Agriculture, Ecosystems & Environment

The potential of alternative agricultural systems, such as organic or conservation agriculture, for biodiversity restoration has been widely investigated. However, variability of practices within each of these two categories of agricultural system has rarely been accounted for. Furthermore, these systems have most often been studied separately, isolating either organic or conservation agriculture (itself often reduced to a soil tillage reduction), and rarely analyzing these systems side by side. This study attempts to disentangle these multiple interrelationships by sampling carabid beetles in a network of 48 commercial Belgian farms including organic agriculture (OA), conservation agriculture (CA), farms combining the two approaches (OCA) and farms applying conventional practices (CVA). In each farm, we sampled carabids using pitfall and emergence traps in one winter cereal field and collected a detailed description of crop management practices. We found that community composition was primarily structured by seasonality early in the season (March, April) followed by convergence (May, June) driven by the aggregation of the most dominant species. Based on agroecosystem classification, organic certification (i.e., the absence of synthetic pesticide use) exerted a twofold stronger effect than application of conservation agriculture principles (i.e., reduced or no soil tillage) on carabid beetle community composition. Notably, OCA supported carabid assemblages that were structurally distinct from those of CA and CVA. Furthermore, carabid communities associated with OA differed significantly in composition from those of CVA. Observed and estimated species richness were also significantly higher in OCA than in CA and CVA, while OA differed from CVA only for observed richness. Beyond differences among agricultural systems, community responses were associated with specific management practices, which explained nearly a quarter of the compositional variation with significant influence of the duration since organic conversion and the frequency of synthetic pesticide application. Carabid abundances were negatively affected by synthetic pesticides and moldboard ploughing, whereas richness was more strongly related to the time since conversion to OA, cover crops, and organic amendments. Overall, these results position synthetic inputs and time since conversion as the main filters over carabid communities. Our study highlights the importance of jointly considering system level analyses and detailed management practices to better understand the complex relationships between agricultural practices and carabid communities.

1. Agriculture is the most significant driver of global land-use change, placing increasing pressure on biodiversity. Balancing rising food demand with the need to conserve biodiversity is therefore an urgent challenge, especially as biodiversity can underpin key ecosystem functions that support agricultural systems. A greater general understanding of how biodiversity influences agroecosystem function is critical for developing agricultural practices that benefit both agricultural production and wider ecosystem processes. 2. Using a global dataset of 184 biodiversity-agroecosystem function relationships covering agricultural and silvicultural systems, we developed a classification system for different biodiversity-enhancing approaches, ranging from the planting of multiple crop species to creating tree islands or flower strips, providing the first comprehensive assessment of how these approaches affect agroecosystem function. 3. We found biodiversity enhancement generally had a positive, or at least neutral, association with multiple agroecosystem functions, indicating that it contributes to agricultural sustainability. Crop diversification had the greatest impact on key agroecosystem functions compared to other practices, likely due to the low heterogeneity already present in agricultural systems and the scale at which crop diversification is applied and measured. Overall, biodiversity's largest effect was on multifunctionality, highlighting its role in supporting the simultaneous delivery of multiple agroecosystem functions. 4. Variability in relationships among systems and agroecosystem function categories suggests that no single biodiversity-enhancing approach will universally benefit all functions simultaneously. Instead, a combination of approaches, assessed through their contribution to overall multifunctionality, is likely to be most effective, ensuring that agricultural sustainability claims reflect benefits across systems. 5. Policies should incentivise biodiversity-enhancing management approaches as effective strategies to improve agroecosystem multifunctionality, benefiting both agricultural productivity and the wider ecosystem.

