Pre-invasion assessment of exotic bark beetle-vectored fungi to detect tree-killing pathogens

2021 ◽  
Author(s):  
You Li ◽  
Craig Bateman ◽  
James Skelton ◽  
Bo Wang ◽  
Adam Black ◽  
...  
Keyword(s):  
Risk Assessment ◽  
North American ◽  
Fungal Species ◽  
Test Dataset ◽  
Continental Scale ◽  
Empirical Risk ◽  
Invasive Organisms ◽  
Bark And Ambrosia Beetles ◽  
Exotic Pathogens ◽  
Imminent Threat

Exotic diseases and pests of trees have caused continental-scale disturbances in forest ecosystems and industries, and their invasions are considered largely unpredictable. We tested the concept of pre-invasion assessment of not-yet invasive organisms, which enables empirical risk assessment of potential invasion and impact. Our example assesses fungi associated with Old World bark and ambrosia beetles and their potential to impact North American trees. We selected 55 Asian and European scolytine beetle species using host-use, economic, and regulatory criteria. We isolated 111 of their most consistent fungal associates and tested their effect on four important Southeastern American pine and oak species. Our test dataset found no highly virulent pathogens that should be classified as an imminent threat. Twenty-two fungal species were minor pathogens, which may require context-dependent response for their vectors at North American borders, while most of the tested fungi displayed no significant impact. Our results are significant in three ways: they ease the concerns over multiple overseas pests suspected of heightened potential risk; they provide basis for focus on the prevention of introduction and establishment of species that may be of consequence; and they demonstrate that pre-invasion assessment, if scaled up, can support practical risk assessment of exotic pathogens.

scholarly journals Inter- and Intra-Continental Genetic Variation in the Generalist Conifer Wood Saprobic Fungus Phlebiopsis gigantea

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 751
Author(s):  
Francesco Dovana ◽  
Paolo Gonthier ◽  
Matteo Garbelotto
Keyword(s):  
North America ◽  
Genetic Differentiation ◽  
Dna Sequences ◽  
North American ◽  
Fungal Species ◽  
Coniferous Forests ◽  
Native Forest ◽  
Western North America ◽  
Phlebiopsis Gigantea ◽  
Conifer Wood

Phlebiopsis gigantea (Fr.) Jülich is a well-known generalist conifer wood saprobe and a biocontrol fungus used in several world countries to prevent stump infection by tree pathogenic Heterobasidion fungal species. Previous studies have reported the presence of regional and continental genetic differentiation in host-specific fungi, but the presence of such differentiation for generalist wood saprobes such as P. gigantea has not been often studied or demonstrated. Additionally, little information exists on the distribution of this fungus in western North America. The main purposes of this study were: (I) to assess the presence of P. gigantea in California, (II) to explore the genetic variability of P. gigantea at the intra and inter-continental levels and (III) to analyze the phylogeographic relationships between American and European populations. Seven loci (nrITS, ML5–ML6, ATP6, RPB1, RPB2, GPD and TEF1-α) from 26 isolates of P. gigantea from coniferous forests in diverse geographic distribution and from different hosts were analyzed in this study together with 45 GenBank sequences. One hundred seventy-four new sequences were generated using either universal or specific primers designed in this study. The mitochondrial ML5–ML6 DNA and ATP6 regions were highly conserved and did not show differences between any of the isolates. Conversely, DNA sequences from the ITS, RPB1, RPB2, GPD and TEF1-α loci were variable among samples. Maximum likelihood analysis of GPD and TEF1-α strongly supported the presences of two different subgroups within the species but without congruence or geographic partition, suggesting the presence of retained ancestral polymorphisms. RPB1 and RPB2 sequences separated European isolates from American ones, while the GPD locus separated western North American samples from eastern North American ones. This study reports the presence of P. gigantea in California for the first time using DNA-based confirmation and identifies two older genetically distinct subspecific groups, as well as three genetically differentiated lineages within the species: one from Europe, one from eastern North America and one from California, with the latter presumably including individuals from the rest of western North America. The genetic differentiation identified here among P. gigantea individuals from coniferous forests from different world regions indicates that European isolates of this fungus should not be used in North America (or vice versa), and, likewise, commercially available eastern North American P. gigantea isolates should not be used in western North America forests. The reported lack of host specificity of P. gigantea was documented by the field survey and further reinforces the need to only use local isolates of this biocontrol fungus, given that genetically distinct exotic genotypes of a broad generalist microbe may easily spread and permanently alter the microbial biodiversity of native forest ecosystems.

