Tree establishment via natural colonisation is increasing globally, due to treeline expansion under climate change, and changing land management practices, such as reduced grazing pressure, land abandonment, and initiatives to increase tree cover such as restoration and rewilding. Natural colonisation of organo-mineral soils at high densities is associated with altered soil physicochemical properties, with consequences for ecosystem services such as soil carbon stocks, biodiversity, and hydrology. But whether sparse natural colonisation of organo-mineral soils has similar effects on soil physicochemical properties to dense natural colonisation is not known. To investigate the effects of sparse natural colonisation on organo-mineral soils, we measured soil physicochemical properties at increasing distances up to 8 metres from single, native (Pinus sylvestris L. or Betula spp.) naturally colonised trees in Cairngorms, Scotland, UK. Distance from single, native, naturally colonised trees was associated with increased soil moisture and decreased carbon-to-nitrogen and carbon-to-phosphorus ratios, but not associated with changes in bulk density, decomposition rates, or pH, in the organic horizon of organo-mineral soils. Sparse natural colonisation (in this study, 43 trees ha− 1) of organo-mineral soils has some, localised effects on the physicochemical properties of the organic horizon, which might affect biodiversity and hydrology in patches around trees. These effects did not extend beyond 2 metres distance from the trees. This suggests that early, sparse tree colonisation has minimal impacts on soil physicochemical properties at the ecosystem scale.

Sitka spruce (Picea sitchensis (Bong.) Carr.), is the most common tree species in UK’s commercial forests. Tree species diversification of the UK’s commercial forests is currently occurring to make them more resilient to new pests and pathogens and climate change. The potential ecosystem implications of this transition are poorly understood. Our aims are to, (i) list the biodiversity known to be supported by Sitka spruce as this has not been collated previously, and (ii) assess the changes, in both ecosystem functioning and biodiversity supported, if Sitka spruce forests are diversified with any of 34 other tree species. Using records from across the UK, we identified 564 species that use the Sitka spruce trees as a living space or for feeding. Most of these associated species were non-specialist and found on a wide range of other trees. Data from an extensive literature review showed that diversification with broad-leaved trees would potentially result in faster nutrient cycling and litter decomposition with potential implications for carbon storage in the litter layer. Diversification with Oak (Quercus petraea/robur (Matt.) Liebl.), sycamore (Acer pseudoplatanus L.), Scots pine (Pinus sylvestris L.), birch (Betula pendula/pubescens Roth), beech (Fagus sylvatica L.), and Norway spruce (Picea abies (L.) H. Karst.) provide the greatest biodiversity benefits both through supporting the biodiversity found on Sitka spruce and additional biodiversity thought to be absent on Sitka spruce. However, except for sycamore, none of these tree species will grow in long-term intimate mixed stands with Sitka spruce. Therefore, we propose that diversification of Sitka spruce plantations should be carried out as ‘blocky mixes’, i.e. small blocks of single tree species, with tree diversity occurring within a management unit, as a pragmatic approach to support timber production and provide biodiversity benefits. However, the optimal size and spatial arrangement of such blocks requires further assessment.

Tree cover is often increased with the aim of increasing ecosystem carbon sequestration and mitigating climate change. However, when planting trees in ecosystems with carbon-rich soils, soil disturbance during ground preparation can cause soil carbon losses not counteracted by tree carbon gains at the decadal timescales relevant to climate change mitigation targets. Tree establishment via natural colonisation, which does not involve soil disturbance, might prevent these soil carbon losses, but this is unknown. We measured soil, ground vegetation, and tree carbon stocks and tree inputs along an 8 metre transect from single, native, 25-year-old naturally colonised trees (Pinus sylvestris or Betula spp.) onto Calluna vulgaris-dominated moorland, at sites with carbon-rich organo-mineral soils in the Cairngorms, UK. Along the transect away from the tree, organic soil carbon stocks increased from 4.0 kg C m-2 at 0.5 m, to 6.0 kg C m-2 at 8 m. Meanwhile, carbon stocks in the top 10 cm of the mineral soil horizon, 3.6 kg C m-2, did not vary. Ground vegetation carbon stocks increased only slightly, from 1.0 kg C m-2 at 0.5 m, to 1.3 kg C m-2 at 8 m. Mean carbon stock per tree was 32.4 kg, so overall, sparse natural colonisation resulted in no net ecosystem carbon gain. Policy implications: Sparse natural colonisation of carbon-rich soils by low biomass trees might not result in net ecosystem carbon gains at decadal timescales, and instead lead to unforeseen soil carbon losses. Soil carbon changes should be taken into account when quantifying the climate change mitigation potential of natural colonisation.

