Pacific Northwest Research Articles

Spatial distribution and long-term trend of wind energy in the Northwest Pacific Ocean

Abstract: Given the threat of fossil fuel depletion, it is essential to proactively strive for carbon neutrality and promote clean, low-carbon and efficient energy use. This study used ERA5 reanalysis data to assess wind energy resources in the Pacific Northwest region. By analyzing key indicators such as wind power density, effective wind speed occurrence, and energy level occurrence, climate statistics and Empirical Orthogonal Function analysis (EOF) were used to examine the spatial distribution and long-term trend of offshore wind energy resources in the Northwest Pacific. The results suggest that there are abundant wind energy resources in this region, which are beneficial for the development of offshore wind energy. The rich areas are the East China Sea, Taiwan islands and reefs in the South China Sea and east of Japan, with prevailing wind power density (500 ∼ 2500 W/m2) and effective wind speed occurrence (80–90%) and energy level occurrence (60% ∼ 90%). Offshore wind energy resources in the Pacific Northwest are more abundant in fall and winter than in summer. The time coefficient of the first mode shows that the offshore wind energy in the Northwest Pacific has no obvious change trend, and the wind energy resources are relatively stable.

Understanding the vertical temperature structure of recent record-shattering heatwaves

Abstract. Extreme heatwaves are one of the most impactful natural hazards, posing risks to human health, infrastructure, and ecosystems. Recent theoretical and observational studies have suggested that the vertical temperature structure during heatwaves limits the magnitude of near-surface heat through convective instability. In this study, we thus examine in detail the vertical temperature structure during three recent record-shattering heatwaves, the Pacific Northwest (PNW) heatwave in 2021, the western Russian (RU) heatwave in 2010, and the western European and UK (UK) heatwave in 2022, by decomposing temperature anomalies (T′) in the entire tropospheric column above the surface into contributions from advection, adiabatic warming and cooling, and diabatic processes. All three heatwaves exhibited bottom-heavy yet vertically deep positive T′ extending throughout the troposphere. Importantly, though, the T′ magnitude and the underlying physical processes varied greatly in the vertical within each heatwave, as well as across distinct heatwaves, reflecting the diverse synoptic storylines of these events. The PNW heatwave was strongly influenced by an upstream cyclone and an associated warm conveyor belt, which amplified an extreme quasi-stationary ridge and generated substantial mid- to upper-tropospheric positive T′ through advection and diabatic heating. In some contrast, positive upper-tropospheric T′ during the RU heatwave was caused by advection, while during the UK heatwave, it exhibited modest positive diabatic contributions from upstream latent heating only during the early phase of the respective ridge. Adiabatic warming notably contributed positively to lower-tropospheric T′ in all three heatwaves, but only in the lowermost 200–300 hPa. Near the surface, all three processes contributed positively to T′ in the PNW and RU heatwaves, while near-surface diabatic T′ was negligible during the UK heatwave. Moreover, there is clear evidence of an amplification and downward propagation of adiabatic T′ during the PNW and UK heatwaves, whereby the maximum near-surface T′ coincided with the arrival of maximum adiabatic T′ in the boundary layer. Additionally, the widespread ageing of near-surface T′ over the course of these events is fully consistent with the notion of heat domes, within which air recirculates and accumulates heat. Our results for the first time document the four-dimensional functioning of anticyclone–heatwave couplets in terms of advection, adiabatic cooling or warming, and diabatic processes and suggest that a complex interplay between large-scale dynamics, moist convection, and boundary layer processes ultimately determines near-surface temperatures during heatwaves.