Polycultures have long been practiced in traditional agriculture, yet their ecology-based benefits have remained underexplored. Here, under realistic conditions, we experimentally evaluated the productivity and ecological interactions in cultivated milpa, a traditional Mesoamerican polyculture of maize, squash and beans, using a substitutive design in which total plant density was held constant while varying species composition. Specifically, we asked whether productivity gains arose through complementary or selection effects, and whether these gains were associated with changes in arthropod communities and herbivory. We additionally evaluated whether prior cultivation influenced maize performance in the following season. Milpa plots produced significantly higher total yields, more than 2.6 times those of monocultures, despite poor bean performance. In particular, squash and maize equivalent yields increased approximately threefold. We found that these improvements were mainly explained by complementary effects rather than selection effects. Arthropod communities responded in species-specific ways to crop diversity, with predator abundance tracking herbivore presence. However, no consistent patterns emerged between herbivore load, predator abundance and plant damage, suggesting that belowground plant interactions may play a more important role than top-down herbivore control in explaining complementarity effects. In the following season, maize yield increased by [~]30% in plots previously planted with squash or beans, with milpa plots showing intermediate responses. These findings demonstrate that milpa can substantially enhance productivity while generating benefits that extend into the advantages and soil into the following growing season. Overall, our results suggest that complementarity among crops is the primary driver of productivity in milpa under low-input conditions.

Carbon farming practices are increasingly adopted as part of regenerative agriculture to enhance soil carbon sequestration and improve agricultural sustainability. However, their effects on the phyllosphere microbiome, and how these interact with field biodiversity, remain poorly understood. We investigated how field biodiversity and carbon farming practices (cover crops, all-in mixes, adaptive grazing and ley mixture) influence leaf microbial communities across 19 Finnish farms using ITS and 16S amplicon sequencing. Foliar fungal - but not bacterial - diversity increased with plant species richness. Carbon farming altered both fungal and bacterial community composition, but only fungal community was positively associated with disease load. Network analysis identified three candidate keystone taxa: Alternaria sp. (FASV 34) and Sporobolomyces roseus (FASV 2070), which were mutually exclusive, and Methylobacterium sp. (BASV 75), which co-occurred with FASV 2070. Together, these findings demonstrate that different carbon farming practices shape distinct leaf microbiomes cover crop systems tending to favor potential fungal pathogens, whereas ley mixture and adaptive grazing strategies promote microbial taxa associated with healthier phyllosphere communities. Our study underscores the importance of understanding the complex microbial interactions within leaf ecosystems to inform sustainable agricultural practices.

Soil degradation is a widespread challenge that requires a broad response at the individual farm level. To ensure effectivity, the practices should be tailored to the farm context: land manager objectives and farm specific challenges. These have however been difficult to quantify. Here we demonstrate that a workable farm context can be created based on a value survey, open satellite and soil data, and published models for vegetation gross primary productivity and soil erosion. Based on the findings, despite individual differences, farmers value profitability and operational efficiency, but also biodiversity and soil health. At least the regenerative farmers surveyed also value working for the greater good more than maintaining tradition or power. In spite of wide differences in farm production orientation, we also found that each farm also had a broad variation in individual fields GPP. Most fields have a stable GPP level, which is either high or low, and that there is a 2-3-fold difference between the weakest and best producing fields indicating the potential for improving GPP by improving the growing conditions on currently weak fields. In addition, soil loss was found to be highly concentrated in critical source areas, where 10% of the field area contributed to 50% of the soil loss. Overall, open data can be linked to modelling workflows to rapidly produce a decision-making context for farmers. This facilitates benchmarking and co-learning as well as enables land managers and advisors to identify the farm context for planning effective responses to soil degradation.

Smallholder farming systems in sub-Saharan Africa are constrained by declining soil fertility, erosion, and rising fertilizer costs, creating an urgent need for scalable inputs that sustain yields while maintaining soil health. While there is some evidence that microbial inoculants may offer a promising complement to conventional fertility management, field-scale evidence in tropical cereal and tuber systems remains limited. Here, we evaluated a multi-species inoculant composed of 20-22 Bacillus and Streptomyces species on potato and maize across four sites in Rwanda over two growing seasons (2025A and 2025B). Treatments included the inoculant applied at two rates (150 and 250 g ha-1), both alone and in combination with standard fertilization (inorganic fertilizer plus manure), alongside untreated and fertilized controls. Co-application of the inoculant with standard fertilization increased yield and plant biomass beyond fertilization alone, with gains of 6-51% for maize and 3-58% for potato. However, while the inoculant applied alone outperformed untreated controls, it generally did not match standard fertilization. Responses were strongest and most consistent for large-grade potato tubers, and application rate interacted with crop type, whereby the lower dose maximized marketable tuber yield, while maize showed a positive dose-response for grain and biomass. Yield increases were not accompanied by reductions in crop nutrient density, which was instead governed by site-level differences. Altogether, these results indicate that multi-species microbial inoculants are an effective complement to existing fertility practices that may offer, pending further research, a potential pathway to partial fertilizer replacement while sustaining productivity and nutritional quality in smallholder tropical agriculture.