Tree diseases may cause the extirpation or functional extinction of a common tree species on large spatial scales. For example, ash dieback (Hymenoscyphus fraxineus) is expected to cause widespread loss of European ash (Fraxinus excelsior). This type of widespread loss of a tree species may have consequences for the ability of some insects to move between woodlands, particularly obligate species (species reliant on one tree species for food). Our aim was to use ddRAD-seq genetic data to determine the population structure of Prays fraxinella (ash bud moth), an ash-obligate micro-moth, and to assess its ability to maintain connectivity across fragmented patches of native broadleaf woodlands. We found no evidence of genetic structuring at local (up to 44 km) spatial scales, and no evidence of inbreeding. At regional scales (up to 426 km), we found evidence of mixed ancestry and long-distance dispersal. Our research highlights that given its ability to maintain gene flow in areas where woodlands have historically been very fragmented, P. fraxinella may continue to maintain connectivity under moderate future tree losses under ongoing ash dieback outbreaks. Implications for insect conservation: Our research highlights the potential indirect impacts of ash-dieback through losses in connectivity. This approach should be extended to other ash-obligate species, under various levels of existing fragmentation, to inform conservation strategies more fully for managing ash dieback.

HO-1 is a key enzyme in the management of heme in humans. A GT(n) repeat length in the gene HMOX1, has previously been widely associated with a variety of phenotypes, including susceptibility and outcomes in diabetes, cancer, infections, and neonatal jaundice. However, studies are generally small and results inconsistent. In this study, we imputed the GT(n) repeat length in two European cohorts (UK Biobank, n = 463,005; and Avon Longitudinal Study of Parents and Children (ALSPAC n = 937), with the reliability of imputation tested in other cohorts (1000 Genomes, HGDP, and UK-PGP). Subsequently, we measured the relationship between repeat length and previously identified associations (diabetes, COPD, pneumonia and infection related mortality in UK Biobank; neonatal jaundice in ALSPAC) and performed a phenome-wide association study (PheWAS) in UK Biobank. Despite high quality imputation (correlation between true repeat length and imputed repeat length >0.9 in test cohorts), no clinical associations were identified in either the PheWAS or specific association studies. These findings were robust to definitions of repeat length and sensitivity analyses. Despite multiple smaller studies identifying associations across a variety of clinical settings; we could not replicate or identify any relevant phenotypic associations with the HMOX1 GT(n) repeat.

Non-native plant pests/pathogens are a mostly overlooked threat to biodiversity. Surveillance for plant pests and pathogens is key to early detection yet is rarely undertaken in natural habitats. Current methodologies to prioritise surveillance are pest-based, there is no methodology available to help managers identify 'at risk' hosts and habitats for targeted surveillance. This study compares four host-based methods. Prioritisation of: (1) plant genera known to host the pests/pathogens most likely to establish (Host-pest); (2) habitats known to host the greatest number of pests/pathogens most likely to establish (Habitat-pest); (3) plants classed as foundation species (those that drive ecosystem functioning and support populations of dependent biodiversity) (Foundation-species); (4) habitats with low plant species diversity and hence low resilience (Habitat-resilience). Twelve habitats and 22 heathland vegetation communities in the UK were used as a case-study. The Host-pest method gave 121 plant genera to monitor across all habitats and 14 within heathlands. The Habitat-pest and Habitat-resilience methods prioritised different habitats because the Habitat-pest method uses existing lists of pests which are biased towards those of commercial importance. The Foundation-species method gave 272 species for surveillance across all habitats and 14 within heathlands. Surveillance of habitats and plants prioritised on potential ecological impact (the Foundation-species and Habitat-resilience methods) is recommended rather than known pests/pathogens (the Host-pest and Habitat-pest methods) as this avoids biases within existing lists of pests/pathogens, removes the need for the prioritisation to be regularly updated as new pests/pathogens are identified and takes account of impacts on associated biodiversity and ecosystem functions.

