Eastern America Research Articles

The stromatoporoidHabrostromain the upper Silurian (uppermost Pridoli)–Lower Devonian (Lochkovian) of North America, and the paleobiogeographic significance ofH.centrotum(Girty, 1895)

AbstractThree species ofHabrostromadominate stromatoporoid faunas in the Lower Devonian (Lochkovian) of five areas in North America: New York, Virginia, Maine, Bathurst Island, and Ellesmere Island. In addition, they occur in what could be the upper Silurian (uppermost Pridoli) of Virginia, and possibly New York. Measurements of nine morphologies from 127 specimens ofHabrostromawere subjected to an average linkage cluster analysis. Using average linkage between groups, three distinct clusters were revealed. Group assignments made from the cluster analysis were saved, and entered into a canonical discriminant analysis with the nine morphological variables. An overall Wilks’ lambda was calculated, and is statistically significant at alpha <0.001. The hit rate for classifying group 1 is 98%, that for group 2 is 100%, and that for group 3 is 97.9%; the total hit rate is 100%. The morphological variables contributing most to group membership are: (1) percent cystlike microlaminae, (2) microlaminae per mm, (3) gallery height, (4) laminae per mm, and (5) laminar thickness. The statistics confirm that there are three species:H.centrotum,H.microporum, andH.consimile.Habrostroma centrotumoccurs in all five areas. This is unusual because Virginia, New York, and Maine are part of the Eastern Americas Realm, and the arctic islands are part of the Old World Realm. Separation of the realms is based on a high percentage of unique genera in each. A breach in the inter-realm barrier is proposed to have existed across the Canadian Shield during the Lochkovian. The nature of the breach is determined to be a shallow-water filter, allowing the passage of a limited number of taxa.

Evaluating Devonian bioregionalization: quantifying biogeographic areas

AbstractThe work of Arthur J. Boucot (vale, 1924–2017) is foundational to Devonian biogeography. Cited more than 1000 times and mentioned in excess of 105,000 times, his classification of the Old World, Eastern Americas, and Malvinokaffric realms has become the framework for Devonian biogeographic and faunal studies. This study is the first to test and quantify the biotic area classification using the distributional data of trilobite, brachiopod, and fish taxa across the Lower, Middle, and Late Devonian. The biotic similarity analysis of 676 genera (ca. 30,000 occurrences) of late Silurian (Ludlow–Pridoli) and Devonian taxa represents the largest quantification of distributional data undertaken in Devonian biogeography. The temporal area approach (TAAp), applied here for the first time, failed to recover in the area phenogram many of the realms and regions used by Devonian biogeographers, excepting the Malvinokaffric realm, across the entirety of the Devonian. The Old World and Western Gondwana realms are found to be artificial and in need of revision. Without natural areas, bioregionalizations (area classifications) become unstable and unusable, resulting in authors creating further artificial regions and provinces. This study offers a better solution, namely, to identify artificial areas in existing area classifications using TAAp and biotic similarity analysis and revise them. Area classifications are modeled on taxonomic process (Wilson and Brown 1953; Starrett 1958) and the movement toward revision is necessary to break the cycle of reinvention of realms and regions within bioregionalization.

Changes in global terrestrial ecosystem water use efficiency are closely related to soil moisture

Ecosystem water use efficiency (WUE), defined as the ratio between gross primary productivity (GPP) and evapotranspiration (ET), is an indicator of the tradeoff between carbon assimilation and water loss that is controlled by climate and ecosystem structure. However, how GPP and ET impact WUE remains poorly understood. In this study, we provide a global analysis of WUE trends from 1982 to 2011 using multi-model ensemble mean WUE values derived from seven process-based carbon cycle models and investigate the relative effects of leaf area index (LAI), soil moisture (SM), and vapor pressure deficit (VPD) on GPP and ET. Increasing WUE trend was derived for all models, with an average rate of 0.0057 ± 0.0018 g C·kg−1 H2O·yr−1 (p = 0.00), with a spatially increasing WUE across ~84% of the global land area, and increasing trends which are statistically significant over ~72% (p < 0.05). Spatially, GPP primarily dominated WUE variability in humid regions, i.e., boreal Eurasia, eastern America, and the tropics, whereas ET dominated WUE variability in dryland regions, i.e., northeast China, the Middle East, southern South America, and South Australia. Soil moisture is likely the most influential factor on GPP and ET variations, with ~63% and ~61% of the global land area dominated by SM, and therefore WUE, for GPP and ET respectively from 1982 to 2011. Our findings enrich the understanding of WUE trends and provide direct evidence for SM-induced variability in WUE.