Aims Although ammonia-oxidising archaea (AOA) dominate nitrifier communities in many agricultural soils, the contribution of the less abundant ammonia-oxidising bacteria (AOB) to nitrogen oxide emissions, particularly nitric oxide, remains poorly understood. This study investigated the roles of AOA and AOB in regulating nitric oxide (NO) and nitrous oxide (N2O) emissions from a urea-fertilised grassland soil and evaluated the nitrification inhibitors dicyandiamide (DCD) and 3,4-dimethylpyrazole phosphate (DMPP). Methods A 28-day soil incubation experiment was conducted using a denitrification incubation system to continuously monitor NO and N2O emissions. In parallel, a destructive incubation experiment was performed to determine the dynamics of ammonium (NH-N) and total oxidised nitrogen (TOxN) and to assess changes in the abundance of AOA and AOB following urea application with or without DCD or DMPP. Results AOA accounted for approximately 66% of the total ammonia-oxidising community. Neither inhibitor significantly affected AOA abundance, whereas both suppressed AOB, with DMPP showing stronger and more persistent inhibition than DCD. DMPP reduced NO emissions by 16 to 75%, whereas N2O emissions decreased by only 0.2 to 27%. The greater reduction in NO, together with the preferential suppression of AOB, suggests that low-abundance AOB contributed disproportionately to NO production despite the numerical dominance of AOA. Conclusions These findings suggest that AOB can contribute disproportionately to NO emissions despite their lower abundance relative to AOA. The preferential suppression of AOB by DMPP was associated with a substantial reduction in NO emissions, highlighting AOB-associated processes as a potential target for mitigating reactive N losses from fertilised soils.

The reintroduction of extinct or endangered species to restore ecosystem function is an essential aspect of rewilding. The Wilder Blean Project at West Blean and Thornden Woods in Canterbury, UK, is committed to rewilding natural processes and enhancing biodiversity in one of England's oldest and largest areas of ancient woodland. The introduction of European bison (Bison bonasus) is an important part of the project. However, how the reintroduction of large herbivores influences local biodiversity and ecosystem functions during the early stages of rewilding remains poorly understood. Soil samples were collected from the same sampling sites before and two years after bison were reintroduced and profiled by metagenomic sequencing using Oxford Nanopore Technologies sequencing platforms. The results showed that the alpha diversity of soil organisms did not change significantly before and after the introduction of European bison, while beta diversity showed modest shifts in community composition. The relative abundance of some nitrogen-fixing and photosynthetic microbial genera showed declines in the 2024 Bison Area, while the mycorrhizal fungus genus Rhizophagus was significantly less abundant than in the 2024 Control Area. Despite relatively stable taxonomic diversity, functional composition differed significantly between the 2022 and 2024 Bison areas and among the 2024 rewilding treatments, revealing a decoupling between taxonomic diversity and functional composition. Amino acid synthesis pathways and carbon metabolism pathways were significantly enriched. These findings highlight the potential of long-read Oxford Nanopore metagenomics to reveal functional shifts that may not be apparent from taxonomic diversity alone. Although these early-stage responses cannot yet predict long-term rewilding trajectories, continued longitudinal monitoring integrating microbial, soil physicochemical, and ecosystem-level measurements will be essential to determine the persistence and ecological significance of these functional shifts.

