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The European gypsy moth (Lymantria dispar L.) was first introduced to Massachusetts in 1869 and within 150 years has spread throughout eastern North America. This large-scale invasion across a heterogeneous landscape allows examination of the genetic signatures of adaptation potentially associated with rapid geographical spread. We tested the hypothesis that spatially divergent natural selection has driven observed changes in three developmental traits that were measured in a common garden for 165 adult moths sampled from six populations across a latitudinal gradient covering the entirety of the range. We generated genotype data for 91,468 single nucleotide polymorphisms based on double digest restriction-site associated DNA sequencing and used these data to discover genome-wide associations for each trait, as well as to test for signatures of selection on the discovered architectures. Genetic structure across the introduced range of gypsy moth was low in magnitude (FST = 0.069), with signatures of bottlenecks and spatial expansion apparent in the rare portion of the allele frequency spectrum. Results from applications of Bayesian sparse linear mixed models were consistent with the presumed polygenic architectures of each trait. Further analyses indicated spatially divergent natural selection acting on larval development time and pupal mass, with the linkage disequilibrium component of this test acting as the main driver of observed patterns. The populations most important for these signals were two range-edge populations established less than 30 generations ago. We discuss the importance of rapid polygenic adaptation to the ability of non-native species to invade novel environments.
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Variação Genética , Espécies Introduzidas , Mariposas/genética , Animais , Teorema de Bayes , Evolução Biológica , Estudo de Associação Genômica Ampla , Heterozigoto , Larva/genética , Desequilíbrio de Ligação , América do Norte , Fenótipo , Polimorfismo de Nucleotídeo Único , PupaRESUMO
Thermal regimes can diverge considerably across the geographic range of a species, and accordingly, populations can vary in their response to changing environmental conditions. Both local adaptation and acclimatization are important mechanisms for ectotherms to maintain homeostasis as environments become thermally stressful, which organisms often experience at their geographic range limits. The spatial spread of the gypsy moth (Lymantria dispar L.) (Lepidoptera: Erebidae) after introduction to North America provides an exemplary system for studying population variation in physiological traits given the gradient of climates encompassed by its current invasive range. This study quantifies differences in resting metabolic rate (RMR) across temperature for four populations of gypsy moth, two from the northern and two from southern regions of their introduced range in North America. Gypsy moth larvae were reared at high and low thermal regimes, and then metabolic activity was monitored at four temperatures using stop-flow respirometry to test for an acclimation response. For all populations, there was a significant increase in RMR as respirometry test temperature increased. Contrary to our expectations, we did not find evidence for metabolic adaptation to colder environments based on our comparisons between northern and southern populations. We also found no evidence for an acclimation response of RMR to rearing temperature for three of the four pairwise comparisons examined. Understanding the thermal sensitivity of metabolic rate in gypsy moth, and understanding the potential for changes in physiology at range extremes, is critical for estimating continued spatial spread of this invasive species both under current and potential future climatic constraints.
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Adaptação Biológica , Metabolismo Basal , Clima , Mariposas/metabolismo , Aclimatação , Animais , Espécies Introduzidas , Larva/crescimento & desenvolvimento , Larva/metabolismo , Massachusetts , Mariposas/crescimento & desenvolvimento , Quebeque , Sudeste dos Estados UnidosRESUMO
INTRODUCTION: Tendinopathy is a common pathology with numerous treatment options. Ultrasound-guided percutaneous tenotomy is a newer procedure to treat chronic tendinopathy. It reduces costs and risks compared to other treatments, such as open surgery and platelet-rich plasma (PRP) injections. The goal of percutaneous tenotomy is to induce an acute inflammatory response that recruits clotting and growth factors, induces bleeding, and transforms scar tissue and diseased tendons into a healing state. METHODS: A tenotomy was performed in 57 patients for elbow epicondylitis (13), supraspinatus tendonitis (4), gluteal tendinopathy (34), and patellar tendinopathy (5). The survey was created and sent electronically to all 57 patients, yielding 46 respondents. Each patient was surveyed postoperatively to determine their pain levels on a numeric scale from 1 to 10 prior to and following the procedure. We also asked patients about their satisfaction with the procedure, whether they would recommend it to a friend, and how long it took them to recover completely. RESULTS: Forty-six of 57 patients responded to the survey. The average healing time was 58 days, and no patients required further surgery. Pain scores significantly improved after tenotomies in the shoulder, elbow, and hip. About 74% of patients were completely satisfied with the procedure, and 80% received enough benefit to recommend it to a friend. CONCLUSIONS: Ultrasonic tenotomy provides significant relief for tendinopathy in the shoulder, elbow, and hip for the majority of patients. The knee pain scores were not significantly reduced, likely due to the small sample size of four patients. Some patients did not experience complete relief and benefited from a PRP injection after tenotomy. Some patients did not benefit, likely due to additional pathology, arthritis, and referred pain. Some limitations to our study include the lack of a control group and each procedure was performed by the same physician, which limits its generalizability. The survey responses were subjective, and the sample size was variable between each body region. More high-quality research is needed to establish the efficacy of tenotomy between different tendons and compare it to other treatment methods.
