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Funder: Consejo Nacional de Ciencia y Tecnolog?a, Funder: Rural and Environment Science and Analytical Services Division, Funder: Montana Department of Agriculture, While wild pollinators play a key role in global food production, their assessment is currently missing from the most commonly used environmental impact assessment method, Life Cycle Assessment (LCA). This is mainly due to constraints in data availability and compatibility with LCA inventories. To target this gap, relative pollinator abundance estimates were obtained with the use of a Delphi assessment, during which 25 experts, covering 16 nationalities and 45 countries of expertise, provided scores for low, typical, and high expected abundance associated with 24 land use categories. Based on these estimates, this study presents a set of globally generic characterization factors (CFs) that allows translating land use into relative impacts to wild pollinator abundance. The associated uncertainty of the CFs is presented along with an illustrative case to demonstrate the applicability in LCA studies. The CFs based on estimates that reached consensus during the Delphi assessment are recommended as readily applicable and allow key differences among land use types to be distinguished. The resulting CFs are proposed as the first step for incorporating pollinator impacts in LCA studies, exemplifying the use of expert elicitation methods as a useful tool to fill data gaps that constrain the characterization of key environmental impacts.

Trophic rewilding that reintroduces large animals into landscapes to re-establish food web interactions and restore biodiverse ecosystems has gained widespread attention. Despite this attention, few empirical studies have assessed the effectiveness of trophic rewilding for promoting biodiversity and its wider ecological benefits. Here we tested if trophic rewilding that introduced functional analogues for extinct large herbivores into former farmland of lowland England delivered additional benefits to biodiversity and ecosystems functioning. We predicted that these benefits would exceed those achieved through passive rewilding, that is unassisted habitat succession after the cessation of agricultural activity. Using a 9-year exclosure experiment, we found trophic rewilding reduced woody plant diversity and total carbon storage by 73% and 23%, respectively, compared to passive rewilding plots that excluded mammalian herbivores. However, trophic rewilding likely increased plant diversity and carbon storage compared to if land was left under continued agricultural production, e.g. artificial pastures associated with intensive livestock production. The vegetation changes accompanying trophic rewilding were further linked to a greater diversity and biomass of ground-dwelling arthropods by 21% and 167%, respectively, relative to passive rewilding, partly by creating more structurally complex vegetation. Given the trade-offs in biodiversity and ecosystem functions between trophic and passive rewilding, our study highlights that trophic rewilding will need to be applied alongside other interventions to tackle biodiversity loss whilst combatting climate change. Ultimately, the utility of trophic rewilding as a restoration tool will depend on the conservation outcomes valued by society.

1. While abiotic drivers of yields represent important limiting factors to crop productivity, the role of biotic drivers that could be directly managed by farmers (e.g. agri-environment schemes supporting key ecosystem services) remains poorly understood. Precision yield mapping provides an opportunity to understand the factors that limit agricultural yield through the interpretation of high-resolution cropping data. This has the potential to inform future precision agricultural management, such as the targeted application of agrochemicals, promoting increased sustainability in modern agricultural systems. 2. We used precision yield measurements from a network of 1174 fields in England (2006–2020) to identify drivers of within-field yield variation in winter wheat and oilseed rape. Potential drivers included climate, topography and landscape composition and configuration. We then explored relationships between in-field yield patterns and local landscape context, including the presence of features associated with ecosystem benefits. 3. Proximity to the field edge was associated with reduced yields in 85% of wheat and 87% of oilseed fields. This translating to an approximate reduction of 10% in wheat and 18% in oilseed yields lost due to field edge effects. 4. We found evidence that reduced yields at the field edges were associated with biotic features of the surrounding landscape, including the occurrence of semi-natural habitats. Specifically, agri-environment scheme (AES) presence increased the rate at which yields at field edges approach those of the field centres. This suggests that AES occurrence within a landscape (rather than field adjacent) may increase edge effects. However, these trends are unclear and suggest interactions between drivers and the spatial and temporal scale of investigation. 5. Synthesis and applications. While we found evidence of landscape context mitigating against field edge effects, these were counterintuitive. For example, AES at a landscape scale appeared to increase the severity of edge effects. This study highlights a lack of environmental data at sufficiently high spatiotemporal resolution to match that of precision agriculture data. This mismatch is hindering the effective integration of precision agriculture data in an environmental policy and/or management context and potentially leading to unnecessarily poorly informed decisions related to AES deployment. This may limit environmental and economic benefits.

SummaryEcological theory posits that temporal stability patterns in plant populations are associated with differences in species’ ecological strategies. However, empirical evidence is lacking about which traits, or trade-offs, underlie species stability, specially across different ecosystems.To address this, we compiled a global collection of long-term permanent vegetation records (>7000 plots from 78 datasets) from a wide range of habitats and combined this with existing trait databases. We tested whether the observed inter-annual variability in species abundance (coefficient of variation) was related to multiple individual traits and multivariate axes of trait variations (PCoA axes).We found that species with greater leaf dry matter content and seed mass were consistently more stable over time (lower variability in species abundance) although other leaf traits played a significant role as well, albeit weaker. Using multivariate axes did not improve predictions by specific traits.Our results confirm existing theory, providing compelling empirical evidence on the importance of specific traits, which point at ecological trade-offs in different resource use and dispersal strategies, on the stability of plant populations worldwide.

Analysing temporal patterns in plant communities is extremely important to quantify the extent and the consequences of ecological changes, especially considering the current biodiversity crisis. Long-term data collected through the regular sampling of permanent plots represent the most accurate resource to study ecological succession, analyse the stability of a community over time and understand the mechanisms driving vegetation change. We hereby present the LOng-Term Vegetation Sampling (LOTVS) initiative, a global collection of vegetation time-series derived from the regular monitoring of plant species in permanent plots. With 79 data sets from five continents and 7,789 vegetation time-series monitored for at least 6 years and mostly on an annual basis, LOTVS possibly represents the largest collection of temporally fine-grained vegetation time-series derived from permanent plots and made accessible to the research community. As such, it has an outstanding potential to support innovative research in the fields of vegetation science, plant ecology and temporal ecology., The authors acknowledge institutional support as follows. Nicola J. Day: Te Apārangi Royal Society of New Zealand (Rutherford Postdoctoral Fellowship). Jiří Danihelka: Czech Science Foundation (project no. 19-28491X) and Czech Academy of Sciences (project no. RVO 67985939). Francesco de Bello: Spanish Plan Nacional de I+D+i (project PGC2018-099027-B-I00). Eric Garnier: La Fage INRA experimental station. Tomáš Herben: GAČR grant 20-02901S. Anke Jentsch: German Federal Ministry of Education and Research (grant 031B0516C - SUSALPS) and Oberfrankenstiftung (grant OFS FP00237). Norbert Juergens: German Federal Ministry of Education and Research (grant 01LG1201N - SASSCAL ABC). Frédérique Louault and Katja Klumpp: AnaEE-France (ANR-11-INBS-0001). Robin J. Pakeman: Strategic Research Programme of the Scottish Government's Rural and Environment Science and Analytical Services Division. Meelis Pärtel: Estonian Research Council (PRG609) and European Regional Development Fund (Centre of Excellence EcolChange). Josep Peñuelas: Spanish Government (grant PID2019-110521GB-I00), Fundación Ramon Areces (grant ELEMENTAL-CLIMATE), Catalan Government (grant SGR 2017-1005), and European Research Council (Synergy grant ERC-SyG-2013-610028, IMBALANCE-P). Ute Schmiedel: German Federal Ministry of Education and Research (Promotion numbers 01LC0024, 01LC0024A, 01LC0624A2, 01LG1201A, 01LG1201N). Hana Skálová: GAČR grant 20-02901S. Karsten Wesche: International Institute Zittau, Technische Universität Dresden. Susan K. Wiser: New Zealand Ministry for Business, Innovation and Employment’s Strategic Science Investment Fund. Ben A. Woodcock: NERC and BBSRC (NE/N018125/1 LTS-M ASSIST - Achieving Sustainable Agricultural Systems). Enrique Valencia: Program for attracting and retaining talent of Comunidad de Madrid (no. 2017-T2/AMB-5406) and Community of Madrid and Rey Juan Carlos University (Young Researchers R&D Project. Ref. M2165 – INTRANESTI). Truman P. Young: National Science Foundation (LTREB DEB 19-31224).