Palm oil is the worlds leading vegetable oil, with production continuing to expand, particularly across Southeast Asia. Within established plantations, conserving and restoring riparian margins can reduce erosion, improve connectivity, and support biodiversity. Simultaneously, climate change is increasing thermal stress within tropical agricultural landscapes, raising the potential importance of riparian buffers as microclimatic refugia, although this has not previously been evaluated. The Riparian Ecosystem Restoration in Tropical Agriculture (RERTA) Project is a long-term Before-After Control-Impact experiment established within oil palm plantations in Riau, Indonesia, to evaluate alternative riparian restoration strategies following plantation replanting. Treatments included passive restoration (retaining mature oil palms and allowing natural regeneration), active restoration (enrichment planting with six native tree species), and a control (replanting immature oil palms to the river edge). Six years after restoration, we assessed vegetation structure using terrestrial laser scanning and thermal stability using temperature loggers and thermal imaging. We also evaluated the long-term temperature buffering capacity of each treatment under current and projected climates using CHELSA climate data and downscaled outputs from multiple General Circulation Models under Shared Socioeconomic Pathway scenarios for 2045 and 2085. Active restoration produced greater structural complexity, a more closed canopy, and cooler, more thermally stable conditions than passive restoration and control treatments. Restored margins also contained significantly more cool surface microhabitats, reducing thermal extremes under both current and future climate scenarios. Our findings demonstrate that active restoration of riparian margins can enhance thermal buffering and create microclimatic refugia for biodiversity within tropical oil palm landscapes. As agricultural intensification and climate change continue to reshape tropical ecosystems, restoring structurally complex riparian vegetation will be critical for sustaining biodiversity and the ecosystem services upon which agricultural production depends.

Temporal stability of plant populations is a key determinant of species coexistence and ecosystem functioning, yet its trait-based explanation has remained largely aboveground. Whether root functional traits contribute to long-term population stability remains poorly understood, despite roots mediating water and nutrient acquisition. We combined 17 years of vegetation monitoring from 150 temperate grassland plots across three regions in Germany with root functional trait data for 72 common grassland species. Temporal stability was computed as coefficient of variation (CV), with lower CV indicating higher stability. We tested whether root traits predict stability, and specifically which belowground dimensions from resource acquisition/conservation or soil exploration dominate, and whether differences in land use intensity modifies these relationships. Root traits were stronger and more consistent predictors of temporal stability than the classical aboveground traits specific leaf area (SLA) and leaf dry matter content (LDMC). Higher average root diameter (AD), root hair incidence (RHI), specific root length (SRL), and root tissue density (RTD) were generally associated with higher temporal stability, although the strength of these relationships varied among regions. Land use modified selected trait and stability relationships, with the strongest shifts occurring along the mowing gradient. Increasing mowing strengthened the associations of higher RHI and RTD with temporal stability, whereas the associations of AD and root N shifted towards lower stability. Our results identify belowground functional traits as an important missing component of trait-based temporal stability research and advance our understanding of the functional strategies underlying population temporal stability in managed semi-natural grasslands.

Morphological variation in insects can indicate responses to habitat change and land use intensification, with potential consequences for trophic interactions. In insect host-parasitoid systems, host body is often a key determinant of offspring development and emergence success, as well as parasitoid host-selection behavior. Yet, most studies in agricultural landscapes have focused on size variation in crop-associated insects (i.e.: pests, pollinators and enemies), leaving those relying on non-crop resources largely unexplored. Here, we investigated how agroenvironmental contexts and trophic resource availability influence puparial size in Protocalliphora sialia (Diptera: Calliphoridae), an obligate hematophagous ectoparasite of Tree Swallow (Tachycineta bicolor) nestlings. We further tested whether puparial size affects emergence probability and risk of parasitoidism by Nasonia spp. (Hymenoptera: Pteromalidae) jewel wasps. Using 1,513 P. sialia puparia from 88 nests within a nest-box monitoring system spanning a 10,200-km^2 east-west intensification gradient in southern Quebec, Canada, we evaluated how agrointensive contexts, avian host availability, and ectoparasite densities influence puparial size, parasitoidism risk, and emergence success. The agricultural context appears to shape puparial size through survival biases and/or altered growth rates. In agroextensive contexts (i.e.: pastures, forages with high tree cover), where Protocalliphora are more numerous, P. sialia puparia were smaller and exhibited greater size variation. Conversely, in agrointensive environments (maize and soybeans monocultures with higher doses of pesticides), where Protocalliphora are fewer, small individuals were underrepresented, suggesting a selective mortality in P. sialia population. However, puparial size explained less than 10% of the variation in emergence or parasitism, likely reflecting consistently high parasitic pressure from Nasonia wasps, which infested 50-90% of puparia, depending on site and year. Our findings highlight the importance of selective mortality in structuring trait distributions and modulating multi-trophic interactions in human-modified landscapes.

