid populations. Overall, increased pest suppression in the mixed treatments was a result of numerous weaker interactions between different flower, aphid, and natural enemy species, rather than a few dominant interactions. Natural enemy communities could be enhanced by incorporating flower species that vary in their ability to attract and host alternative prey (i.e., non‐pest aphids) as well as suitable nectar provisioning. We can use our knowledge of ecological interactions to tailor floral plantings to increase the effectiveness of pest control services. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to investigate the role of traits in beetle community assembly and test for consistency in these effects among several bioclimatic regions. We asked (1) whether traits predicted species' responses to environmental gradients (i.e. their niches), (2) whether these same traits could predict co-occurrence patterns and (3) how consistent were niches and the role of traits among study regions. Location: Boreal forests in Norway and Finland, temperate forests in Germany. Taxon: Wood-living (saproxylic) beetles. Methods: We compiled capture records of 468 wood-living beetle species from the three regions, along with nine morphological and ecological species traits. Eight climatic and forest covariates were also collected. We used Bayesian hierarchical joint species distribution models to estimate the influence of traits and phylogeny on species' niches. We also tested for correlations between species associations and trait similarity. Finally, we compared species niches and the effects of traits among study regions. Results: Traits explained some of the variability in species' niches, but their effects differed among study regions. However, substantial phylogenetic signal in species niches implies that unmeasured but phylogenetically structured traits have a stronger effect. Degree of trait similarity was correlated with species associations but depended idiosyncratically on the trait and region. Species niches were much more consistent--widespread taxa often responded similarly to an environmental gradient in each region. Main conclusions: The inconsistent effects of traits among regions limit their current use in understanding beetle community assembly. Phylogenetic signal in niches, however, implies that better predictive traits can eventually be identified. Consistency of species niches among regions means niches may remain relatively stable under future climate and land use changes; this lends credibility to predictive distribution models based on future climate projections but may imply that species' scope for short-term adaptation is limited. [ABSTRACT FROM AUTHOR]

Schall et al. (2020) assessed how a combination of different forest management systems in managed forest landscapes dominated by European beech may affect the biodiversity (alpha, beta and gamma) of 14 taxonomic groups. Current forest policy and nature conservation often demand for combining uneven‐aged managed and unmanaged, set‐aside for nature conservation, beech forests in order to promote biodiversity. In contrast to this, Schall et al. (2020) found even‐aged shelterwood forests, represented by different developmental phases, to support highest regional (gamma) diversity.By pointing out that unmanaged forests included in our study are not old‐growth forests, Bruun and Heilmann‐Clausen (2021) challenge our conclusion as not providing sound scientific advice to societies. It is true that the studied unmanaged forests are not representing old‐growth forests as defined in the literature. However, we demonstrate the representativeness of our unmanaged forests for current beech forest landscapes of Central Europe, where managed forests were more or less recently set‐aside in order to develop old‐growth structures. We also show that the managed and recently unmanaged forests in our study already differ distinctively in their forest structures.We use this response to stress the role of forest reserves for promoting certain species groups, and to emphasise their importance as valuable research sites today and in the future.Synthesis and applications. We see two main conclusions from our study. First, unmanaged forests still matter. We agree with Bruun and Heilmann‐Clausen (2021) on the general importance of unmanaged, old‐growth or long‐untouched forests, and we do not question the importance of set‐aside forests for biodiversity conservation. However, a complete complementarity to managed systems may only reveal after many decades of natural development. Second, safeguarding biodiversity in largely managed forest landscapes should focus on providing a landscape matrix of different developmental phases with varying environmental conditions rather than on maximising the vertical structure within stands. Such landscapes can partly compensate for structures that are still missing in vital, dense and closed forests recently set‐aside or for unsuitable phases that may occur due to a cyclic synchronisation of forest structures in unmanaged forests. [ABSTRACT FROM AUTHOR]

Intraguild predation is the killing and consuming of a heterospecific competitor that uses similar resources as the prey, and also benefit from preying on each other. We investigated the foraging behaviour of the gallmidge, Aphidoletes aphidimyza, a predator of aphids used for biological control that is also the intraguild prey for most other aphid natural enemies. We focus on how aphid alarm pheromone can alter the behaviour of the gallmidge, and predation by the anthocorid bug Orius laevigatus (O. laevigatus). We hypothesised that gallmidges would respond to the presence of (E)-β-farnesene (EBF) by leaving the host plant. Since feeding by Aphidoletes gallmidge larvae does not induce EBF emission by aphids, this emission indicates the presence of an intraguild predator. We found that gallmidge larvae reduced their foraging activities and left the plant earlier when exposed to EBF, particularly when aphids were also present. Contrastingly, gallmidge females did not change the time visiting plants when exposed to EBF, but lay more eggs on plants that had a higher aphid density. Lastly, EBF reduced the number of attacks of the intraguild predator, O. laevigatus, on gallmidge larvae, potentially because more gallmidges stopped aphid feeding and moved off the plant at which point O. laevigatus predated on aphids. Our work highlights the importance of understanding how intraguild predation can influence the behaviour of potential biological control agents and the impact on pest control services when other natural enemies are also present. [ABSTRACT FROM AUTHOR]