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Under global climate change, high and low temperature extremes can drive shifts in species distributions. Across the range of a species, thermal tolerance is based on acclimatization, plasticity, and may undergo selection, shaping resilience to temperature stress. In this study, we measured variation in cold temperature tolerance of early instar larvae of an invasive forest insect, Lymantria dispar dispar L. (Lepidoptera: Erebidae), using populations sourced from a range of climates within the current introduced range in the Eastern United States. We tested for population differences in chill coma recovery (CCR) by measuring recovery time following a period of exposure to a nonlethal cold temperature in 2 cold exposure experiments. A 3rd experiment quantified growth responses after CCR to evaluate sublethal effects. Our results indicate that cold tolerance is linked to regional climate, with individuals from populations sourced from colder climates recovering faster from chill coma. While this geographic gradient is seen in many species, detecting this pattern is notable for an introduced species founded from a single point-source introduction. We demonstrate that the cold temperatures used in our experiments occur in nature during cold spells after spring egg hatch, but impacts to growth and survival appear low. We expect that population differences in cold temperature performance manifest more from differences in temperature-dependent growth than acute exposure. Evaluating intraspecific variation in cold tolerance increases our understanding of the role of climatic gradients on the physiology of an invasive species, and contributes to tools for predicting further expansion.
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Plantar taping has been used in clinical settings as a short-term conservative treatment for plantar heel pain and related pathologies. The rise of at-home taping methods may offer patients more independence, but effectiveness has not been established. The purpose of this study was to evaluate the effects of plantar taping on foot mechanics during gait. We hypothesized that material compliance would drive mechanical effectiveness, with longitudinally inelastic tape reducing medial longitudinal arch (MLA) motion and anterior/posterior (A/P) plantar tissue spreading forces, and laterally inelastic tape reducing medial/lateral (M/L) tissue spreading. We also hypothesized that these effects would be influenced by foot structure. Fifteen healthy participants were tested in a randomized cross-over study design. Barefoot (BF) plus four taping methods were evaluated, including two inelastic tapes (Low-Dye, LD, and FasciaDerm, FD) along with longitudinally elastic kinesiology tape (KT) and a novel laterally elastic kinesiology tape (FAST, FS). Participants' arch height and flexibility were measured followed by instrumented gait analysis with a multi-segment foot model. Ankle eversion and MLA drop/rise were calculated from rearfoot and forefoot reference frames, while plantar tissue spreading was calculated from shear stresses. ANOVAs with Holm pairwise tests evaluated tape effects while correlations connected arch structure and taping effectiveness (α = 0.05). The three longitudinally inelastic tapes (LD, FD, FS) reduced MLA drop by 11-15% compared with KT and BF. In late stance, these tapes also inhibited MLA rise (LD by 29%, FD and FS by 10-15%). FS and FD reduced A/P spreading forces, while FD reduced M/L spreading forces compared with all other conditions. Arch height had a moderately strong correlation (r = -0.67) with the difference in MLA drop between BF and FS. At-home plantar taping can affect the mechanical function of the foot, but tape elasticity direction matters. Longitudinally elastic kinesiology tape has little effect on mechanics, while inelastic tapes control MLA drop but also restrict MLA rise in late stance. Lateral elasticity does not limit tissue spreading and may increase comfort without sacrificing MLA control. At-home taping has the potential to broaden conservative treatment of plantar heel pain, flat foot deformity, and related pathologies, but additional studies are needed to connect mechanics with symptom relief.
