Conservation and genetics of the frosted flatwoods salamander (Ambystoma cingulatum) on the Atlantic coastal plain

The federally threatened frosted flatwoods salamander, Ambystoma cingulatum, occurs in isolated populations on the coastal plain of northern Florida, Georgia and South Carolina. An earlier phylogeographic study based primarily on mitochondrial DNA (mtDNA) and morphometrics demonstrated that the previously recognized species A. cingulatum contained two cryptic species, and that two distinct mtDNA clades were contained within the newly restricted A. cingulatum. However, salamanders from the northern extent of the species range in South Carolina were not previously available for analysis. Here, we used individuals from a newly discovered South Carolina breeding site to determine whether A. cingulatum from South Carolina are genetically distinct from their more southerly conspecifics. These analyses included the mitochondrial gene studied previously as well as broad geographic sampling of three rapidly evolving nuclear genes that allowed us to further investigate lineage diversification of flatwoods salamanders. The mitochondrial and nuclear results are largely congruent, yielding strong support for two distinct species of flatwoods salamanders and also two lineages within the eastern species. Further, the South Carolina specimens are closely related to other haplotypes found in eastern Georgia and Florida. Our summary of field surveys over the past 20 years indicates that this South Carolina population may be one of only three remaining in the entire Atlantic coastal plain distribution of this rare and declining amphibian species.     

Density and genetic structure of black bears in coastal South Carolina

The frequency of black bear (Ursus americanus) sightings, vehicle collisions, and nuisance incidents in the coastal region of South Carolina has increased over the past 4 decades. To develop the statewide Black Bear Management and Conservation Strategy, the South Carolina Department of Natural Resources needed reliable information for the coastal population. Because no such data were available, we initiated a study to determine population density and genetic structure of black bears. We selected 2 study areas that were representative of the major habitat types in the study region: Lewis Ocean Bay consisted primarily of Carolina Bays and pocosin habitats, whereas Carvers Bay was representative of extensive pine plantations commonly found in the region. We established hair snares on both study areas to obtain DNA from hair samples during 8 weekly sampling periods in 2008 and again in 2009. We used genotypes to obtain capture histories of sampled bears. We estimated density using spatially explicit capture–recapture (SECR) models and used information-theoretic procedures to fit parameters for capture heterogeneity and behavioral responses and to test if density and model parameters varied by year. Model-averaged density was 0.046 bears/km² (SE = 0.011) for Carvers Bay and 0.339 bears/km² (SE = 0.056) for Lewis Ocean Bay. Next, we sampled habitat covariates for all locations in the SECR sampling grid to derive spatially explicit estimates of density based on habitat characteristics. Addition of habitat covariates had substantial support, and accounted for differences in density between Carvers Bay and Lewis Ocean Bay; black bear density showed a negative association with the area of pine forests (4.5-km² scale) and a marginal, positive association with the area of pocosin habitat (0.3-km² scale). Bear density was not associated with pine forest at a smaller scale (0.3-km²), nor with major road density or an index of largest patch size. Predicted bear densities were low throughout the coastal region and only a few larger areas had high predicted densities, most of which were centered on public lands (e.g., Francis Marion National Forest, Lewis Ocean Bay). We sampled a third bear population in the Green Swamp area of North Carolina for genetic structure analyses and found no evidence of historic fragmentation among the 3 sampled populations. Neither did we find evidence of more recent barriers to gene exchange; with the exception of 1 recent migrant, Bayesian population assignment techniques identified only a single population cluster that incorporated all 3 sampled areas. Bears in the region may best be managed as 1 population. If the goal is to maintain or increase bear densities, demographic connectivity of high-density areas within the low-density landscape matrix is a key consideration and managers would need to mitigate potential impacts of planned highway expansions and anticipated development. Because the distribution of black bears in coastal South Carolina is not fully known, the regional map of potential black bear density can be used to identify focal areas for management and sites that should be surveyed for occupancy or where more intensive studies are needed. © 2012 The Wildlife Society.     