Improved thermal preferences and a stressor index derived from modeled stream temperatures and regional taxonomic standards for freshwater macroinvertebrates of the Pacific Northwest, USA

Benthic macroinvertebrate taxa vary in their sensitivities to water quality and habitat conditions, contributing to their extensive use as ecological indicators. As climate change and landscape alteration increasingly impact stream temperatures, interest is growing in expanding our knowledge of how macroinvertebrates are affected by current and future thermal conditions. Using samples from 3501 sites, we evaluated relationships between macroinvertebrate taxa and modeled stream temperatures across Oregon and Washington, in the U.S. Pacific Northwest. We used Maximum Weekly Maximum Temperature (MWMT) values from the NorWeST temperature dataset, which is the same metric used for numeric water temperature standards in Oregon and Washington. MWMT captures peak thermal stress, when cold-water adapted aquatic biota are closest to their upper physiological limits. For each macroinvertebrate taxon, we characterized relationships between MWMT and their distributions with three measures: 1) central thermal tendency, based on weighted average (WA) optima calculations and relative abundance data; 2) lower and upper thermal limits, based on the 10th and 90th percentiles of taxon occurrence, using presence data; and 3) thermal sensitivity curve shape, based on Generalized Additive Model (GAM) plots. We assigned 521 taxa, from species to phyla, to seven thermal preference categories, ranging from cold and warm stenotherms (narrow range) to eurythermal (wide range). Thermal sensitivity and variability within each taxonomic group were identified for establishing taxonomic targets for regional monitoring programs. We also developed the Macroinvertebrate Thermal Tolerance Index (MTTI) to represent the assemblage-level response to available thermal habitats, using WA optima and relative abundances for 324 taxa. The MTTI model had a strong relationship with modeled temperatures (R2 = 0.68) and a root-mean-square-error of 2.5 °C. Our work builds on previous regional and national efforts to identify thermal indicator taxa by using modeled stream network temperatures and a thermal metric that corresponds directly to regional water temperature standards. Both the taxa thermal preferences and the MTTI can be used to help identify causes of biological impairment, prioritize restoration and protection actions, and monitor assemblage-wide changes in thermal tolerance over time.

Nurse-Led Models of Care: Practice and Policy to Support Aging in Place.

Research demonstrates that aging in place is the goal of most adults aged >50 years. Unfortunately, multiple barriers to aging in place continue to exist, especially for vulnerable populations. Achieving this goal will require innovative nurse-led models of care and new policies for RN reimbursement. The current article describes a nurse-led clinic implemented in one community. Using an evidence-based nurse-led model of care, a team of university faculty, students, and a family nurse practitioner designed and implemented a nurse-led clinic for a religious community in the Pacific Northwest. Today, the nurse-led clinic offers care coordination and primary care to support aging in place and is one example of a nurse-led model well-positioned to address the aging in place needs of vulnerable populations. Replication and sustainability of this nurse-led model requires sweeping policy change, including consideration of requiring all nurses to attain a National Provider Identification number to expand RN reimbursement and ultimately increase access to care. [Journal of Gerontological Nursing, 50(3), 13-17.].

Spatio-temporal patterns and trends in MODIS-retrieved radiative forcing by snow impurities over the Western US from 2001 to 2022

The seasonal mountain snowpack of the Western US (WUS) is a key water resource to millions of people and an important component of the regional climate system. Impurities at the snow surface can affect snowmelt timing and rate through snow radiative forcing (RF), resulting in earlier streamflow, snow disappearance, and less water availability in dry months. Predicting the locations, timing, and intensity of impurities is challenging, and little is known concerning whether snow RF has changed over recent decades. Here we analyzed the relative magnitude and spatio-temporal variability of snow RF across the WUS at three spatial scales (pixel, watershed, regional) using remotely sensed RF from spatially and temporally complete (STC) MODIS data sets (STC-MODIS Snow Covered Area and Grain Size/MODIS Dust Radiative Forcing on Snow) from 2001 to 2022. To quantify snow RF impacts, we calculated a pixel-integrated metric over each snowmelt season (1st March–30th June) in all 22 years. We tested for long-term trend significance with the Mann–Kendall test and trend magnitude with Theil–Sen’s slope. Mean snow RF was highest in the Upper Colorado region, but notable in less-studied regions, including the Great Basin and Pacific Northwest. Watersheds with high snow RF also tended to have high spatial and temporal variability in RF, and these tended to be near arid regions. Snow RF trends were largely absent; only a small percent of mountain ecoregions (0.03%–8%) had significant trends, and these were typically decreasing trends. All mountain ecoregions exhibited a net decline in snow RF. While the spatial extent of significant RF trends was minimal, we found declining trends most frequently in the Sierra Nevada, North Cascades, and Canadian Rockies, and increasing trends in the Idaho Batholith. This study establishes a two-decade chronology of snow impurities in the WUS, helping inform where and when RF impacts on snowmelt may need to be considered in hydrologic models and regional hydroclimate studies.

