Pacific Northwestern United States Research Articles

Applying climate change refugia to forest management and old-growth restoration.

Recent studies highlight the potential of climate change refugia (CCR) to support the persistence of biodiversity in regions that may otherwise become unsuitable with climate change. However, a key challenge in using CCR for climate resilient management lies in how CCR may intersect with existing forest management strategies, and subsequently influence how landscapes buffer species from negative impacts of warming climate. We address this challenge in temperate coastal forests of the Pacific Northwestern United States, where declines in the extent of late-successional forests have prompted efforts to restore old-growth forest structure. One common approach for doing so involves selectively thinning forest stands to enhance structural complexity. However, dense canopy is a key forest feature moderating understory microclimate and potentially buffering organisms from climate change impacts, raising the possibility that approaches for managing forests for old-growth structure may reduce the extent and number of CCR. We used remotely sensed vegetation indices to identify CCR in an experimental forest with control and thinned (restoration) treatments, and explored the influence of biophysical variables on buffering capacity. We found that remotely sensed vegetation indices commonly used to identify CCR were associated with understory temperature and plant community composition, and thus captured aspects of landscape buffering that might instill climate resilience and be of interest to management. We then examined the interaction between current restoration strategies and CCR, and found that selective thinning for promoting old-growth structure had only very minor, if any, effects on climatic buffering. In all, our study demonstrates that forest management approaches aimed at restoring old-growth structure through targeted thinning do not greatly decrease buffering capacity, despite a known link between dense canopy and CCR. More broadly, this study illustrates the value of using remote sensing approaches to identify CCR, facilitating the integration of climate change adaptation with other forest management approaches.

Spatial Bayesian models project shifts in suitable habitat for Pacific Northwest tree species under climate change

AbstractWe developed spatial Bayesian hierarchical models to assess potential climate change impacts on suitable habitat for five important tree species in the Pacific northwestern United States (California, Oregon, and Washington). Individual‐species models were fit with presence–absence data from forest inventory field plots and spatial relationships were specified through a conditional autoregressive model. This modeling approach allowed us to visualize uncertainty in response curves, map current and future prediction uncertainty, and provide interval estimates for change. Upward elevational or northward latitudinal shifts in climatically suitable habitat were projected for all species. Climate change impacts were the most damaging for noble fir (Abies procera), for which 79%–100% of the current range was projected to become climatically unsuitable by the 2080s. Although coastal Douglas‐fir (Pseudotsuga menziesii var. menziesii) has been projected by others to gain habitat in Canada, within our study area we projected a net loss of climatically suitable habitat (ca. 8000–31,400 km2) under three of four future climate scenarios. A net loss in habitat was also projected for Oregon white oak (Quercus garryana) under three of four scenarios, with 40%–60% of the current range becoming unsuitable. Although there was no net loss of habitat for forest land blue oak under any scenario, other factors like competition may inhibit blue oak (Quercus douglasii) and white oak from occupying areas projected to increase in climatic suitability. Additionally, between 13% and 32% of blue oak's current range was projected to become unsuitable; some of these areas aligned with dieback following the 2012–2015 California drought, which our data set predates. Unlike the other four species, we projected a 17%–25% increase in climatically suitable habitat for California black oak (Quercus kelloggii), although 1%–20% of the current range was still projected to become unsuitable. Our findings indicate that, although some species will face more pressure in tracking climatically suitable habitat than others, climate change will impact the location of suitable habitat for many species.