Ecological restoration has a paradigm of re-establishing ‘indigenous reference' communities. One resulting concern is that focussing on target communities may not necessarily create systems which function at a high level or are resilient in the face of ongoing global change. Ecological complexity – defined here, based on theory, as the number of components in a system and the number of connections among them – provides a complementary aim, which can be measured directly and has several advantages. Ecological complexity encompasses key ecosystem variables including structural heterogeneity, trophic interactions and functional diversity. Ecological complexity can also be assessed at the landscape scale, with metrics including β diversity, heterogeneity among habitat patches and connectivity. Thus, complexity applies, and can be measured, at multiple scales. Importantly, complexity is linked to system emergent properties, e.g. ecosystem functions and resilience, and there is evidence that both are enhanced by complexity. We suggest that restoration ecology should consider a new paradigm to restore complexity at multiple scales, in particular of individual ecosystems and across landscapes. A complexity approach can make use of certain current restoration methods but also encompass newer concepts such as rewilding. Indeed, a complexity goal might in many cases best be achieved by interventionist restoration methods. Incorporating complexity into restoration policies could be quite straightforward. Related aims such as enhancing ecosystem services and ecological resilience are to the fore in initiatives such as the Sustainable Development Goals and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Implementation in policy and practice will need the development of complexity metrics that can be applied at both local and regional scales. Ultimately, the adoption of an ecological complexity paradigm will be based on an acceptance that the ongoing and unprecedented global environmental change requires new ways of doing restoration that is fit for the future.

Analysing temporal patterns in plant communities is extremely important to quantify the extent and the consequences of ecological changes, especially considering the current biodiversity crisis. Long-term data collected through the regular sampling of permanent plots represent the most accurate resource to study ecological succession, analyse the stability of a community over time and understand the mechanisms driving vegetation change. We hereby present the LOng-Term Vegetation Sampling (LOTVS) initiative, a global collection of vegetation time-series derived from the regular monitoring of vascular plants in permanent plots. With 79 datasets from five continents and 7789 vegetation time-series monitored for at least six years and mostly on an annual basis, LOTVS possibly represents the largest collection of temporally fine-grained vegetation time-series derived from permanent plots and made accessible to the research community. As such, it has an outstanding potential to support innovative research in the fields of vegetation science, plant ecology and temporal ecology.

The importance of wild bees for crop pollination is well established, but less is known about which species contribute to service delivery to inform agricultural management, monitoring and conservation. Using sites in Great Britain as a case study, we use a novel qualitative approach combining ecological information and field survey data to establish a national list of crop pollinating bees for four economically important crops (apple, field bean, oilseed rape and strawberry). A traits data base was used to establish potential pollinators, and combined with field data to identify both dominant crop flower visiting bee species and other species that could be important crop pollinators, but which are not presently sampled in large numbers on crops flowers. Whilst we found evidence that a small number of common, generalist species make a disproportionate contribution to flower visits, many more species were identified as potential pollinators, including rare and specialist species. Furthermore, we found evidence of substantial variation in the bee communities of different crops. Establishing a national list of crop pollinators is important for practitioners and policy makers, allowing targeted management approaches for improved ecosystem services, conservation and species monitoring. Data can be used to make recommendations about how pollinator diversity could be promoted in agricultural landscapes. Our results suggest agri-environment schemes need to support a higher diversity of species than at present, notably of solitary bees. Management would also benefit from targeting specific species to enhance crop pollination services to particular crops. Whilst our study is focused upon Great Britain, our methodology can easily be applied to other countries, crops and groups of pollinating insects., SCOPUS: ar.j, info:eu-repo/semantics/published

1. Increased farming intensity led to massive declines across multiple farmland taxa. In Europe, measures introduced to counteract these losses include those considered agronomically productive, such as organic farming, as well as those that support no direct production of crops, such as non‐crop flowering fields in conventional farming systems. 2. We studied biodiversity effects of non‐productive flowering fields managed under conventional farming compared to both an organically managed cereal mono‐crop (organic winter spelt fields) and a flowering mixed‐crop (organic lentil mixed‐crop fields) as well as conventionally managed winter wheat fields, which served as control crop. These four crop‐use types were studied on six sites over three years (17 sites in total) to assess their impact on the activity density (cover for plants), species richness and community composition of wild plants, carabids, spiders, butterflies and wild bees. 3. Species richness of wild plants was highest under organic farming and at field edges when compared to the interior. In the case of carabids and spiders, species richness was highest at the field edges, but there was no difference between the four crop‐use types. In contrast, activity density and species richness of butterflies and wild bees responded only to flowering crop‐use types, showing no edge effects. Arable land cover in 500 m buffer area also affected community composition of all taxa, with the exception of spiders, but had only minor effects on activity densities and species richness. 4. Synthesis and applications: Our findings underline that there is no single best measure to promote biodiversity on arable land. Instead a mosaic of non‐productive and productive measures such as conventional flowering fields, organic crops and field edge habitats might be more appropriate to support the regional species pool in arable‐dominated landscapes. To support a range of complementary biodiversity promoting farming practices, agricultural policy should foster the coordination and collaboration between multiple farmers within the same region by covering additional costs for coordination and prioritising collaborative schemes.

