High Foliar and Soil Nitrogen Concentrations in Central Appalachian Forests

Regional topography and climate variation yield differences in ecosystem attributes that make spatially scaled estimates of forest productivity challenging. Foliar nitrogen is a primary indicator of forest ecosystem productivity and is used in regional estimates of terrestrial productivity, but this characteristic has not been well described in the Central Appalachian region. Here we describe foliar and soil N variation among species and elevations at two spatial scales in the Central Appalachian region: (1) across the Elklick watershed in the Fernow Experimental Forest and (2) across the state of West Virginia. We found higher foliar N concentrations at both scales than those previously reported for other temperate forest regions. Canopy and soil nitrogen concentrations were also much greater in the Fernow than generally observed across West Virginia. Soil N concentrations in the Fernow were two times greater than those observed across West Virginia. Species-related differences were observed at both spatial scales, but were not always consistent. Canopy N ranges are generally consistent across elevations throughout the state of West Virginia, but should be scaled according to species-related elevation effects for studies that estimate productivity differences in response to harvest or changing species composition. The incongruence of foliar and soil N concentrations at the Fernow Experimental Forest are not explained by elevation or species composition, but are likely a consequence of greater historical N and H⁺ deposition relative to the surrounding West Virginia region.     

Old-growth red spruce communities in the mid-Appalachians

Old-growth stands of red spruce (Picea rubens) were sampled at the only four localities in the mountains of southwestern Virginia and central West Virginia where examples of such are known to exist. Based upon mean ages (±SE) of cored trees, sampled stands ranged in age from 164±18 to 201±10 yr. Dendro-ecological (tree-ring) analysis showed a marked decline in growth of trees at three localities during the late 1800s, followed by recovery to previous levels of growth within two decades. This growth-trend decline generally coincides with a period of extensive mortality of red spruce reported to have occurred in central West Virginia. Basal area of trees 2.5 cm DBH ranged from 35.4 to 46.1 m²/ha. These figures are considerably lower than those recorded at earlier dates for similar old-growth stands in the Appalachians, which suggests that a general decline has occurred over the last half-century.     

Meiotic characterization and sex determination system of neotropical primates: Bolivian squirrel monkey Saimiri boliviensis (primates: Cebidae)

The chromosomal sex determination system differs among platyrrhine monkeys more than any other group of primates. Although a number of studies have investigated mitotic chromosomes across platyrrhine species, the meiotic chromosomes of many genera have not yet been described. The goal of this study was to characterize the sex determination system of Saimiri boliviensis. We described for the first time the meiotic cycle, confirming the sexual system in germ cells from testicular biopsies of four adult male S. boliviensis. All specimens were weighed and testicular volume was measured. We observed 22 bivalents corresponding to 2N = 44, and a "human-like" XY bivalent was found in diakinesis/metaphase I. In addition, mitotic studies from blood samples of both sexes were performed and G- and C-banding patterns agreed with previously reported karylogy of S. boliviensis boliviensis. Further meiotic studies should be performed in New World primates based on the great value of those studies for systematic evolutionary biology and conservation programs.     

Babesia odocoilei Emerson and Wright, 1970 in white-tailed deer, Odocoileus virginianus (Zimmermann), in Virginia

Pooled blood samples from six white-tailed deer from the Great Dismal Swamp in Virginia were inoculated into two splenectomized deer. A moderately severe clinical reaction ensued, characterized by a hemolytic anemia, and a Babesia found in both recipient animals was presumptively identified as B. odocoilei. This is the first reported identification of this parasite in white-tailed deer in Virginia.     

Infection of spotted salamanders (Ambystoma maculatum) with Ichthyophonus-like organisms in Virginia

Ichthyophonus-like organisms were found in two free-ranging adult spotted salamanders (Ambystoma maculatum) captured within two different vernal ponds in the Virginia Commonwealth University Rice Center for Environmental Life Sciences in Charles City County, Virginia. Histopathologic examination of necropsied specimens revealed large spores, often enclosed by granulomas. These enclosed spores resembled those caused by the fish pathogen Ichthyophonus hoeferi. One salamander displayed an externally visible large swelling beneath the jaws. The other lacked macroscopic abnormalities, but histologic sections of ventral muscle revealed early-stage Ichthyophonus-like organisms and minimal granulomatous reactions. This is the first report of Ichthyophonus-like infection of Ambystoma maculatum in Virginia.     