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Fita Atlética , Pé , Humanos , Elasticidade , Marcha , Dor , Estudos Cross-OverRESUMO
Introduction: Scarless healing is the ideal outcome of wound healing and is exhibited in some species. This narrative review assembles the current understanding of fibroblast heterogenicity along with the latest fibroblast-related targets for scar reduction therapies. Human regenerative wound healing is deemed possible due to the wound regeneration already seen in the early gestation foetus. Methods: This literature narrative review was undertaken by searching PubMed and Web of Science databases and Google Scholar to find articles concerning the fibroblast involvement in wound healing. We evaluated and collated these articles to form a consensus of the current understanding of the field. Discussion: This article describes current understanding of fibroblast heterogenicity and involvement in wound healing, focusing on the role of fibroblasts during physiological scarring. We also present the current most promising targets involving fibroblasts in the reduction of scarring and how we can manipulate the behaviour of fibroblasts to mimic the wound regeneration models in the human foetus. These targets include the pro-fibrotic EN1 positive fibroblast lineage, TGFß1 inhibition, and genetic therapies utilising miRNAs and siRNAs. Conclusion: No therapies are currently available to eradicate scarring; however, treatment options are available to reduce the appearance of scarring. Further research into the heterogenicity and interactions of fibroblasts in both the foetus and adult is needed, and this may lead to the development of novel treatments against scarring. Lay Summary: Scarless healing refers to the repair of a wound with minimal residual scarring. The main cell responsible for the repair process is the fibroblast. It is now understood that there are different types of fibroblasts. Simply, some of these fibroblasts lead to scarring and some lead to regeneration. The early human foetus has mainly regenerative fibroblasts, but during aging the number of scarring fibroblasts increase to become the majority in the adult . Understanding how we can modify this process may ultimately result in the reduction in scarring. Currently, scar reduction therapies are aimed at optimal wound healing, surgical removal of abnormal scars, and using steroids and other drugs to encourage better wound repair by limiting the effect of scarring fibroblasts. Future therapies aim to target specific groups of fibroblasts to encourage regenerative wound healing. This narrative review aims to cover the current understanding of the different groups of fibroblasts and their effect on wound healing. We also cover the current and potential therapies that can be used to reduce scarring and suggest further areas for research in this field.
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For capital-breeding insects, all resources available for adult metabolic needs are accumulated during larval feeding. Therefore, body size at adult eclosion represents the total energetic capacity of the individual. For female capital breeders, body size is strongly correlated with lifetime fecundity, while in males, body size, which correlates with fitness, is less understood. In capital-breeding species with wingless, flightless, or dispersal-limited females, flight potential for male Lepidoptera has important implications for mate-finding and may be correlated with body size. At low population densities, failure to mate has been identified as an important Allee effect and can drive the success or failure of invasive species at range edges and in species of conservation concern. Th capital-breeding European subspecies of Lymantria dispar (L.), was introduced to North America in 1869 and now ranges across much of eastern North America. In L. dispar, females are flightless and mate-finding is entirely performed by males. We quantified male L. dispar flight capacity and propensity relative to morphological and physiological characteristics using fixed-arm flight mills. A range of male body sizes was produced by varying the protein content of standard artificial diets while holding other dietary components constant. Wing length, a proxy for body size, relative thorax mass, and forewing aspect were all important predictors of total flight distance and maximum speed. These results have important implications for mate-finding and invasion dynamics in L. dispar and may apply broadly to other capital-breeding insects.
