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The precise and accurate identification and quantification of transcriptional start sites (TSSs) is key to understanding the control of transcription. The core promoter consists of the TSS and proximal non-coding sequences, which are critical in transcriptional regulation. Therefore, the accurate identification of TSSs is important for understanding the molecular regulation of transcription. Existing protocols for TSS identification are challenging and expensive, leaving high-quality data available for a small subset of organisms. This sparsity of data impairs study of TSS usage across tissues or in an evolutionary context. To address these shortcomings, we developed Smart-Seq2 Rolling Circle to Concatemeric Consensus (Smar2C2), which identifies and quantifies TSSs and transcription termination sites. Smar2C2 incorporates unique molecular identifiers that allowed for the identification of as many as 70 million sites, with no known upper limit. We have also generated TSS data sets from as little as 40 pg of total RNA, which was the smallest input tested. In this study, we used Smar2C2 to identify TSSs in Glycine max (soybean), Oryza sativa (rice), Sorghum bicolor (sorghum), Triticum aestivum (wheat) and Zea mays (maize) across multiple tissues. This wide panel of plant TSSs facilitated the identification of evolutionarily conserved features, such as novel patterns in the dinucleotides that compose the initiator element (Inr), that correlated with promoter expression levels across all species examined. We also discovered sequence variations in known promoter motifs that are positioned reliably close to the TSS, such as differences in the TATA box and in the Inr that may prove significant to our understanding and control of transcription initiation. Smar2C2 allows for the easy study of these critical sequences, providing a tool to facilitate discovery.

An equitable approach by the American College of Medical Genetics and Genomics (ACMG) has recently recommended carrier screening for genes associated with moderate to severe autosomal recessive conditions with a carrier frequency of ≥1/200 in the Genome Aggregation Database exomes (gnomADv2.0.2). We analyzed carrier frequencies in gnomADv3.1.1 genomes representing diverse populations. ClinVar data on 35 996 pathogenic/likely pathogenic variants in 419 genes were used to estimate the gnomAD frequency of heterozygous carriers. We found that ninety-two genes had a carrier frequency of ≥1/200, of which 63 were shared between v3.1.1 and v2.0.2 and 29 were new in v3.1.1. Addition of new populations (Amish, Finnish and Middle Eastern) increased the number of new genes with a carrier frequency of ≥1/200 to 71. Changes in carrier frequencies were attributed to new gnomAD populations, different sample sizes, new ClinVar data, and technical differences between exomes and genomes. This study highlights the dynamic changes in carrier frequencies due to new datasets from diverse populations and provides updated carrier frequencies based on the combined data from 184 352 genomes and exomes in gnomAD. We recommend a periodic review for inclusion of new population data to update carrier screening panels in the future.

Genome-scale, constraint-based models (GEM) and their derivatives are commonly used to model and gain insights into microbial metabolism. Often, however, their accuracy and predictive power are limited and enable only approximate designs. To improve their usefulness for strain and bio-process design, we studied here their capacity to accurately predict metabolic changes in response to operational conditions in a bioreactor, as well as intracellular, active reactions. We used flux balance analysis (FBA) and dynamic FBA (dFBA) to predict growth dynamics of the model organism Saccharomyces cerevisiae under different industrially relevant conditions. We compared simulations with the latest developed GEM for this organism (Yeast8) and its enzyme-constrained version (ecYeast8) herein described with experimental data and found that ecYeast8 outperforms Yeast8 in all the simulations. EcYeast8 was able to predict well-known traits of yeast metabolism including the onset of the Crabtree effect, the order of substrate consumption during mixed carbon cultivation and production of a target metabolite. We showed how the combination of ecGEM and dFBA links reactor operation and genetic modifications to flux predictions, enabling the prediction of yields and productivities of different strains and (dynamic) production processes. Additionally, we present flux sampling as a tool to analyze flux predictions of ecGEM, of major importance for strain design applications. We showed that constraining protein availability substantially improves accuracy of the description of the metabolic state of the cell under dynamic conditions. This therefore enables more realistic and faithful designs of industrially relevant cell-based processes and, thus, the usefulness of such models