A Multimodal Pain Management Strategy for Burn Patients

BackgroundAcute burn pain is difficult to manage, and poorly managed pain can lead to deleterious consequences such as post-traumatic stress disorder, prolonged recovery, chronic pain and long-term dependence on opioids. Understanding the role of nursing in promoting self-efficacy and minimizing opioid use is valuable. It is unknown whether strategic efforts aimed at enhancing patient self-efficacy will improve pain managment and lessen opioid requirements in the adult burn population. AimThe aim of this study was to examine the effect of a multi-modal, interdisciplinary pain management strategy on coping self-efficacy, pain scores, and opioid use in adult burn patients in the acute care setting. MethodA quasi-experimental pre-test/post-test design was employed in an American Burn Association (ABA) verified burn center in the Pacific Northwestern United States. Data were collected prospectively for a 6-month period on 44 burn patients. The comparison group received usual care (n = 28), and the intervention received a pain management protocol (n = 16). Coping self-efficacy was measured on admission and at discharge in both groups using the Coping Self-Efficacy Scale. Numeric pain scores and opioid use in morphine milligram equivalents were averaged for each participant. Burn nurse perceptions were gathered via an anonymous electronic survey post data collection in February 2021. ResultsThere were no significant differences in measured coping self-efficacy, pain scores, or opioid use between the intervention and comparison groups. A significant positive correlation was found between length of stay, size of burn, and coping self-efficacy and problem focused self-efficacy. Burn nurses reported increased use of nonpharmacologic adjuncts since protocol implementation. ConclusionNonpharmacologic adjuncts are more likely to be used consistently when protocolized. There is also evidence to support that certain aspects of self-efficacy may be enhanced during acute phase of burn care.

Pseudocybaeota (Araneae: Cybaeidae): a new spider genus endemic to coastal Pacific Northwestern United States of America.

The forested habitats of the west coast of North America are home to a diverse array of endemic Cybaeinae spider taxa (Araneae: RTA clade: Cybaeidae). Most of those taxa have very restricted distributions within an area of the western United States of America from the Olympic Peninsula of northwestern Washington to the northern half of the Californian Floristic Province of California, a well-known biodiversity hotspot. Here we describe Pseudocybaeota Bennett gen. nov. with type species Cybaeus perditus Chamberlin Ivie (= Pseudocybaeota perdita (Chamberlin Ivie) comb. nov.) and including two new species, P. butterfieldi Bennett spec. nov. and P. tuberculata Bennett spec. nov. These rarely collected species are restricted to forested habitats in small areas of the coastal watersheds of the Olympic Peninsula (P. perdita comb. nov.), southern Curry and adjacent northern Del Norte Counties in Oregon and California, respectively (P. tuberculata spec. nov.), and Humboldt County in northwestern California (P. butterfieldi spec. nov.). In addition to descriptions of the genus and both sexes of its included species we provide diagnoses, illustrations, an identification key, and distribution maps for the species of this distinctive new genus.

Teacher Perceptions of Implementation Climate Related to Feasibility of Implementing Schoolwide Positive Behavior Supports and Interventions

For Schoolwide Positive Behavior Interventions and Supports (SWPBIS) to be effective, educators must use the practices as intended. Whether a teacher uses a practice as intended can depend, in part, on how feasible the practice is perceived to be. Identifying malleable factors associated with teachers’ perceptions of SWPBIS feasibility can help schools identify targeted supports to improve feasibility. Implementation climate, or the shared perception among implementers that their school supports implementation efforts, is known to promote high quality implementation. However, little is known about how individuals’ perceptions of their school’s implementation climate may influence their perceptions of feasibility. The lack of empirical evidence points to a need to explore whether educators’ shared and individual perceptions of implementation climate influence feasibility of implementing SWPBIS. Therefore, this study examines the link between teachers’ individual and shared perceptions of implementation climate related to the feasibility of implementing SWPBIS in a sample of 348 K-5 general education teachers across 39 elementary schools in the pacific northwestern United States. Results indicate that teachers who experience their schools’ implementation climate as positive are more likely to report SWPBIS as feasible, controlling for teachers’ shared perceptions of implementation climate. Implications for schools aiming to improve their implementation of SWPBIS, including the development of individualized implementation supports (e.g., tailoring implementation strategies to support each and every teacher), are discussed.

Environmental Life-Cycle Assessment and Life-Cycle Cost Analysis of a High-Rise Mass Timber Building: A Case Study in Pacific Northwestern United States

Global construction industry has a huge influence on world primary energy consumption, spending, and greenhouse gas (GHGs) emissions. To better understand these factors for mass timber construction, this work quantified the life cycle environmental and economic performances of a high-rise mass timber building in U.S. Pacific Northwest region through the use of life-cycle assessment (LCA) and life-cycle cost analysis (LCCA). Using the TRACI impact category method, the cradle-to-grave LCA results showed better environmental performances for the mass timber building relative to conventional concrete building, with 3153 kg CO2-eq per m2 floor area compared to 3203 CO2-eq per m2 floor area, respectively. Over 90% of GHGs emissions occur at the operational stage with a 60-year study period. The end-of-life recycling of mass timber could provide carbon offset of 364 kg CO2-eq per m2 floor that lowers the GHG emissions of the mass timber building to a total 12% lower GHGs emissions than concrete building. The LCCA results showed that mass timber building had total life cycle cost of $3976 per m2 floor area that was 9.6% higher than concrete building, driven mainly by upfront construction costs related to the mass timber material. Uncertainty analysis of mass timber product pricing provided a pathway for builders to make mass timber buildings cost competitive. The integration of LCA and LCCA on mass timber building study can contribute more information to the decision makers such as building developers and policymakers.