Using species distribution models to define nesting habitat of the eastern metapopulation of double‐crested cormorants

When organisms with similar phenotypes have conflicting management and conservation initiatives, approaches are needed to differentiate among subpopulations or discrete groups. For example, the eastern metapopulation of the double‐crested cormorant (Phalacrocorax auritus) has a migratory phenotype that is culled because they are viewed as a threat to commercial and natural resources, whereas resident birds are targeted for conservation. Understanding the distinct breeding habitats of resident versus migratory cormorants would aid in identification and management decisions. Here, we use species distribution models (SDM: Maxent) of cormorant nesting habitat to examine the eastern P. auritus metapopulation and the predicted breeding sites of its phenotypes. We then estimate the phenotypic identity of breeding colonies of cormorants where management plans are being developed. We transferred SDMs trained on data from resident bird colonies in Florida and migratory bird colonies in Minnesota to South Carolina in an effort to identify the phenotype of breeding cormorants there based on the local landscape characteristics. Nesting habitat characteristics of cormorant colonies in South Carolina more closely resembled those of the Florida phenotype than those of birds of the Minnesota phenotype. The presence of the resident phenotype in summer suggests that migratory and resident cormorants will co‐occur in South Carolina in winter. Thus, there is an opportunity for separate management strategies for the two phenotypes in that state. We found differences in nesting habitat characteristics that could be used to refine management strategies and reduce human conflicts with abundant winter migrants and, at the same time, conserve less common colonies of resident cormorants. The models we use here show potential for advancing the study of geographically overlapping phenotypes with differing conservation and management priorities.     

The intersection of ecological risk assessment and plant communities: an analysis of <Emphasis Type="Italic">Agrostis</Emphasis> and <Emphasis Type="Italic">Panicum</Emphasis> species in the northeastern U.S.

Ecological risk assessments for grass species with novel traits are advisable, or required, in order to identify potential environmental harms prior to large-scale cultivation. Credible risk assessments are built upon knowledge of the communities that could be negatively affected by crop-to-wild gene flow, new weeds, or invasive plants. This study focused on two cultivated grasses with different life histories: the exotic, weedy Agrostis stolonifera (creeping bentgrass) and the native Panicum virgatum (switchgrass). Vascular plant communities were analyzed in 190 transects (50 m) in ten habitat types across two ecoregions (inland and coastal) in the northeastern U.S. Ordination plots and dendrogram analysis showed clustering of inland plant community assemblages within habitat types, while coastal plant communities were similar across the habitats studied. Agrostis and Panicum species had unequal distribution across the habitat types and ecoregions. Agrostis species were more common in the inland ecoregion and habitats receiving moderate management or disturbance events. In both ecoregions, A. stolonifera had high co-occurrence values with other exotic Agrostis species, suggesting potential for interspecific gene flow. P. virgatum was most common in inland roadside and wasteland habitats, but was distributed equally in the three coastal habitats. Co-occurrence between P. virgatum and congenerics was infrequent, although one transect had both P. virgatum and the state-listed coastal species Panicum amarum. This is the first study to characterize Agrostis and Panicum plant communities and distribution providing the basis for ecological risk assessments, coexistence-strategies, and geographic exclusion zones.     

Evaluating Intertidal Oyster Reef Development in South Carolina Using Associated Faunal Indicators

Eastern oyster (Crassostrea virginica) habitat is increasingly being restored for the ecosystem services it provides rather than solely as a fishery resource. Community‐based projects with the goal of ecological restoration have successfully constructed oyster reefs; however, the habitat benefits of these restoration efforts are usually not assessed or reported. In this study, we examined oyster habitat development at five community‐based oyster restoration sites in South Carolina using oyster population parameters, resident fauna densities, and sedimentation (percent sediment coverage) as assessment metrics. All sites included multiple‐aged reefs (1–3 years old) at the time of the fall 2004 sampling. Resident crabs and mussels were abundant at all five sites and crab assemblages were related to the size structure of the oyster microhabitat. Scorched mussel (Brachidontes exustus) abundances were most frequently correlated with oyster and other resident species abundances. Associations among oysters and resident crabs and mussels were not evident when analyses were conducted with higher level taxonomic groupings (e.g., total number of crabs, mussels, or oysters), indicating that species‐level identifications improve our understanding of interactions among reef inhabitants and oyster populations. Community‐based restoration sites in South Carolina provide habitat for mussels and resident crabs, in some cases in the absence of dense populations of relatively large oysters. Monitoring programs that neglect species‐level identifications and counts of mussels and crabs may underestimate the successful habitat provision that can arise independent of large, dense oyster assemblages.     