The historical ecological paradigm of wetland ecosystems emphasized the role of physical or “bottom‐up” factors in maintaining functions and services. However, recent studies have shown that the loss of predators in coastal salt marshes can lead to a significant reduction in wetland extent due to overgrazing of vegetation by herbivores. Such studies indicate that consumers or “top‐down” factors may play a much larger role in the maintenance of wetland ecosystems than was previously thought. The objective of this study was to evaluate whether altering top‐down control by manipulating the presence of predators can lead to measurable changes in salt marsh ecosystem properties. Between May and August of 2015 and 2016, we established exclosure and enclosure cages within three New England coastal wetland areas and manipulated the presence of green crab predators to assess how they and their fiddler and purple marsh crab prey affect changes in ecosystem properties. Predator presence was associated with changes in soil nitrogen and aboveground biomass at two of the three field sites, though the magnitude and direction of these effects varied from site to site. Further, path analysis results indicate that across field sites, a combination of bottom‐up and top‐down factors influenced changes in measured variables. These results challenge the growing consensus that consumers have strong effects, indicating instead that predator impacts may be highly context‐dependent., The objective of this study was to evaluate whether altering top‐down control by manipulating the presence of predators can lead to measurable changes in salt marsh ecosystem properties. Predator presence was associated with changes in soil nitrogen and aboveground biomass at two of the three field sites, though the magnitude and direction of these effects varied from site to site. These results challenge the growing consensus that consumers have strong effects, indicating instead that predator impacts may be highly context‐dependent.

Energy, nutrients and organisms move over landscapes, connecting ecosystems across space and time. Meta-ecosystem theory investigates the emerging properties of local ecosystems coupled spatially by these movements of organisms and matter, by explicitly tracking exchanges of multiple substances across ecosystem borders. To date, meta-ecosystem research has focused mostly on abiotic flows-neglecting biotic nutrient flows. However, recent work has indicated animals act as spatial nutrient vectors when they transport nutrients across landscapes in the form of excreta, egesta and their own bodies. Partly due to its high level of abstraction, there are few empirical tests of meta-ecosystem theory. Furthermore, while animals may be viewed as important mediators of ecosystem functions, better integration of tools is needed to develop predictive insights of their relative roles and impacts on diverse ecosystems. We present a methodological roadmap that explains how to do such integration by discussing how to combine insights from movement, foraging and ecosystem ecology to develop a coherent understanding of animal-vectored nutrient transport on meta-ecosystems processes. We discuss how the slate of newly developed technologies and methods-tracking devices, mechanistic movement models, diet reconstruction techniques and remote sensing-that when integrated have the potential to advance the quantification of animal-vectored nutrient flows and increase the predictive power of meta-ecosystem theory. We demonstrate that by integrating novel and established tools of animal ecology, ecosystem ecology and remote sensing, we can begin to identify and quantify animal-mediated nutrient translocation by large animals. We also provide conceptual examples that show how our proposed integration of methodologies can help investigate ecosystem impacts of large animal movement. We conclude by describing practical advancements to understanding cross-ecosystem contributions of animals on the move. Understanding the mechanisms by which animals shape ecosystem dynamics is important for ongoing conservation, rewilding and restoration initiatives around the world, and for developing more accurate models of ecosystem nutrient budgets. Our roadmap will enable ecologists to better qualify and quantify animal-mediated nutrient translocation for animals on the move.