Immunological memory to vaccination and viral infection involves coordinated action of B and T-cells, thus integrated analysis of these two components is critical for understanding their contributions to protection against breakthrough infections (BI). We investigated cellular and humoral immune responses to SARS-CoV-2 infection and/or COVID-19 vaccination in participants from the Avon Longitudinal Study of Parents and Children (ALSPAC). The magnitude of antibody and T-cell responses following the second vaccine dose was associated with protection against BI in participants with a history of SARS-CoV-2 infection (cases), but not in infection-naive controls. Youdens index thresholds for protection against BI were calculated for all immune measures. Anti-Spike IgG (>666.4 BAU/mL) and anti-nucleocapsid N pan Ig (>0.1332 BAU/mL) thresholds combined were 100% sensitive and 83% specific for cases without BI over 8-months follow-up. Collectively these results point to the superior protective effect of hybrid immunity and have implications for the design of next-generation COVID-19 vaccines. ### Competing Interest Statement AF was a lead investigator on trials of COVID-19 vaccines funded by Oxford/Astra-Zeneca, Valneva and Sanofi and the UK government. He also leads a University of Bristol sponsored epidemiological study of adult respiratory disease funded by Pfizer which has evaluated COVID-19 vaccine effectiveness. During the pandemic he was a member of the Joint Committee on Vaccination and Immunisation which advised the UK government on COVID-19 vaccine policy and of the WHO Specialist Advisory Group of Experts COVID-19 vaccine working group. No other authors declare competing interests. ### Funding Statement This work was funded by UK Research and Innovation (UKRI) and the National Institute of Health Research (NIHR) through the UK COVID-19 Immunology Consortium (UK CIC). This work was supported by the Elizabeth Blackwell Institute, University of Bristol, with funding from the Wellcome Trust ISSF3 grant 204813/Z/16/Z, and the University Alumni and Friends (LW, LR, AH, AD, AF and OF). NJT is the PI of the Avon Longitudinal Study of Parents and Children (MRC & WT 217065/Z/19/Z), is supported by the University of Bristol NIHR Biomedical Research Centre (BRC-1215-2001), the MRC Integrative Epidemiology Unit (MC\_UU\_00011/1) and works within the CRUK Integrative Cancer Epidemiology Programme (C18281/A29019). MK is supported by the Medical Research Council (MR/W021315/1). MS is supported by the Academy of Medical Sciences (Springboard Award SB007\100173). The UK Medical Research Council and the Wellcome Trust (Grant ref: 217065/Z/19/Z) and the University of Bristol provide core support for ALSPAC. This publication is the work of the authors; LR, AH, LW, HEB and MS will serve as guarantors for the contents of this paper. A comprehensive list of grant funding is available on the ALSPAC website (http://www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf). This research was specifically funded by Wellcome Trust and MRC grant 102215/2/13/2. The funders had no role in the study design, data collection, data analysis nor preparation of the manuscript or decision to publish. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The ALSPAC Ethics and Law Committee at the University of Bristol gave ethical approval for this work (NHS REC 20/HRA/4854). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.

Aims: We introduce ReSurveyEurope - a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions. Results: ReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover-abundance classes such as variants of the Braun-Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020. Conclusions: ReSurveyEurope is a new resource to address a wide range of research questions on fine-scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well-established European Vegetation Archive (EVA). ReSurvey:Europe data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome.