Ecological risk assessment of atrazine in North American surface waters

2012 ◽  
Vol 32 (1) ◽  
pp. 10-11 ◽  
Author(s):  
Keith R. Solomon ◽  
John P. Giesy ◽  
Thomas W. LaPoint ◽  
Jeffrey M. Giddings ◽  
R. Peter Richards
Keyword(s):  
Risk Assessment ◽  
Ecological Risk ◽  
Ecological Risk Assessment ◽  
Surface Waters ◽  
North American

scholarly journals Evolutionary Algorithms for Community Detection in Continental-Scale High-Voltage Transmission Grids

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1472 ◽  
Author(s):  
Manuel Guerrero ◽  
Raul Baños ◽  
Consolación Gil ◽  
Francisco G. Montoya ◽  
Alfredo Alcayde
Keyword(s):  
Genetic Algorithm ◽  
Evolutionary Algorithms ◽  
Power Systems ◽  
Community Detection ◽  
North American ◽  
Flow Analysis ◽  
Power Grids ◽  
Improved Genetic Algorithm ◽  
Continental Scale ◽  
The North

Symmetry is a key concept in the study of power systems, not only because the admittance and Jacobian matrices used in power flow analysis are symmetrical, but because some previous studies have shown that in some real-world power grids there are complex symmetries. In order to investigate the topological characteristics of power grids, this paper proposes the use of evolutionary algorithms for community detection using modularity density measures on networks representing supergrids in order to discover densely connected structures. Two evolutionary approaches (generational genetic algorithm, GGA+, and modularity and improved genetic algorithm, MIGA) were applied. The results obtained in two large networks representing supergrids (European grid and North American grid) provide insights on both the structure of the supergrid and the topological differences between different regions. Numerical and graphical results show how these evolutionary approaches clearly outperform to the well-known Louvain modularity method. In particular, the average value of modularity obtained by GGA+ in the European grid was 0.815, while an average of 0.827 was reached in the North American grid. These results outperform those obtained by MIGA and Louvain methods (0.801 and 0.766 in the European grid and 0.813 and 0.798 in the North American grid, respectively).

Investigating the Linear and Nonlinear Stationary Wave Response to Anomalous North American Snow Cover

2011 ◽  
Vol 68 (4) ◽  
pp. 904-917 ◽  
Author(s):  
Stefan Sobolowski ◽  
Gavin Gong ◽  
Mingfang Ting
Keyword(s):  
Snow Cover ◽  
North American ◽  
Land Surface ◽  
Large Scale ◽  
Wave Model ◽  
Stationary Wave ◽  
Response Analysis ◽  
Stationary Waves ◽  
Continental Scale ◽  
Wave Response