Coastal vegetation on the Western, Southern, and Eastern coasts of South Korea

We used the Braun-Blanquet method to study the vegetation of coastal wetlands in South Korea. Three habitat types were found, i.e., salt marshes, salt swamps, and sand dunes. These plant communities were classified as: 1) two groups (five associations each) in the salt marshes that comprised either annual herbaceous halophytes (ClassThero-Salicornietea), or biennial/perennial herbaceous species (ClassAsteretea tripolii); 2) one group in the salt swamps consisting of five hydrophilous halo-tolerant associations (ClassPhragmitetea); and 3) three groups in the sand dunes, including one association of annual herbaceous halophytes (ClassSalsoletea komarovii), seven associations of herbaceous perennial halophytes (ClassGlehnietea littoralis), and one association of shrub perennial halophytes (ClassVrticetea rotundifoliae). These three habitat types accounted for the majority of the six main classifications of coastal vegetation distributed in South Korea.     

A Spatially Explicit Model of the Wild Hog for Ecological Risk Assessment Activities at the Department of Energy's Savannah River Site

In North America, wild hogs (Sus scrofa) are both sought after as prime game and despised due to their detrimental impacts to the environment from their digging and rooting behavior. They are also a potentially useful indicator species for environmental health for both ecological- and human-based risk assessments. An inductive approach was used to develop probabilistic resource selection models using logistic regression to quantify the likelihood of hogs being in any area of the Department of Energy's 805 km² Savannah River Site (SRS) in west-central South Carolina. These models were derived by using available SRS hog hunt data from 1993–2000 and a Geographic Information System database describing the habitat structure of the SRS. The model's significant parameters indicated that wild hogs preferred hardwoods and avoided pine and shrubby areas. Further, landscape metric analyses revealed that hogs preferred areas with large complex patch areas and low size variation. These resource selection models were then utilized to better estimate exposure of wild hogs to radionuclides and metals in a disturbed riparian ecosystem on the SRS using two different possible diets based on food availability. Contaminant exposure can be better estimated using these resource selection models than has been previously possible, because past practices did not consider home range and habitat utilization probability in heterogeneously contaminated habitats. Had these models not been used, risk calculations would assume that contaminated areas were utilized 100% of the time, thus overestimating exposure by a factor of up to 25.     

Home on the range: spatial ecology of loggerhead turtles in Atlantic waters of the USA

Aim Although satellite tracking has yielded much information regarding the migrations and habitat use of threatened marine species, relatively little has been published about the environmental niche for loggerhead sea turtles Caretta caretta in north‐west Atlantic waters. Location North Carolina, South Carolina and Georgia, USA. Methods We tracked 68 adult female turtles between 1998 and 2008, one of the largest sample sizes to date, for 372.2 ± 210.4 days (mean ± SD). Results We identified two strategies: (1) ‘seasonal’ migrations between summer and winter coastal areas (n = 47), although some turtles made oceanic excursions (n = 4) and (2) occupation of more southerly ‘year‐round’ ranges (n = 18). Seasonal turtles occupied summer home ranges of 645.1 km² (median, n = 42; using α‐hulls) predominantly north of 35 ° latitude and winter home ranges of 339.0 km² (n = 24) in a relatively small area on the narrow shelf off North Carolina. We tracked some of these turtles through successive summer (n = 8) and winter (n = 3) seasons, showing inter‐annual home range repeatability to within 14.5 km of summer areas and 10.3 km of winter areas. For year‐round turtles, home ranges were 1889.9 km². Turtles should be tracked for at least 80 days to reliably estimate the home range size in seasonal habitats. The equivalent minimum duration for ‘year‐round’ turtles is more complex to derive. We define an environmental envelope of the distribution of North American loggerhead turtles: warm waters (between 18.2 and 29.2 °C) on the coastal shelf (in depths of 3.0–89.0 m). Main conclusions Our findings show that adult female loggerhead turtles show predictable, repeatable home range behaviour and do not generally leave waters of the USA, nor the continental shelf (< 200m depth). These data offer insights for future marine management, particularly if they were combined with those from the other management units in the USA.     