Too Latinx or Not Latinx Enough? Racial Subtexts and Subjectivities in a Predominantly White University

ABSTRACT This study examines how Latina students attending a predominantly white university in the Pacific Northwestern United States describe their academic and social wellbeing in relation to their racial subjectivities and the racially-charged campus interactions they have experienced. Critical Race Theory and Latina/o Critical Race Theory help us interpret how these students assert the authenticity of their identities in ways that either validate or contest the whiteness that tacitly frames so many aspects of their academic and social lives. These findings open a conversation on a subject that is taboo within Latinx communities and largely invisible within Predominantly White Institutions: how simultaneous claims to Latinx belonging and white privilege play into systemic racism on campus and throughout the U.S.

Genomic signatures of demographic declines in an imperiled amphibian inform conservation action

AbstractCatastrophic population declines due to disease often lead to fragmented remnant populations and loss of gene flow. Managers are left to determine appropriate conservation actions to recover and maintain population persistence. The recent utilization of genomic data to assist in species recovery now allows us to combine genome‐wide surveys of differentiation and diversity with the identification of potentially adaptive regions to develop conservation plans that incorporate ecological and evolutionary processes. The unprecedented global decline of amphibian populations due to the pathogen Batrachochytrium dendrobatidis has increased the need to apply genomic tools to amphibian conservation practices. We show here how understanding genetic characteristics of remnant frog populations affected by disease can be applied directly to restoration efforts. Cascades frogs (Rana cascadae) occur in the mountainous regions of the Pacific northwestern United States and have declined dramatically at the southern edge of their range in California. We conducted genome‐wide surveys within this region to inform conservation and reintroduction efforts. We found strong north‐south genetic differentiation between Oregon and California and novel spatial structure within California. Genetic diversity was lower in California than Oregon and genetic drift was the most important driver of genetic diversity and population structure in California, making conservation efforts aimed at boosting overall genetic diversity most urgent. Spatial genetic structure of populations within California suggests that reintroductions to Lassen Volcanic National Park, where they were recently extirpated, should use remaining source populations south of the park. Our findings support the treatment of California's R. cascadae populations separately from the rest of their range and highlight the importance of conservation genomics in applied species conservation.

Delayed Early Season Irrigation: Impacts on Hop Yield and Quality

Irrigation is essential for hop production in the Pacific Northwestern United States, the primary growing region in the U.S. Irrigation water supplies can be inadequate in drought years and may become more variable in the future due to climate variability and increasing non-agricultural demand. In this research, the impact of delayed timing of the first irrigation of the season on hop yield and cone quality metrics in the cultivars Cascade and Zeus over three years was evaluated. The impact of delayed irrigation depended on year and cultivar, with larger impacts on yield of Cascade as compared to Zeus in this study. In Cascade, yield decreased 10.8% to 16.2% when the timing of the first irrigation was delayed by 10 or 18 days after training, respectively. However, cone quality factors were statistically similar when data were aggregated over all three years. In Zeus, delaying the first irrigation did not have detectable effects on brewing quality or yield in any individual year or when data were aggregated over all years. Thus, while even a brief delay in irrigation may substantially reduce yield in some cultivars such as Cascade, these effects were cultivar-dependent and impacts on brewing quality appeared small or undetectable.

