Wooded Sites Research Articles

Mosquito diversity and dog heartworm prevalence in suburban areas

BackgroundUrbanization is occurring rapidly on a global scale and is altering mosquito communities, creating assemblages that are characteristically less diverse. Despite high rates of urbanization and ample examples of vector-borne diseases transmitted by multiple species, the effects of urbanization-driven mosquito diversity losses on disease transmission has not been well explored. We investigated this question using the dog heartworm, a filarial parasite vectored by numerous mosquito species.MethodsWe trapped host-seeking mosquitoes in undeveloped areas and neighborhoods of different ages in Wake County, North Carolina, USA, analyzing captured mosquitoes for heartworm DNA. We compared within-mosquito heartworm infection across land-use types by Kruskal–Wallis and likelihood ratio tests. Using zip code level data acquired from dogs in a local shelter, we performed linear regressions of within-host heartworm prevalence by within-mosquito heartworm prevalence as well as by three mosquito diversity measures. We also determined the best predictor of host-level prevalence among models including within-mosquito infection, mosquito diversity and abundance, and socioeconomic status as variables.ResultsSuburban areas had lower within-mosquito heartworm prevalence and lower likelihood of heartworm-positive mosquitoes than did undeveloped field sites, although no differences were seen between suburban and undeveloped wooded sites. No relationships were noted between within-mosquito and within-host heartworm prevalence. However, mosquito diversity metrics were positively correlated with host heartworm prevalence. Model selection revealed within-host prevalence was best predicted by a positive relationship with mosquito Shannon–Wiener diversity and a negative relationship with household income.ConclusionsOur results demonstrate that decreases in mosquito diversity due to urbanization alter vector-borne disease risk. With regard to dog heartworm disease, this loss of mosquito diversity is associated with decreased heartworm prevalence within both the vector and the host. Although the response is likely different for diseases transmitted by one or few species, mosquito diversity losses leading to decreased transmission could be generalizable to other pathogens with multiple vectors. This study contributes to better understanding of the effects of urbanization and the role of vector diversity in multi-vectored pathosystems.

Protecting small populations of rare species. Case study on Dactylorhiza viridis (Orchidaceae) in Fancott Woods and Meadows SSSI, Bedfordshire, UK

Dactylorhiza viridis is a small orchid species, sensitive to competition with dense and tall herbaceous vegetation. Its populations in Europe and in the UK have been declining over the last century. Small, isolated populations have remained in Protected Areas. The population of the species in Fancott Woods and Meadows Site of Special Scientific Interest (SSSI) was studied in 2011–2019. The number of orchid plants varies substantially from year to year, but the areas occupied by the population remain the same. Fruit production is high. The population is under threat from herbivores and from competition with tall vegetation on the meadow. Expansion of the vigorous herb Filipendula ulmaria was recorded on the meadow in 2009 that negatively affected the rare plant community. Additional management of an early hay cut was implemented on the meadow as a trial. A botanical survey of managed and control plots showed a reduction in the vigorous herbs, an increase in species number in the cut plots and a resulting more open sward. The orchid population also benefits from a more open sward. The management of the site is the key to the survival of this small orchid population.

Dead wood diversity in a Norway spruce forest from the Calimani National Park (Eastern Carpathians)

The role of dead wood in forests encompasses the preservation of biodiversity, the productivity, and the storage of carbon. In this study, we aimed to investigate the variation of the dead wood volume in a subalpine Norway spruce forests. Using a regular grid, the size of the wood, ordered in a five-class scale for snags and logs and a six-class scale for stumps, was recorded. The relationship between the dead wood volume and site respectively stand characteristics by some predictive factors (stand age, altitude, human influence and site productivity) was modelled using mixed linear/nonlinear models. Dead wood volume (74.3 m3·ha-1) accounted for 18.3% of the volume (live trees and dead wood). Regarding the dead wood only, snags amounted to 44.8% of the volume and logs and stumps amounted to 46.5, and 8.7%, respectively. Snags (57.5% of the total) and logs (42.8%), were most common in the 2nd decay class, while stumps were most common in the 6th (51.2%). The distribution of the number of dead wood pieces, in terms of diameter, was obtained according to the Meyer theoretical distribution for snags and to the Gamma theoretical distribution for logs and stumps. This study completes the dead wood database from Norway spruce forests in the subalpine area to find the common features across the Carpathians Mountains. It contributes to the understanding of the dead wood dynamics in a young National Park, considering the year of establishment, consists of forests where forestry work was carried out and stands that were exempt from cutting.