1. Grassland ecosystems are pivotal for global biodiversity, carbon (C) storage and food security. This biome, however, together with the ecosystem services it provides, is threatened by global change perturbations. These perturbations rarely occur in isolation and most often affect environments simultaneously, which is a pressing issue in ecology. Nevertheless, most of the research conducted so far has focussed on single simultaneous perturbations or pairs thereof. The few examples considering the effect of more than two simultaneous perturbations focussed only on plants or soil separately, which ignores the potential buffering or feedback effects on ecosystem functioning induced by plant-soils interactions. 2. To tackle this knowledge gap, we used an experimental setup involving mesocosms (soil and plants intact) collected in an extensively managed permanent grassland. Mesocosms were arranged in a greenhouse experiment where we applied individual and combined global change perturbations (up to ten in total) including application of fertilisers, pesticides and antibiotics, simulated trampling and grazing, heat stress and drought. Measured ecosystem functions and properties included a large set of biological, physical and chemical soil and plant associated variables. 3. Results showed that multiple perturbations in most cases had negative effects irrespective of the direction found for individual perturbations. However, in contrast to previous bare soil experiments, we only found scarce evidence for substantial synergistic effects of simultaneous perturbations in our experiment conducted with mesocosms that contained vegetation. This suggests a mitigating impact of plants on soil responses to global change. Moreover, we found a strong dominative effect of drought on ecosystem functioning, driving most of the effects observed. 4. Synthesis: Our results highlight the importance of evaluating global change impacts under more realistic settings, i.e., applying multiple perturbations simultaneously and including plant-soil interactions. Mitigation of global change in terrestrial ecosystems will only be possible once we holistically understand how ecosystems respond to altered conditions.

Exotic pests and pathogens pose a major threat to forest ecosystems. Early detection of newly introduced organisms is critical for implementing effective eradication measures before they become established. Citizen science platforms have emerged as promising sources of biodiversity data for detecting invasive pests and pathogens, yet their integration into formal biosecurity surveillance remains limited. Using France as a case study, we surveyed 101 professionals involved in forest and urban tree management and pest surveillance to assess their knowledge of regulated tree pests and pathogens and their attitudes towards online citizen science platforms for biosecurity applications. We focused on ten focal species representing different regulatory statuses under EU legislation. We assessed the knowledge professionals have of these species and their regulatory status, and explored sources of variation in their opinions regarding the use of citizen science platforms as a tool for post-border biosecurity. Experts involved in mandatory surveillance of regulated organisms (SORE experts) demonstrated consistent knowledge of quarantine pests, whereas other professionals knowledge varied by species, with greater familiarity for non-quarantine, widely distributed pests. Half of respondents used citizen science platforms, predominantly to consult species distribution rather than to contribute observations. Professionals receptivity to citizen science increased significantly when species were perceived as easy to identify, but they expressed more confidence in citizen science for monitoring established pests than for the early detection of quarantine species. The survey reveals that while citizen science platforms are known and valued as information sources, they remain underutilized as mechanisms for sharing field observations, even among surveillance professionals.

Soil is one of the most biodiverse habitats on the planet, yet the extent of soil biodiversity knowledge in Canada is unknown. To better understand our knowledge, we systematically mapped soil invertebrate biodiversity knowledge from peer-reviewed literature to identify spatial and taxonomic gaps and to assess whether areas projected to experience different magnitudes of climate change are adequately sampled. A total of 1,176 Canadian sampling locations were identified from 427 articles. We found biases in sampling coverage spatially and in relation to current and projected climatic conditions. The geographic region above 60 degrees North is sparsely sampled. Colder regions (< -0.12 C) and regions receiving the least (< 646.47 mm), moderately high (2268.67 to 2809.40 mm), and high (2809.40 to 3350.14 mm) amounts of precipitation were under sampled. Regions projected to have the smallest (< 0.86 C) and greatest (> 1.59 C) magnitudes in temperature change and regions projected to have moderate (-2.06 to +2.69 mm) to large changes (+2.69 to +7.44 mm) in precipitation were underrepresented. The sampled locations also suffer from taxonomic biases which were skewed toward Nematoda (19%), Annelida (18%), Acari (15%), and Collembola (14%). Our results suggest that methods such as stratified sampling is essential to capture underrepresented regions, taxonomic groups, and an array of current and projected climatic conditions. Additionally, shifting to a multispecies sampling approach is essential for broader soil ecosystem knowledge. Importantly, data from well-sampled areas should be examined to determine how it can be leveraged to advance conservation management of soil invertebrates.