Technology is revolutionizing the Alternative Dispute Resolution (ADR) field. Despite the long-held assumptions that increasing understanding, building empathy, and crafting resolution are only possible in-person, effective ways have emerged for assisting the resolution of the exploding number of disputes that have burgeoned online. Technology has become the “fourth party” through the growing field of online dispute resolution (ODR), which includes use of technology and computer-mediated-communication (CMC) in negotiation, mediation, arbitration and other dispute resolution processes. ODR is infiltrating family law and even courts are starting to employ ODR in family cases. Expedited divorces and tracking parenting plans with little court involvement garner appeal amidst growing expectation that everything should be available with a few “clicks” or “swipes” on our technological devices. These expectations and opportunities place new responsibilities on the field and its practitioners. How can we best integrate technology into ADR—both online and off? How can we prevent the rush to digitization from ignoring due process and transparency in the name of efficiency? Accordingly, this Article will discuss the value of ODR for family disputes and highlight key concepts and ODR standards to consider for ethical design and employment of technology in family dispute resolution. This is the submitted version of the article. The published version may be found at 59 Family Court Review 250 (April 2021) Wiley Online Library

The use of CRISPR‐Cas proteins for the creation of multiplex genome engineering represents an important avenue for crop improvement, and further improvements for creation of knock‐in plant lines via CRISPR‐based technologies may enable the high‐throughput creation of designer alleles. To circumvent limitations of the commonly used CRISPR‐Cas9 system for multiplex genome engineering, we explored the use of Moraxella bovoculi 3 Cas12a (Mb3Cas12a) for multiplex genome editing in Arabidopsis thaliana. We identified optimized cis‐regulatory sequences for driving expression of single‐transcript multiplex crRNA arrays in A. thaliana, resulting in stable germline transmission of Mb3Cas12a‐edited alleles at multiple target sites. By utilizing this system, we demonstrate single‐transcript multiplexed genome engineering using of up to 13 crRNA targets. We further show high target specificity of Mb3Cas12a‐based genome editing via whole‐genome sequencing. Taken together, our method provides a simplified platform for efficient multiplex genome engineering in plant‐based systems.

This work demonstrates how a series of complex, chiral cyclobutane derivatives can be accessed in four steps from the terpene verbenone through the application of a directed C-H functionalization approach. The developed synthetic route involved an 8-aminoquinoline-directed C(sp3 )-H arylation as the key step, and this reaction could be carried out with a wide range of aryl and heteroaryl iodides to furnish a variety of cyclobutane products with three contiguous stereocenters. Moreover, it was shown that the 8-aminoquinoline auxiliary could be effectively removed from the cyclobutane derivatives using an ozonolysis-based cleavage method.

A concise synthesis of protected 5-cyano-l-tryptophan (Trp5CN ) has been developed for 2D IR spectroscopic investigations within either peptides or proteins. To assess the potential of differently substituted cyano-tryptophans, several model cyano-indole systems were characterized using IR spectroscopy. Upon assessment of their spectroscopic properties, Trp5CN was integrated into a model peptide sequence, Trp5CN -Gly-Phe4CN , to elucidate its structure. This peptide demonstrates the capability of this probe to capture structural information by 2D IR spectroscopy. The 2D IR spectrum of the peptide in water was simulated to reveal a unique spectral signature resulting from the presence of dipolar coupling. The coupling strength between cyano labels was determined to be 1.4 cm-1 by matching the slopes along the max contour for the simulated and experimental spectrum. Using transition dipole coupling, a distance between the two probes of 13 A was calculated.

The number of rachis nodes (spikelets) on a wheat spike is a component of grain yield that correlates with flowering time. The genetic basis regulating flowering in cereals is well understood, but there are reports that flowering time can be modified at a high frequency by selective breeding, suggesting that it may be regulated by both epigenetic and genetic mechanisms. We investigated the role of DNA methylation in regulating spikelet number and flowering time by treating a semi-spring wheat with the demethylating agent, Zebularine. Three lines with a heritable increase in spikelet number were identified. The molecular basis for increased spikelet number was not determined in 2 lines, but the phenotype showed non-Mendelian inheritance, suggesting that it could have an epigenetic basis. In the remaining line, the increased spikelet phenotype behaved as a Mendelian recessive trait and late flowering was associated with a deletion encompassing the floral promoter, FT-B1. Deletion of FT-B1 delayed the transition to reproductive growth, extended the duration of spike development, and increased spikelet number under different temperature regimes and photoperiod. Transiently disrupting DNA methylation can generate novel flowering behaviour in wheat, but these changes may not be sufficiently stable for use in breeding programs.