FLOWERING PHENOLOGY AT BIG RUN BOG,WEST VIRGINIA

In each of four major plant communities at Big Run Bog, a 15-ha Sphagnum-dominated wetland in the Appalachian Mountains of West Virginia, the flowering phenology of 21 species was measured by counting the number of flowering stems at frequent intervals throughout the growing season. The four plant communities exhibited no consistent differences with regard to the patterns of flowering phenology. Mean flowering duration was 30 days for all species, and was 32 and 31 days for wind- and insect-pollinated species, respectively. Peak flowering times for the 21 species were randomly distributed throughout the growing season. Results from Big Run Bog are not markedly different from those reported for other bogs in North America.     

A Probabilistic Ecological Risk Assessment of Tributyltin in Surface Waters of the Chesapeake Bay Watershed

The goal of this study was to conduct a probabilistic ecological risk assessment for tributyltin (TBT) in surface waters of the Chesapeake Bay watershed. Ecological risk was characterized by comparing the probability distributions of environmental exposure concentrations with the probability distributions of species response data determined from laboratory studies. The overlap of these distributions was a measure of risk to aquatic life. Tributyltin exposure data from the Chesapeake Bay watershed were available from over 3600 water column samples from 41 stations in nine basins from 1985 through 1996. Most of the stations were located in the Virginia waters of Chesapeake Bay, primarily the James, Elizabeth and York Rivers. In Maryland waters of the Bay, various marina, harbor and river systems were also sampled. As expected, the highest environmental concentrations of tributyltin (based on 90th percentiles) were reported in and near marina areas. The sources of TBT causing these high concentrations were primarily boat hulls and painting/depainting operations. Lower concentrations of TBT were reported in open water areas, such as the Potomac River, Choptank River and C and D Canal, where the density of boats was minimal. Temporal data from a ten year data base (1986-1996) from two areas in Virginia showed that TBT water column concentrations have declined since 1987 legislation prohibited the use of TBT paints on recreation boats (<25?m). Acute saltwater and freshwater TBT toxicity data were available for 43 and 23 species, respectively. Acute effects for saltwater species were reported for concentrations exceeding 420?ng/L; the lowest acute value for a freshwater species was 1110?ng/L. The acute 10th percentiles for all saltwater and freshwater species were 320 and 103?ng/L, respectively. The order of sensitivity from most to least sensitive for saltwater trophic groups and corresponding acute 10th percentiles were as follows: zooplankton (5?ng/L), phytoplankton (124?ng/L), benthos (312?ng/L) and fish (1009?ng/L). For freshwater species, the order of sensitivity from most to least sensitive trophic groups and corresponding acute 10th percentiles were: benthos (44?ng/L), zooplankton (400?ng/L), and fish (849?ng/L). Chronic data for both saltwater and freshwater species were limited to a few species in each water type. Based on these limited data, the saltwater and freshwater chronic 10th percentiles were 5 and 102?ng/L, respectively. Limited mesocosm and microcosm studies in saltwater suggested that TBT concentrations less than 50?ng/L did not impact the structure and function of biological communities. The saltwater acute (320?ng/L) and chronic (5?ng/L) 10th percentiles were used to determine ecological risk because all exposure data were from saltwater areas of the Chesapeake Bay watershed. Highest ecological risk was reported for marina areas in Maryland waters of Chesapeake Bay and for areas in Virginia such as the Elizabeth River, Hampton Creek and Sarah Creek. Low ecological risk was reported for areas such as the Potomac River, Choptank River, C and D Canal and Norfolk Harbor. Regulation of TBT on recreational watercraft in 1987 has successfully reduced water column concentrations of this organometallic compound. However, various studies have showed that TBT may remain in the sediment for years and continue to be source for water column exposures.     

Local Climate Experts: The Influence of Local TV Weather Information on Climate Change Perceptions

Individuals who identify changes in their local climate are also more likely to report that they have personally experienced global climate change. One way that people may come to recognize that their local climate is changing is through information provided by local TV weather forecasters. Using random digit dialing, 2,000 adult local TV news viewers in Virginia were surveyed to determine whether routine exposure to local TV weather forecasts influences their perceptions of extreme weather in Virginia, and their perceptions about climate change more generally. Results indicate that paying attention to TV weather forecasts is associated with beliefs that extreme weather is becoming more frequent in Virginia, which in turn is associated with stronger beliefs and concerns about climate change. These associations were strongest for individuals who trust their local TV weathercaster as a source of information about climate change, and for those who identify as politically conservative or moderate. The findings add support to the literature suggesting that TV weathercasters can play an important role in educating the public about climate change.     