Using Multistaged Magnetic Survey and Excavation to Assess Community Settlement Organization: A Case Study from the Central Peninsular Gulf Coast of Florida

AbstractIntegrating geophysical survey with the study of community settlement patterns can be challenging because of cultural and environmental factors including (1) site formation and house preservation, (2) the coordination of domestic tasks at extra-household scales, and (3) the survey environment of the study area. In this article, we present the results of a program of geophysical survey comprising magnetic susceptibility and magnetometry at Weeden Island (8Pi1)—a shell-bearing, wooded site with nearly pure sand soils on the Gulf Coast of Florida. Combining remote sensing techniques mitigated some of the challenges of surveying forested terrain while providing insight into community organization at a site with minimal preserved structural remains. Compared with previous traditional surveys of the area, the geophysical survey extended the recognized boundaries of occupational activity, provided additional definition to the spatial structure of deposits, and allowed us to identify specific domestic features. Excavations at each area of intensive occupation provided evidence about the organization of the domestic economy at the site and showed the potential of this approach to reveal significant patterns of community settlement.

Effects of altitude on density and biometric properties of hornbeam wood (Carpinus betulus)

Aim of the study: This study aimed to investigate the effect of altitude difference on the wood dry density, fiber dimensions, and morphological properties of hornbeam wood (Carpinus betulus L.).Area of study: The study area was located in the province of Mazandaran, north of Iran.Material and method: 18 mature trees were randomly selected and harvested at six altitude levels (300, 500, 700, 900, 1100, and 1300 m) in the north of Iran. The clear test samples‎ were prepared‎ at diameter at breast height (DBH) to measure the wood dry density, fiber length, fiber diameter, cell wall thickness, Runkel coefficients, flexibility coefficients, and slenderness coefficients. Further ‎analyses included the relationships between the wood properties and site conditions (temperature, ‎precipitation, crown canopy, ‎and understory herb layer) as well as tree’s main dimensions ‎(tree height and the DBH).Main results: The results indicated significant effects of altitude variations on the studied ‎properties. The pattern variations of wood properties were very regular at different levels of height. The average fiber length and fiber diameter decreased while the wood dry density and cell wall thickness increased with increasing the altitude levels. The average values of wood dry density, fiber length, fiber diameter, cell wall thickness, slenderness coefficients, flexibility coefficients, and Runkel coefficients of hornbeam wood were 698 kg/m3, 1.42mm, 25.58 µm, 5.72µm, 55.55, 54.04%, and 0.93, respectively, in the above six altitudes. Pearson matrix correlation showed that there were significant relationships between temperature, crown canopy, tree height and DBH ‎with the studied wood properties (except the slenderness coefficients)‎.Research highlights: The hornbeams grown at altitudes above 900-1300 m were not suitable for pulp and ‎paper production‎ due to relatively higher Runkel coefficients, the lower flexibility coefficients, as well as smaller fiber length than other altitude levels.Additional Keywords: Carpinus betulus; altitude variation; density; fiber dimensions; morphological properties.Abbreviations used: WDD (wood dry density); FL (fiber length); FD (fiber diameter), CWT (cell wall thickness); FC (flexibility coefficient); RC (Runkel coefficients); SC (slenderness coefficient).