Global genetic diversity, lineage distribution, and Wolbachia infection of the alfalfa weevil Hypera postica (Coleoptera: Curculionidae).

The alfalfa weevil (Hypera postica) is a well‐known example of a worldwide‐distributed pest with high genetic variation. Based on the mitochondrial genes, the alfalfa weevil clusters into two main mitochondrial lineages. However, there is no clear picture of the global diversity and distribution of these lineages; neither the drivers of its diversification are known. However, it appears likely that historic demographic events including founder effects played a role. In addition, Wolbachia, a widespread intracellular parasite/symbiont, likely played an important role in the evolution of the species. Wolbachia infection so far was only detected in the Western lineage of H. postica with no information on the infecting strain, its frequency, and its consequences on the genetic diversity of the host. We here used a combination of mitochondrial and nuclear sequences of the host and sequence information on Wolbachia to document the distribution of strains and the degree of infection. The Eastern lineage has a higher genetic diversity and is found in the Mediterranean, the Middle East, Eastern Europe, and eastern America, whereas the less diverse Western lineage is found in Central Europe and the western America. Both lineages are infected with the same common strain of Wolbachia belonging to Supergroup B. Based on neutrality tests, selection tests, and the current distribution and diversification of Wolbachia in H. postica, we suggested the Wolbachia infection did not shape genetic diversity of the host. The introduced populations in the United States are generally genetically less diverse, which is in line with founder effects.

Seismic imaging the D″ region beneath the Central Atlantic

The lowermost mantle beneath the central Atlantic is bounded by the western edge of African Large Low Shear Wave Province (LLSVP) and a high-velocity region beneath the eastern Americas, which is attributed to the accumulated subducted slab material at the core-mantle boundary (CMB). Data recorded at broadband seismic arrays in western Europe and Morocco allow us to investigate the detailed structure beneath the Central Atlantic, which provides an important constraint on how remnant slab material and LLSVP interact and reshape the D″ layer. Here, we exploit lower mantle triplicated S waveform data from deep earthquakes beneath South America. Our modelling results show that the D″ discontinuity is constantly observed from north to south beneath the Central Atlantic but at varied depths and with varied shear velocities. In the lowermost mantle beneath east of Caribbean, our results indicate a sharp 2.1% shear velocity increase at 340 km above the CMB, representing a possible bridgmanite dominant normal mantle D″ layer. Whereas, the models of northern and southern portions of Central Atlantic indicate a gradual velocity increase of 4.2% across 200 km starting from 360 km above the CMB downwards. We also find a distinct low velocity zone on top of the velocity jump, which can be interpreted as an upwelling produced by the dynamic response of ancient slab material reaching the CMB.

The invasive speciesCylindrodesmus hirsutusPocock (Diplopoda: Polydesmida: Haplodesmidae) spreads to the northern Caribbean, with a compilation of published localities

AbstractMillipede diversity in tropical regions, and in Mexico in particular, is still mostly unknown. A modest but recurrent source of new Mexican species is the colonization of exotic species, due to human activity. The invasive speciesCylindrodesmus hirsutusPocock, 1889 has spread from its area of origin in Indonesia or Melanesia and become a virtually pantropical species. Although long known from South and Central America, reports from the Caribbean are sparse and limited to some eastern islands and southern Central America. On 9 March 2016, two adult specimens were found on Cozumel Island, Quintana Roo, in an area of medium semideciduous tropical forest. This paper comprises the first record of this species from Mexico and the northern Caribbean. Given the intense commercial activity in the region, the presence of more populations both in Cozumel Island and in the mainland coast is highly probable.