Stink bugs (Hemiptera Pentatomidae) are major agricultural pests worldwide, including both native and invasive species. In France, for instance, Halyomorpha halys has rapidly expanded its range, affecting key crops such as hazelnuts, apples, and vegetables. Meanwhile, several native, polyphagous species - Nezara viridula, Palomena prasina and, to a lesser extent, Graphosoma italicum - are re-emerging and impacting diverse crops because of changes in agricultural practices and climatic conditions. Egg parasitoids represent promising biological control agents for these pests, be it through conservation, augmentation or introduction biological control. However, their actual potential is not precisely documented due to a lack of ambitious surveys and possible taxonomic issues. This study aims to address this gap by compiling results obtained from various of egg parasitism surveys of Pentatomidae in France and implementing a large-scale DNA Barcoding approach (2000 individuals) for the emerged parasitoids. Our results indicate a high diversity of egg parasitoids, and detected some taxonomic issues and molecular inconsistencies that warrant further study. Among the three families of egg parasitoids recovered (Encyrtidae, Eupelmide, and Scelionidae), Scelionidae was the most abundant and diverse with nine species of Trissolcus (including the two adventive species, Tr. japonicus and Tr. mitsukurii) and four Telenomus species (including two unidentified to species). Scelionidae dominated the parasitoid assemblages associated with most of the Pentatomidae host species, except for H. halys for which the eupelmid Anastatus bifasciatus was the most common species.

Background and aims Alpine ecosystems are highly sensitive to climate change, with rising temperatures threatening ecosystem structure and function. This study examined the short-term responses of alpine grassland ecosystems (Mont Blanc, Italy) to projected climate scenarios using an Ecotron mesocosm experiment. Methods Ecosystem monoliths were exposed to current (~420 ppm CO2) and future CO2; concentrations (~550 and ~800 ppm) under RCP 4.5 and RCP 8.5 scenarios, incorporating changes in temperature, precipitation, humidity, and radiation. CO2; fluxes (NEP, GPP, Reco), soil chemistry, vegetation coverage, above- and belowground biomass, and plant functional traits were assessed throughout the experiment. Results Alpine grassland ecosystems withstood moderate warming (RCP 4.5), while under severe warming (RCP 8.5), GPP, vegetation cover and biomass increased with a shift toward aboveground allocation, although daytime NEP remained stable as gains were offset by higher Reco, with no detectable water and nutrients limitations. On a diel basis, higher GPP was offset by enhanced Reco, indicating a potential towards net C loss. Salix herbacea exhibited functional trait adjustments-higher LMA and Na, and elevated delta15N-reflecting greater leaf longevity, water-use efficiency, and altered nitrogen metabolism, suggesting potential community reorganization. Conclusion Over a single growing season, alpine ecosystems appeared relatively stable under moderate warming. However, under the more severe RCP 8.5 scenario, biomass allocation shifted toward greater aboveground and reduced belowground investment, leading to altered C fluxes that, if sustained over the long-term, could drive the ecosystem C balance from a sink to a source. Responses were plant species-specific, indicating uneven acclimation within the community.