Sustainable intensification will require the development of new management systems to support global food demands, whilst conserving the integrity of ecosystem functions. Here, we test and identify management strategies to maintain or enhance agricultural production in grasslands whilst simultaneously supporting the provision of multiple ecosystem services. Over four years, we investigated how the establishment of three plant functional groups (grasses, legumes, and other flowering forbs), using different cultivation (minimum tillage and deep ploughing) and management (cutting, grazing and their intensity) techniques, affected provision and complementarity between key ecosystem services. These ecosystem services were agronomic production, pollination, pest control, food resources for farmland birds, and soil services. We found that the establishment of floristically diverse swards, particularly those containing grasses, legumes and forbs, maximised forage yield and quality, pollinator abundance, soil nitrogen, and bird food resources, as well as enhancing populations of natural predators of pests. Cutting management increased bird food resources and natural predators of pests without depleting other services considered. However, a single management solution to maximise the delivery of all ecosystem services is unlikely to exist, as trade-offs also occurred. Consequently, management options may need to be tailored to strategically support localised deficits in key ecosystem services.

Agricultural pesticides are a key component of the toolbox of most agricultural systems and are likely to continue to play a role in meeting the challenge of feeding a growing global population. However, pesticide use has well documented and often significant consequences for populations of native wildlife. Although rigorous, regulatory processes for the approval of new chemicals for agronomic use do have limitations which may fail to identify real-world negative effects of products. Here, we describe a possible approach to complement the existing regulatory process, which is to combine long-term and national-scale data sets on native wildlife with pesticide use data to understand long-term and large-scale impacts of agrochemicals on wildlife populations.

2017-2018 Belmont Forum and BiodivERsA joint call for research proposals, under the BiodivScen ERA-Net COFUND programme, and with the funding organisations AEI, NWO, ECCyT and NSF Funding information, Allen-Perkins A, Magrach A, Dainese M, Garibaldi LA, Kleijn D, Rader R, Reilly JR, Winfree R, Lundin O, McGrady CM, Brittain C, Biddinger DJ, Artz DR, Elle E, Hoffman G, Ellis JD, Daniels J, Gibbs J, Campbell JW, Brokaw J, Wilson JK, Mason K, Ward KL, Gundersen KB, Bobiwash K, Gut L, Rowe LM, Boyle NK, Williams NM, Joshi NK, Rothwell N, Gillespie RL, Isaacs R, Fleischer SJ, Peterson SS, Rao S, Pitts-Singer TL, Fijen T, Boreux V, Rundlöf M, Viana BF, Klein AM, Smith HG, Bommarco R, Carvalheiro LG, Ricketts TH, Ghazoul J, Krishnan S, Benjamin FE, Loureiro J, Castro S, Raine NE, de Groot GA, Horgan FG, Hipólito J, Smagghe G, Meeus I, Eeraerts M, Potts SG, Kremen C, García D, Miñarro M, Crowder DW, Pisanty G, Mandelik Y, Vereecken NJ, Leclercq N, Weekers T, Lindstrom SAM, Stanley DA, Zaragoza-Trello C, Nicholson CC, Scheper J, Rad C, Marks EAN, Mota L, Danforth B, Park M, Bezerra ADM, Freitas BM, Mallinger RE, Oliveira da Silva F, Willcox B, Ramos DL, D da Silva E Silva F, Lázaro A, Alomar D, González-Estévez MA, Taki H, Cariveau DP, Garratt MPD, Nabaes Jodar DN, Stewart RIA, Ariza D, Pisman M, Lichtenberg EM, Schüepp C, Herzog F, Entling MH, Dupont YL, Michener CD, Daily GC, Ehrlich PR, Burns KLW, Vilà M, Robson A, Howlett B, Blechschmidt L, Jauker F, Schwarzbach F, Nesper M, Diekötter T, Wolters V, Castro H, Gaspar H, Nault BA, Badenhausser I, Petersen JD, Tscharntke T, Bretagnolle V, Willis Chan DS, Chacoff N, Andersson GKS, Jha S, Colville JF, Veldtman R, Coutinho J, Bianchi FJJA, Sutter L, Albrecht M, Jeanneret P, Zou Y, Averill AL, Saez A, Sciligo AR, Vergara CH, Bloom EH, Oeller E, Badano EI, Loeb GM, Grab H, Ekroos J, Gagic V, Cunningham SA, Åström J, Cavigliasso P, Trillo A, Classen A, Mauchline AL, Montero-Castaño A, Wilby A, Woodcock BA, Sidhu CS, Steffan-Dewenter I, Vogiatzakis IN, Herrera JM, Otieno M, Gikungu MW, Cusser SJ, Nauss T, Nilsson L, Knapp J, Ortega-Marcos JJ, González JA, Osborne JL, Blanche R, Shaw RF, Hevia V, Stout J, Arthur AD, Blochtein B, Szentgyorgyi H, Li J, Mayfield MM, Woyciechowski M, Nunes-Silva P, Halinski de Oliveira R, Henry S, Simmons BI, Dalsgaard B, Hansen K, Sritongchuay T, O'Reilly AD, Chamorro García FJ, Nates Parra G, Magalhães Pigozo C, Bartomeus I

In Europe, extensively managed grasslands have undergone large-scale declines due to intensive agriculture and abandonment. Their restoration supports arthropod biodiversity within farming systems. We investigated limiting factors for arthropod establishment during grassland restoration across a chronosequence of 52 restoration sites established by either natural regenerating or direct seeding. Our study covered 363 arthropod species of 10 orders, including detritivores, herbivores, predators and pollinators. These were sampled using pitfall traps, suction sampling and transect walks. The similarity of plant communities on restoration sites to target species rich grasslands was positively correlated with the similarity of the arthropod communities to these same grasslands. There was evidence that restoration sites located in landscapes suffering from historic large-scale loss of species rich grassland (1930–2015) had lower success in replicating the composition of arthropod communities and supported the lowest levels of species richness. The age of the restoration site was a predictor of restoration success for some trophic levels. For example, predator species richness was greatest in the oldest restoration sites. However, this was only the case were sites were either of large size or located in landscapes with the lowest historic loss of species rich grassland. Impacts of within site management also affected arthropod communities. The annual frequency of cutting negatively affected detritivores species richness, and selected against traits including herbivore monophagy. Overall arthropod species richness was positively correlated with sward height. These results emphasise the relative importance of the success with which the floral community is replicated, as well as landscape and management factors, during grassland restoration. This has implications for future agri-environmental schemes. In particular, achieving high quality within-site management that maximises establishment of the plant communities needs to be the initial focus of any restoration program.

Risks posed to bees from neonicotinoid seed treatments (clothianidin, thiamethoxam, imidacloprid) led in 2013 to the European Union instigating a moratorium for their use on mass-flowering crops, including oilseed rape in the UK. This restriction did allow for the continued use of these seed treatments, in particular clothianidin, on non-flowering crops like winter wheat. To determine the impacts of the moratorium, we assessed neonicotinoid concentrations pre- (2014) and post- (2015−17) moratorium in 347 honey samples collected across Great Britain. While the probability of detecting clothianidin declined immediately following the moratorium, detection rates remained constant over the following three years (mean = 0.10 ppb, maximum = 2.8 ppb). In contrast, after three years thiamethoxam residues entirely disappeared while detection of imidacloprid was infrequent but persistent over the whole period. For those hives where neonicotinoids were detected, there was no evidence that the concentrations in the honey declined over the three years following the ban. Using metabarcoding approaches, we identified plants foraged upon by honeybees during the production of honey. After the moratorium came into effect, the highest neonicotinoid residues were associated with honey produced by foraging on both oilseed rape and several wild plants found in arable field margins. Concerns about soil persistence and uptake by non-target flowering plants ultimately led to a full European Union ban in 2018. Our results suggest that before this full ban came into effect, the use of clothianidin on non-flowering crops maintained a low-level probability of encountering this neonicotinoid within honey. However, these concentrations were low and would have been unlikely to pose significant risks to honeybees.