Internal feeding is considered to shield sessile herbivorous insects from exposure to nonsystemic insecticides aerially sprayed against forest defoliators, although this has not been tested. It is, however, established that leaf damage caused by defoliators affects the survivorship and oviposition behavior of sessile herbivores. Thus feeding ecology and competition may mediate nontarget effects of insecticides on these insects. We tested the ecological sensitivity of 3 guilds of sessile herbivores (upper‐surface leaf‐miners, lower‐surface leaf‐miners, and gall‐inducers) to the lipophilic larvicides diflubenzuron and tebufenozide aerially applied either at operational rates (12 g active ingredient [a.i.]/ha and 69.6 g [a.i.]/ha, respectively) or at maximum legal rates (60 g [a.i.]/ha and 180 g [a.i.]/ha, respectively), in German oak forests. Diflubenzuron affected leaf‐miners at different life stages depending on their position on the leaf but had no effect on gall‐inducers. Tebufenozide showed a similar, but not significant, pattern in leaf‐miners and did not affect gall‐inducers. By reducing the incidence of chewing damage on leaves, both insecticides offset the negative effect of competition on leaf‐miner and gall‐inducers. The net outcome of insecticide treatment was positive for guilds avoiding exposure, but negative for upper‐surface leaf‐miners. Exposure to insecticides in situ can be mediated by subtle differences in species biology and species interactions, with potential implications for organisms usually considered safe in risk assessment studies. Environ Toxicol Chem 2021;00:1–17. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Pearl bodies are produced by some plant species as food reward for ants and in exchange, ants defend these plants against insect pests. Sap-sucking pests such as aphids also excrete honeydew as food reward for ants, leading to potential conflict where ants could preferentially defend either the plant or the aphid. How pest insects might influence plant pearl body production, is yet to be investigated. Okra is a widely consumed vegetable worldwide and is attacked by the ant-tended cotton aphid. The plants produce pearl bodies, which are predominantly found on the underside of the leaves and formed from epidermal cells. We conducted a set of field and greenhouse experiments to explore plant-aphid-ant interactions, their influence on pearl body production and resulting performance of okra plants, across okra varieties. We found that ants of Pheidole genus, which are dominant in okra fields, preferred pearl bodies over aphid honeydew; although, their highest abundance was recorded in presence of both these food rewards, and on one okra variety. Removal of pearl bodies from the plants increased their production; however, plant growth and chlorophyll content were negatively associated with pearl body replenishment. Potentially to mitigate this resource cost, plants developed such a novel defense response because we found that aphid presence reduced pearl body production, but only when there were no ants. Finally, aphids negatively affected plant performance, but only at very high densities. As aphids also attract ants, plants may tolerate their presence at low densities to attract higher ant abundances. Our study highlights that plants can adapt their defense strategies in pest presence for efficient resource use. We suggest that understanding pearl body associated interactions in crop plants can assist in using such traits for pest management. [ABSTRACT FROM AUTHOR]

Aim: Despite increasing interest in β‐diversity, that is the spatial and temporal turnover of species, the mechanisms underlying species turnover at different spatial scales are not fully understood, although they likely differ among different functional groups. We investigated the relative importance of dispersal limitations and the environmental filtering caused by vegetation for local, multi‐taxa forest communities differing in their dispersal ability, trophic position and body size. Location: Temperate forests in five regions across Germany. Methods: In the inter‐region analysis, the independent and shared effects of the regional spatial structure (regional species pool), landscape spatial structure (dispersal limitation) and environmental factors on species turnover were quantified with a 1‐ha grain across 11 functional groups in up to 495 plots by variation partitioning. In the intra‐region analysis, the relative importance of three environmental factors related to vegetation (herb and tree layer composition and forest physiognomy) and spatial structure for species turnover was determined. Results: In the inter‐region analysis, over half of the explained variation in community composition (23% of the total explained 35%) was explained by the shared effects of several factors, indicative of spatially structured environmental filtering. Among the independent effects, environmental factors were the strongest on average over 11 groups, but the importance of landscape spatial structure increased for less dispersive functional groups. In the intra‐region analysis, the independent effect of plant species composition had a stronger influence on species turnover than forest physiognomy, but the relative importance of the latter increased with increasing trophic position and body size. Main conclusions: Our study revealed that the mechanisms structuring assemblage composition are associated with the traits of functional groups. Hence, conservation frameworks targeting biodiversity of multiple groups should cover both environmental and biogeographical gradients. Within regions, forest management can enhance β‐diversity particularly by diversifying tree species composition and forest physiognomy. [ABSTRACT FROM AUTHOR]