Abstract Background: Soil microbiomes play critical roles in plant health and resilience, yet it is still poorly understood how disruptions in local microbial communities, such as during soil management, impact these ecological functions. In this study, we investigated how compost addition, a widely used soil management practice, and microbiome origin influence microbiome-mediated plant resistance to insects. We combined surveys of working organic farms across New York with controlled laboratory experiments, amplicon sequencing, plant-insect bioassays, and mass spectrometry. Results: Compost use was associated with shifts in the relative abundance of 20 fungal and 2 bacterial genera across ten working farms. However, no consistent changes in bacterial or fungal diversity or community structure in fields with compost were observed across the farms. Under controlled conditions using a common compost source, compost increased rhizosphere microbial diversity and significantly altered rhizosphere community structure, including the relative abundance of 6 fungal and 41 bacterial genera. Despite these substantial community-level changes, compost did not affect populations of green peach aphids (Myzus persicae) on kale (Brassica oleracea). Instead, aphid populations and plant salicylic acid concentrations were more strongly associated with microbiome origin, demonstrating that compost can substantially restructure soil and rhizosphere microbial communities without corresponding changes in microbiome-mediated plant resistance to insects. Conclusions: Our findings demonstrate that microbial diversity and compositional responses to management are not necessarily reliable indicators of all microbiome functions. More broadly, this work highlights the importance of local soil microbiome variation in shaping plant-insect interactions and emphasizes the need to link community-level responses to direct functional measurements when evaluating microbiome responses to agricultural management.

1. As city populations expand globally, understanding how urbanization shapes ecosystem services is increasingly important. Urban agriculture plays a key role in food access, particularly in low-income areas with limited access to fresh produce. Arthropods play important roles in these systems through pollination, herbivory, pest control, and nutrient cycling. Urban development of natural areas often reduces biodiversity, including that of arthropods. Additionally, urban biodiversity frequently correlates positively with socioeconomic conditions, a pattern known as the luxury effect. 2. In this study, we examined how gradients in urbanization and socioeconomic context relate to local and landscape habitat quality, arthropod abundance, and pollination services across 21 community gardens in the Denver, CO Metro Area. To quantify ecosystem services, we employed a sentinel plant, Cucumis sativus (cucumber), and collected arthropods (insects, myriapods, arachnids, isopods), assigning them to functional groups based on their known feeding behavior. We evaluated direct and indirect pathways linking urban matrix characteristics to arthropod-mediated ecosystem services. 3. The abundance of all arthropod groups (including pollinators, herbivores, and natural enemies) declined steeply with increasing impervious surface. Neighborhood wealth was associated only with bee species richness and Shannon diversity and displayed a hump-shaped pattern that peaked at wealth levels 35-46% above the national average, then declined. Multivariate GLMs revealed that Western honeybees (Apis mellifera) were the only species driving differences in bee community composition, with their abundance positively related to neighborhood wealth. 4. We also observed pollen limitation in our cucumber plants, and as bee Shannon diversity increased, cucumber production increased. Environmental covariates alone showed no direct relationship with cucumber production, indicating that insect pollination mediated this effect. This work identifies the biophysical and social-ecological drivers of urban arthropod biodiversity and ecosystem services, revealing where crop production may be most vulnerable to decline in cities.

1. Grassland biodiversity restoration efforts have largely focused on re-establishing diverse plant communities, with less attention paid to higher trophic levels such as invertebrates. 2. We established a controlled, field-scale restoration experiment across twelve lowland grassland sites in Switzerland in close collaboration with farmers. We manipulated seed addition (hay transfer, directly harvested seeds, or multiplied seed mixtures) and soil disturbance (shallow or deep tillage), with treatments applied to meadows covering, on average, 0.5 ha. Four to six years after restoration, we quantified the components of species richness change (lost, persisting, gained from site surroundings, and gained from donors), and estimated dark diversity (species that are absent from a location but could potentially occur there) for plants, Auchenorrhyncha and Orthoptera. 3. Compared to plants, invertebrates exhibited greater species turnover, with higher proportions of species lost and gained from the surroundings, but much lower contributions from the donor meadows. However, species persistence was high across taxa. Restoration operations strongly influenced components of species richness change in plants but had weaker effects on invertebrates. In particular, multiplied seed mixtures + deep tillage had the highest proportion of plant species not transferred, suggesting that many species in the seed mixture were poorly suited to local conditions. In both plants and Auchenorrhyncha, components of species richness change were strongly mediated by site characteristics, with initial species richness in both receiver and donor emerging as the strongest predictors. 4. Within each taxonomic group, 41% of species not transferred from the donor belonged to the dark diversity, suggesting substantial unrealized restoration potential. Restoration operations impacted dark diversity for plants and Auchenorrhyncha but not for Orthoptera. In plants, dark diversity was substantially lower under multiplied seed mixtures + deep tillage than under other treatments. The probability of a species belonging to dark diversity was associated with specific leaf area in plants and initial relative abundance in Auchenorrhyncha. 5. Synthesis and applications. Components of species richness change were influenced by both restoration operations and site characteristics, with their relative importance varying among taxa, underscoring the need for multi-taxon restoration strategies.