The demographic and socioeconomic factors predictive for populations at high-risk for La Crosse virus infection in West Virginia

Although a large body of literature exists for the environmental risk factors for La Crosse virus (LACV) transmission, the demographic and socioeconomic risk factors for developing LACV infection have not been investigated. Therefore, this study investigated the demographic and socioeconomic risk factors for LACV infection in West Virginia from 2003 to 2007, using two forward stepwise discriminant analyses. The discriminant analyses were used to evaluate a number of demographic and socioeconomic factors for their ability to predict: 1) those census tracts with at least one reported case of LACV infection versus those census tracts with no reported cases of LACV infection and 2) to evaluate significantly high-risk clusters for LACV infection versus significantly low-risk clusters for LACV infection. In the first model, a high school education diploma or a general education diploma or less and a lower housing densitywere found to be predictive of those census tracts with at least one case of LACV infection. A high school or a general education diploma or less, lower housing density, and housing built in 1969 and earlier were all found to be predictive of those census tracts displaying high-risk clusters versus census tracts displaying low-risk clusters in the second model. The cluster discriminant analysis was found to be more predictive than the census tract discriminant analysis as indicated by the Eigenvalues, canonical correlation, and grouping accuracy. The results of this study indicate that socioeconomically disadvantaged populations are at the highest risk for LACV infection and should be a focus of LACV infection prevention efforts.     

Survey of haircoat fungal flora for the presence of dermatophytes in a population of white-tailed deer (Odocoileus virginianus) in Virginia

Before releasing rehabilitated wildlife, patients should be cured of all infectious agents that pose a risk to free-roaming wildlife or humans after release. Dermatophyte fungi, commonly known as "ringworm," have zoonotic potential and may be carried as normal flora on the haircoats of certain species. Outbreaks of ringworm are anecdotally reported to occur in white-tailed deer (Odocoileus virginianus) fawns, but no prevalence surveys have been conducted on the haircoat flora of free-roaming individuals. In November 2008, we tested 60 legally hunted white-tailed deer for dermatophyte flora by using a modified MacKenzie technique. Results indicate it is unlikely that wild, mature white-tailed deer in Virginia, USA, carry dermato-phyte fungi as normal haircoat flora. Therefore, wildlife rehabilitators and hunters are at low risk for dermatophyte infection by direct contact with this species. In addition, the RapidVet-D 3 Day Test for Veterinary Dermatophytosis was determined to have poor specificity for presence of dermatophyte fungi on asymptomatic white-tailed deer in Virginia.     

Applying a Watershed-Level,Risk-Based Approach to Addressing Legacy Mercury Contamination in the South River,Virginia: Planning and Problem Formulation

In 2001, the DuPont Company and various Virginia regulatory agencies (Virginia) established the South River Science Team (SRST) as a multi-stakeholder and collaborative program to address legacy Hg contamination of the South River, Virginia. Specifically, the SRST began to apply a watershed-level risk-based assessment process to evaluate the potential impact of a former DuPont facility adjacent to the South River. Mercury had been found in facility soils in 1976 spawning numerous chemical and biological studies. However, prior to 1999, with the exception of a structured, long-term fish monitoring plan developed by Virginia, these studies were conducted by diverse, independent organizations resulting in limited scientific oversight and implementation, or interaction with the public. This article focuses on some key findings (e.g., defining/refining the issues, setting up the team, the role of the different stakeholders in making the process work) from the problem formulation and planning phase of this multi-stakeholder effort. The SRST effort draws heavily on the concepts of problem formulation (PF) and planning (as described by the U.S. Environmental Protection Agency) to guide the overall risk-based approach. PF is one of the most important steps in the process and, if done correctly can lead to a well-conceived and implemented assessment.     

Prevalence of antibodies to Toxoplasma gondii in raccoons (Procyon lotor) from an urban area of Northern Virginia

Raccoons (Procyon lotor) are intermediate hosts for Toxoplasma gondii, and clinical toxoplasmosis in raccoons has been reported. A 2-yr serological survey was conducted to determine the prevalence of antibodies to T. gondii in raccoons collected from Fairfax County, Virginia, a suburban/urban area outside Washington, D.C. Serum samples from 256 raccoons were examined for T. gondii antibodies at a 1:50 dilution using the modified direct agglutination test. Results indicated that 216 (84.4%) of the raccoons had been exposed to T. gondii. Our results indicate that raccoons in this area of Virginia are frequently exposed to T. gondii. Domestic cats were common in the study area and may have served as a source of oocysts for raccoons and the food items of raccoons.     