Background: How land use shapes biodiversity and functional trait composition of animal communities is an important question and frequently addressed. Land-use intensification is associated with changes in abiotic and biotic conditions including environmental homogenization and may act as an environmental filter to shape the composition of species communities. Here, we investigated the responses of land snail assemblages to land-use intensity and abiotic soil conditions (pH, soil moisture), and analyzed their trait composition (shell size, number of offspring, light preference, humidity preference, inundation tolerance, and drought resistance). We characterized the species' responses to land use to identify 'winners' (species that were more common on sites with high land-use intensity than expected) or 'losers' of land-use intensity (more common on plots with low land-use intensity) and their niche breadth. As a proxy for the environmental 'niche breadth' of each snail species, based on the conditions of the sites in which it occurred, we defined a 5-dimensional niche hypervolume. We then tested whether land-use responses and niches contribute to the species' potential vulnerability suggested by the Red List status. Results: Our results confirmed that the trait composition of snail communities was significantly altered by land-use intensity and abiotic conditions in both forests and grasslands. While only 4% of the species that occurred in forests were significant losers of intensive forest management, the proportion of losers in grasslands was much higher (21%). However, the species' response to land-use intensity and soil conditions was largely independent of specific traits and the species' Red List status (vulnerability). Instead, vulnerability was only mirrored in the species' rarity and its niche hypervolume: threatened species were characterized by low occurrence in forests and low occurrence and abundance in grasslands and by a narrow niche quantified by land-use components and abiotic factors. Conclusion: Land use and environmental responses of land snails were poorly predicted by specific traits or the species' vulnerability, suggesting that it is important to consider complementary risks and multiple niche dimensions. [ABSTRACT FROM AUTHOR]

Reports of major losses in insect biodiversity have stimulated an increasing interest in temporal population changes. Existing datasets are often limited to a small number of study sites, few points in time, a narrow range of land‐use intensities and only some taxonomic groups, or they lack standardised sampling. While new monitoring programs have been initiated, they still cover rather short time periods.Daskalova et al. 2021 (Insect Conservation and Diversity, 14, 1‐18) argue that temporal trends of insect populations derived from short time series are biased towards extreme trends, while their own analysis of an assembly of shorter‐ and longer‐term time series does not support an overall insect decline. With respect to the results of Seibold et al. 2019 (Nature, 574, 671–674) based on a 10‐year multi‐site time series, they claim that the analysis suffers from not accounting for temporal pseudoreplication.Here, we explain why the criticism of missing statistical rigour in the analysis of Seibold et al. (2019) is not warranted. Models that include 'year' as random effect, as suggested by Daskalova et al. (2021), fail to detect non‐linear trends and assume that consecutive years are independent samples which is questionable for insect time‐series data.We agree with Daskalova et al. (2021) that the assembly and analysis of larger datasets is urgently needed, but it will take time until such datasets are available. Thus, short‐term datasets are highly valuable, should be extended and analysed continually to provide a more detailed understanding of insect population changes under the influence of global change, and to trigger immediate conservation actions. [ABSTRACT FROM AUTHOR]