Ecological analyses of climate warming explore how rising mean temperature will affect the species composition of communities and their associated functioning. Experimentation usually presumes that warming arises from simultaneous increase in daily maximum (daytime) and minimum (nighttime) temperatures. Yet evidence shows that mean warming arises largely from increasing nighttime temperatures. We report on a three-year experiment that compared the effects of daytime and nighttime warming on a community comprising herbaceous plants, grasshopper herbivores and predatory spiders. We warmed experimental mesocosms 3-4˚ C above ambient control treatments during the daytime (06:00-18:00 h) or nighttime (18:00-06:00 h). Daytime warming caused spiders to seek a thermal refuge low in the plant canopy and away from grasshopper prey, which allowed grasshoppers to spend more time feeding on a competitively dominant plant species. Nighttime had the opposite effect, where spider activity increased causing grasshoppers to reduce feeding. Two consecutive years of daytime warming resulted in a suppression of the competitive dominant plant and increased the diversity and evenness of the plant community, whereas nighttime warming had opposite effects. These results show that ignoring the nuanced effects of asymmetrical warming may lead to inaccurate conclusions about the net effects of climate change on ecosystems. This article is protected by copyright. All rights reserved.

The cyclohexane derivative cis-2-(carboxymethyl)cyclohexane-1-carboxylic acid [(1R,2R)-/(1S,2S)-2-(carboxymethyl)cyclohexane-1-carboxylic acid] has previously been identified as metabolite in the pathway of anaerobic degradation of naphthalene by sulfate-reducing bacteria. We tested the corresponding CoA esters of isomers and analogues of this compound for conversion in cell free extracts of the anaerobic naphthalene degraders Desulfobacterium strain N47 and Deltaproteobacterium strain NaphS2. Conversion was only observed for the cis-isomer, verifying that this is a true intermediate and not a dead-end product. Mass-spectrometric analyses confirmed that conversion is performed by an acyl-CoA dehydrogenase and a subsequent hydratase yielding an intermediate with a tertiary hydroxyl-group. We propose that a novel kind of ring-opening lyase is involved in the further catabolic pathway proceeding via pimeloyl-CoA. In contrast to degradation pathways of monocyclic aromatic compounds where ring-cleavage is achieved via hydratases, this lyase might represent a new ring-opening strategy for the degradation of polycyclic compounds. Conversion of the potential downstream metabolites pimeloyl-CoA and glutaryl-CoA was proved in cell free extracts, yielding 2,3-dehydropimeloyl-CoA, 3-hydroxypimeloyl-CoA, 3-oxopimeloyl-CoA, glutaconyl-CoA, crotonyl-CoA, 3-hydroxybutyryl-CoA and acetyl-CoA as observable intermediates. This indicates a link to central metabolism via β-oxidation, a non-decarboxylating glutaryl-CoA dehydrogenase and a subsequent glutaconyl-CoA decarboxylase.

Soil carbon (C) storage is a major component of the carbon cycle. Consensus holds that soil C uptake and storage is regulated by plant-microbe-soil interactions. However, the contribution of animals in aboveground food webs to this process has been overlooked. Using insights from prior long-term experimentation in an old-field ecosystem and mathematical modeling, we predicted that the amount of soil C retention within a field should increase with the proportion of active hunting predators comprising the aboveground community of active hunting and sit-and-wait predators. This comes about because predators with different hunting modes have different cascading effects on plants. Our test of the prediction revealed that the composition of the arthropod predator community and associated cascading effects on the plant community explained 41% of variation in soil C retention among 15 old fields across a human land use gradient. We also evaluated the potential for several other candidate factors to explain variation in soil C retention among fields, independent of among-field variation in the predator community. These included live plant biomass, insect herbivore community composition, soil arthropod decomposer community composition, degree of land use development around the fields, field age, and soil texture. None of these candidate variables significantly explained soil C retention among the fields. The study offers a generalizable understanding of the pathways through which arthropod predator community composition can contribute to old-field ecosystem carbon storage. This insight helps support ongoing efforts to understand and manage the effects of anthropogenic land use change on soil C storage.