Worldwide honeybees (Apis mellifera L.) are one of the most widely kept domesticated animals, supporting domestic and commercial livelihoods through the production of honey and wax, as well as in the delivery of pollination services to crops. Quantifying which plant species are foraged upon by honeybees provides insights into their nutritional status as well as patterns of landscape scale habitat utilization. Here we outline a rapid and reproducible methodology for identifying environmental DNA (eDNA) originating principally from pollen grains suspended within honey. The process is based on a DNA extraction incorporating vacuum filtration prior to universal eukaryotic internal transcribed spacer 2 region (ITS2) amplicon generation, sequencing and identification. To provide a pre-cursor to sequence phylotyping, we outline systems for error-corrected processing amplicon sequence variant abundance tables that removes chimeras. This methodology underpins the new UK National Honey Monitoring Scheme.•We compare the efficacy and speed of centrifugation and filtration systems for removing pollen from honey samples as a precursor to plant DNA barcoding.•We introduce the ‘HONEYPI’ informatics pipeline, an open access resource implemented in python 2.7, to ensure long-term reproducibility during the process of amplicon sequence variant classification., Graphical abstract Image, graphical abstract

1. Sustainable agriculture aims to produce sufficient food while minimizing environmental damage. To achieve this, we need to understand the role of agricultural landscapes in providing diverse ecosystem services and how these affect crop production and resilience, that is, maintaining yields despite environmental perturbation. 2. We used 10 years of English wheat yield data to derive three metrics of resilience (relative yield across the time series, yield stability around a moving average and resistance to an extreme weather event) at 10 km × 10 km resolution. We used remotely sensed maps to calculate measures of landscape structure, including composition (proportions of different land cover types) and configuration (metrics of connectivity and proximity), known to affect ecosystem service delivery (e.g. control of pests by beneficial invertebrates). We then used an information‐theoretic approach to identify the best‐fitting combination of landscape structure predictors for each resilience metric, using a potential yield model to account for the effects of climate and soils. 3. Relative yield showed a strongly positive relationship with the area of arable land. For yield stability, this relationship was evident but alongside other landscape structure variables in the best‐fitting model. No relationship with arable land was evident for resistance. 4. Yield stability showed a strongly positive effect of proximity to semi‐natural habitats. For resistance, the best‐fitting model included positive relationships with the cover of semi‐natural habitats and proximity to semi‐natural grasslands. 5. Synthesis and applications. Landscapes with the highest relative wheat yields did not show the highest yield stability or resistance to extreme events. As resilience metrics were derived from shorter portions of the time series, the importance of semi‐natural habitats compared to arable land increased. This is probably driven by the complex interplay between landscape structure, agricultural management and ecosystem services. These results demonstrate that measuring relative yield over time may be insufficient to capture the full effect that non‐arable components of the landscape, and the ecosystem services they deliver, have on other aspects of resilience, and that there are clear trade‐offs in managing agricultural landscapes to maximize different aspects of crop yield resilience.

The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved. Our analysis of time series from 79 datasets across the world showed that stability was associated more strongly with the degree of synchrony among dominant species than with species richness. The relatively weak influence of species richness is consistent with theory predicting that the effect of richness on stability weakens when synchrony is higher than expected under random fluctuations, which was the case in most communities. Land management, nutrient addition, and climate change treatments had relatively weak and varying effects on stability, modifying how species richness, synchrony, and stability interact. Our results demonstrate the prevalence of biotic drivers on ecosystem stability, with the potential for environmental drivers to alter the intricate relationship among richness, synchrony, and stability., We were supported by US NSF Grants DEB-8114302, DEB8811884, DEB-9411972, DEB-0080382, DEB-0620652, DEB-1234162, and DEB0618210; the Nutrient Network (https://nutnet.org/) experiment from NSF Research Coordination Network Grant NSF-DEB-1042132; the New Zealand National Vegetation Survey Databank; and Institute on the Environment Grant DG-0001-13. Data (Dataset 56, SI Appendix, Supplementary Text S4) owned by NERC Database Right/Copyright NERC. Further support was provided by the Jornada Basin Long-Term Ecological Research project, Cedar Creek Ecosystem Science Reserve, and the University of Minnesota. The Rothamsted Long-term Experiments National Capability is supported by UK Biotechnology and Biological Sciences Research Council Grant BBS/E/C/000J0300 and the Lawes Agricultural Trust. This research was funded by Czech Science Foundation Grant GACR16-15012S and Czech Academy of Sciences Grant RVO 67985939. E.V. was funded by 2017 Program for Attracting and Retaining Talent of Comunidad de Madrid Grant 2017-T2/AMB-5406.

Questions. Compensatory dynamics are described as one of the main mechanisms that increase community stability, e.g., where decreases of some species on a year‐to‐year basis are offset by an increase in others. Deviations from perfect synchrony between species (asynchrony) have therefore been advocated as an important mechanism underlying biodiversity effects on stability. However, it is unclear to what extent existing measures of synchrony actually capture the signal of year‐to‐year species fluctuations in the presence of long‐term directional trends in both species abundance and composition (species directional trends hereafter). Such directional trends may lead to a misinterpretation of indices commonly used to reflect year‐to‐year synchrony. Methods. An approach based on three‐term local quadrat variance (T3) which assesses population variability in a three‐year moving window, was used to overcome species directional trend effects. This “detrending” approach was applied to common indices of synchrony across a worldwide collection of 77 temporal plant community datasets comprising almost 7,800 individual plots sampled for at least six years. Plots included were either maintained under constant “control” conditions over time or were subjected to different management or disturbance treatments. Results. Accounting for directional trends increased the detection of year‐to‐year synchronous patterns in all synchrony indices considered. Specifically, synchrony values increased significantly in ~40% of the datasets with the T3 detrending approach while in ~10% synchrony decreased. For the 38 studies with both control and manipulated conditions, the increase in synchrony values was stronger for longer time series, particularly following experimental manipulation. Conclusions. Species’ long‐term directional trends can affect synchrony and stability measures potentially masking the ecological mechanism causing year‐to‐year fluctuations. As such, previous studies on community stability might have overemphasised the role of compensatory dynamics in real‐world ecosystems, and particularly in manipulative conditions, when not considering the possible overriding effects of long‐term directional trends., We thank multiple entities for the financial support necessary to obtain the different databases: the U.S. National Science Foundation under grant numbers DEB‐8114302, DEB‐8811884, DEB‐9411972, DEB‐0080382, DEB‐0620652, DEB‐1234162, DEB‐9707477, DEB‐0316402, DEB‐08‐16453, and DEB‐12‐56034, DEB‐0618210, the Nutrient Network (http://www.nutnet.org) experiment from the National Science Foundation Research Coordination Network (NSF‐DEB‐1042132), the New Zealand National Vegetation Survey Databank, the Spanish MINECO (Project CGL2014‐53789‐R), the Madrid Regional Government (Projects REMEDINAL‐3 and REMEDINAL‐TE), the European Research Council Synergy grant 610028 (IMBALANCE‐P), the Institute on the Environment (DG‐0001‐13), the SOERE‐ACBB financed through French National Agency for Research (ANAEE‐F, ANR‐11‐INBS‐0001), the Estonian Research Council (IUT 20‐28, IUT 20‐29), Czech Science Foundation (GAČR 17‐05506S and 19‐28491X), the European Regional Development Fund (Centre of Excellence EcolChange), the German Federal Environmental Foundation (DBU) for a grant to the NABU Hamburg (management experiment Calamagrostis epigejos), and the German Federal Ministry of Education and Research within the framework of the project BIOTA Southern Africa (promotion numbers 01LC0024, 01LC0024A and 01LC0624A2), Task 159 of SASSCAL (promotion number 01LG1201) and the Scottish Government's Rural and Environmental Science and Analytical Services division. Acknowledgement Data owned by NERC© Database Right/Copyright NERC. Further support was provided by the Jornada Basin Long‐Term Ecological Research (LTER) project, Cedar Creek Ecosystem Science Reserve and the University of Minnesota. We also thank the Lawes Agricultural Trust and Rothamsted Research for data from the e‐RA database. The Rothamsted Long‐term Experiments National Capability (LTE‐NCG) is supported by the UK Biotechnology and Biological Sciences Research Council (Grant BBS/E/C/000J0300) and the Lawes Agricultural Trust.