Occurrence ofDipleura dekayiGreen, 1832 (Trilobita; Homalonotidae) in the Devonian of Colombia

ABSTRACT A large and almost complete dorsal exoskeleton of a homalonotid trilobite from the Middle Devonian of Colombia (Floresta Formation) is described and referred to Dipleura dekayi Green, 1832, confirming prior suggestions of biogeographical affinity between Colombia and the North Eastern Americas Realm during Devonian times.

Eocene shallow-marine ostracods from Madagascar: southern end of the Tethys?

Twenty-five genera and 32 species of Eocene shallow-marine ostracods from Madagascar were examined for taxonomy and palaeobiogeography. Eight new species – Paijenborchellina madagascarensis sp. nov., Neocyprideis polygonoreticulata sp. nov., Alciella irizukii sp. nov., Neomonoceratina afroangulosa sp. nov., Muellerina eocenica sp. nov., Stigmatobradleya hunti gen. et sp. nov., Uroleberis paranuda sp. nov., Xestoleberis renemai sp. nov. – and one new genus – Stigmatobradleya gen. nov. – are described. Eocene Malagasy ostracods showed a strong affinity to the Eocene East Tethyan fauna in Arab-Africa and Indo-Pakistan. They also showed certain affinity to the Eocene West Tethyan fauna in Europe. One species, Pokornyella lamarckiana sensu lato, showed a very wide Eocene geographical distribution, covering Europe, Indo-Pakistan, Arab-Africa, Japan and perhaps North America. These results indicate that the East African, Arabian, and Indo-Pakistan regions constitute the East Tethyan palaeobiogeographical sub-realm, with considerable faunal similarity found across the regions. This sub-realm extends to south-eastern Africa in the south and is a part of the broader Tethyan palaeobiogeographical realm with certain, but less, palaeobiogeographical similarity. The spatial extent of the Tethys palaobiogeographical realm sensu lato includes Asia-Oceania in the east and eastern America in the west. Based on our results, we suggest a need to update the scheme of global ostracod biogeographical division.http://zoobank.org/urn:lsid:zoobank.org:pub:C98E65A2-FEB8-4D63-B294-7A1A22C51F5E

Promise and Disillusionment in the Shape of a Woman: Conquistadors in Florida and New France, A Comparative Perspective

The purpose of this study is to provide greater insight into the power of native women as understood by sixteenth century North American conquistadors by juxtaposing two analogous but geographically distinct settings. Depictions of women in New France by Jacques Cartier, Samuel Champlain and their followers in the northern borderlands of North America are compared to those depictions made by Hernando de Soto, Pedro Menendez de Avilés and their contemporaries during the same general period in the southern borderlands (Florida). The accounts of these figures, who came from varied backgrounds and promoted differing world views, provide evidence for the earliest foundations of the “imperial gaze” in reference to distant poles along North America's eastern seaboard. They also demonstrate the key role that native women played in orchestrating intercultural encounters with conquistadors during the sixteenth century.

Population status and fishery potential of the mangrove crab,Ucides cordatus(Linnaeus, 1763) in North-eastern Brazil