Approaches to quantifying and predicting soil biogeochemical cycles mostly consider microbial biomass and community composition as products of the abiotic environment. Current numerical approaches then primarily emphasise the importance of microbe-environment interactions and physiology as controls on biogeochemical cycles. Decidedly less attention has been paid to understanding control exerted by community dynamics and biotic interactions. Yet a rich literature of theoretical and empirical contributions highlights the importance of considering how variation in microbial population ecology, especially biotic interactions, is related to variation in key biogeochemical processes like soil carbon formation. We demonstrate how a population and community ecology perspective can be used to (1) understand the impact of microbial communities on biogeochemical cycles and (2) reframe current theory and models to include more detailed microbial ecology. Through a series of simulations we illustrate how density dependence and key biotic interactions, such as competition and predation, can determine the degree to which microbes regulate soil biogeochemical cycles. The ecological perspective and model simulations we present lay the foundation for developing empirical research and complementary models that explore the diversity of ecological mechanisms that operate in microbial communities to regulate biogeochemical processes.

Mitigation of large carnivore depredation is essential to increasing stakeholder support for human–carnivore coexistence. Lethal and non-lethal techniques are implemented by managers, livestock producers, and other stakeholders to reduce livestock depredations by large carnivores. However, information regarding the relative effectiveness of techniques commonly used to reduce livestock depredations is currently lacking. We evaluated 66 published, peer-reviewed research papers that quantitatively measured livestock depredation before and after employing 4 categories of lethal and non-lethal mitigation techniques (livestock husbandry, predator deterrents and removal, and indirect management of land or wild prey) to assess their relative effectiveness as livestock protection strategies. Effectiveness of each technique was measured as the reported percent change in livestock losses. Husbandry (42–100% effective) and deterrents (0–100% effective) demonstrated the greatest potential but also the widest variability in effectiveness in reducing livestock losses. Removal of large carnivores never achieved 100% effectiveness but exhibited the lowest variation (67–83%). Although explicit measures of effectiveness were not reported for indirect management, livestock depredations commonly decreased with sparser and greater distances from vegetation cover, at greater distances from protected areas, and in areas with greater wild prey abundance. Information on time duration of effects was available only for deterrents; a tradeoff existed between the effectiveness of tools and the length of time a tool remained effective. Our assessment revealed numerous sources of bias regarding the effectiveness of techniques as reported in the peer-reviewed literature, including a lack of replication across species and geographic regions, a focus on Canid carnivores in the United States, Europe, and Africa, and a publication bias toward studies reporting positive effects. Given these limitations, we encourage managers and conservationists to work with livestock producers to more consistently and quantitatively measure and report the impacts of mitigation techniques under a wider range of environmental, economic, and sociological conditions. © 2016 The Wildlife Society.

A key remit of the NSF‐funded “Arabidopsis Research and Training for the 21st Century” (ART‐21) Research Coordination Network has been to convene a series of workshops with community members to explore issues concerning research and training in plant biology, including the role that research using Arabidopsis thaliana can play in addressing those issues. A first workshop focused on training needs for bioinformatic and computational approaches in plant biology was held in 2016, and recommendations from that workshop have been published (Friesner et al., Plant Physiology, 175, 2017, 1499). In this white paper, we provide a summary of the discussions and insights arising from the second ART‐21 workshop. The second workshop focused on experimental aspects of omics data acquisition and analysis and involved a broad spectrum of participants from academics and industry, ranging from graduate students through post‐doctorates, early career and established investigators. Our hope is that this article will inspire beginning and established scientists, corporations, and funding agencies to pursue directions in research and training identified by this workshop, capitalizing on the reference species Arabidopsis thaliana and other valuable plant systems.