Climate change poses a threat to global food security with extreme heat events causing drought and direct damage to crop plants. However, by altering behavioural or physiological responses of insects, extreme heat events may also affect pollination services on which many crops are dependent. Such effects may potentially be exacerbated by other environmental stresses, such as exposure to widely used agro-chemicals. To determine whether environmental stressors interact to affect pollination services, we carried out field cage experiments on the buff-tailed bumble bee (Bombus terrestris). Using a Bayesian approach, we assessed whether heat stress (colonies maintained at an ambient temperature of 25 &deg, C or 31 &deg, C) and insecticide exposure (5 ng g-1 of the neonicotinoid insecticide clothianidin) could induce behavioural changes that affected pollination of faba bean (Vicia faba). Only the bumble bee colonies and not the plants were exposed to the environmental stress treatments. Bean plants exposed to heat-stressed bumble bee colonies (31 &deg, C) had a lower proportional pod set compared to colonies maintained at 25 &deg, C. There was also weak evidence that heat stressed colonies caused lower total bean weight. Bee exposure to clothianidin was found to have no clear effect on plant yields, either individually or as part of an interaction. We identified no effect of either colony stressor on bumble bee foraging behaviours. Our results suggest that extreme heat stress at the colony level may impact on pollination services. However, as the effect for other key yield parameters was weaker (e.g. bean yields), our results are not conclusive. Overall, our study highlights the need for further research on how environmental stress affects behavioural interactions in plant-pollinator systems that could impact on crop yields.

Context Maximising insect pollination of mass-flowering crops is a widely-discussed approach to sustainable agriculture. Management actions can target landscape-scale semi-natural habitat, cropping patterns or field-scale features, but little is known about their relative effectiveness. Objective To test how landscape composition (area of mass-flowering crops and semi-natural habitat) and field-scale habitat (margins and hedges) affect pollinator species richness, abundance, and pollen deposition within crop fields. Methods We surveyed all flower visitors (Diptera, Coleoptera and Hymenoptera) in oilseed rape fields and related them to landscape composition and field features. Flower visitors were classified as bees, non-bee pollinators and brassica specialists. Total pollen deposition by individual taxa was estimated using single visit pollen deposition on stigmas combined with insect abundance. Results The area of mass-flowering crop had a negative effect on the species richness and abundance of bees in fields, but not other flower visitors. The area of semi-natural habitat in the surrounding landscape had a positive effect on bees, but was not as important as the area of mass-flowering crop. Taxonomic richness and abundance varied significantly between years for non-bee pollinators. Greater cover of mass-flowering crops surrounding fields had a negative effect on pollen deposition, but only when non-bee pollinator numbers were reduced. Conclusions Management choices that result in landscape homogenisation, such as large areas of mass-flowering crops, may reduce pollination services by reducing the numbers of bees visiting fields. Non-bee insect pollinators may buffer these landscape effects on pollen deposition, and management to support their populations should be considered.

1. Biological pest control has become one of the central principles of ecological intensification in agriculture. However, invertebrate natural enemies within agricultural ecosystems are exposed to a myriad of different pesticides at both lethal and sub-lethal doses, that may limit their capacity to carry out pest control. An important question is how underlying diversity in invertebrate predator species, linked to their unique susceptibility to insecticides, can act to increase the resilience of natural pest control. 2. We explore this issue by assessing the effects of sub-lethal insecticide exposure on the predation rates of 12 generalist predators feeding on the aphid Sitobion avenae (Aphididae). Predation rates within a 24-hr period were assessed (predation assessment) for each species after receiving one of the following treatments: (a) no prior deltamethrin exposure before the predation assessment (control); (b) deltamethrin exposure immediately before the predation assessment (resistance) and (c) deltamethrin exposure 5 days before the predation assessment (recovery). Extrapolating from these species-specific measures of resistance and recovery, we predicted the resilience of community level predation to insecticide exposure for predator communities associated with 256 arable fields in the UK. 3. There was large variation in sub-lethal effects of the insecticide between even closely related species. This ranged from species showing no change in predation rates following sub-lethal insecticide exposure (high resistance), species showing only immediate depressed feeding rates after 24 hr (high recovery) or those with depressed feeding rates after 5 days (low resistance and recovery). 4. The community level analysis showed that resistance and recovery of natural pest control was predicted by both community phylogenetic diversity (positively) and weighted mean body mass (negatively). However, the removal of numerically dominant species from the analysis modified these effects. 5. Synthesis and applications: Our results highlight the role of community diversity in maintaining the resilience of natural pest control following insecticide use. Importantly, less diverse assemblages dominated by predator species that show low resilience to insecticide exposure, may show a greater depression in pest control than diverse assemblages under insecticide based farmland management.