Some Concerns With Roundup Ready Spring Canola for Italian Ryegrass Control

AbstractSpring canola acreage in the Inland Pacific Northwest increased from just over 52,00 acres in 2017 to just under 191,000 acres in 2023. A large percentage of the spring canola acreage is planted to glyphosate‐resistant (Roundup Ready) varieties. And while glyphosate has provided excellent control of Italian ryegrass in glyphosate‐resistant spring canola, herbicide resistance can develop when a single site of action is used repeatedly over time. Thus, over the past two years (2022 and 2023), field studies were conducted to evaluate the benefits of using herbicides with different sites of action, both with and without glyphosate, for the control of Italian ryegrass in glyphosate‐resistant spring canola. Earn 0.5 CEUs in Integrated Pest Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning‐Center/Courses.

Strong Winds and Widow Makers: Workers, Nature, and Environmental Conflict in the Pacific Northwest Timber Country

Strong Winds and Widow Makers: Workers, Nature, and Environmental Conflict in the Pacific Northwest Timber Country

Subsurface acoustic ducts in the Northern California current system.

This study investigates the subsurface sound channel or acoustic duct that appears seasonally along the U.S. Pacific Northwest coast below the surface mixed layer. The duct has a significant impact on sound propagation at mid-frequencies by trapping sound energy and reducing transmission loss within the channel. A survey of the sound-speed profiles obtained from archived mooring and glider observations reveals that the duct is more prevalent in summer to fall than in winter to spring and offshore of the shelf break than over the shelf. The occurrence of the subsurface duct is typically associated with the presence of a strong halocline and a reduced thermocline or temperature inversion. Furthermore, the duct observed over the shelf slope corresponds to a vertically sheared along-slope velocity profile, characterized by equatorward near-surface flow overlaying poleward subsurface flow. Two potential duct formation mechanisms are examined in this study, which are seasonal surface heat exchange and baroclinic advection of distinct water masses. The former mechanism regulates the formation of a downward-refracting sound-speed gradient that caps the duct near the sea surface, while the latter contributes to the formation of an upward-refracting sound-speed gradient that defines the duct's lower boundary.

First report of Meloidogyne hapla on hemp (Cannabis sativa) in Oregon.

Hemp is a crop that has gained interest in Washington and Oregon. As with other crops, hemp production faces challenges due to biotic factors, including plant-parasitic nematodes. During a survey for plant-parasitic nematodes associated with hemp, Meloidogyne sp. was found in a composite root sample collected in Oregon. Morphological characterization of second-stage juveniles identified the nematode as Meloidogyne hapla. Molecular identification confirmed the population as M. hapla. To our knowledge, this is the first report of M. hapla on hemp in the Pacific Northwest of the United States.