Abstract Non-native plant pests/pathogens are a mostly overlooked threat to biodiversity. Surveillance for plant diseases is key to early detection yet is rarely undertaken in semi-natural habitats. Currently there is no standard methodology available to help managers prioritise where surveillance should occur. This study compared five potential methods (M). Prioritisation of: pests/pathogens most likely to establish (M1); plant genera known to host the pests/pathogens most likely to establish (M2); habitats known to host the greatest number of pests/pathogens most likely to establish (M3); plants classed as foundation species (those that drive ecosystem functioning and support populations of dependent biodiversity) (M4); habitats with low plant species diversity and hence low resilience (M5). Twelve habitats and 22 heathland vegetation communities in the UK were used as a case-study. M1 gave 91 pests/pathogens to monitor and relied on having up-to-date lists of pests/pathogens relevant to plant species in semi-natural habitats. M2 gave 121 plant genera to monitor across all habitats and 14 within heathlands. M3 and M5 prioritised different habitats because M3 is based on existing lists of pests which are biased towards those of commercial importance. M4 gave 272 foundation species for surveillance across all habitats and 14 within heathlands. Surveillance of habitats and plants prioritised on potential ecological impact (M4-5) is recommended rather than known pests/pathogens (M2-3) as this avoids biases within existing lists of pests/pathogens, removes the need for the prioritisation to be regularly updated as new pests/pathogens are identified and takes account of impacts on associated biodiversity and ecosystem functions.

Observational studies have suggested a protective role for eosinophils in colorectal cancer (CRC) development and implicated neutrophils, but the causal relationships remain unclear. Here, we aimed to estimate the causal effect of circulating white blood cell (WBC) counts (N = ~550 000) for basophils, eosinophils, monocytes, lymphocytes and neutrophils on CRC risk (N = 52 775 cases and 45 940 controls) using Mendelian randomisation (MR). For comparison, we also examined this relationship using individual-level data from UK Biobank (4043 incident CRC cases and 332 773 controls) in a longitudinal cohort analysis. The inverse-variance weighted (IVW) MR analysis suggested a protective effect of increased basophil count and eosinophil count on CRC risk [OR per 1-SD increase: 0.88, 95% CI: 0.78-0.99, P = .04; OR: 0.93, 95% CI: 0.88-0.98, P = .01]. The protective effect of eosinophils remained [OR per 1-SD increase: 0.88, 95% CI: 0.80-0.97, P = .01] following adjustments for all other WBC subtypes, to account for genetic correlation between the traits, using multivariable MR. A protective effect of increased lymphocyte count on CRC risk was also found [OR: 0.84, 95% CI: 0.76-0.93, P = 6.70e-4] following adjustment. Consistent with MR results, a protective effect for eosinophils in the cohort analysis in the fully adjusted model [RR per 1-SD increase: 0.96, 95% CI: 0.93-0.99, P = .02] and following adjustment for the other WBC subtypes [RR: 0.96, 95% CI: 0.93-0.99, P = .001] was observed. Our study implicates peripheral blood immune cells, in particular eosinophils and lymphocytes, in CRC development, highlighting a need for mechanistic studies to interrogate these relationships.

Ecological restoration, which encompasses habitat restoration and creation is essential to “bend the curve of biodiversity loss.” However, well‐intentioned actions could alter plant pest/pathogen distributions resulting in unanticipated detrimental impacts on both host plants and associated biodiversity. Awareness among practitioners of this risk is unknown but likely to be limited. Using an online survey, with responses from 224 participants involved in ecological restoration in the United Kingdom, we assessed: (1) their awareness of plant health biosecurity risks; (2) whether they had risk assessments and biosecurity guidance/best practices for plant pests/pathogens; and (3) what, if any, new guidance was required. Participants perceived that their neighbors' activities, rather than their own, were the most likely source of pests/pathogens establishing. Their perceptions of the activities most likely to be a source of pests/pathogens did not match the literature, with the introduction of both mature plants and seeds viewed as the same level of risk. Over half the participants did not have a risk assessment for plant pests/pathogens. More of the participants (70%) had biosecurity guidance. However, of those participants that had biosecurity guidance 22% failed to check whether this guidance was followed, while 40% did not have anyone in their organization responsible for biosecurity. The most frequent requests from participants for guidance were: (1) what biosecurity to put in place for staff/contractors?; (2) the current legislation on plant pests/pathogens and movement of plants/soil/equipment. We conclude that risk assessments for plant pests/pathogens must become standard practice in ecological restoration.