Abstract Continental-scale snow cover represents a broad thermal forcing on monthly-to-intraseasonal time scales, with the potential to modify local and remote atmospheric circulation. A previous GCM study reported robust transient-eddy responses to prescribed anomalous North American (NA) snow cover. The same set of experiments also indicated a robust upper-level stationary wave response during spring, but the nature of this response was not investigated until now. Here, the authors diagnose a deep, snow-induced, tropospheric cooling over NA and hypothesize that this may represent a pathway linking snow to the stationary wave response. A nonlinear stationary wave model is shown to reproduce the GCM stationary wave response to snow more accurately than a linear model, and results confirm that diabatic cooling is the primary driver of the stationary wave response. In particular, the total nonlinear effects due to cooling, and its interactions with transient eddies and orography, are shown to be essential for faithful reproduction of the GCM response. The nonlinear model results confirm that direct effects due to transients and orography are modest. However, with interactions between forcings included, the total effects due to these terms make important contributions to the total response. Analysis of observed NA snow cover and stationary waves is qualitatively similar to the patterns generated by the GCM and linear/nonlinear stationary wave models, indicating that the snow-induced signal is not simply a modeling artifact. The diagnosis and description of a snow–stationary wave relationship adds to the understanding of stationary waves and their forcing mechanisms, and this relationship suggests that large-scale changes in the land surface state may exert considerable influence on the atmosphere over hemispheric scales and thereby contribute to climate variability.

Object-based flood risk modelling of the European road network: physical damage and mobility disruptions

2020 ◽  
Author(s):  
Ana Laura Costa ◽  
Elco Koks ◽  
Kees van Ginkel ◽  
Frederique de Groen ◽  
Lorenzo Alfieri ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Flood Risk ◽  
Road Network ◽  
Road Transport ◽  
Transport Infrastructure ◽  
Network Data ◽  
Physical Damage ◽  
Continental Scale ◽  
Object Based ◽  
Grid Based

<p>River flooding is among the most profound climate hazards in Europe and poses a threat to its road transport infrastructure. Traditional continental-scale flood risk studies do not accurately capture these disruptions because they are typically grid-based, whereas roads are relatively narrow line elements which are therefore omitted. Moreover, these grid-approaches disregard the network properties of roads, whereas the costs of reduced mobility could largely exceed the costs of the physical damage to the infrastructure.</p><p>We address these issues by proposing and applying an improved physical damage assessment coupled with the assessment of mobility disruption for a comprehensive risk assessment at a continental level.</p><p>In this study, we introduce an object-based, continental scale flood risk assessment of the European road network. We improve the estimates of direct, physical damage, by drawing road network data from OpenStreetMap, while making optimal use of the available metadata. We also introduce a set of road-specific flood damage functions, which are validated for an observed flood event in Germany. The results of this approach are compared to the traditional, grid-based approach to modelling road transport damage.</p><p>Next, we showcase how the object-based approach can be used to study potential mobility disruptions. In this study we present how the network data from OpenStreetMap and available metadata can be used to assess the flood impacts in terms of decreased connectivity, that is, increased distance, time and/or costs. The approach is flexible in physical scope, able to address national and continental resilience assessments and provide advice on tipping points of service performance. Furthermore, flexibility is also incorporated in terms of different resilience perspectives including decision-making by the asset owner or the national or trans-national supply chain disruption to a particular economic sector or company.</p><p>Finally, the risk assessment is discussed based on applications for the impacts of floods on European roads and the potential to extend to multi-hazard assessments (landslides, earthquakes, pluvial flooding) and other types of critical networks is discussed.  </p><p> </p><p>This paper has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 776479 for the project CO-designing the Assessment of Climate CHange costs. https://www.coacch.eu/</p><p> </p>

scholarly journals La collaboration scientifique et technologique en Amérique du Nord : un point de vue Canadien

2005 ◽  
Vol 24 (2) ◽  
pp. 269-296
Author(s):  
Charles H. David ◽  
Paul Dufour ◽  
Janet Halliwell
Keyword(s):  
United States ◽  
Open Economy ◽  
North American ◽  
Small Open Economy ◽  
Innovation System ◽  
The United States ◽  
Technology And Innovation ◽  
Continental Scale ◽  
Science Technology ◽  
Science Technology And Innovation