Experimental warming and nitrogen deposition in clear‐cuts and forest edges: Assessing impacts on plant communities and tree seedling performance

AbstractQuestionsDo nitrogen deposition and climate warming affect tree seedlings and plant communities in different habitats? In these habitats, how do microenvironments, including soil properties and, when applicable, edge effects relate to plant performance?LocationThe University of British Columbia Malcolm Knapp Research Forest, Maple Ridge, British Columbia, Canada.MethodsWe assessed performance of Pseudotsuga menziesii (Mirb.) Franco, Thuja plicata Donn ex D. Don and Tsuga heterophylla (Raf.) Sarg. planted tree seedlings and associated vascular plant communities. Performance of tree seedlings (height) and under vascular plant communities (percent cover) were examined in an experiment with warming (open‐top chambers) and nitrogen deposition (ammonium nitrate applied at 10 kg N ha−1 year−1) treatments applied to subplots in six forest edges and six clear‐cuts (N = 298 total subplots).ResultsIn clear‐cuts, tree seedling height increased with experimental warming and differed among species, and vascular plant cover increased with warming. In clear‐cuts, species identity, not soil variables, was a strong predictor of height, and plant cover was negatively related to pH. In forest edges, edge position and some soil variables were related to height, but not plant cover. There were no interaction effects found between experimental nitrogen deposition and warming.ConclusionsOur results suggest that moderate warming can enhance tree seedling height and understorey vascular plant cover in clear‐cuts in Pacific Northwest coastal ecosystems, but low nitrogen deposition may not have an effect alone or synergistically with warming.

STEM in Higher Education: Analysis of Gendered Themes Across Pacific Northwest Institutional Policies

Despite efforts to reach gender parity, women remain underrepresented in academic STEM fields. Structural conditions within universities are known to contribute to this underrepresentation, but existing studies have not adequately address university policies and their connection to persistent gender inequality in the academy. To bridge this gap, we apply Acker’s Theory of Gendered Organizations (1990) to the university setting by analyzing policy texts from thirteen diverse institutions, including doctorate-granting and primarily undergraduate serving universities, as well as community colleges. Specifically, we assessed the extent to which the language contained in these documents is gendered. Through the creation of conceptual lexicons and use of several metrics (i.e., polarity scores, n-grams, and radar charts), we determined that the university policy texts were largely written as gender-neutral. However, future studies should examine the implementation of these policies, as the latter may be responsible for perpetuating gender inequities.

Assembly and analysis of the genome of Notholithocarpus densiflorus.

Tanoak (Notholithocarpus densiflorus) is an evergreen tree in the Fagaceae family found in California and southern Oregon. Historically, tanoak acorns were an important food source for Native American tribes and the bark was used extensively in the leather tanning process. Long considered a disjunct relictual element of the Asian stone oaks (Lithocarpus spp.), phylogenetic analysis has determined that the tanoak is an example of convergent evolution. Tanoaks are deeply divergent from oaks (Quercus) of the Pacific Northwest and comprise a new genus with a single species. These trees are highly susceptible to 'sudden oak death' (SOD), a plant pathogen (Phytophthora ramorum) that has caused widespread mortality of tanoaks. Here, we set out to assemble the genome and perform comparative studies among a number of individuals that demonstrated varying levels of susceptibility to SOD. First, we sequenced and de novo assembled a draft reference genome of N. densiflorus using co-barcoded library processing methods and an MGI DNBSEQ-G400 sequencer. To increase the contiguity of the final assembly, we also sequenced Oxford Nanopore (ONT) long reads to 30X coverage. To our knowledge, the draft genome reported here is one of the more contiguous and complete genomes of a tree species published to date, with a contig N50 of ∼1.2 Mb, a scaffold N50 of ∼2.1 Mb, and a complete gene score of 95.5% through BUSCO analysis. In addition, we sequenced 11 genetically distinct individuals and mapped these onto the draft reference genome enabling the discovery of almost 25 million single nucleotide polymorphisms and ∼4.4 million small insertions and deletions. Finally, using co-barcoded data we were able to generate complete haplotype coverage of all 11 genomes.