Corema album: unbiased dioecy in a competitive environment

• Corema album is a dioecious coastal shrub. Dioecious plants growing in these resource‐limited habitats may present spatial segregation of the sexes (SSS) or demographic biases because of the different reproductive effort between sexes. In these environments facilitation is a more common interaction between plants than competition. To assess factors determining the distribution of C. album male and female plants, we investigated the influence of habitat type (sand dunes and coastal woodlands), assessed the occurrence of SSS or demographic biases and also a possible role of these shrubs as nurse plants.
• We selected three C. album populations with the two habitat types. All C. album individuals were sexed, mapped and measured in three plots (20 m × 20 m) per population/habitat type. Presence and abundance of all plant species were recorded under five female and five male C. album plants as well as in equivalent open ground area in each of 15 plots.
• According to Ripley's K function result, C. album did not display SSS. Generalised linear mixed models (GLMM) show that differences in plant size were not related to plant sex. Plant inventory correspondence analysis showed that species composition and abundance were influenced by habitat type, population and the presence of a C. album individual, but not by its sex. GLMM indicated a detrimental effect of C. album on the co‐occurring plants.
• Our results show that sexual dimorphism has allowed C. album to adapt to the environment avoiding SSS or significant demographic bias, suggesting a positive outlook for its conservation.

     

An AFLP-based survey of genetic diversity among accessions of sea oats (Uniola paniculata, Poaceae) from the southeastern Atlantic and Gulf coast states of the United States

Uniola paniculata, commonly known as sea oats, is a C₄ perennial grass capable of stabilizing sand dunes. It is most abundant along the Gulf of Mexico and southeastern Atlantic coastal regions of the United States. The species exhibits low seed set and low rates of germination and seedling emergence, and so extensive clonal reproduction is achieved through production of rhizomes, which may contribute to a decline in genetic diversity. To date, there has been no systematic assessment of genetic variability and population structure in naturally occurring stands in the USA. This study was conducted to assess the genetic relationship and diversity among nineteen U. paniculata accessions representing eight states: Texas, Louisiana, Mississippi, Alabama, Florida, South Carolina, North Carolina, and Virginia, using amplified fragment length polymorphism (AFLP). Twelve AFLP EcoRI+MseI primer combinations generated a wide range of polymorphisms (42–81%) with a mean of 59%. Overall, the sea oats plants exhibited a low range of genetic similarity. Florida accessions, FL-33 and FL-39, were most genetically diverse and the accessions from both Carolinas and Virginia (NC-1, NC-11, SC-15, and VA-53) harbored less genetic variability. Cluster analysis using the UPGMA approach separated U. paniculata plants into four major clusters which were also confirmed by principal coordinate analysis (PCO). Further examination of the different components of genetic variation by analysis of molecular variance (AMOVA) indicated the largest proportion of variability at the state level (47.8%) followed by the variation due to the differences among the genotypes within an accession (34.4%), and the differences among the accessions within a state (17.8%). The relationship between genetic diversity and geographic source of sea oats populations of the United States as revealed through this comprehensive study will be helpful to resource managers and commercial nurseries in identifying suitable plant materials for restoration of new areas without compromising the adaptation and genetic diversity.     

How can we improve information delivery to support conservation and restoration decisions?

Incorporating science into resource conservation and management is becoming increasingly important, but it is not yet clear how to provide information to decision makers most effectively. To evaluate sources of information used to support the management and conservation of California’s riparian bird habitat, we distributed a questionnaire to restoration practitioners and public and private land managers. We asked respondents to rate the importance and availability of different sources of information they use to inform their decisions. Synthetic reviews and peer-reviewed publications both received high importance and availability ratings. Web-based tools received low importance and availability ratings. One-on-one interactions between ecologists and decision makers received high importance ratings, similar to those of peer-reviewed publications and synthetic reviews, but their availability was rated lower than any other method of decision support. Our results suggest that the decision makers we surveyed are already using a wide variety of information, but that prioritizing one-on-one interactions between scientists and decision makers will enhance the delivery of all sources of information.     