Background Sepsis is characterised by dysregulated, life-threatening immune responses, which are thought to be driven by cytokines such as interleukin 6 (IL-6). Genetic variants in IL6R known to down-regulate IL-6 signalling are associated with improved Coronavirus Disease 2019 (COVID-19) outcomes, a finding later confirmed in randomised trials of IL-6 receptor antagonists (IL6RAs). We hypothesised that blockade of IL6R could also improve outcomes in sepsis. Methods and findings We performed a Mendelian randomisation (MR) analysis using single nucleotide polymorphisms (SNPs) in and near IL6R to evaluate the likely causal effects of IL6R blockade on sepsis (primary outcome), sepsis severity, other infections, and COVID-19 (secondary outcomes). We weighted SNPs by their effect on CRP and combined results across them in inverse variance weighted meta-analysis, proxying the effect of IL6RA. Our outcomes were measured in UK Biobank, FinnGen, the COVID-19 Host Genetics Initiative (HGI), and the GenOSept and GainS consortium. We performed several sensitivity analyses to test assumptions of our methods, including utilising variants around CRP and gp130 in a similar analysis. In the UK Biobank cohort ( N = 486,484, including 11,643 with sepsis), IL6R blockade was associated with a decreased risk of our primary outcome, sepsis (odds ratio (OR) = 0.80; 95% confidence interval (CI) 0.66 to 0.96, per unit of natural log-transformed CRP decrease). The size of this effect increased with severity, with larger effects on 28-day sepsis mortality (OR = 0.74; 95% CI 0.47 to 1.15); critical care admission with sepsis (OR = 0.48, 95% CI 0.30 to 0.78) and critical care death with sepsis (OR = 0.37, 95% CI 0.14 to 0.98). Similar associations were seen with severe respiratory infection: OR for pneumonia in critical care 0.69 (95% CI 0.49 to 0.97) and for sepsis survival in critical care (OR = 0.22; 95% CI 0.04 to 1.31) in the GainS and GenOSept consortium, although this result had a large degree of imprecision. We also confirm the previously reported protective effect of IL6R blockade on severe COVID-19 (OR = 0.69, 95% CI 0.57 to 0.84) in the COVID-19 HGI, which was of similar magnitude to that seen in sepsis. Sensitivity analyses did not alter our primary results. These results are subject to the limitations and assumptions of MR, which in this case reflects interpretation of these SNP effects as causally acting through blockade of IL6R, and reflect lifetime exposure to IL6R blockade, rather than the effect of therapeutic IL6R blockade. Conclusions IL6R blockade is causally associated with reduced incidence of sepsis. Similar but imprecisely estimated results supported a causal effect also on sepsis related mortality and critical care admission with sepsis. These effects are comparable in size to the effect seen in severe COVID-19, where IL-6 receptor antagonists were shown to improve survival. These data suggest that a randomised trial of IL-6 receptor antagonists in sepsis should be considered.