Ucides cordatusis a semi-terrestrial crab and key species endemic to mangrove areas of eastern Americas. In North-eastern Brazil this crab holds a major socio-economic function for artisanal fisheries, as in the São Francisco River Estuary (10°30′27″S 36°23′45″W). Nevertheless, decreases in this species’ stock have been reported since 2000, requiring assessments of the crab population for conservation and management purposes. This study aims at assessing the population status and the fishery potential of this species in the mangroves of this estuary and suggests strategies for its fishery and conservation, according to the guidelines of the National Management Plan forU. cordatusSustainable Use. Six different sites established in 30 km2of mangroves were sampled, with the density ofU. cordatusburrows estimated to evaluate the population structure using the measure of burrow diameters. Results show that the crab mean burrow size was 56.82 (±12.2) mm and that the medium-size crabs (40–70 mm) are the most abundant. The total mean crab density was 1.2 crabs m−2, from which the density of crabs in commercial size (0.85 ± 0.55 crabs m−2) was significantly higher than those in non-commercial size (0.35 ± 0.21 burrow m−2). These mangroves showed a high potential for the crab fishery, with an immediate extractive potential (IEP) of 71.2% and future extractive potential (FEP) of 28.8%. Nevertheless, a lower crab density, probably due to high crab mortality, mangrove deforestation for shrimp farming and high fishery pressure, is a limiting factor for local fishery. We conclude that mangrove areas more appropriate forU. cordatusfishery (extractive areas) show higher mean crab size, IEP and density of commercial crabs, wherein a fixed exploitation rate or/and a fixed escapement rule should be considered. Exclusion areas, intended for the conservation, show lower values of these population parameters and higher FEP, wherein the fishery should be prohibited. These management strategies should also be considered in other Brazilian mangrove areas showing similar crab population structure, thus contributing to the National Management Plan forU. cordatusSustainable Use.

Recent amplification of the North American winter temperature dipole.

During the winters of 2013–2014 and 2014–2015, anomalously warm temperatures in western North America and anomalously cool temperatures in eastern North America resulted in substantial human and environmental impacts. Motivated by the impacts of these concurrent temperature extremes and the intrinsic atmospheric linkage between weather conditions in the western and eastern United States, we investigate the occurrence of concurrent “warm‐West/cool‐East” surface temperature anomalies, which we call the “North American winter temperature dipole.” We find that, historically, warm‐West/cool‐East dipole conditions have been associated with anomalous mid‐tropospheric ridging over western North America and downstream troughing over eastern North America. We also find that the occurrence and severity of warm‐West/cool‐East events have increased significantly between 1980 and 2015, driven largely by an increase in the frequency with which high‐amplitude “ridge‐trough” wave patterns result in simultaneous severe temperature conditions in both the West and East. Using a large single‐model ensemble of climate simulations, we show that the observed positive trend in the warm‐West/cool‐East events is attributable to historical anthropogenic emissions including greenhouse gases, but that the co‐occurrence of extreme western warmth and eastern cold will likely decrease in the future as winter temperatures warm dramatically across the continent, thereby reducing the occurrence of severely cold conditions in the East. Although our analysis is focused on one particular region, our analysis framework is generally transferable to the physical conditions shaping different types of extreme events around the globe.

Chinese Sub-culture and Parental Involvement Strategies: An Anthropological Case Study of a Public School in Eastern America

Chinese Sub-culture and Parental Involvement Strategies: An Anthropological Case Study of a Public School in Eastern America

Phylogeographic perspective on the distribution and dispersal of a marine pathogen, the oyster parasite Bonamia exitiosa

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 536:65-76 (2015) - DOI: https://doi.org/10.3354/meps11425 Phylogeographic perspective on the distribution and dispersal of a marine pathogen, the oyster parasite Bonamia exitiosa Kristina M. Hill-Spanik1,2,*, Jan R. McDowell1, Nancy A. Stokes1, Kimberly S. Reece1, Eugene M. Burreson1, Ryan B. Carnegie1 1Virginia Institute of Marine Science, College of William & Mary, PO Box 1346, Gloucester Point, Virginia 23062, USA 2Present address: Grice Marine Laboratory, College of Charleston, 205 Fort Johnson Road, Charleston, South Carolina 29412, USA *Corresponding author: hillkm1@cofc.edu ABSTRACT: The significance of infectious disease has intensified as our marine ecosystems are increasingly altered, with molluscan taxa being among the affected. One of the important pathogens to emerge in recent years, the oyster parasite Bonamia exitiosa, has a broad geographic distribution and has been found to infect a number of oyster species. In order to better understand how B. exitiosa achieved this wide distribution, a gene genealogy was constructed using internal transcribed spacer region ribosomal DNA sequencing data from across the host species range. The analysis revealed population structure in the form of 4 well-defined groups of sequences: 3 corresponding to geographic regions (temperate Atlantic and Pacific waters of the Southern Hemisphere, California, and the western Atlantic along the coast of the Americas) and the fourth geographically cosmopolitan. Inclusion of B. exitiosa sequences from New Zealand, Australia, and Argentina in the Southern Hemisphere group may reflect natural dispersal of the parasite via rafting with oyster hosts, whereas the California group may reflect limited anthropogenic movement of a host species, Ostrea lurida. The extensive geographic distribution of B. exitiosa parasites belonging to the cosmopolitan and Atlantic Coast groups may relate to both natural and anthropogenic dispersal of a single host, O. stentina, which is distributed from the eastern Americas to the Mediterranean and African coast to New Zealand—that is, in most regions where B. exitiosa has been found to occur. KEY WORDS: Marine disease · Bonamia · Haplosporidia · Phylogeography · Ostrea stentina Full text in pdf format PreviousNextCite this article as: Hill-Spanik KM, McDowell JR, Stokes NA, Reece KS, Burreson EM, Carnegie RB (2015) Phylogeographic perspective on the distribution and dispersal of a marine pathogen, the oyster parasite Bonamia exitiosa . Mar Ecol Prog Ser 536:65-76. https://doi.org/10.3354/meps11425 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 536. Online publication date: September 29, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Eliciting a predatory response in the eastern corn snake (Pantherophis guttatus) using live and inanimate sensory stimuli: implications for managing invasive populations