The invasive gallwasp Dryocosmus kuriphilus was first detected in Italy in 2002, although likely to have initially arrived in the late 90s. Its ability to utilise sweet chestnut species non-native to its original Chinese range has allowed it to spread rapidly, and throughout Europe via European sweet chestnut Castanea sativa. Given the severity of its impact on C. sativa crop production, particularly in Mediterranean countries, previous studies have aimed to assess damage levels caused by D. kuriphilus, the efficacy of and potential non-target effects of the introduced biocontrol agent Torymus sinensis, and the possibility of regulation by native parasitoids. As yet a broad overview and analytical synthesis of these native parasitoid communities are absent. This review focuses on important aspects of the D. kuriphilus invasion. In particular, the invasion history and currently known distribution of D. kuriphilus, and several aspects of its associated parasitoid community. For native species to plausibly suppress D. kuriphilus, we might expect rates of parasitoid attack to increase with establishment time as native populations adapt to exploit the new resource, and this is a key focus of the review. We answer the following questions: 1) What is the distribution of D. kuriphilus in Europe, and has D. kuriphilus fully utilised the available niche space within its 20+ years in Europe? 2) Which species of native parasitoids attack D. kuriphilus in Europe and what are their ecological characteristics? 3) How consistent is the parasitoid community of D. kuriphilus across its range, and are there signs of convergence over time? 4) What effect does establishment time have on the species richness and abundance of parasitoid communities? We report the following: 1) D. kuriphilus has expanded its range throughout Europe and is present in nearly every major region where sweet chestnut is present. Native and non-native naturalised chestnut forests may be less susceptible to invasion than areas of industry due to differing socioeconomic and ecological factors, though areas with large chestnut industries also tend to be in the most heavily forested areas in the non-native range of sweet chestnut. D. kuriphilus has reportedly been eradicated from some countries, and effectively eradicated in a number of countries implementing biocontrol with T. sinensis, although successive invasions from neighbouring regions are still possible, and eradication may be transient. 2) 72 parasitoid species are identified attacking D. kuriphilus in Europe (far more species than any other gallwasp in the Western Palearctic). Its members are predominantly oak gallwasp parasitoids (82% of species), followed by gall-specialists of different host plants, leaf miner parasitoids and a minority of others with differing host life stages and ecologies. Parasitoids attacking D. kuriphilus are dominated by idiobiont ectoparasitoids of the superfamily Chalcidoidea (>96%). 3) The parasitoid community is highly variable, both temporally and spatially, although the vast proportion (>95%) of parasitoids at any one time are composed of locally common generalist oak gall parasitoids. The most common members include Bootanomyia dorsalis, Eupelmus urozonus, Eurytoma brunniventris, Mesopolobus sericeus and Torymus flavipes. 4) The length of establishment time has minimal effect on the species richness, abundance, and composition of the community, suggesting that regulation by natives, if it occurs, may take longer than the 20+ years that D. kuriphilus has persisted. While little evidence of increasing parasitoid attack of D. kuriphilus is apparent, we exercise caution by stating that the heterogeneity in available data are large, and that common biocontrol interventions using T. sinensis interrupt the natural process of community development dramatically. D. kuriphilus has been present in Europe for nearly three decades and few localities have repeated years of data collection. Even fewer studies have communities with establishment times exceeding ten years. Proper biocontrol by natives may not occur within short timeframes, although studies of other gallwasp invaders find similar results over periods exceeding 40 years. Given that many countries have chosen to implement T. sinensis for biocontrol, the focus may be better spent monitoring native gall communities for potential non-target effects.