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Mariposas , Animais , Feminino , Voo Animal , Espécies Introduzidas , Larva , Masculino , Mariposas/fisiologia , Reprodução , Asas de Animais/anatomia & histologiaRESUMO
Temperature and its impact on fitness are fundamental for understanding range shifts and population dynamics under climate change. Geographic climate heterogeneity, behavioral and physiological plasticity, and thermal adaptation to local climates make predicting the responses of species to climate change complex. Using larvae from seven geographically distinct wild populations in the eastern United States of the non-native forest pest Lymantria dispar dispar (L.), we conducted a simulated reciprocal transplant experiment in environmental chambers using six custom temperature regimes representing contemporary conditions near the southern and northern extremes of the US invasion front and projections under two climate change scenarios for the year 2050. Larval growth and development rates increased with climate warming compared with current thermal regimes and tended to be greater for individuals originally sourced from southern rather than northern populations. Although increases in growth and development rates with warming varied somewhat by region of the source population, there was not strong evidence of local adaptation, southern populations tended to outperform those from northern populations in all thermal regimes. Our study demonstrates the utility of simulating thermal regimes under climate change in environmental chambers and emphasizes how the impacts from future increases in temperature can vary based on geographic differences in climate-related performance among populations.
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BACKGROUND: Orthopedic walker boots are often used to treat foot ulcers and other wounds with the goal of offloading plantar pressure. However, poor ulcer healing outcomes and high recurrence rates show a need for additional solutions in the growing diabetes epidemic. We compared a novel spring-loaded walker boot to a traditional rigid ankle boot and a hinged ankle boot as well as a control shoe. Our aim was to better understand how boot design affects offloading mechanisms. We hypothesized that all boots would offload force from the foot to the shank, but that the hinged boot would have fewer gait alterations and the spring boot would further reduce pressure in early and late stance. METHODS: Ten healthy participants tested each of the four conditions in static stance and walking gait. Offloading was quantified by the difference between pressure insole and platform forces, while joint mechanics changes were calculated from instrumented gait analysis and inverse dynamics. RESULTS: Minimal offloading was found in the rigid and hinged boots compared to athletic shoes. In contrast, the spring boot offloaded nearly 50% of total load in static stance, with similarly large reductions in peak pressures during gait, particularly under the hindfoot during early stance. All boots resulted in some ankle joint mechanics compensations, with the rigid and spring boots showing similar restrictions in ankle motion and propulsive work. While the hinged boot resulted in ankle mechanics more like the shoe condition, it increased dorsiflexion and negative work, suggesting energetic inefficiency. CONCLUSIONS: The novel spring boot shows promise for more effective offloading that could lead to improved healing outcomes.
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Marcha , Sapatos , Tornozelo , Fenômenos Biomecânicos , Pé , Humanos , CaminhadaRESUMO
American chestnut (Castanea dentata [Marsh.] Borkh.) was once the dominant hardwood species in Eastern North America before an exotic fungal pathogen, Cryphonectria parasitica (Murrill) Barr, functionally eliminated it across its range. One promising approach toward restoring American chestnut to natural forests is development of blight-tolerant trees using genetic transformation. However, transformation and related processes can result in unexpected and unintended phenotypic changes, potentially altering ecological interactions. To assess unintended tritrophic impacts of transgenic American chestnut on plant-herbivore interactions, gypsy moth (Lymantria dispar L.) caterpillars were fed leaf disks excised from two transgenic events, Darling 54 and Darling 58, and four control American chestnut lines. Leaf disks were previously treated with an LD50 dose of either the species-specific Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) or the generalist pathogen Bacillus thuringiensis subsp. kurstaki (Btk). Mortality was quantified and compared to water blank controls. Tree genotype had a strong effect on the efficacies of both pathogens. Larval mortality from Btk-treated foliage from only one transgenic event, Darling 54, differed from its isogenic progenitor, Ellis 1, but was similar to an unrelated wild-type American chestnut control. LdMNPV efficacy was unaffected by genetic transformation. Results suggest that although genetic modification of trees may affect interactions with other nontarget organisms, this may be due to insertion effects, and variation among different genotypes (whether transgenic or wild-type) imparts a greater change in response than transgene presence.