North America's eastern corn snake (Pantherophis guttatus) has been introduced to several islands throughout the Caribbean and Australasia where it poses a significant threat to native wildlife. Invasive snake control programmes often involve trapping with live bait, a practice that, as well as being costly and labour intensive, raises welfare and ethical concerns. This study assessed corn snake response to live and inanimate sensory stimuli in an attempt to inform possible future trapping of the species and the development of alternative trap lures. We exposed nine individuals to sensory cues in the form of odour, visual, vibration and combined stimuli and measured the response as rate of tongue-flick (RTF). The RTF was significantly higher in odour and combined cues treatments, and there was no significant difference in RTF between live and inanimate cues during odour treatments. Our findings suggest chemical cues are of primary importance in initiating investigatory behaviours and that an inanimate odour stimulus, absent of simultaneous visual and vibratory cues, is potentially a low-cost alternative trap lure for the control of invasive corn snake populations.

Forests for the People: The Story of America's Eastern National Forests. By Christopher Johnson and David Govatski. Washington, DC: Island Press, 2013. 326 pp. Illustrations, maps, tables, notes, bibliography, and index. Paper and e-book $35.00.

<i>Forests for the People: The Story of America's Eastern National Forests</i>. By Christopher Johnson and David Govatski. Washington, DC: Island Press, 2013. 326 pp. Illustrations, maps, tables, notes, bibliography, and index. Paper and e-book $35.00.

Evolutionary relationships amongst polymorphic direct-developing frogs in the Craugastor rhodopis Species Group (Anura: Craugastoridae)

The Craugastor rhodopis Species Group includes two leaf-litter frog species (C. loki and C. rhodopis). These direct-developing frogs inhabit tropical regions of Mexico and northern Central America. Characterizing diversity within the group has been difficult due to high levels of phenotypic polymorphism within and between species. Because of these polymorphisms, each taxon has junior synonyms. Using a fragment of mitochondrial DNA (mtDNA), we investigated genetic diversity in the C. rhodopis Species Group. We then examined type specimens (including types of junior synonyms) to match nomenclature to geographically circumscribed genetic clusters. Our molecular analyses revealed four major lineages within the C. rhodopis Species Group: (1) a widely distributed clade in western Mexico, (2) a highland clade in eastern Mexico, (3) a widely distributed lowland clade occurring in eastern Mexico, Guatemala and El Salvador, and (4) a haplotype from Volcán San Martín in Veracruz, Mexico. We identified the first clade as C. occidentalis, a taxon currently placed in the ecologically similar but phylogenetically distant C. mexicanus Species Series. In light of this we place C. occidentalis in the C. rhodopis Species Group and designate a lectotype and paralectotype for the species. The second and third clades inhabiting eastern Mexico and northern Central America correspond to C. rhodopis and C. loki, respectively. Additionally, we examined the taxonomic distribution of certain colour pattern traits and compensatory mutations in Domain III of the mtDNA 12S ribosomal RNA gene. Our recovery of the divergent Veracruz haplotype and extensive mtDNA structure within species indicates that additional taxonomic revision will be necessary.