Nursing student experiences of remote learning during the COVID‐19 pandemic

BackgroundThe emergence of the COVID‐19 pandemic resulted in a sudden transition to remote learning. These circumstances presented many challenges for higher education faculty and students around the world but especially for nursing education programs which are traditionally conducted in a face‐to‐face learning environment that includes hands‐on experiential learning.MethodsGuided by Meleis' Transition Theory, a qualitative descriptive design was utilized to explore prelicensure nursing students’ experiences of the transition to remote learning during the Spring 2020 semester. Participants were recruited from one baccalaureate program in the Pacific Northwestern United States. Interviews were conducted and transcribed using a web conferencing platform. Data were analyzed using Colaizzi's phenomenological reduction.ResultsEleven students participated. Interviews revealed four overarching themes: technological challenges, academic relationship changes, role stress and strain, and resilience.ConclusionThe sudden transition to remote learning resulted in a number of challenges for nursing students. Despite these challenges, students demonstrated a remarkable sense of resilience and perseverance. Faculty have an opportunity to address student stressors and design remote courses in such a way to facilitate student engagement and community building.

The Materiality of Anti-Japanese Racism: “Foreignness” and Racialization at Barneston, Washington (1898-1924)

Archaeologies of Japanese American labor reveal how company towns served as vehicles for racialization. Labor hierarchies at sawmill towns in Pacific Northwestern United States reified Nikkei immigrants as “foreign,” incapable of being full members of American society. Contests over “foreignness” are materialized on the landscape of Barneston, Washington. Community responses to anti-Japanese racism are visible through signage, while sawmill town owner strategies are reflected in the Nikkei’s spatial segregation. These arguments demonstrate how historical archaeology can link research in Asian American studies, racism and racialization, and company town labor to develop new syntheses of labor history.

Climate change alters flood magnitudes and mechanisms in climatically-diverse headwaters across the northwestern United States

Flooding caused by high streamflow events poses great risk around the world and is projected to increase under climate change. This paper assesses how climate change will alter high streamflow events by changing both the prevalence of different driving mechanisms (i.e. ‘flood generating processes’) and the magnitude of differently generated floods. We present an analysis of simulated changes in high streamflow events in selected basins in the hydroclimatically diverse Pacific Northwestern United States, classifying the events according to their mechanism. We then compare how the different classes of events respond to changes in climate at the annual scale. In a warmer future, high flow events will be caused less frequently by snowmelt and more frequently by precipitation events. Also, precipitation-driven high flow events are more sensitive to increases in precipitation than are snowmelt-driven high flow events, so the combination of the increase in both frequency and magnitude of precipitation-driven high flow events leads to higher flood likelihood than under each change alone. Our comparison of the results from two emissions pathways shows that a reduction in global emissions will limit the increase in magnitude and prevalence of these precipitation-driven events.

Population Diversity and Structure of Podosphaera macularis in the Pacific Northwestern United States and Other Populations.

Powdery mildew, caused by Podosphaera macularis, is one of the most important diseases of hop. The disease was first reported in the Pacific Northwestern United States, the primary hop-growing region in this country, in the mid-1990s. More recently, the disease has reemerged in newly planted hopyards of the eastern United States, as hop production has expanded to meet demands of local craft brewers. The spread of strains virulent on previously resistant cultivars, the paucity of available fungicides, and the potential introduction of the MAT1-2 mating type to the western United States, all threaten sustainability of hop production. We sequenced the transcriptome of 104 isolates of P. macularis collected throughout the western United States, eastern United States, and Europe to quantify genetic diversity of pathogen populations and elucidate the possible origins of pathogen populations in the western United States. Discriminant analysis of principal components grouped isolates within three to five geographic populations, dependent on stringency of grouping criteria. Isolates from the western United States were phenotyped and categorized into one of three pathogenic races based on disease symptoms generated on differential cultivars. Western U.S. populations were clonal, irrespective of pathogenic race, and grouped with isolates originating from Europe. Isolates originating from wild hop plants in the eastern United States were genetically differentiated from all other populations, whereas isolates from cultivated hop plants in the eastern United States mostly grouped with isolates originating from the west, consistent with origins from nursery sources. Mating types of isolates originating from cultivated western and eastern U.S. hop plants were entirely MAT1-1. In contrast, a 1:1 ratio of MAT1-1 and MAT1-2 was observed with isolates sampled from wild plants or Europe. Within the western United States a set of highly differentiated loci were identified in P. macularis isolates associated with virulence to the powdery mildew R-gene R6. The weight of genetic and phenotypic evidence suggests a European origin of the P. macularis populations in the western United States, followed by spread of the pathogen from the western United States to re-emergent production regions in the eastern United States. Furthermore, R6 compatibility appears to have been selected from an extant isolate within the western United States. Greater emphasis on sanitation measures during propagation and quarantine policies should be considered to limit further spread of novel genotypes of the pathogen, both between and within production areas.