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Bacillus thuringiensis/fisiologia , Fagus/genética , Genótipo , Herbivoria , Mariposas/fisiologia , Nucleopoliedrovírus/fisiologia , Animais , Ascomicetos/fisiologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Larva/virologia , Mariposas/crescimento & desenvolvimento , Mariposas/microbiologia , Mariposas/virologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Folhas de Planta/virologia , Plantas Geneticamente Modificadas/genéticaRESUMO
Scant attention has been paid to invasive species whose range and abundance has decreased after an initial range expansion. One such species is the browntail moth Euproctis chrysorrhoea L, which was discovered in the eastern United States in 1897. Its range expanded until 1914; after 1915, however, its range contracted and now it persists in only two isolated coastal locations. Although a biological control agent has been implicated in this range collapse, cold inland winter temperatures may also help to restrict browntail moth populations. We surveyed coastal versus inland habitats in Maine and Massachusetts for browntail moth overwintering mortality and larval density per web. We also performed an experiment assessing these same variables in coastal versus inland habitats on different host plant species and at different initial larval densities. We also analyzed temperature records to assess whether winter temperatures correlated with changes in the invasive range. Overwintering mortality was lower in coastal populations for both the experimental populations and in the Maine field survey. Experimental populations in Cape Cod coastal areas also had lower rates of fall mortality and higher larval densities, suggesting that coastal areas are better year-round habitats than inland areas. There were no consistent differences between coastal and inland populations in their response to larval density or host plant, although overall survival in both areas was higher at low initial larval densities and affected by host identity. There was also no difference in two measures of the coldest winter temperatures during browntail moth's expansion and contraction. Our results show that climate affects browntail moth, but suggest that winter temperatures cannot explain both the rapid expansion and subsequent collapse of this pest.
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Clima Frio , Temperatura Baixa , Ecossistema , Mariposas/fisiologia , Animais , Larva , New England , Estações do AnoRESUMO
Recent attention has focused on the harmful effects of introduced biological control agents on nontarget species. The parasitoid Compsilura concinnata is a notable example of such biological control gone wrong. Introduced in 1906 primarily for control of gypsy moth, Lymantria dispar, this tachinid fly now attacks more than 180 species of native Lepidoptera in North America. While it did not prevent outbreaks or spread of gypsy moth, we present reanalyzed historical data and experimental findings suggesting that parasitism by C. concinnata is the cause of the enigmatic near-extirpation of another of North America's most successful invaders, the browntail moth (Euproctis chrysorrhoea). From a range of approximately 160,000 km2 a century ago, browntail moth (BTM) populations currently exist only in two spatially restricted coastal enclaves, where they have persisted for decades. We experimentally established BTM populations within this area and found that they were largely free of mortality caused by C. concinnata. Experimental populations of BTM at inland sites outside of the currently occupied coastal enclaves were decimated by C. concinnata, a result consistent with our reanalysis of historical data on C. concinnata parasitism of the browntail moth. The role of C. concinnata in the disappearance of browntail moth outside these enclaves has not been reported before. Despite the beneficial role played by C. concinnata in reversing the browntail moth invasion, we do not advocate introduction of generalist biological control agents. Our findings illustrate that the impact of such organisms can be both unpredictable and far-reaching.
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Dípteros/fisiologia , Mariposas/parasitologia , Animais , Ecossistema , Interações Hospedeiro-Parasita , New England , Plantas , Densidade DemográficaRESUMO
We examined the effects of fertilization and gypsy moth defoliation on condensed tannin concentration (%CT) of hybrid poplar (Populus x canadensis cv 'Eugeneii') fine roots in the summers of 1997 and 1998. This factorial experiment included two defoliation treatments (defoliated and a foliated control) and fertilization treatments (100 kg nitrogen (N) ha(-1) and an unfertilized control). Gypsy moth (Lymantria dispar L.) populations were experimentally increased to obtain defoliation in the summers of 1996, 1997 and 1998; fertilization subplots were supplemented with NH4NO3 (100 kg N ha(-1)) in the spring of each year. Despite the severity of defoliation, the effects were small, and significant on only two sampling dates: in May 1997, when fine root %CT was 23% lower in the defoliated trees, and in November 1997, when trees in the defoliated unfertilized plots had 35% higher root %CT than trees in all other plots. Defoliation effects on root %CT did not follow the same seasonal pattern as defoliation effects on root starch content, N uptake capacity or leaf %CT. Regulation of root condensed tannin concentration appeared to be partially uncoupled from these traits. The small transient effects on root defense reflect the resilience of this early successional tree to severe early season defoliation.