Exploring the effects of pasture trees on plant community patterns

AbstractQuestionsWe aim to answer three questions: (a) what are the effects of canopy shading of different tree species on seed germination of eight understorey grassland species? (b) how is plant species’ occurrence in understorey communities affected by differences in canopy cover and does that depend on tree species composition? and (c) are there mechanistic links between the effects of trees on species’ germination and their occurrence in the understorey plant community?LocationSemi‐natural wooded pastures in the biosphere reserve Östra Vätterbranterna, southern Sweden.MethodsIn this study, we examined the germination of eight grassland plant species in a seed sowing experiment under natural conditions in the field. Seeds were sown beneath and outside the canopy of two tree species within 48 plots split up by four wooded pasture sites. We combined observed germination responses with a plant community survey to assess the effects of canopy cover in relation to tree species composition on plant community responses. We analysed these data in relation to species’ seed mass and vegetative shade tolerance.ResultsShade‐tolerant species germinated better beneath compared to outside tree canopies, without any clear advantage of large‐seeded over small‐seeded species. As expected, species’ shade tolerance was also positively related to canopy cover within the understorey plant community. Importantly, we found strong tree species‐specific effects of canopy shading on the species’ germination response, but not on their presence within the plant community. However, optimal canopy cover conditions for germination and for the mature plants differed across grassland species and depended on tree species.ConclusionsOur results show that different tree species play key ecosystem engineering roles in shaping wooded grassland plant community composition at the germination stage. Management practices favouring specific tree species may therefore be highly relevant for targeted biodiversity conservation of wooded semi‐natural grasslands.

Functional traits of hyporheic and benthic invertebrates reveal importance of wood‐driven geomorphological processes in rivers

Abstract Large wood (LW) is a natural element of river environments and an integral component of many river restoration schemes to promote biodiversity. It is an important habitat in itself, but it also induces a wide range of hydraulic, hydrological, geomorphological and chemical conditions that influence the ecological community. However, the effects of hydro‐geomorphological processes induced by LW on local benthic and hyporheic invertebrates have not been well characterized. A functional approach was applied to invertebrate data collected in a field survey at sites with LW and without LW (control) to investigate the response of hyporheic and benthic invertebrates' trait profiles in response to local LW‐induced processes. We hypothesized LW sites to be associated with different trait modalities than control sites in relation to wood‐induced processes and conditions (i.e., hyporheic exchange flow, oxygen availability, temporal stability, organic matter, denitrification, hydraulic conductivity). Multivariate analyses and partial least squares (PLS) path modelling were used to detect the differences in trait profiles between LW and control sites and to study the variation of traits as a function of hydrological, sedimentological, physical and chemical variables. Biological (i.e., aquatic stages, reproduction), physiological (i.e., dispersal, feeding habits) and behavioural (i.e., substrate preferences) trait utilization by the hyporheic meiofauna differed between LW and control sites. At LW sites, the hyporheic meiofaunal assemblage was significantly associated with aquatic active dispersal, aquatic eggs and hard substrate preferences. This trait category selection was linked to changes in physical–sedimentological processes at LW sites when compared to control sites. Macrofaunal benthic and hyporheic functional traits did not differ significantly between wood and control sites, suggesting similar functioning of these assemblages at the surface–subsurface interface. This study found that LW affects invertebrate traits by altering fluvial processes to produce, locally, a mosaic of habitats. Hyporheic meiofauna trait responses to LW processes have suggested (a) the crucial role of LW in supporting river benthic zone functioning and thus (b) a possible benefit to river restoration by enhancing functional interactions among different ecological niches. A free Plain Language Summary can be found within the Supporting Information of this article.

An assessment of soil respiration on two contrasting urban forestry areas using the SolvitaTM Gel System

ABSTRACTInadequate soil conditions can affect tree health and longevity but there are few tools available to urban foresters to carry out soil assessments. The SolvitaTM Gel System field test, developed for agricultural purposes, assesses biological activity in soil samples by measuring CO2 respiration rates. This test was used alongside other analytical tests using soil samples from two contrasting urban sites; a wooded area and a grassed area with semi-mature trees. The wooded site had 156% higher levels of NPK, 240% more soil organic matter and 252% more easily oxidisable soil organic carbon than the grassed site. In addition, the SolvitaTM Digital Colour Reader value and basal respiration was 196% higher for the wooded site. Soil bulk densities were recorded at 0.97 g cm-3 and 1.45 g cm-3 for the wooded and grassed sites respectively. There were significant correlations between basal respiration results and soil organic matter content. A calibrating laboratory experiment identified significant differences in SolvitaTM test values between five soil sample groups with increasing leaf mould content. We conclude that the SolvitaTM Gel System field test has the potential to be used as an urban forest soil assessment tool and its use warrants further research.