The inability of species to adapt to changing climate may cause ecological communities to disassemble and lose ecological functioning. However, theory suggests that communities may be resilient whenever populations within species exhibit variation in thermal plasticity or adaptation whereby thermally tolerant populations replace thermally sensitive ones. But will they maintain the functional roles of the populations being replaced? This study evaluated whether "like replaces like" functionally by measuring how four populations of a grasshopper herbivore and its co-occurring spider predator cope with environmental warming. The study occurred across a latitudinal gradient bounded by southerly, warmer Connecticut and northerly, cooler New Hampshire, USA. The study compared the survival rates, thermal performance, habitat usage, and food chain interactions of each grasshopper and spider population between its home field site (field of origin) and a Connecticut transplant site, and the native Connecticut population. Three grasshopper populations exhibited physiological plasticity by adjusting metabolic rates. The fourth population selected cooler habitat locations. Spider populations did not alter their metabolism and instead selected cooler habitat locations, thereby altering spatial overlap with their prey and food chain interactions. Grasshopper populations that coped physiologically consumed plants in different ratios than the fourth population and the Connecticut population. Hence, "like may not replace like" whenever populations adapt physiologically to warming.

Zoonotic Salmonella infections cause approximately 130 000 illnesses annually in the United States. Of 72.9 million US households owning at least one pet, five million own small mammals; 3000 hedgehogs were documented by USDA in USDA-licensed breeding facilities and pet stores in 2012. State health department collaborators and PulseNet, the national bacterial subtyping network, identified human infections of a Salmonella Typhimurium outbreak strain, which were investigated by CDC, USDA-APHIS and state public and animal health officials. A case was defined as an illness in a person infected with the outbreak strain identified between 1 December 2011 and 3 June 2013. Investigators collected information on patient exposures, cultured animal and environmental specimens for Salmonella, and conducted traceback investigations of USDA-licensed hedgehog facilities. There were 26 cases in 12 states. Illness onset dates ranged from 26 December 2011 to 8 April 2013. The median patient age was 15 years (range =

Prey at risk of predation may experience stress and respond physiologically by altering their metabolic rates. Theory predicts that such physiological changes should alter prey nutrient demands from N-rich to C-rich macronutrients and shift the balance between maintenance and growth/reproduction. Theory further suggests that for ectotherms, temperature stands to exacerbate this stress. Yet, the interactive effects of predation stress and temperature stress on diet, metabolism, and survival of ectotherms are not well known. This knowledge gap was addressed with a laboratory study in which wild juvenile grasshoppers were collected, assigned to one of three groups, and raised at three different temperatures. All grasshoppers had access to equal quantities of two diets composed of opposite carbohydrate : protein ratios. Half of the individuals in each temperature group were exposed to predation risk cues from spider predators, while the other half were kept in risk free conditions. Grasshoppers consumed more carbohydrates when exposed to predation risk, but consumption favored greater protein intake as temperature increased. Moreover, the difference in carbohydrate intake between risk cue and risk free treatments diminished as temperature increased. Furthermore, variability between individual consumption patterns both within and between treatments decreased markedly as temperature increased, suggesting that higher temperatures promote more consistent individual consumption behaviors. Grasshoppers grew faster and larger as temperature increased, which translated into higher survival rates at higher temperatures. Warmer grasshoppers also did not alter their metabolic rates in response to predation risk cues, in contrast to colder grasshoppers. Digestive efficiency increased with temperature as well -- further indicating that lower temperatures were much more stressful than higher temperatures for grasshoppers. The study shows that physiological responses of ectothermic herbivores to predation stress are highly plastic and temperature dependent, with higher temperatures promoting increased protein intake, growth, development, survival, and digestive efficiency relative to colder temperatures. These findings help to reconcile why dietary responses (proportion of protein vs. carbohydrate intake) to predation stress may vary among different prey taxa studied previously.