Multicultural exceptionalism: Race and gender in the Sikh diaspora of the transnational Pacific Northwest

ABSTRACT Multiculturalism discourse simultaneously produces, celebrates, and erases differences. This paper explores racial violence within the Sikh diaspora of the transnational Pacific Northwest (PNW) to understand how multicultural discourse has obfuscated the criminalization, incarceration, and surveillance of the Sikh diaspora. I draw from an analysis of Deepa Mehta's film Beeba Boys as well as ethnographic fieldwork to analyze the tropes of the ‘Surrey Jack' and the ‘Kent Boy,' two pervasive stereotypes attached to young Punjabi men in the PNW. I show that these caricatured masculinities reveal the limits of racial inclusion by reproducing stereotypes that characterize Punjabi Sikh men as ‘dangerous.’

Therapeutic Hypothermia in Low-Risk Nonpumped Brain-Dead Kidney Donors

Delayed graft function in kidney-transplant recipients is associated with increased financial cost and patient burden. In donors with high Kidney Donor Profile Index whose kidneys are not pumped, therapeutic hypothermia has been shown to confer a protective benefit against delayed graft function. To determine whether hypothermia is superior to normothermia in preventing delayed graft function in low-risk nonpumped kidney donors after brain death. In a multicenter randomized clinical trial, brain-dead kidney donors deemed to be low risk and not requiring machine perfusion per Organ Procurement Organization protocol were prospectively randomized to hypothermia (34.0-35 °C) or normothermia (36.5-37.5 °C) between August 10, 2017, and May 21, 2020, across 4 Organ Procurement Organizations in the US (Arizona, Upper Midwest, Pacific Northwest, and Texas). The final analysis report is dated June 15, 2022, based on the data set received from the United Network for Organ Sharing on June 2, 2021. A total of 509 donors (normothermia: n = 245 and hypothermia: n = 236; 1017 kidneys) met inclusion criteria over the study period. Donor hypothermia (34.0-35.0 °C) or normothermia (36.5-37.5 °C). The primary outcome was delayed graft function in the kidney recipients, defined as the need for dialysis within the first week following kidney transplant. The primary analysis follows the intent-to-treat principle. A total of 934 kidneys were transplanted from 481 donors, of which 474 were randomized to the normothermia group and 460 to the hypothermia group. Donor characteristics were similar between the groups, with overall mean (SD) donor age 34.2 (11.1) years, and the mean donor creatinine level at enrollment of 1.03 (0.53) mg/dL. There was a predominance of Standard Criteria Donors (98% in each treatment arm) with similar low mean (SD) Kidney Donor Profile Index (normothermia: 28.99 [20.46] vs hypothermia: 28.32 [21.9]). Cold ischemia time was similar in the normothermia and hypothermia groups (15.99 [7.9] vs 15.45 [7.63] hours). Delayed graft function developed in 87 of the recipients (18%) in the normothermia group vs 79 (17%) in the hypothermia group (adjusted odds ratio, 0.92; 95% CI, 0.64-1.33; P = .66). The findings of this study suggest that, in low-risk non-pumped kidneys from brain-dead kidney donors, therapeutic hypothermia compared with normothermia does not appear to prevent delayed graft function in kidney transplant recipients. ClinicalTrials.gov Identifier: NCT02525510.

A comparison of two snapshot studies half a century apart suggests stability in a Pacific Northwest winter forest bird community