Impacts of burning on soil trace gas fluxes in two wooded savanna sites in Burkina Faso

In this study, we report the impacts woodland savanna burning has on the soil trace gas fluxes in seasonally dry woodland savannas in Burkina Faso. We measured nitrous oxide (N2O), nitric oxide (NO), carbon dioxide (CO2) and methane (CH4) fluxes at two ongoing long-term experimental sites (Tiogo and Dindéresso), each included three fire-exclusion plots and four annually burnt plots (0.24–0.25 ha plot size). We measured soil trace gas fluxes using chamber methods before and after fire during the dry season and at the start of and during the wet season. There was considerable volatilization of aboveground biomass C and N during fire, but soil N2O, NO, CO2 and CH4 fluxes were not significantly influenced following fire events. Instead, soil moisture dynamics were more important in regulating soil CO2 and N2O emissions. The onset of the wet season induced a short-term pulse of N2O emissions, when water-filled pore space exceeded 60%. We also detected a short-term pulse of NO emissions, lasting only four hours, following fire. The low soil N-oxide fluxes reflected the sites’ extremely low inorganic N levels in the soil.

Beta diversity patterns reveal positive effects of farmland abandonment on moth communities

Farmland abandonment and the accompanying natural succession are largely perceived as unwanted amongst many European conservationists due to alleged negative effects on biodiversity levels. Here, we test this assumption by analysing alpha, beta and gamma diversity patterns of macro-moth communities in habitats on an ecological succession gradient, from extensively managed meadows to scrub-encroached and wooded sites. Macro-moths were light-trapped at 84 fixed circular sampling sites arranged in a semi-nested design within the National Park of Peneda-Gerês, NW-Portugal. In total, we sampled 22825 individuals belonging to 378 species. Alpha, beta and gamma diversity patterns suggest that farmland abandonment is likely to positively affect both overall macro-moth diversity and forest macro-moth diversity, and to negatively affect species diversity of non-forest macro-moth species. Our results also show that spatial habitat heterogeneity is important to maintain gamma diversity of macro-moths, especially for rare non-forest species and habitat specialists.

The response of wild bees to tree cover and rural land use is mediated by species' traits

Worldwide, bees have an important role in ecosystem function and the provision of ecosystem services through their role as pollinators. The diversity of bee species in rural landscapes is influenced by the type of landscape features present, and by land-use and management practices. A key challenge is to understand and predict how species vary across the landscape; and the role of functional traits in determining compositional patterns. We systematically sampled wild bees in four types of landscape feature – open farmland, scattered farmland trees, roadside vegetation and streamside vegetation – in rural landscapes in southern Australia. Landscapes were selected to represent wooded or non-wooded combinations of these site types (e.g. roadside vegetation with or without trees), embedded in farmland with different land-uses (e.g. cropping, grazing). The species richness and abundance of bees was greater at sites containing little or no tree cover; and the cumulative richness of species was greater for tree-less sites than for those with trees. In contrast, species evenness was greatest in wooded site types, indicating these were less dominated by abundant generalist species. Open farmland and treeless roadsides had greater functional diversity (based on species traits) than wooded site types. Strong species trait associations were more numerous with open parts of the landscape, reflecting the greater functional diversity of open site types. These results suggest that a suite of the extant bee fauna can exploit large-scale transformation from former extensively wooded ecosystems to open agricultural landscapes. However, not all species are able to exploit modified landscapes and may disappear with further loss of wooded vegetation. Trait-based approaches provide insight into how changes in landscape pattern affect the bee fauna. Failure to adequately cater for multiple functional groups of bees across all landscape features could mean a substantial loss in species that rely on more natural cover, thus affecting ecosystem function.