Summary The genomes of kinetoplastids are organized into polycistronic gene clusters that are flanked by the modified DNA base J. Previous work has established a role of base J in promoting RNA polymerase II termination in Leishmania spp. where the loss of J leads to termination defects and transcription into adjacent gene clusters. It remains unclear whether these termination defects affect gene expression and whether read through transcription is detrimental to cell growth, thus explaining the essential nature of J. We now demonstrate that reduction of base J at specific sites within polycistronic gene clusters in L. major leads to read through transcription and increased expression of downstream genes in the cluster. Interestingly, subsequent transcription into the opposing polycistronic gene cluster does not lead to downregulation of sense mRNAs. These findings indicate a conserved role for J regulating transcription termination and expression of genes within polycistronic gene clusters in trypanosomatids. In contrast to the expectations often attributed to opposing transcription, the essential nature of J in Leishmania spp. is related to its role in gene repression rather than preventing transcriptional interference resulting from read through and dual strand transcription.

The primary aim of this study was to evaluate whether being treated for mental health or nonbattle physical injury during military combat deployment was associated with higher risk for postdeployment mental disorders and poorer career outcomes than seen in the general combat-deployed population. Service members treated in theater for mental health (n = 964) or noncombat injury (n = 853) were compared with randomly sampled personnel (n = 7,220) from the general deployed population on diagnosed mental disorders and early separation from service. Deployment, medical, and career information were obtained from Department of Defense archival databases. Over half of the personnel who received mental health treatment while deployed were diagnosed with 1 or more mental disorders postdeployment and/or were separated from service before completing their full-term enlistment. This was significantly higher than expected compared to the general deployed group, adjusting for demographic/military characteristics and mental health history (adjusted odds ratios [ORs] ranging 1.62 to 2.96). Frequencies of problems also were higher in the mental health-treated group than in the group treated for nonbattle physical injuries (significant adjusted ORs ranging 1.65 to 2.58). The documented higher risks for postdeployment adjustment problems suggested that especially those treated in theater by mental health providers might benefit from postdeployment risk-reduction programs.

Understanding the mechanisms regulating the diversity and distribution of arthropods is essential to understanding food web interactions and ecosystem functioning. Local arthropod diversity is known to be linked to features of surrounding landscapes, including the area of human-developed land. Yet, how such landscape moderation of diversity affects processes within local sites remains understudied. We report on a study that 1) measured the impacts of human development surrounding old-field habitats of arthropods on arthropod food web structure within those habitats and 2) determined if these shifts were associated with cascading impacts on the plant community. We sampled the arthropod community in 16 old-fields that span an urban-rural gradient throughout southern New England, USA. In each field, we also established paired mesocosms enclosing vegetation, one of which allowed arthropod herbivory while the other excluded such interactions, to isolate impacts of arthropod herbivory on three functional groups of plants: grasses, goldenrod and non-goldenrod forbs. Biomass of both herbivorous and predatory arthropods were positively related to the proportion of natural area surrounding a field early in the growing season (June). This relationship persisted later into the season for predatory arthropods (through July), but not for herbivorous arthropods. We found no evidence that the biomass of predators was related to the abundance of herbivorous arthropods in a field; or that biomass of herbivores was correlated to change in plant biomass between the two types of mesocosms. We did, however, find that in fields with low predator abundance there was greater herbivory on grasses (nutritious host), but that in high predator fields goldenrod was increasingly impacted (safe host), as is predicted by past work in old-field ecosystems. The findings support the generalizability of landscape moderated biodiversity to non-agricultural systems and suggests that observed shifts in food webs have implications for community and ecosystem dynamics.