Insecticides represent an important management tool in agriculture. They provide a low cost and efficacious approach to pest control, where they may be employed both reactively and pre-emptively. It is likely insecticides will continue to play a role in meeting the challenge of feeding a growing global population. The widespread use of insecticides creates potential for negative impacts on non-target invertebrate populations. Many countries have regulatory processes in place to manage these. However, there regulatory processes have potential limitations when it comes to detecting the long-term and large-scale consequences of insecticide use. For example, long-term sub-lethal effects resulting from low dose exposure durations are rarely considered in toxicity tests, while predictable additive effects of mixtures of active ingredient are often ignored. In order to address this data gap, there is substantial scope for using existing spatially and temporally explicit biological records of species occurrence. This could help in monitoring and assessment to support our responsibilities to maintain biodiversity while continuing to grow enough food to feed the human population. How this is achieved poses several problems, both practical and analytical. Here, we describe how national-scale data on the spatial and temporal distribution of native invertebrates can be combined with maps of large-scale insecticide application and exposure risk to explore the actual consequences for non-target native biodiversity. Understanding these impacts on native invertebrates will provide a vital evidence base to inform policy decisions that could complement existing regulatory processes.

Grassland restoration is a key measure for re-establishing damaged floral communities. As seed banks are often degraded, methods are needed to overcome dispersal limitation of the remnant vegetation. One approach is to vacuum harvest seeds from donor sites. While this is a cost-effective method, individual species’ traits describing reproduction methods and dispersal mechanisms may affect the success with which seeds are collected and subsequently germinate. We collected seeds using low-cost vacuum harvesters in species-rich meadows in Poland. We predicted the relative success with which seedlings emerged from this collected material with respect to their percentage cover in the donor sites on the basis of individual species’ functional traits. Prolific species that rely on seed as opposed to vegetative reproduction, and those that germinate in late summer/autumn, exhibited the highest level of emergence. To a lesser extent, drought-tolerant or shade-intolerant species were well represented in the collected material. There was also weak evidence that wind-dispersed seeds would have a higher likelihood of being collected by this method. Our results suggest that vacuum harvesting is a valuable method to collect seeds for use in grassland restoration; however, it has limitations. In particular, additional methods may be needed to introduce into grassland restoration sites the propagules of species that vegetatively reproduce or seed early. The overrepresentation of species that produce large numbers of seed may potentially introduce priority effects that could also have unintended long-term implications for the structure of the floral community.

Agri-environmental management has been promoted as an approach to enhance delivery of multiple ecosystem services. Most agri-environment agreements include several actions that the farmer agrees to put in place. But, most studies have only considered how individual agri-environmental actions affect particular ecosystem services. Thus, there is little understanding of how the range of agri-environmental actions available to a farmer might be deployed on any individual farm to enhance multiple services. To address this knowledge gap, we carried out an experimental study in which we deployed a set of agri-environmental actions on a commercial farm in southern England. Agri-environmental actions comprised wildflower margins and fallow areas in arable fields, creating and enhancing grassland with wildflowers, and digging ponds. Alongside biodiversity responses, we measured effects on a number of ecosystem services: pollination, pest control, crop and forage yield, water quality, climate regulation and cultural services. Wildflower margins enhanced invertebrates, pest control and crop yield, and aesthetic appeal. A greater number of pollinators was linked to enhanced oilseed rape yield. But these margins and the fallows did not prevent run-off of nutrients and sediment into waterways, and showed limited carbon sequestration or reduction of greenhouse gas emissions. Newly-dug ponds captured large amounts of sediment and provided aesthetic appeal. Grasslands had higher soil carbon content and microbial biomass, lower N20 emissions, and net sequestration of carbon compared to arable land. Enhancement of grassland plant diversity increased forage quality and aesthetic appeal. Visitors and residents valued a range of agri-environmental features and biodiversity across the farm. Our findings suggest one cannot necessarily expect any particular agri-environmental action will enhance all of a hoped-for set of ecosystem services in any particular setting. A bet-hedging strategy would be for farmers to apply a suite of options to deliver a range of ecosystem service benefits, rather than assuming that one or two options will work as catch-all solutions. © 2021

Sentinel prey (an artificially manipulated patch of prey) are widely used to assess the level of predation provided by natural enemies in agricultural systems. Whilst a number of different methodologies are currently in use, little is known about how arthropod predators respond to artificially manipulated sentinel prey in comparison with predation on free‐living prey populations. We assessed how attack rates on immobilized (aphids stuck to cards) and artificial (plasticine lepidopteran larvae mimics) sentinel prey differed to predation on free‐moving live prey (aphids). Predation was assessed in response to density of the common invertebrate predators, a foliar‐active ladybird Harmonia axyridis (Coleoptera: Coccinellidae), and a ground‐active beetle Pterostichus madidus (Coleoptera: Carabidae). Significant increases in attack rates were found for the immobilized and artificial prey between the low and high predator density treatments. However, an increased predator density did not significantly reduce numbers of free‐living live aphids included in the mesocosms in addition to the alternate prey. We also found no signs of predation on the artificial prey by the predator H. axyridis. These findings suggest that if our assessment of predation had been based solely on the foliar artificial prey, then no increase in predation would have been found in response to increased predator density. Our results demonstrate that predators differentially respond to sentinel prey items which could affect the level of predation recorded where target pest species are not being used.

Pollination is a critical ecosystem service underpinning the productivity of agricultural systems across the world. Wild insect populations provide a substantial contribution to the productivity of many crops and seed set of wild flowers. However, large-scale evidence on species-specific trends among wild pollinators are lacking. Here we show substantial inter-specific variation in pollinator trends, based on occupancy models for 353 wild bee and hoverfly species in Great Britain between 1980 and 2013. Furthermore, we estimate a net loss of over 2.7 million occupied 1 km2 grid cells across all species. Declines in pollinator evenness suggest that losses were concentrated in rare species. In addition, losses linked to specific habitats were identified, with a 55% decline among species associated with uplands. This contrasts with dominant crop pollinators, which increased by 12%, potentially in response agri-environment measures. The general declines highlight a fundamental deterioration in both wider biodiversity and non-crop pollination services., Pollinator loss is a concern but data on their status is lacking. Here Powney et al. use occupancy modelling to estimate the degree of loss in wild bee and hoverfly species across Great Britain, and report a 55% decline in upland species and a 12% increase in dominant crop pollinators.

1. Honeybees have world-wide importance as crop pollinators. To ensure their persistence in agricultural systems, statistically robust field trials of plant protection products are vital. 2. We consider the implications of regulations from the European Food Safety Authority that require the detection of a 7% effect size change in bee colony sizes under field conditions. 3. Based on a power analysis, we argue that the necessary levels of replication (68 replicates) may pose practical constraints to field testing. 4. Policy implications. Regulatory studies benefit from data sources collated over a range of spatial scales, from laboratory to landscapes. Basing effect size thresholds solely on expert judgement, as has been done, may be inappropriate. Rather, definition through experimental or simulation studies that assess the biological consequences of changes in colony size for bee pop- ulations is required. This has implications for regulatory bodies outside the European Union.