Celebrating 50 Years of Neuroscience Research at Lilly's Erl Wood site

On 14 July 2017, Eli Lilly & Company (Lilly) celebrated 50 years of pioneering research and development at its site in Erl Wood (Surrey, UK). The Lilly Research Centre was established in 1967 and has played a key role in some of the company's most important scientific breakthroughs, including the discovery of olanzapine (Zyprexa®) for the treatment of schizophrenia and bipolar disorders. Launched in 1996, olanzapine became Lilly's most successful medicine and has been used to treat millions of patients worldwide. Over 600 people, representing 45 nationalities and 30 different functional disciplines, continue to collaborate from Erl Wood on the discovery and development of new medicines to meet areas of major unmet medical need. The day of celebration saw leading figures from the world of Alzheimer's research, neuroscience and medicines development come together to hear about the latest advances in the fight against Alzheimer's and reflect on the history of the Erl Wood site. Michael Hutton, David Reynolds, Daniel Skovronsky, Virginia Acha and Susan Forda, spoke to Future Neurology while attending the Erl Wood 50th Anniversary Symposium.

Biotechnology for bioenergy dedicated trees: meeting future energy demands

With the increase in human demands for energy, purpose-grown woody crops could be part of the global renewable energy solution, especially in geographical regions where plantation forestry is feasible and economically important. In addition, efficient utilization of woody feedstocks would engage in mitigating greenhouse gas emissions, decreasing the challenge of food and energy security, and resolving the conflict between land use for food or biofuel production. This review compiles existing knowledge on biotechnological and genomics-aided improvements of biomass performance of purpose-grown poplar, willow, eucalyptus and pine species, and their relative hybrids, for efficient and sustainable bioenergy applications. This includes advancements in tree in vitro regeneration, and stable expression or modification of selected genes encoding desirable traits, which enhanced growth and yield, wood properties, site adaptability, and biotic and abiotic stress tolerance. Genetic modifications used to alter lignin/cellulose/hemicelluloses ratio and lignin composition, towards effective lignocellulosic feedstock conversion into cellulosic ethanol, are also examined. Biotech-trees still need to pass challengeable regulatory authorities' processes, including biosafety and risk assessment analyses prior to their commercialization release. Hence, strategies developed to contain transgenes, or to mitigate potential transgene flow risks, are discussed.

Preliminary investigation of soil bacterial communities from sites experiencing diverse human activity.

Students in the Microbial Ecology class at Shepherd University investigated the bacterial communities present in soil samples collected from four sites across Shepherd University that experience different vegetation and distinct human activities: a wooded site, a perennial garden, an organic garden at the Campus Sustainability Site, and a grass lawn that experiences heavy student traffic. To identify bacterial species present in the soil samples, DNA was extracted from the soil and sent to Molecular Research Labs for 16S rRNA microbiome sequencing. The resulting sequences were then organized into operational taxonomic units for each site and biodiversity estimated for each site. Principal coordinate analysis revealed that the bacterial community in soil from the heavily trafficked lawn site was distinct from the bacterial communities found in soils collected from the other three sites. This initial research provides a basis for a longitudinal study investigating the effect of human activity on microbial communities in soil at Shepherd University. This course-based research project was supported by a West Virginia Space Grant Consortium College Course Development Grant, Authentic Research Experience in Microbiology (NSF-TUES #1323225), and the Shepherd University Biology Department.

EFFECT OF RECREATIONAL TRAIL TRAFFIC LEVEL ON EASTERN RED-BACKED SALAMANDER (PLETHODON CINEREUS) RELATIVE ABUNDANCE

The effects of roads and trails on terrestrial salamanders, primarily plethodontids, can be important. The abundance of terrestrial salamanders often increases with distance from roads. Less is known about the effects of recreational or hiking trails on terrestrial salamanders than is known about the effects of roads. We explored how low and high traffic trails in a suburban biological reserve affect the relative abundance of Eastern Red-backed Salamanders (Plethodon cinereus). We found more salamanders under cover objects next to low traffic trails compared to either high traffic trails or wooded areas without trails. At wooded sites, we found only striped morphs whereas at high traffic sites we found only unstriped morphs. Low traffic sites included a range of color morph frequencies. The proportion of females found in each site did not differ, nor did the mean size of the salamanders. Our results suggest that the impact of recreational walking trails needs to be examined more closely to see how and why the distributions of P. cinereus, and potentially other woodland salamanders, are affected and what trail characteristics are important in driving the apparent effects. Such information will contribute to the design and maintenance of walking trails in natural areas that minimize effects on terrestrial salamanders, and likely other organisms.