Using Motivational Interviewing to Improve Parenting Skills and Prevent Problem Behavior During the Transition to Kindergarten

In this study, we examined the efficacy of a version of the Family Check-Up (FCU) adapted for kindergarten school entry with regard to parenting skills during the transition to school. We also examined whether improvements in parenting skills would mediate improvements in parent- and teacher-rated child behavior problems from kindergarten to second grade. The FCU is a motivational interviewing (MI) intervention designed to engage parents in treatment to improve parenting skills. Participants were parents of 365 children enrolled in one of five elementary schools in the Pacific Northwestern United States. Main and indirect effects were tested with structural equation path modeling using an intent-to-treat approach. The FCU was associated with improved change in parenting skills, and changes in parenting skills, in turn, predicted reductions in child behavior problems. Implications for embedding MI in family-centered interventions at kindergarten school entry are discussed. Trial registration: NCT02289092

Evidence of region-wide bat population decline from long-term monitoring and Bayesian occupancy models with empirically informed priors.

Strategic conservation efforts for cryptic species, especially bats, are hindered by limited understanding of distribution and population trends. Integrating long‐term encounter surveys with multi‐season occupancy models provides a solution whereby inferences about changing occupancy probabilities and latent changes in abundance can be supported. When harnessed to a Bayesian inferential paradigm, this modeling framework offers flexibility for conservation programs that need to update prior model‐based understanding about at‐risk species with new data. This scenario is exemplified by a bat monitoring program in the Pacific Northwestern United States in which results from 8 years of surveys from 2003 to 2010 require updating with new data from 2016 to 2018. The new data were collected after the arrival of bat white‐nose syndrome and expansion of wind power generation, stressors expected to cause population declines in at least two vulnerable species, little brown bat (Myotis lucifugus) and the hoary bat (Lasiurus cinereus). We used multi‐season occupancy models with empirically informed prior distributions drawn from previous occupancy results (2003–2010) to assess evidence of contemporary decline in these two species. Empirically informed priors provided the bridge across the two monitoring periods and increased precision of parameter posterior distributions, but did not alter inferences relative to use of vague priors. We found evidence of region‐wide summertime decline for the hoary bat (λ^ = 0.86 ± 0.10) since 2010, but no evidence of decline for the little brown bat (λ^ = 1.1 ± 0.10). White‐nose syndrome was documented in the region in 2016 and may not yet have caused regional impact to the little brown bat. However, our discovery of hoary bat decline is consistent with the hypothesis that the longer duration and greater geographic extent of the wind energy stressor (collision and barotrauma) have impacted the species. These hypotheses can be evaluated and updated over time within our framework of pre–post impact monitoring and modeling. Our approach provides the foundation for a strategic evidence‐based conservation system and contributes to a growing preponderance of evidence from multiple lines of inquiry that bat species are declining.

Identification and Mapping of Eastern Filbert Blight Resistance Quantitative Trait Loci in European Hazelnut Using Double Digestion Restriction Site Associated DNA Sequencing

European hazelnut (Corylus avellana L.) is an economically important edible nut producing species, which ranked sixth in world tree nut production in 2016. European hazelnut production in the United States is primarily limited to the Willamette Valley of Oregon, and currently nonexistent in the eastern United States because of the presence of a devastating endemic disease, eastern filbert blight (EFB) caused by Anisogramma anomala (Peck) E. Muller. The primary commercial means of control of EFB to date is through the development and planting of genetically resistant european hazelnut cultivars, with an R-gene introduced from the obsolete, late-shedding pollinizer ‘Gasaway’. Although the ‘Gasaway’ resistance source provides protection against EFB in the Pacific northwestern United States (PNW), recent reports have shown that it is not effective in parts of the eastern United States. This may be in part because the identification and selection of ‘Gasaway’ and ‘Gasaway’-derived cultivars occurred in an environment (PNW) with limited genetic diversity of A. anomala. The objectives of the current research were to develop a genetic linkage map using double digestion restriction site associated DNA sequencing (ddRADseq) and identify quantitative trait loci (QTL) markers associated with EFB resistance from the resistant selection Rutgers H3R07P25 from southern Russia. A mapping population composed of 119 seedling trees was evaluated in a geographic location (New Jersey) where the EFB fungus is endemic, exhibits high disease pressure, and has a high level of genetic diversity. The completed genetic linkage map included a total of 2217 markers and spanned a total genetic distance of 1383.4 cM, with an average marker spacing of 0.65 cM. A single QTL region associated with EFB resistance from H3R07P25 was located on european hazelnut linkage group (LG) 2 and was responsible for 72.8% of the phenotypic variation observed in the study. Based on its LG placement, origin, and disease response in the field, this resistance source is different from the ‘Gasaway’ source located on LG6. The current results, in combination with results from previous research, indicate that the H3R07P25 source is likely exhibiting resistance to a broader range of naturally occurring A. anomala isolates. As such, H3R07P25 will be important for the development of new european hazelnut germplasm that combines EFB resistance from multiple sources in a gene pyramiding approach. Identification of EFB resistance in high disease pressure environments representing a diversity of A. anomala populations is likely a requirement for identifying plants expressing durable EFB resistance, which is a precursor to the development of a commercially viable european hazelnut industry in the eastern United States.