Populations of many North American bird species have declined throughout the past half century. The majority of studies quantifying these declines have analyzed counts of birds taken during spring and summer, not during the season of scarcity, winter. We re-surveyed seven large study plots in Douglas fir (Pseudotsuga menziesii) forests initially surveyed in winter during the late 1960s in the Oregon Coast Range, USA. We compared density estimates, observed species richness and vegetation structure within plots, and inspected aerial photography to describe changes in landscape-level landcover. To assess potential drivers of change, we reviewed historical climate data and explored patterns of abundance associated with forest age. Observed species richness was greater in the modern surveys. Abundances of four of the six most common bird species appeared to be similar to or slightly lower than 50 years ago as the historical point estimates usually fell within or above 95% confidence intervals generated from our analyses. We found no clear associations with changes in bird communities and forest structure, climate, or forest age. The historical data are unique in providing point estimates of abundance for the entire bird community on each study plot. Yet, some uncertainties in accuracy of the historic counting methods could still influence interpretation of multi-decadal changes in apparent abundance. We conclude that this Pacific Northwest bird community was relatively stable in its abundances of the most common forest-dwelling species and that largely the communities are still intact. Additional production of precisely repeatable surveys of winter bird communities are needed in all habitats to adequately characterize long-term population dynamics during the season of scarcity.

Sensitivity Testing of Marine Turbidite Age Estimates along the Cascadia Subduction Zone

ABSTRACT Marine turbidite studies infer that 19–20 ∼Mw 9 earthquakes ruptured the full Cascadia subduction zone (CSZ) in the past 10 kyr, a hypothesis that relies on concurrent turbidite deposition generated from seismogenic strong ground motion along the ∼1100 km margin. Correlation of marine turbidite deposits is based on petrophysical characteristics and radiocarbon geochronology, the latter of which relies on a series of age corrections and calibrations for marine radiocarbon age and sedimentological parameters. In this work, I isolate several key variables in turbidite age assessment and systematically test how previous assumptions and new calibration curves affect estimated ages, and thus whether geochronologic analyses independently support coeval turbidite deposition. For radiocarbon age calibration, I test the impact of (1) updating global marine reservoir age corrections; (2) updating local marine reservoir age estimates; and (3) selectively applied marine reservoir age excursions. From the calibrated radiocarbon ages, I calculate turbidite age and uncertainty using a Monte Carlo approach with a broad range of sedimentation rates and substratal erosion. By simply updating the global marine radiocarbon calibration, individual radiocarbon ages differ from published estimates by several hundred years. Updates to the local reservoir age corrections are minimal because existing data remain limited yet have potential for great impact on turbidite ages. Of the sedimentological parameters tested, sedimentation rate has the largest impact on estimated turbidite age, with individual ages changing up to 500 yr from published estimates. For radiocarbon samples of turbidites previously inferred to correlate, the individual ages typically show increased scatter and overall uncertainty, even for models that only update the global marine reservoir calibration. These results highlight the major age uncertainty associated with current coseismic turbidite age analyses in Cascadia and how independent constraints on local reservoir corrections and sedimentation rate are critical for accurate turbidite age estimates in the Pacific Northwest.

Parts-Per-Million Carbonate Mineral Quantification with Thermogravimetric Analysis-Mass Spectrometry.

Mitigating the deleterious effects of climate change requires the development and implementation of carbon capture and storage technologies. To expand the monitoring, verification, and reporting (MRV) capabilities of geologic carbon mineralization projects, we developed a thermogravimetric analysis-mass spectrometry (TGA-MS) methodology to enable quantification of <100 ppm calcite (CaCO3) in complex samples. We extended TGA-MS calcite calibration curves to enable a higher measurement resolution and lower limits of quantification for evolved CO2 from a calcite-corundum mixture. We demonstrated <100 ppm carbonate mineral quantification with TGA-MS for the first time, an outcome applicable across earth, environmental, and materials science fields. We applied this carbonate quantification method to a suite of Columbia River Basalt Group (CRBG) well cuttings recovered in 2009 from Pacific Northwest National Laboratory's Wallula #1 Well. Our execution of this new combined calcite and calcite-corundum calibration curve TGA-MS method on our CRBG sample suite indicated average carbonate contents of 0.050 wt % in flow interiors (caprocks) and 0.400 wt % in interflow zones (reservoirs) in the upper 1250 m of the Wallula #1 Well. By advancing our knowledge of continental flood basalt-hosted carbonates in the mafic subsurface and reaching new TGA-MS quantification limits for carbonate minerals, we expand MRV capabilities and support the commercial-scale deployment of carbon mineralization projects in the Pacific Northwest United States and beyond.