Population origin of Atlantic sturgeon Acipenser oxyrinchus oxyrinchus by‐catch in U.S. Atlantic coast fisheries

Microsatellite DNA and mitochondrial DNA control‐region sequence analyses were used to determine the population and distinct population segment (DPS) origin of 173 Atlantic sturgeon Acipenser oxyrinchus oxyrinchus encountered from the Gulf of Maine to Cape Hatteras, North Carolina, in NOAA's Northeast Fisheries Observer Program. It was found that the Hudson River was by far the greatest contributor to this coastal by‐catch, with 42·2–46·3% of specimens originating there. Generally, specimens represented the geographic province of the river in which they were spawned, but some specimens, particularly those originating in the South Atlantic DPS, moved to great distances. Genetic mixed‐stock analyses provide an accurate approach to determine the DPS and population origin of A. o. oxyrinchus by‐catch in coastal waters, but most informative management requires that these results be partitioned by locale, season, target fishery and gear type.     

Isolation of faecal coliform bacteria from the American alligator (Alligator mississippiensis)

Aims: To determine whether American alligators (Alligator mississippiensis) are an unrecognized poikilothermic source of faecal coliform and/or potential pathogenic bacteria in South Carolina’s coastal waters. Methods and Results: Bacteria from the cloaca of American alligators, as well as bacteria from surface water samples from their aquatic habitat, were isolated and identified. The predominant enteric bacteria identified from alligator samples using biochemical tests included Aeromonas hydrophila, Citrobacter braakii, Edwardsiella tarda, Escherichia coli, Enterobacter cloacae, Plesiomonas shigelloides and putative Salmonella, and these were similar to bacteria isolated from the surface waters in which the alligators inhabited. Based on most‐probable‐number enumeration estimates from captive alligator faeces, faecal coliform bacteria numbered 8·0 × 10⁹ g^?1 (wet weight) of alligator faecal material, a much higher concentration than many other documented endothermic animal sources. Conclusions: A prevalence of enteric bacteria, both faecal coliforms and potential pathogens, was observed in American alligators. The high faecal coliform bacterial density of alligator faeces may suggest that alligators are a potential source of bacterial contamination in South Carolina coastal waters. Significance and Impact of the Study: These findings help to increase our understanding of faecal coliform and potential pathogenic bacteria from poikilothermic reptilian sources, as there is the potential for these sources to raise bacterial water quality levels above regulatory thresholds.     

Seasonal changes in habitat preferences of two closely related millipede species

The habitat preferences of two closely related millipede species, Centrobolus richardii and C. fulgidus, were investigated on three different seral stages of a coastal dune forest successional sere north of Richards Bay, South Africa. Fixed‐width transects were used to survey millipedes in three habitats of different ages. Habitat preference occurred on both inter‐ and intra‐site levels and was influenced by season. A habitat shift was recorded for C. richardii, while C. fulgidus was dormant during the winter months, reflecting two different strategies used by these closely related species to meet their resource requirements. Successional changes previously reported are masked by these differential responses.     

Why less complexity produces better forecasts: an independent data evaluation of kelp habitat models

Understanding how species are distributed in the environment is increasingly important for natural resource management, particularly for keystone and habitat – forming species, and those of conservation concern. Habitat suitability models are fundamental to developing this understanding; however their use in management continues to be limited due to often‐vague model objectives and inadequate evaluation methods. Along the Northeast Pacific coast, canopy kelps (Macrocystis pyrifera and Nereocystis luetkeana) provide biogenic habitat and considerable primary production to nearshore ecosystems. We investigated the distribution of these species by examining a series of increasingly complex habitat suitability models ranging from process‐based models based on species’ ecology to complex generalised additive models applied to purpose‐collected survey data. Seeking empirical limits to model complexity, we explored the relationship between model complexity and forecast skill, measured using both cross‐validation and independent data evaluation. Our analysis confirmed the importance of predictors used in models of coastal kelp distributions developed elsewhere (i.e. depth, bottom type, bottom slope, and exposure); it also identified additional important factors including salinity, and potential interactions between exposure and salinity, and slope and tidal energy. Comparative results showed how cross‐validation can lead to over‐fitting, while independent data evaluation clearly identified the appropriate model complexity for generating habitat forecasts. Our results also illustrate that, depending on the evaluation data, predictions from simpler models can out‐perform those from more complex models. Collectively, the insights from evaluating multiple models with multiple data sets contribute to the holistic assessment of model forecast skill. The continued development of methods and metrics for evaluating model forecasts with independent data, and the explicit consideration of model objectives and assumptions, promise to increase the utility of model forecasts to decision makers.     