Surveillance for Ixodes ricinus ticks (Acari, Ixodidae) on the Faroe Islands

Ixodes ricinus ticks are expanding their geographic range in Europe, both latitudinally in Scandinavia, and altitudinally in the European Alps. This paper details the findings of both passive and active surveillance on the Faroe Islands. Active field surveillance, using tick dragging, was conducted at 38 sites across the main seven inhabited islands of the Faroes during June-August 2015. Field sampling was conducted at all wooded sites on the islands of Vágar, Streymoy, Eysturoy, Borðoy, Kunoy and Suðuroy as well as in urban parks in the capital Tórshavn, among seabird colonies and at a bird observatory on Nólsoy, at moorland sites on Vágar and Borðoy, and a coastal headland on Suðuroy. In addition, as part of the promotion of a new passive surveillance scheme for the Faroes, new tick records were submitted during summer 2015 and early spring 2016. During tick dragging, only three questing I. ricinus ticks (two nymphs, one male) were found at two separate sampling locations in the village of Tvøroyri on the southernmost island of Suðuroy. No questing ticks were found at any other field site. The passive surveillance of ticks identified an additional 33 records of I. ricinus collected during the last 10 years on the Faroes, with almost half of these records from 2015. Although this represents the first finding of questing I. ricinus and overwintering I. ricinus on the Faroe Islands, there appears to be little evidence so far to suggest that Ixodes ricinus are established on the Faroe Islands. Additional reports of ticks through the passive surveillance scheme are reported from seven inhabited islands. Reports of ticks on both companion animals and humans suggest that ticks are being acquired locally, and the records of ticks on migratory birds highlight a possible route of importation. This paper details the likely ecological constraints on I. ricinus establishment and density on Faroe and makes recommendations for future surveillance and research.

Eurasian beaver activity increases water storage, attenuates flow and mitigates diffuse pollution from intensively-managed grasslands

Beavers are the archetypal keystone species, which can profoundly alter ecosystem structure and function through their ecosystem engineering activity, most notably the building of dams. This can have a major impact upon water resource management, flow regimes and water quality. Previous research has predominantly focused on the activities of North American beaver (Castor canadensis) located in very different environments, to the intensive lowland agricultural landscapes of the United Kingdom and elsewhere in Europe.Two Eurasian beavers (Castor fiber) were introduced to a wooded site, situated on a first order tributary, draining from intensively managed grassland. The site was monitored to understand impacts upon water storage, flow regimes and water quality. Results indicated that beaver activity, primarily via the creation of 13 dams, has increased water storage within the site (holding ca. 1000m3 in beaver ponds) and beavers were likely to have had a significant flow attenuation impact, as determined from peak discharges (mean 30±19% reduction), total discharges (mean 34±9% reduction) and peak rainfall to peak discharge lag times (mean 29±21% increase) during storm events. Event monitoring of water entering and leaving the site showed lower concentrations of suspended sediment, nitrogen and phosphate leaving the site (e.g. for suspended sediment; average entering site: 112±72mgl−1, average leaving site: 39±37mgl−1). Combined with attenuated flows, this resulted in lower diffuse pollutant loads in water downstream. Conversely, dissolved organic carbon concentrations and loads downstream were higher. These observed changes are argued to be directly attributable to beaver activity at the site which has created a diverse wetland environment, reducing downstream hydrological connectivity. Results have important implications for beaver reintroduction programs which may provide nature based solutions to the catchment-scale water resource management issues that are faced in agricultural landscapes.