Systematics of dusky salamanders, Desmognathus (Caudata: Plethodontidae), in the mountain and Piedmont regions of Virginia and North Carolina, USA

We analysed mitochondrial (cytochrome  b ) nucleotide sequences, nuclear allozyme markers, and morphometric characters to investigate species boundaries and phylogenetic relationships among dusky salamanders ( Desmognathus ) in the southern Blue Ridge and adjacent Piedmont Physiographic Provinces of Virginia and North Carolina. Our results revealed four distinct mitochondrial DNA clades that are also characterized by distinct allozyme markers. One clade consists of sequences derived from populations distributed from New England to south-western Virginia that are referable to Desmognathus fuscus Rafinesque, 1820, although there is considerable sequence and allozyme divergence within this clade. A second clade consists of sequences derived from populations referable to Desmognathus planiceps Newman, 1955, a form that we resurrect from its long synonymy under D. fuscus . Desmognathus planiceps and D. fuscus also differ in mandibular tooth shape. Two other cytochrome  b sequences recovered from populations along the Blue Ridge escarpment in southern Virginia are quite divergent from those of the previous two clades, and these populations may represent yet another distinct species. Sequences from a population in the Brushy Mountains in the Piedmont of northern North Carolina are similar to those of Desmognathus carolinensis . Population groupings indicated by allozyme data generally correspond to the cytochrome  b clades. Cryptic diversity in Appalachian desmognathan salamanders clearly requires further study. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 115–130.     

Serological response of cats to experimental Besnoitia darlingi and Besnoitia neotomofelis infections and prevalence of antibodies to these parasites in cats from Virginia and Pennsylvania

Besnoitia darlingi and Besnoitia neotomofelis are cyst-forming tissue apicomplexan parasites that use domestic cats (Felis domesticus) as definitive hosts and opossums (Didelphis virginiana ) and Southern Plains woodrats (Neotoma micropus) as intermediate hosts, respectively. Nothing is known about the prevalence of B. darlingi or B. neotomofelis in cats from the United States. Besnoitia darlingi infections have been reported in naturally infected opossums from many states in the United States, and B. neotomofelis infections have been reported from Southern Plains woodrats from Texas, but naturally infected cats have not been identified. The present study examined the IgG antibody response of cats to experimental infection (B. darlingi n = 1 cat; B. neotomofelis n = 3 cats). Samples from these cats were used to develop an indirect immunofluorescent antibody test (IFAT), which was then used to examine seroprevalence of IgG antibodies to tachyzoites of B. darlingi and B. neotomofelis in a population of domestic cats from Virginia (N = 232 cats) and Pennsylvania (N = 209). The serum from cats inoculated with B. darlingi or B. neotomofelis cross-reacted with each other's tachyzoites. The titers to heterologous tachyzoites were 1 to 3 dilutions lower than to homologous tachyzoites. Sera from B. darlingi- or B. neotomofelis-infected cats did not react with tachyzoites of Toxoplasma gondii or Neospora caninum or merozoites of Sarcocystis neurona using the IFAT. Antibodies to B. darlingi were found in 14% and 2% of cats from Virginia and Pennsylvania, respectively. Antibodies to B. neotomofelis were found in 5% and 4% of cats from Virginia and Pennsylvania, respectively. Nine cats from Virginia and 1 cat from Pennsylvania were positive for both.     

Out of the mouths of baboons: stress,life history,and dental development in the Awash National Park hybrid zone,Ethiopia

The techniques of dental histology provide a method for reconstructing much of the life history of an individual, as accentuated increments visible in polarized light microscopy record incidents of physiological stress during the formation of dental tissues. Combined with counts of the normal periodic growth increments, they provide a means of reconstructing the chronology of dental development, age at death, and the ages at which stress occurs. In this study, we determine age at death and reconstruct the chronology of dental development in two male anubis baboons from Uganda and two female baboons from the Awash National Park hybrid zone. For the female baboons, we used the dates of death and rainfall records for the region to determine date of birth, ages at periods of physiological stress, dates at which these stresses occurred, and rainfall amounts for those months.Ages determined histologically for each specimen are comparable to ages estimated from dental emergence schedules and dental scores for wild baboons. Crown formation times are longer than those reported in radiographic studies of captive yellow baboons. Age at initiation of crown formation is similar to that reported for radiographic studies, but ages at completion of crown formation are consistently later. The pattern of stresses is similar in the two female baboons, suggesting that individual life history intersects with local ecology to produce a pattern of accentuated increments occurring during the weaning process and at the onset of menarche, as well as during the first postweaning dry and rainy periods.     