The use of salmonid epithelial cells to characterize the toxicity of Tenacibaculum maritimum soluble extracellular products.

This study assessed how the etiological agent of mouth rot in farmed Atlantic salmon, Tenacibaculum maritimum, induces toxicity in host salmonid barrier cells, and determined whether environmental changes are relevant for these effects. Tenacibaculum maritimum soluble extracellular products (ECPs) were collected and used to treat Atlantic salmon and rainbow trout intestinal barrier cell lines as a comparative model of bacterial-salmonid cell interactions. Cellular assays that examine cell membrane integrity, marker expression, and metabolic activity revealed that T. maritimum ECPs induced salmonid epithelial cell death through an apoptosis mechanism. Changes in salinity (25, 29, and 33 ppt) and temperature (12°C, 18°C, and 24°C) within the natural ranges observed in Pacific Northwest aquaculture facilities affected bacterial growth and cytotoxicity of T. maritimum ECPs. Our results suggest epithelial barriers as targets of T. maritimum-mediated toxicity in farmed mouth rot-infected Atlantic salmon. The induction of apoptosis by T. maritimum soluble ECPs may also help to explain the absence of overt inflammation typically reported for these fish.

Quantifying clean energy justice: Impact of Solarize programs on rooftop solar disparities in the Pacific Northwest

This study investigates the dynamics of rooftop solar deployment disparities in relation to Solarize programs in metropolitan cities in the Pacific Northwest. We introduce four equity domains and five disparity indices that encompass aspects of distributional and recognition justice, placing emphasis on spatial distribution and deployment patterns. We find that Solarize programs have a discernible impact on spatial and Gini disparities, with these disparities intensifying as installations increase. However, while spatial disparities rise with cumulative installations, Gini disparities consistently decrease over time. Interestingly, less advantageous communities exhibit heightened Gini disparities with cumulative installations, underscoring the need to focus on these communities. Additionally, communities with higher socioeconomic and demographic attributes exhibit more prominent Gini disparities, emphasizing the role of these attributes in shaping deployment disparities. Our results underscore the importance of considering spatial clustering tendencies in Solarize program advocacy and emphasize the pivotal role of community characteristics in rooftop solar deployment disparities. This study addresses energy equity trends with a unique focus on spatiotemporal dimensions, Solarize programs, and their impact on deployment disparities, offering valuable insights for policymakers and urban planners striving for socially and physically resilient cities.

Phylogeographic Reconstruction to Trace the Source Population of Asian Giant Hornet Caught in Nanaimo in Canada and Blaine in the USA.

The Asian giant hornet, Vespa mandarinia, is an invasive species that could potentially destroy the local honeybee industry in North America. It has been observed to nest in the coastal regions of British Columbia in Canada and Washington State in the USA. What is the source population of the immigrant hornets? The identification of the source population can shed light not only on the route of immigration but also on the similarity between the native habitat and the potential new habitat in the Pacific Northwest. We analyzed mitochondrial COX1 sequences of specimens sampled from multiple populations in China, the Republic of Korea, Japan, and the Russian Far East. V. mandarinia exhibits phylogeographic patterns, forming monophyletic clades for 16 specimens from China, six specimens from the Republic of Korea, and two specimens from Japan. The two mitochondrial COX1 sequences from Nanaimo, British Columbia, are identical to the two sequences from Japan. The COX1 sequence from Blaine, Washington State, clustered with those from the Republic of Korea and is identical to one sequence from the Republic of Korea. Our geophylogeny, which allows visualization of genetic variation over time and space, provides evolutionary insights on the evolution and speciation of three closely related vespine species (V. tropica, V. soror, and V. mandarinia), with the speciation events associated with the expansion of the distribution to the north.