Forests for the People: The Story of America's Eastern National Forests

Forests for the People: The Story of America's Eastern National Forests

Forests for the people: the story of America's eastern national forests

At the turn of the twentieth century, widespread clearcutting resulted in ecological ruin and devastating fires in America's Eastern forests. A coalition of citizens, organisations, and business and political leaders fought against this pattern, and in 1911, they achieved a landmark victory with the Weeks Act, which protected millions of acres of Eastern forests. Forests of the People tells the fascinating story of this vital legislation. While these protected forests survive today, many of the critical issues facing American forests in the twentieth century persist, and new threats have arisen - including oil shale drilling, invasive species, and development around national parks. In Forests for the People, Christopher Johnson and David Govatski draw upon the lessons and victories of the past to examine the vital issues facing American forests today and illuminate paths to better forest management.

Nested atmospheric inversion for the terrestrial carbon sources and sinks in China

Abstract. In this study, we establish a nested atmospheric inversion system with a focus on China using the Bayesian method. The global surface is separated into 43 regions based on the 22 TransCom large regions, with 13 small regions in China. Monthly CO2 concentrations from 130 GlobalView sites and 3 additional China sites are used in this system. The core component of this system is an atmospheric transport matrix, which is created using the TM5 model with a horizontal resolution of 3° × 2°. The net carbon fluxes over the 43 global land and ocean regions are inverted for the period from 2002 to 2008. The inverted global terrestrial carbon sinks mainly occur in boreal Asia, South and Southeast Asia, eastern America and southern South America. Most China areas appear to be carbon sinks, with strongest carbon sinks located in Northeast China. From 2002 to 2008, the global terrestrial carbon sink has an increasing trend, with the lowest carbon sink in 2002. The inter-annual variation (IAV) of the land sinks shows remarkable correlation with the El Niño Southern Oscillation (ENSO). The terrestrial carbon sinks in China also show an increasing trend. However, the IAV in China is not the same as that of the globe. There is relatively stronger land sink in 2002, lowest sink in 2006, and strongest sink in 2007 in China. This IAV could be reasonably explained with the IAVs of temperature and precipitation in China. The mean global and China terrestrial carbon sinks over the period 2002–2008 are −3.20 ± 0.63 and −0.28 ± 0.18 PgC yr−1, respectively. Considering the carbon emissions in the form of reactive biogenic volatile organic compounds (BVOCs) and from the import of wood and food, we further estimate that China's land sink is about −0.31 PgC yr−1.

Monitoring of atmospheric nitrogen dioxide using Ozone Monitoring Instrument remote sensing data

Measurements from the Ozone Monitoring Instrument are used to investigate the temporal and spatial dynamics of global nitrogen dioxide (NO 2 ). The results show that the global tropospheric column NO 2 increased by 11.10% during 2005 to 2010 at a 1.76% annual growth rate. The largest tropospheric and total NO 2 columns are mainly concentrated in the industrialized regions of North America, Europe, and east Asia. The large values of column NO 2 are also observed and scattered in South America, Africa, and Indonesia due to biomass burning and savannah fires. Average tropospheric column NO 2 increased by 32.62% at a 4.82% annual rate over eastern Asia. On the contrary, the trend decreased by 35.47% at a 7.04% annual rate over eastern America. The trend was not significant over Europe as a whole, where a decrease was observed over western and southern Europe and an increase was observed over eastern and northern Europe. Over the polluted urban areas, the ratios of tropospheric to total column NO 2 are larger than 0.6 and the correlation coefficients are larger than 0.8. This can be mainly attributed to the anthropogenic NO x emissions over land, and it is noteworthy that the ratios are higher than 0.8 (correlation coefficients >0.95 ) over northern China.