INFLUENCE OF SEED SOURCE UPON PHENOLOGY OF FLOWERING OF SPARTINA ALTERNIFLORA LOISEL. AND THE LIKELIHOOD OF CROSS POLLINATION

Seedlings of Spartina alterniflora Loisel., from seed harvested from nine marshes ranging from Maine to Virginia, were grown for three seasons in plots established on two different soils in Delaware and were flooded regularly with water from two estuarine sources. Substantial differences in the time of flowering were observed. Each year plants from Maine seed flowered first and were followed by those from Connecticut and New York. Last to flower were plants from Virginia seed. The latter initiated flowering after flowering of the Maine source had been completed. These two would not cross-pollinate under this circumstance. The phenology of anthesis and number of seeds set on inflorescences enclosed in bags indicate that this species is largely open pollinated.     

Geographic variation in patterns of nestedness among local stream fish assemblages in Virginia

Nestedness of faunal assemblages is a multi-scale phenomenon, potentially influenced by a variety of factors. Prior small-scale studies have found freshwater fish species assemblages to be nested along stream courses as a result of either selective colonization or extinction. However, within-stream gradients in temperature and other factors are correlated with the distributions of many fish species and may also contribute to nestedness. At a regional level, strongly nested patterns would require a consistent set of structuring mechanisms across streams, and correlation among species tolerances of the environmental factors that influence distribution. Thus, nestedness should be negatively associated with the spatial extent of the region analyzed and positively associated with elevational gradients (a correlate of temperature and other environmental factors). We examined these relationships for the freshwater fishes of Virginia. Regions were defined within a spatial hierarchy and included whole river drainages, portions of drainages within physiographic provinces, and smaller subdrainages. In most cases, nestedness was significantly stronger in regions of smaller spatial extent and in regions characterized by greater topographic relief. Analysis of hydrologic variability and patterns of faunal turnover provided no evidence that inter-annual colonization/extinction dynamics contributed to elevational differences in nestedness. These results suggest that, at regional scales, nestedness is influenced by interactions between biotic and abiotic factors, and that the strongest nestedness is likely to occur where a small number of organizational processes predominate, i.e., over small spatial extents and regions exhibiting strong environmental gradients.The Virginia Cooperate Fish and Wildlife Research Unit is jointly sponsored by United States Geological Survey, Virginia Polytechnic Institute and State University, and Virginia Department of Game and Inland Fisheries.     

Persistently high levels of intersexuality in male-biased amphipod populations

In a study conducted over 30 years ago, a remarkable population of amphipod crustaceans (Gammarus minus) was discovered in which 100% of the females displayed intersex characteristics. Such high levels of intersexuality are atypical amongst gonochoristic crustaceans and current theories relating to sex allocation suggest intermediate (intersex) forms should be competitively selected against. This study set out to confirm the existence of this extraordinary population and to compare it with other G. minus populations in various spring and cave systems across Pennsylvania, Virginia and West Virginia (USA), with varying environmental characteristics in an attempt to elucidate the prevalence and cause of intersexuality in this species. Results from this study verify the continued existence of these highly abundant, intersex female populations of G. minus, with proportions ranging between 73% and 100%. These populations were also associated with highly male-biased sex ratios, which is equally unusual amongst gonochoristic crustaceans. Intersex female specimens had a reduced fecundity compared to normal females, although this result was not statistically significant. Although no feminising microsporidian parasites were observed through histological examination, the presence of a novel feminising parasitic factor cannot be ruled out. The continued vigour of these populations over three decades suggests that anthropomorphic factors are not causing the high levels of intersexuality observed. Intersexuality was absent or very low in frequency (<1%) in most other springs that we investigated. Therefore, G. minus appears to represent an interesting and novel model system for studying sex determination.     

Modeling regulatory networks at Virginia Tech

The life of a cell is governed by the physicochemical properties of a complex network of interacting macromolecules (primarily genes and proteins). Hence, a full scientific understanding of and rational engineering approach to cell physiology require accurate mathematical models of the spatial and temporal dynamics of these macromolecular assemblies, especially the networks involved in integrating signals and regulating cellular responses. The Virginia Tech Consortium is involved in three specific goals of DARPA's computational biology program (Bio-COMP): to create effective software tools for modeling gene-protein-metabolite networks, to employ these tools in creating a new generation of realistic models, and to test and refine these models by well-conceived experimental studies. The special emphasis of this group is to understand the mechanisms of cell cycle control in eukaryotes (yeast cells and frog eggs). The software tools developed at Virginia Tech are designed to meet general requirements of modeling regulatory networks and are collected in a problem-solving environment called JigCell.