Cannabis Use and Cognition in Adults Prescribed Opioids for Persistent Pain

BackgroundAdults with persistent pain frequently report cannabis use to help manage their symptoms. The impact of cannabis use on cognition in the presence of concurrent symptoms of depression and anxiety is poorly understood. AimsOur study explored how cannabis use affects relationships among symptoms of depression, anxiety, and cognition. DesignA cross-sectional survey study was conducted. SettingsSurveys were distributed at outpatient clinics treating adults for pain in the Pacific Northwestern United States. ParticipantsA total of 150 adults prescribed an opioid medicine for persistent pain were recruited. MethodsA pencil and paper survey was used to collect several self-reported ratings of cognition, symptoms of depression and anxiety, and the average potency of cannabis consumed as measured by the percentage of delta-9-tetrahydrocannibinol (THC) and cannabidiol (CBD), as well as frequency of cannabis use. ResultsDepression, anxiety and cognition significantly worsened as the reported percentage of CBD, THC and overall frequency of cannabis use in the past 30 days increased. Depression and anxiety both significantly predicted worsening cognition in the sample. The relationship between depressive symptoms and cognition was strengthened as reported percentages of CBD use increased. The relationship was the same for anxiety and cognition, although not as strong. ConclusionsMore cannabis use, particularly high CBD products, may be linked with increased symptom burdens and may strengthen relationships between negative affect and cognition. Further cannabis research within persistent pain populations is warranted to add evidence that can assist patients in managing mood and mental processes. Nurses should evaluate how negative affective health symptoms may impact cognition among adults with persistent pain using prescription opioid medications, especially in the context of concurrent cannabis use.

Risk Factors for Bud Perennation of Podosphaera macularis on Hop.

The hop powdery mildew fungus Podosphaera macularis persists from season to season in the Pacific Northwestern United States through infection of crown buds because only one of the mating types needed to produce the ascigerous stage is presently found in this region. Bud infection and successful overwintering of the fungus leads to the emergence of heavily infected shoots in early spring (termed flag shoots). Historical data of flag shoot occurrence and incidence in Oregon and Washington State during 2000 to 2017 were analyzed to identify their association with the incidence of powdery mildew, growers' use of fungicides, autumn and winter temperature, and other production factors. During this period, flag shoots were found on 0.05% of plants evaluated in Oregon and 0.57% in Washington. In Oregon, the incidence of powdery mildew on leaves was most severe and the number of fungicide applications made by growers greatest in yards where flag shoots were found in spring. Similarly, the incidence of plants with powdery mildew in Washington was significantly associated with the number of flag shoots present in early spring, although the number of fungicide applications made was independent of flag shoot occurrence. The occurrence of flag shoots was associated with prior occurrence of flag shoots in a yard, the incidence of foliar powdery mildew in the previous year, grower pruning method, and, in Washington, winter temperature. A census of hop yards in the eastern extent of the Oregon production region during 2014 to 2017 found flag shoots in 27 of 489 yards evaluated. In yards without flag shoots, 338 yards (73.2%) were chemically pruning or not pruned, whereas the remaining 124 (26.8%) were mechanically pruned. Of the 27 yards with flag shoots, 22 were either chemically pruned or not pruned and 4 were mechanically pruned in mid-April, well after the initial emergence of flag shoots. The prevalence of yards with flag shoots also was related to thoroughness of pruning in spring (8.1% of yards with incomplete pruning versus 1.9% of yards with thorough pruning). A Bayesian logistic regression model was fit to the data from the intensively assessed yards in Oregon, with binary risk factors for occurrence of a flag shoot in the previous year, occurrence of foliar mildew in the previous year, and thoroughness of pruning in spring. The model indicated that the median and 95% highest posterior density interval of the probability of flag shoot occurrence was 0.0008 (0.0000 to 0.0053) when a yard had no risk factors but risk increased to 0.0065 (0.0000 to 0.0283) to 0.43 (0.175 to 0.709) when one to all three of the risk factors were present. The entirety of this research indicates that P. macularis appears to persist in a subset of chronically affected hop yards, particularly yards where spring pruning is conducted poorly. Targeted management of the disease in a subset of fields most at risk for producing flag shoots could potentially influence powdery mildew development regionwide.