Damage confirmed Early studies of the impacts of neonicotinoid insecticides on insect pollinators indicated considerable harm. However, lingering criticism was that the studies did not represent field-realistic levels of the chemicals or prevailing environmental conditions. Two studies, conducted on different crops and on two continents, now substantiate that neonicotinoids diminish bee health (see the Perspective by Kerr). Tsvetkov et al. find that bees near corn crops are exposed to neonicotinoids for 3 to 4 months via nontarget pollen, resulting in decreased survival and immune responses, especially when coexposed to a commonly used agrochemical fungicide. Woodcock et al. , in a multicounty experiment on rapeseed in Europe, find that neonicotinoid exposure from several nontarget sources reduces overwintering success and colony reproduction in both honeybees and wild bees. These field results confirm that neonicotinoids negatively affect pollinator health under realistic agricultural conditions. Science , this issue p. 1395 , p. 1393 ; see also p. 1331

Insects provide vital ecosystem services to agricultural systems in the form of pollination and natural pest control. However, there are currently widespread declines in the beneficial insects which deliver these services (i.e. pollinators and ‘natural enemies’ such as predators and parasitoids). Two key drivers of these declines have been the expansion of agricultural land and intensification of agricultural production. With an increasing human population requiring additional sources of food, further changes in agricultural land use appear inevitable. Identifying likely trajectories of change and predicting their impacts on beneficial insects provides a scientific basis for making informed decisions on the policies and practices of sustainable agriculture. We created spatially explicit, exploratory scenarios of potential changes in the extent and intensity of agricultural land use across Great Britain (GB). Scenarios covered 52 possible combinations of change in agricultural land cover (i.e. agricultural expansion or grassland restoration) and intensity (i.e. crop type and diversity). We then used these scenarios to predict impacts on beneficial insect species richness and several metrics of functional diversity at a 10km (hectad) resolution. Predictions were based on species distribution models derived from biological records, comprising data on 116 bee species (pollinators) and 81 predatory beetle species (natural enemies). We identified a wide range of possible consequences for beneficial insect species richness and functional diversity as result of future changes in agricultural extent and intensity. Current policies aimed at restoring semi-natural grassland should result in increases in the richness and functional diversity of both pollinators and natural enemies, even if agricultural practices remain intensive on cropped land (i.e. land-sparing). In contrast, any expansion of arable land is likely to be accompanied by widespread declines in richness of beneficial insects, even if cropping practices become less intensive (i.e. land-sharing), although effects of functional diversity are more mixed.

Understanding spatial variation in the structure and stability of plant-pollinator networks, and their relationship with anthropogenic drivers, is key to maintaining pollination services and mitigating declines. Constructing sufficient networks to examine patterns over large spatial scales remains challenging. Using biological records (citizen science), we constructed potential plant-pollinator networks at 10km resolution across Great Britain, comprising all potential interactions inferred from recorded floral visitation and species co-occurrence. We calculated network metrics (species richness, connectance, pollinator and plant generality) and adapted existing methods to assess robustness to sequences of simulated plant extinctions across multiple networks. We found positive relationships between agricultural land cover and both pollinator generality and robustness to extinctions under several extinction scenarios. Increased robustness was attributable to changes in plant community composition (fewer extinction-prone species) and network structure (increased pollinator generality). Thus, traits enabling persistence in highly agricultural landscapes can confer robustness to potential future perturbations on plant-pollinator networks.

The restoration of grasslands is a key management practice that supports biodiversity across Europe. On species poor grasslands and ex-arable fields, the establishment of plant species is often limited by the availability of habitat niches, in particular space to germinate. We investigated the impacts of full inversion tillage and its interaction with site conditions and functional traits on the abundance of 51 plant species sown into a 2 ha ex-arable site in Poland. Soils of the donor site were characterized by high levels of heterogeneity in terms of water content and plant availability of N, P and K. One year after sowing the cover of species typical of semi-natural grasslands was significantly higher on the tilled plots than on the non-tilled plots. However, in the case of widespread generalist species the tillage of soil resulted in no significant effect on their establishing percentage cover. The establishment of plants on the tilled area was more successful where soils were relatively rich in mineral N. It was also more successful for species with low Ellenberg’s N values. Species indicative of moist soil established poorly where the soil was tilled. This study has clear implications for the applied restoration of grasslands, demonstrating a vital role of soil tillage to promote the establishment of species typical of semi-natural grasslands. This is particularly important where seed mixtures may contain both desirable and undesirable competitive species that would disproportionately benefit from the absence of tillage management.

Due to concerns over negative impacts on insect pollinators, the European Union has implemented\ud a moratorium on the use of three neonicotinoid pesticide seed dressings for mass flowering crops. We assessed the effectiveness of this policy in reducing the exposure risk to honeybees by collecting 130 samples of honey from bee keepers across the UK before (2014: N = 21) and after the moratorium was in effect (2015: N = 109). Neonicotinoids were present in about half of the honey samples taken before the moratorium, and they were\ud present in over a fifth of honey samples following the moratorium. Clothianidin was the most frequently detected neonicotinoid. Neonicotinoid concentrations declined from May to September in the year following the ban. However, the majority of post-moratorium neonicotinoid residues were from honey harvested early in the year, coinciding with oilseed rape flowering. Neonicotinoid concentrations were correlated with the area of oilseed rape surrounding the hive location. These results suggest mass flowering crops may contain neonicotinoid residues where they have been grown on soils contaminated by previously seed treated crops. This may include winter seed treatments applied to cereals that are currently exempt from\ud EU restrictions. Although concentrations of neonicotinoids were low (

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies., This work was supported through the National Socio-Environmental Synthesis Center (SESYNC) National Science Foundation Award DBI-1052875 for the project “Evidence and Decision-Support Tools for Controlling Agricultural Pests with Conservation Interventions” organized by D.S.K. and R.C.-K

Understanding patterns in predator:prey systems and the mechanisms that underlie trophic interactions provides a basis for predicting community structure and the delivery of natural pest control services. The functional response of predators to prey density is a fundamental measure of interaction strength and its characterisation is essential to understanding these processes. We used mesocosm experiments to quantify the functional responses of five ground beetle species that represent common generalist predators of north-west European arable agriculture. We investigated two mechanisms predicted to be key drivers of trophic interactions in natural communities: predator:prey body size ratio and multiple predator effects. Our results show regularities in foraging patterns characteristic of similarly sized predators. Ground beetle attack rates increased and handling times decreased as the predator:prey body-mass ratio rose. Multiple predator effects on total prey consumption rates were sensitive to the identity of the interacting species but not prey density. The extent of interspecific interactions may be a result of differences in body mass between competing beetle species. Overall these results add to the growing evidence for the importance of size in determining trophic interactions and suggest that body mass could offer a focus on which to base the management of natural enemy assemblages.

Pollinators face many challenges within agricultural systems due to landscape changes and intensification which can affect resource availability that can impact pollination services. This paper examines pigeon pea pollination and considers how landscape context and agricultural intensification in terms of pesticide use affects the abundance of bees characterized by species guilds on crops. The study was conducted on six paired farms across a gradient of habitat complexity based on the distance of each farm from adjacent semi-natural vegetation in Kibwezi Sub-county, Kenya. The study found that farms which do not use insecticides in farm management, but are in close proximity to natural habitat have greater bee guild abundance, but at further distances, overall abundance is reduced with or without insecticide use. At 1 km landscape radius, the complexity of habitats but not patch size had a positive impact on the abundance of cavity nesting bees and mason bees, which can be attributed to the interspersion of the small-holder farms with semi-natural habitats across the landscapes producing mosaics of heterogeneous habitats. The study revealed the strongest relationships between fruit set and bee abundance to be with the carpenter bee, social bee and solitary bee guilds, which are among the most abundant bees visiting pigeon pea flowers in this system. Our findings provide the foundation for conservation efforts by identifying which bee guilds pollinated pigeon peas. From this study, we suggest managing the floral and nesting resources that would best support the most abundant crop pollinators, and also reducing insecticide application to the crop.