Background: Tansy plants (Tanacetum vulgare L.) are known for their high intraspecific chemical variation, especially of volatile organic compounds (VOC) from the terpenoid compound group. These VOCs are closely involved in plant-insect interactions and, when profiled, can be used to classify plants into groups known as chemotypes. Tansy chemotypes have been shown to influence plant-aphid interactions, however, to date no information is available on the response of different tansy chemotypes to simultaneous herbivory by more than one insect species. Results: Using a multi-cuvette system, we investigated the responses of five tansy chemotypes to feeding by sucking and/or chewing herbivores (aphids and caterpillars; Metopeurum fuscoviride Stroyan and Spodoptera littoralis Boisduval). Herbivory by caterpillars following aphid infestation led to a plant chemotype-specific change in the patterns of terpenoids stored in trichome hairs and in VOC emissions. The transcriptomic analysis of a plant chemotype represents the first de novo assembly of a transcriptome in tansy and demonstrates priming effects of aphids on a subsequent herbivory. Overall, we show that the five chemotypes do not react in the same way to the two herbivores. As expected, we found that caterpillar feeding increased VOC emissions, however, a priori aphid infestation only led to a further increase in VOC emissions for some chemotypes. Conclusions: We were able to show that different chemotypes respond to the double herbivore attack in different ways, and that pre-treatment with aphids had a priming effect on plants when they were subsequently exposed to a chewing herbivore. If neighbouring chemotypes in a field population react differently to herbivory/dual herbivory, this could possibly have effects from the individual level to the group level. Individuals of some chemotypes may respond more efficiently to herbivory stress than others, and in a group environment these "louder" chemotypes may affect the local insect community, including the natural enemies of herbivores, and other neighbouring plants. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The enemy release hypothesis (ERH) attributes the success of some exotic plant species to reduced top‐down effects of natural enemies in the non‐native range relative to the native range. Many studies have tested this idea, but very few have considered the simultaneous effects of multiple kinds of enemies on more than one invasive species in both the native and non‐native ranges. Here, we examined the effects of two important groups of natural enemies–insect herbivores and soil biota–on the performance of Tanacetum vulgare (native to Europe but invasive in the USA) and Solidago canadensis (native to the USA but invasive in Europe) in their native and non‐native ranges, and in the presence and absence of competition.In the field, we replicated full‐factorial experiments that crossed insecticide, T. vulgare–S. canadensis competition, and biogeographic range (Europe vs. USA) treatments. In greenhouses, we replicated full‐factorial experiments that crossed soil sterilization, plant–soil feedback, and biogeographic range treatments. We evaluated the effects of experimental treatments on T. vulgare and S. canadensis biomass.The effects of natural enemies were idiosyncratic. In the non‐native range and relative to populations in the native range, T. vulgare escaped the negative effects of insect herbivores but not soil biota, depending upon the presence of S. canadensis; and S. canadensis escaped the negative effects of soil biota but not insect herbivores, regardless of competition. Thus, biogeographic escape from natural enemies depended upon the enemies, the invader, and competition. Synthesis: By explicitly testing the ERH in terms of more than one kind of enemy, more than one invader, and more than one continent, this study enhances our nuanced perspective of how natural enemies can influence the performance of invasive species in their native and non‐native ranges. [ABSTRACT FROM AUTHOR]

Climate change is altering the dynamics of crop pests and diseases resulting in reduced crop yields. Using beneficial soil bacterial to increase crop health is a quickly developing area in sustainable agriculture, but it is unknown if climate change or interactions with other species could alter their effect. The plant growth-promoting rhizobacterium Acidovorax radicis N35 is known to increase barley (Hordeum vulgare) plant growth under laboratory conditions, and we tested the stability of the plant-bacterial interactions when exposed to elevated carbon dioxide (CO2) and ozone (O3) levels while infesting the aboveground leaves with cereal aphids (Sitobion avenae) and the soil with beneficial earthworms. Acidovorax radicis N35 increased plant growth and reduced insect growth – with greatest effect in a high-stress elevated O3 environment, but reduced effects under elevated CO2. Earthworms promoted both plant and insect growth, but inoculation with A. radicis N35 alleviated some of the earthworm-mediated increase in pest abundance, particularly in the ambient environment. The consistency of these beneficial effects highlights the potential of exploiting local species interactions for predicting and mitigating climate change effects in managed systems. We conclude that microbial bioprotectants have high potential for benefiting agriculture via plant-growth promotion and pest suppression. [ABSTRACT FROM AUTHOR]

Agricultural intensification is one of the main drivers of species loss worldwide, but there is still a lack of information about its effect on functional diversity of arable weed communities.Using a large‐scale pan European study including 786 fields within 261 farms from eight countries, we analysed differences in the taxonomic and functional diversity of arable weeds assemblages across different levels of agricultural intensification. We estimated weed species frequency in each field, and collected species' traits (vegetative height, SLA and seed mass) from the TRY plant trait database. With this information, we estimated taxonomic (species richness), functional composition (community weighted means) and functional diversity (functional richness, evenness, divergence and redundancy). We used indicators of agricultural management intensity at the individual field scale (e.g. yield, inputs of nitrogen fertilizer and herbicides, frequency of mechanical weed control practices) and at the landscape scale surrounding the field (i.e. number of crop types, mean field size and proportion of arable land cover within a radius of 500 m from the sampling points).The effects of agricultural intensification on species and functional richness at the field scale were stronger than those of intensification at the landscape scale, and we did not observe evidence of interacting effects between the two scales. Overall, assemblages in more intensified areas had fewer species, a higher prevalence of species with ruderal strategies (low stature, high leaf area, light seeds), and lower functional redundancy.Maintaining the diversity of Europe's arable weed communities requires some simple management interventions, for example, reducing the high intensity of field‐level agricultural management across Europe, which could be complemented by interventions that increase landscape complexity. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)