Canada, as a country with a small, open economy, faces the immediate challenge of learning to shape dynamic comparative advantage in the emerging international economy. About 75 % of Canada's trade linkages are with the United States, and a very large component of the Canadian experience of « globalization » is driven by North American economic integration. This integration is taking place in the absence of institutions and policy mechanisms to promote and manage science, technology, and innovation relations on a continental scale. Bilateral s & T arrangements centered on the United States presently characterize the North American innovation System. Circumstances in North America pose three sets of challenges to Canadian s & T policy. 1) Science and technology are increasing in importance in international trade, environmental, and social/cultural matters. This means that Canada must learn to improve its management of an increasingly internationalized domestic s & T System. 2) Canada must cultivate mutually beneficial bilateral s & T relationships with its two partners in NAFTA, Mexico and the United States. 3) Canada must identify where its interests lie in the development and governance of trilateral and international rules and arrangements for science, technology, and innovation.

Taxonomy, ultrastructure, and distribution of some gomphonemoid diatoms (Bacillariophyceae: Gomphonemataceae) from rivers in the United States

1999 ◽  
Vol 77 (5) ◽  
pp. 686-705 ◽  
Author(s):  
J P Kociolek ◽  
J C Kingston
Keyword(s):  
Water Quality ◽  
Quality Assessment ◽  
North American ◽  
Large Scale ◽  
Taxonomic Status ◽  
Water Quality Assessment ◽  
The United States ◽  
Great Promise ◽  
Continental Scale ◽  
National Water

Using the continental-scale collections of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program, we examined selected members of the family Gomphonemataceae to expand the current state of knowledge of diatom taxonomy, morphology, and distribution. Ten taxa in the genera Gomphonema, Gomphoneis, and Gomphosphenia are examined. The taxonomic status of two taxa is revised, and one new species is described. Two new features are described for the genus Gomphonema: slit-like areolae and ridge-like flaps or flanges on pseudosepta. Many North American gomphonemoid species appear to be restricted to certain geographic regions; the differences between western and eastern North America are striking. Trained analysts have had difficulty identifying and discriminating many of these taxa. We believe that this difficulty, in large part, results from our poor knowledge of the North American flora. Large-scale monitoring programs such as NAWQA, when teamed up with research organizations with common interests, hold great promise to expand our knowledge of the biodiversity of North American ecosystems.Key words: biogeography, Gomphoneis, Gomphonema, Gomphosphenia, National Water-Quality Assessment (NAWQA) Program, taxonomy; ultrastructure.

scholarly journals Environmental correlates of genetic variation in the invasive and largely panmictic European starling in North America

2019 ◽  
Author(s):  
Natalie R. Hofmeister ◽  
Scott J. Werner ◽  
Irby J. Lovette
Keyword(s):  
North America ◽  
Local Adaptation ◽  
North American ◽  
Winter Season ◽  
Bird Species ◽  
Genomic Diversity ◽  
Rapid Expansion ◽  
Continental Scale ◽  
High Dispersal ◽  
Local Selection

ABSTRACTPopulations of invasive species that colonize and spread in novel environments may differentiate both through demographic processes and local selection. European starlings (Sturnus vulgaris) were introduced to New York in 1890 and subsequently spread throughout North America, becoming one of the most widespread and numerous bird species on the continent. Genome-wide comparisons across starling individuals and populations can identify demographic and/or selective factors that facilitated this rapid and successful expansion. We investigated patterns of genomic diversity and differentiation using reduced-representation genome sequencing (ddRADseq) of 17 winter-season starling populations. Consistent with this species’ high dispersal rate and rapid expansion history, we found low geographic differentiation and few FST outliers even at a continental scale. Despite starting from a founding population of approximately 180 individuals, North American starlings show only a moderate genetic bottleneck, and models suggest a dramatic increase in effective population size since introduction. In genotype-environment associations we found that ∼200 single-nucleotide polymorphisms are correlated with temperature and/or precipitation against a background of negligible genome- and range-wide divergence. Local adaptation in North American starlings may have evolved rapidly even in this wide-ranging and evolutionarily young population. This survey of genomic signatures of expansion in North American starlings is the most comprehensive to date and complements ongoing studies of world-wide local adaptation in these highly dispersive and invasive birds.

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