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Mariposas/fisiologia , Nitrogênio/metabolismo , Raízes de Plantas/metabolismo , Populus/metabolismo , Proantocianidinas/metabolismo , Animais , Fertilizantes , Interações Hospedeiro-Parasita/fisiologia , Folhas de Planta/parasitologia , Populus/parasitologiaRESUMO
The effects of long-term mass rearing of laboratory insects on ecologically relevant traits is an important consideration when applying research conclusions to wild populations or developing management strategies. Laboratory strains of the gypsy moth, Lymantria dispar (L.), an invasive forest pest in North America, have been continuously reared since 1967. Selection on these strains has enhanced a variety of traits, resulting in faster development, shorter diapause, and greater fecundity. As in many mass-reared insects, laboratory strains of the gypsy moth are also reared exclusively on artificial diets that lack much of the phytochemical and nutritional complexity associated with natural foliage. We tested for differences in growth and development of wild gypsy moth populations from across the invasive range in comparison to laboratory strains when reared on artificial diet and a preferred foliage host species, northern red oak (Quercus rubra L.). Overall, caterpillars reared on foliage had higher survival and faster development rates, with smaller differences among populations. When reared on artificial diet, laboratory strains had the highest performance as expected. The response from the wild populations was mixed, with two populations performing poorly on artificial diet and another performing nearly as well as the laboratory strains. Performance on diet was enhanced when larvae received cubed portions changed regularly, as opposed to filled cups. Understanding these relationships between food source and population performance is important for informing studies that examine population comparisons using wild and laboratory-reared strains.
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Ração Animal/análise , Dieta , Mariposas/fisiologia , Quercus/química , Animais , Larva/crescimento & desenvolvimento , Larva/fisiologia , Longevidade , Massachusetts , Mariposas/genética , Mariposas/crescimento & desenvolvimento , Folhas de Planta/química , Pupa/crescimento & desenvolvimento , Pupa/fisiologia , Quebeque , VirginiaRESUMO
Large-scale outbreaks of defoliating insects are common in temperate forests. The effects of defoliation on tree physiology are expected to cascade through the entire forest ecosystem, altering carbon, nitrogen, and water fluxes, and subsequently affecting nitrogen cycling and plant-herbivore interactions. If these post-defoliation changes are largely driven by N deficiency, tree root system responses to defoliation should be central to regulating the long-term effects of defoliation; N fertilization should reverse the effects. We examined these phenomena in a 3-year large-scale replicated manipulative field experiment in a hybrid poplar plantation, where we regulated defoliation by gypsy moths as well as nitrogen availability. To our knowledge, this is the first manipulative field experiment at this scale to examine the effects of severe insect defoliation on whole-tree physiology. Defoliation decreased tree growth and increased the rate of top dieback in the stand. Defoliation led to transient declines in carbon allocation to starch in fine roots, trunk, and twigs in the year of heaviest defoliation. Root production and root mortality were unaffected by the heaviest defoliation, but nitrate and ammonium uptake were strongly depressed. N fertilization increased tree growth, but did not alter defoliation effects on starch accumulation or top dieback. Defoliation and fertilization treatments did not interact. In this system, defoliation effects on tree recovery of leaf nitrogen lost to herbivory were primarily driven by effects on nitrogen uptake, rather than effects on root production or mortality.
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Late-summer starch accumulation in fine roots of poplars (Populus x canadensis Moench.) defoliated by gypsy moth (Lymantria dispar L.) lagged behind that in fine roots of undefoliated trees. If starch concentration declines with age, defoliation-induced changes in root system age structure could be partly responsible for this difference. To test this hypothesis, we measured fine-root starch and soluble sugar concentrations in roots of known age from trees in defoliated and undefoliated plots. There was a significant interaction between the effects of defoliation and root type (white, brown, or dead) on fine root soluble sugar concentration because of the high concentration of soluble sugars in white roots from trees in undefoliated plots. Both root starch and soluble sugar concentrations were variable among individuals of each age class. The population frequency distributions for starch and soluble sugar concentrations were both right-skewed, and fit by exponential functions. These data are most consistent with direct defoliation effects on a labile and dynamic pool of carbohydrates in poplar fine roots, rather than indirect defoliation effects on root system age structure.