Increased global movement of biological materials, coupled with climate change, and other environmental pressures are leading to increasing threats to plants from pests and pathogens. These pests and pathogens are relevant to plant conservation translocations as a source of translocation failure, and because the translocation itself can lead to pest and pathogen transmission. Many plant conservation translocations are relatively low risk, especially those involving the small-scale local movement of plant material between proximal sites. In contrast, plant translocations that involve movement of large amounts of material, and/or large geographical distances or crossing natural ecological barriers, are intrinsically higher risk. Additional high-risk factors include the potential for pest and pathogen transmission to occur at nursery/propagation facilities, especially if the translocated material is held in close proximity to other plants infected with pests and pathogens and/or material sourced from distant localities. Despite the importance of these issues, plant health risks are often not explicitly considered in plant conservation translocations. To support greater awareness and the effective uptake of appropriate biosecurity steps in plant conservation translocations, there is a pressing need to develop generally applicable best-practice guidelines targeted at translocation practitioners.

Iron deficiency is associated with a substantial burden of morbidity. However, supplementation of iron has been linked to increased rates of serious infection in randomised trials of children in sub-Saharan Africa. Randomised trials in other settings have been inconclusive and it is unknown if changes in levels of iron biomarkers are linked to sepsis in these other settings. We used genetic variants associated with levels of iron biomarkers as instrumental variables in a Mendelian randomisation (MR) analysis to test the hypothesis that increasing levels of iron biomarkers increase the risk of sepsis. In observational and MR analyses we found that increases in iron biomarkers increase the odds of sepsis. In stratified analyses, we show that this risk may be larger in those with iron deficiency and/or anaemia. Taken together, results here suggest a required caution in supplementation of iron and underline the role of iron homeostasis in severe infection.

Atopic dermatitis (AD) is a common inflammatory skin condition and prior genome-wide association studies (GWAS) have identified 71 associated loci. In the current study we conducted the largest AD GWAS to date (discovery N = 1,086,394, replication N = 3,604,027), combining previously reported cohorts with additional available data. We identified 81 loci (29 novel) in the European-only analysis (which all replicated in a separate European analysis) and 10 additional loci in the multi-ancestry analysis (3 novel). Eight variants from the multi-ancestry analysis replicated in at least one of the populations tested (European, Latino or African), while two may be specific to individuals of Japanese ancestry. AD loci showed enrichment for DNAse I hypersensitivity and eQTL associations in blood. At each locus we prioritised candidate genes by integrating multi-omic data. The implicated genes are predominantly in immune pathways of relevance to atopic inflammation and some offer drug repurposing opportunities.

Non‐native plant pests and pathogens are increasing exponentially, causing extirpation of foundation species. The impact of large‐scale declines in a single host on associated biodiversity is widely documented. However, the impact of multiple host loss on biodiversity and whether these impacts are multiplicative has not been assessed. Ecological theory suggests that systems with greater functional redundancy (alternative hosts) will be more resilient to the loss of sympatric hosts. We test this theory and show its importance in relation to pest/pathogen impact assessments. We assessed the potential impact on biodiversity of the loss of two widely occurring sympatric European tree species, Fraxinus excelsior and Quercus petraea/robur , both of which are currently threatened by a range of pests and pathogens. At the UK scale, the total number of associated species at risk of extirpation from plant diseases affecting these two sympatric hosts is greater than the sum of the associated species at risk from declines in either host alone. F. excelsior hosts 45 obligate species (species only found on that host) and Q. petraea/robur hosts 326. However, a decline in both these trees would impact 512 associated species, across multiple taxon groups, a 38% increase. Assessments at a local scale, 24 mixed F. excelsior–Q. petraea/robur woodlands revealed that these impacts may be even greater due to a lack of functional redundancy. Only 21% of sites were able to provide functional redundancy for F. excelsior and Q. petraea/robur associated species which can use other tree species. In most woodlands, the tree species required to provide functional redundancy were not present, although the site conditions were often suitable for them to grow. Synthesis . Understanding of functional redundancy should be applied to assessments of pests/pathogens impact on biodiversity. In risk assessments, higher impact scores should be given to pests/pathogens affecting hosts occurring with other host plant species already impacted by pests/pathogens. Current pest/pathogen risk assessment approaches that ignore the cumulative, cascading effects shown in this study may allow an insidious, mostly overlooked, driver of biodiversity loss to continue.