Biological control of sentinel egg masses of the exotic invasive stink bug Halyomorpha halys (Stål) in Mid-Atlantic USA ornamental landscapes

Biological invasions have far reaching effects on native plant and arthropod communities. This study evaluated the effect of natural enemies on eggs of the exotic invasive brown marmorated stink bug Halyomorpha halys (Stål) in experimental plots comprising species pairs of 16 ornamental trees and shrub genera from either Eurasia or North America and in wooded areas adjacent to the plots. Sentinel egg masses were placed on leaves of Acer, Cercis, Hydrangea, and Prunus in the plots and in seven genera of trees and shrubs in adjacent woods. Overall, rates of parasitism and predation in experimental plots were low, accounting for only 3.8% and 4.4% of egg mortality, respectively. There were no significant differences in parasitism and predation rates between native or exotic plots or between plants of different genera. In 2015, predation was significantly higher in the experimental plots than in the wooded sites, but parasitism was significantly higher in the wooded sites. In the experimental plots, seven native and one exotic parasitoid species attacked sentinel egg masses. Six native parasitoid species attacked sentinel egg masses in the wooded sites. Parasitoids in the genus Trissolcus were more likely to attack egg masses in exotic plots than in native plots. There is no evidence that native natural enemies attacking eggs of the exotic BMSB were more prevalent in landscapes with native ornamental trees and shrubs than those with exotic trees and shrubs.

AHR-related activities in a creosote-adapted population of adult atlantic killifish, Fundulus heteroclitus, two decades post-EPA superfund status at the Atlantic Wood Site, Portsmouth, VA USA

Atlantic killifish, Fundulus heteroclitus, are adapted to creosote-based PAHs at the US EPA Superfund site known as Atlantic Wood (AW) on the southern branch of the Elizabeth River, VA USA. Subsequent to the discovery of the AW population in the early 1990s, these fish were shown to be recalcitrant to CYP1A induction by PAHs under experimental conditions, and even to the time of this study, killifish embryos collected from the AW site are resistant to developmental deformities typically associated with exposure to PAHs in reference fish. Historically, however, 90 +% of the adult killifish at this site have proliferative hepatic lesions including cancer of varying severity. Several PAHs at this site are known to be ligands for the aryl hydrocarbon receptor (AHR). In this study, AHR-related activities in AW fish collected between 2011 and 2013 were re-examined nearly 2 decades after first discovery. This study shows that CYP1A mRNA expression is three-fold higher in intestines of AW killifish compared to a reference population. Using immunohistochemistry, CYP1A staining in intestines was uniformly positive compared to negative staining in reference fish. Livers of AW killifish were examined by IHC to show that CYP1A and AHR2 protein expression reflect lesions-specific patterns, probably representing differences in intrinsic cellular physiology of the spectrum of proliferative lesions comprising the hepatocarcinogenic process. We also found that COX2 mRNA expression levels were higher in AW fish livers compared to those in the reference population, suggesting a state of chronic inflammation. Overall, these findings suggest that adult AW fish are responsive to AHR signaling, and do express CYP1A and AHR2 proteins in intestines at a level above what was observed in the reference population.

The Urban Heat Island and its spatial scale dependent impact on survival and development in butterflies of different thermal sensitivity.

Climate alteration is one of the most cited ecological consequences of urbanization. However, the magnitude of this impact is likely to vary with spatial scale. We investigated how this alteration affects the biological fitness of insects, which are especially sensitive to ambient conditions and well‐suited organisms to study urbanization‐related changes in phenotypic traits. We monitored temperature and relative air humidity in wooded sites characterized by different levels of urbanization in the surroundings. Using a split‐brood design experiment, we investigated the effect of urbanization at the local (i.e., 200 × 200 m) and landscape (i.e., 3 × 3 km) scale on two key traits of biological fitness in two closely related butterfly species that differ in thermal sensitivity. In line with the Urban Heat Island concept, urbanization led to a 1°C increase in daytime temperature and an 8% decrease in daytime relative humidity at the local scale. The thermophilous species Lasiommata megera responded at the local scale: larval survival increased twofold in urban compared to rural sites. Urbanized sites tended to produce bigger adults, although this was the case for males only. In the woodland species Pararge aegeria, which has recently expanded its ecological niche, we did not observe such a response, neither at the local, nor at the landscape scale. These results demonstrate interspecific differences in urbanization‐related phenotypic plasticity and larval survival. We discuss larval pre‐adaptations in species of different ecological profiles to urban conditions. Our results also highlight the significance of considering fine‐grained spatial scales in urban ecology.