The use of pesticides within agricultural ecosystems has led to wide concern regarding negative effects on the environment. One possible alternative is the use of predators of pest species that naturally occur within agricultural ecosystems. However, the mechanistic basis for how species can be manipulated in order to maximize pest control remains unclear. We carried out a meta‐analysis of 51 studies that manipulated predator species richness in reference to suppression of herbivore prey to determine which components of predator diversity affect pest control. Overall, functional diversity (FD) based on predator's habitat domain, diet breadth and hunting strategy was ranked as the most important variable. Our analysis showed that increases in FD in polycultures led to greater prey suppression compared to both the mean of the component predator species, and the most effective predator species, in monocultures. Further analysis of individual traits indicated these effects are likely to be driven by broad niche differentiation and greater resource exploitation in functionally diverse predator communities. A decoupled measure of phylogenetic diversity, whereby the overlap in variation with FD was removed, was not found to be an important driver of prey suppression. Our results suggest that increasing FD in predatory invertebrates will help maximize pest control ecosystem services in agricultural ecosystems, with the potential to increase suppression above that of the most effective predator species.

1.Riparian invertebrate communities occupy a dynamic ecotone where hydrogeomorphological (e.g. river flows) and ecological (e.g. succession) processes may govern assemblage structure by filtering species according to their traits (e.g. dispersal capacity, niche).2.We surveyed terrestrial invertebrate assemblages (millipedes, carabid beetles, spiders) in 28 river islands across four river catchments over 2 years. We predicted that distinct ecological niches would produce taxon-specific responses of abundance and species richness to: (i) disturbance from episodic floods, (ii) island area, (iii) island vegetation structure, and (iv) landscape structure. We also predicted that responses would differ according to species’ dispersal ability (aerial vs. terrestrial only), indicating migration was sustaining community structure.3.Invertebrate abundance and richness was affected by different combinations of vegetation structure, island area, and flood disturbance according to species’ dispersal capacity. Carabid abundance related negatively to episodic floods, particularly for flightless species, but the other taxa were insensitive to this disturbance. Larger islands supported greater abundance of carabids and all invertebrates able to disperse aerially. Vegetation structure, particularly tree canopy density and plant richness, related positively to invertebrate abundance across all taxa and aerial dispersers, whereas terrestrial disperser richness related positively to tree cover. Landscape structure did not influence richness or abundance.4.Multiple ecological processes govern riparian invertebrate assemblages. Overall insensitivity to flood disturbance and responses contingent on dispersal mode imply that spatial dynamics subsidise the communities through immigration. Particular habitat features (e.g. trees, speciose vegetation) may provide refuges from disturbance and concentration of niches and food resources.

1. Pollinator network structure arising from the extent and strength of interspecific mutualistic interactions can promote species persistence and community robustness. However, environmental change may re-organise network structure limiting capacity to absorb or resist shocks and increasing species extinctions. 2. We investigated if habitat disturbance and the level of mutualism dependence between species affected the robustness of insect–flower visitation networks Following a recently developed Stochastic Co-extinction Model (SCM), we ran simulations to produce the number of extinction episodes (cascade degree), which we correlated with network structure in undisturbed and disturbed habitat. We also explicitly modelled whether a species’ intrinsic dependence on mutualism affected the propensity for extinction cascades in the network. 3. Habitat disturbance generated a gradient in network structure with those from disturbed sites being less connected, but more speciose and so larger. Controlling for network size (z-score standardisation against the null model) revealed that disturbed networks had disproportionately low linkage density, high specialisation, fewer insect visitors per plant species (vulnerability) and lower nestedness (NODF). 4. This network structure gradient driven by disturbance increased and decreased different aspects of robustness to simulated plant extinction. Disturbance decreased the risk that an initial insect extinction would follow a plant species loss. Although, this effect disappeared when network size and connectance were standardised, suggesting the lower connectance of disturbed networks increased robustness to an initial secondary extinction. 5. However, if a secondary extinction occurred then networks from disturbed habitat were more prone to large co-extinction cascades, likely resulting from a greater chance of extinction in these larger, speciose networks. Conversely, when species mutualism dependency was explicit in the SCM simulations the disturbed networks were disproportionately more robust to very large co-extinction cascades, potentially caused by non-random patterns of interaction between species differing in dependence on mutualism. 6. Our results showed disturbance altered the size and the distribution of interspecific interactions in the networks to affect their robustness to co-extinction cascades. Controlling for effects due to network size and the interspecific variation in demographic dependence on mutualism can improve insight into properties conferring the structural robustness of networks to environmental changes.

To address the decline in farmland birds across agricultural landscapes a key approach under agri-environment schemes has been the widespread creation of perennial grass-only buffer strips along field boundaries. However, despite a high dependency on these strips to enhance biodiversity in agricultural landscapes, it appears that benefits for farmland birds during the breeding season have been limited. We investigated the provision of plant and invertebrate resources for farmland birds in buffer strips that were established with three different seed mixes, including the standard grass-only habitat. We hypothesised that resource provision would differ between seed mix types due to differences in original composition. We also investigated three different types of management aimed at influencing sward composition and habitat structure, namely cutting, scarification and the application of graminicide. These approaches were used to influence the accessibility of structurally complex swards to farmland birds. We hypothesised that the abundance of plant and invertebrate resources and access to these resources would be directly related to management type. The abundance of plant resources and sward structure were determined using quadrats and the drop disc method respectively, whilst the invertebrates were assessed using suction sampling. The study demonstrated the value of including forbs (herbaceous plant species) in seed mixes used to establish buffer strips by increasing plant resources for farmland birds, although this was not coupled with an increase in beetle abundance and mass. However, grass-only buffer strips managed with annual cutting were shown to provide similar levels of invertebrate resources to farmland birds as with the more complex seed mixes, but it is likely that access to these resources was restricted by tall homogenous swards and a limited amount of bare ground. The study demonstrated that novel buffer strip management techniques can strongly influence both the resource abundance and resource access by farmland birds. Scarification in particular was shown to be highly effective at opening up the sward to increase access by farmland birds, but was associated with a reduction in plant resources. Given the financial barriers for the use of seed mixes that contain forbs to establish buffer strips, importantly the study has shown that the value of existing grass-only buffer strips for farmland birds can be enhanced through the use of scarification. Consequently, as an alternative to annual cutting, we recommend that scarification is periodically applied to narrow (1–3 m) strips next to the crop edge to enhance the value of grass-only buffer strips for farmland birds.