The influence of food supplementation on a coastal dune rodent community

Studies of the rodent community in regenerating coastal dune forest areas north of Richards Bay, South Africa, have indicated that a number of species occupy newly rehabilitating areas. Unstable environmental conditions result in habitat changes, rather than competitive interactions, being the major determinant of rodent community development. This led to the present study, which investigated the effects of supplementary food on rodent assemblages. We attempted to stabilize food availability in order to elucidate some of the mechanisms responsible for the development of the rodent community. By only increasing an existing portion of the resource spectrum, we reduced species diversity, probably through dominance by competitive superior exploiters of the augmented resource. Thus, species diversity decreased with food supplementation, as a result of an increase in the abundance of Mastomys natalensis rather than because of a change in the number of species or the abundance of other species.     

710. SATYRIUM PRINCEPS

The South African terrestrial orchid Satyrium princeps Bolus is endemic to coastal sands in the southern part of the Western and Eastern Cape. Details of its history, taxonomy, life cycle, distribution and cultivation are given, together with an illustration and habitat photograph.     

EXTRAFLORAL NECTARIES AND PLANT GUARDING IN IPOMOEA PANDURATA (L.) G. F. W. MEY. (CONVOLVULACEAE)

Throughout the range of Ipomoea pandurata in North and South Carolina, ants and wasps are attracted to the pedicellar extrafloral nectaries. These hymenopterans are aggressive toward phytophagous insects that visit the plants. Protection of the plant is afforded by these pugnacious hymenopteran nectar feeders.     

Historical isolation and hydrodynamically constrained gene flow in declining populations of the South-African abalone, Haliotis midae

Over the past two decades, the South African abalone (Haliotis midae), has been under serious threat mainly due to overexploitation. To assure successful management and conservation of wild stocks, the consideration of species-specific evolutionary and population dynamic aspects is critical. In this study, eight microsatellites and 12 single nucleotide polymorphic loci (SNPs) were applied to determine genetic structure in nine populations sampled throughout the species?? natural distribution range. It spans along three biogeographical regions of the South African coastline: temperate in the West coast, warm temperate in the South coast and subtropical in the East coast. Data analysis applying frequentist and Bayesian-based clustering methods indicated weak genetic differentiation between populations of the West, South and East coast. Spatial Bayesian inference further revealed clinal variation along a longitudinal gradient and a transitional zone in the South coast. Coalescent analysis of long-term migration showed restricted interchange among the sampling locations of the South coast while estimates of effective population size were comparable between coastal regions. Furthermore demographic analysis of microsatellite data suggested population expansion, probably reflecting range expansion that occurred following glacial retreat during the Pleistocene. Overall, population structure analysis suggested contemporary (hydrographical conditions) as well as historical (Pleistocene contraction of habitat) restrictions to gene flow. This study provides the foundation for the establishment of an integrated management policy for preserving the natural diversity and adaptive potential of H. midae.     

A relic wood of Juniperus turbinata Guss. (Cupressaceae) in Sicily: Structural and ecological features,conservation perspectives

Abstract

Juniperus turbinata Guss. (Cupressaceae) is a threatened tree species occurring in the Mediterranean area. It is listed as a vulnerable species in the Red Book of Italian plants and its various communities are included in Annex I of the Habitats Directive 92/43/EEC as a priority habitat for conservation. During field investigations carried out to analyse the plant biodiversity of coastal habitats in southern Sicily, a new interesting population was found. This study aims to characterize this relevant new finding with a marked focus on demography and synecology of the plant community in question in order to define its habitat, assess its conservation status and propose conservation measures. Our data highlight that the juniper is characterized by low turnover population dynamics. In order to understand the role of J. turbinata in sandy soil communities of south-eastern Sicily, comparisons of 21 plots (relevés) with 25 established plots in south-eastern Sicily were carried out using cluster analysis and canonical component analysis. This has allowed three different plant communities with different ecological features to be identified.