Increasing the availability and spatial variation of spawning habitats through ascending baseflows

AbstractPrecipitation in fall and winter is important to recharge aquifers in Northern California and the Pacific Northwestern United States, causing the baseflow in rivers ascend during the time when Chinook salmon (Oncorhynchus tshawytscha) construct redds. Herein, we evaluate the availability of spawning habitats under a constant streamflow common in regulated rivers against ascending baseflows patterned from free‐flowing rivers. A binomial logistic regression model was applied to predict the suitability of redd locations based on physical characteristics. Next, two‐dimensional hydrodynamic habitat models were developed at two locations representing a broad range of channel forms common in large rivers. Hydrodynamic and habitat models were leveraged together to simulate the quality, amount, and spatial distribution of spawning habitat at a series of individual flow rates, as well as the combined effect of those flow rates through a spawning season with ascending baseflows. Ascending baseflows increased the abundance of spawning habitat over individual streamflows at a site where the river channel is confined by levee‐like features. However, improvements were greater at an unconfined site that facilitated lateral connectivity and greater expansion of wetted channel area as streamflows increased. Ascending baseflows provided spatial separation in preferred habitats over a spawning season, which may reduce the risk of superimposition among runs or among species. Ascending baseflows provided a benefit across the range of hydrologic regimes in a 100‐year gauge record ranging from 20% to 122% improvements in habitat area over low streamflows that are currently used to manage for spawning habitat. Although replicating natural flow regimes in managed systems can be impossible or impractical, these results demonstrate that incorporating elements of the natural flow regime like ascending baseflows can benefit the restoration and conservation of riverine species.

Contribution of a Winter Wheat Cover Crop to the Maintenance of Root Lesion Nematode Populations in the Red Raspberry Production System

One of the primary production challenges red raspberry (Rubus idaeus) growers in the Pacific northwestern United States confront is root lesion nematode [RLN (Pratylenchus penetrans)]. In this perennial production system, red raspberry serves as a sustained host for RLN. When a red raspberry planting is slated for removal in the fall, a new red raspberry planting quickly follows in the same field the following spring. The primary crop that occurs in rotation with red raspberry is a winter wheat cover crop to provide soil coverage and protection during the winter. The objectives of this research were to determine if winter wheat (Triticum aestivum) provides a green bridge for RLN in continuous red raspberry production systems and to determine if modified winter cover cropping practices can be used to reduce population densities of RLN before replanting red raspberry. Four trials were established in fields being replanted to red raspberry and the following modified winter cover cropping practices were considered: cover crop planting date (at fumigation or 2 weeks after fumigation), termination date (cover crop kill with herbicide 2 or 6 weeks before incorporation compared with the industry standard of incorporation immediately before planting), and the additional application of methomyl. ‘Rosalyn’ and ‘Bobtail’ winter wheat planted as cover crops in these trials were demonstrated to be maintenance hosts for RLN (ranging from 10 to 947 RLN/g winter wheat root across trials) allowing them to be a green bridge for RLN to infect the following red raspberry crop. Altering winter wheat cover crop planting date, termination date with herbicide, or methomyl application did not affect RLN population densities in the subsequent red raspberry crop. Although planting an RLN maintenance host may be of concern to growers, the advantages of reduced soil erosion and nitrate leaching associated with cover cropping outweigh the perceived risk to the subsequent red raspberry crop.