Pacific Northwest United States Research Articles

Comparison of soil-aggregate crushing-energy meters

Dry aggregate stability (DAS) is an important factor influencing soil wind erosion, dust emission and crop production. Historically and to the present, DAS has been determined using a horizontal- or vertical-plate crushing meter (Soil-Aggregate Crushing-Energy Meter, hereafter SACEM). The intent of this paper was to compare the performance of horizontal-plate SACEM with a commercial penetrometer (Mohr Digi-Test, hereafter MDT). The performance of both instruments was tested on aggregates collected from various soil types, crop rotations, soil amendments, and tillage systems across the inland Pacific Northwest United States (iPNW). Results indicated no consistently significant difference in DAS measured by the MDT and SACEM. However, there was evidence that SACEM under-estimated or MDT over-estimated DAS by 74 to 368% in measuring the stability of strong aggregates (DAS > 3 J kg⁻¹). Both instruments measured higher DAS for no-tillage summer fallow, winter wheat-summer fallow (WW-SF) rotations, and no green manure treatments compared with other tillage practices, oilseed rotations, and green manure treatments. The SACEM that has historically been used in measuring soil DAS can be replaced by the commercial penetrometer (MDT). Nonetheless, differences in the performance of instruments in measuring the stability of strong aggregates poses risks.

Contrasting the Pathogen Loads in Co-Existing Populations of Phytophthora pluvialis and Nothophaeocryptopus gaeumannii in Douglas Fir Plantations in New Zealand and the Pacific Northwest United States.

The emergence of Phytophthora pluvialis as a foliar pathogen of Douglas fir in New Zealand and the Pacific Northwest United States has raised questions about its interaction with the widespread Swiss needle cast (SNC) disease. During Spring 2017, we repeatedly sampled 30 trees along an environmental gradient in each region and 292 additional trees in a longitudinal transect to assess the P. pluvialis epidemic and the association between P. pluvialis and Nothophaeocryptopus gaeumannii, which are causal agents of SNC. Both pathogens were consistently more abundant in the host's exotic environment in New Zealand. In both areas, the two pathogens co-exist in different spatial scales for regions and needles. The relative abundance of both pathogens was negatively correlated in the Pacific Northwest, where both presumably have co-existed for longer. Our findings confirmed the interaction of P. pluvialis and N. gaeumannii as foliar pathogens of Douglas fir and suggest a within-site spatial variation in the Pacific Northwest.

Coexistence of three specialist predators of the hemlock woolly adelgid in the Pacific Northwest USA.

The hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) is an invasive insect, introduced from Japan to eastern North America, where it causes decline and death of hemlock trees. There is a closely related lineage of A. tsugae native to western North America. To inform classical biological control of A. tsugae in the eastern USA, the density and phenology of three native western adelgid specialist predators, Leucopis argenticollis (Zetterstedt), Le. piniperda (Malloch) (Diptera: Chamaemyiidae), and Laricobius nigrinus Fender (Coleoptera: Derodontidae), were quantified in the Pacific Northwest. Infested branches were collected from western hemlock (Pinaceae: Tsuga heterophylla (Raf.) Sarg.) at four sites around the Puget Sound, Washington and three sites in Oregon. Immature Leucopis were identified to species using DNA barcodes. Leucopis argenticollis was roughly twice as abundant as Le. piniperda. Laricobius nigrinus larvae were more abundant than the two species of Leucopis during the egg stage of the first adelgid generation, but Leucopis were present as feeding larvae during the second adelgid generation when La. nigrinus was aestivating in the soil, resulting in Leucopis being more abundant than La. nigrinus across the entire sampling period. Adelges tsugae and La. nigrinus densities were not correlated, while A. tsugae and Leucopis spp. densities were positively correlated. Leucopis spp. and La. nigrinus densities were negatively correlated. These results support the complementary use of La. nigrinus and the two Leucopis species for biological control of A. tsugae in the eastern USA, and point to the need for further investigation of spatial and temporal niche partitioning among the three predator species.

Patient Satisfaction With Geriatric Psychiatry Services via Video Teleconference

ObjectiveThe objective for the current study is to examine patient satisfaction with geropsychiatry services provided via video telehealth. MethodsParticipants included community-dwelling older Veterans receiving geriatric psychiatry services via telehealth across regions of the Pacific Northwest and Southwestern United States. Participants completed a paper-based survey examining satisfaction with services following the completion of two medication management visits with a geropsychiatrist. ResultsThe majority of participants (90%) reported liking or even preferring geriatric telepsychiatry, despite the experience being novel for the majority of patients. Eighty-three percent of participants reported that receiving telegeropsychiatry services was the same (n = 30) or better (n = 3) than being seen in-person. Participants saved an average of 168 driving miles (means and standard deviations = 59.2; range 2–480) each visit. ConclusionThe findings of the current study suggest that older adults accept and are broadly satisfied with telegeropsychiatry services. This modality of care increased access to specialty care and decreased travel hardship.

Development and implementation of an empirical habitat change model and decision support tool for estuarine ecosystems

Widespread land use change in coastal ecosystems has led to a decline in the amount of habitat available for fish and wildlife, lower production of ecosystem goods and services, and loss of recreational and aesthetic value. This has prompted global efforts to restore the natural hydrologic regimes of developed shorelines, especially resource-rich estuaries, but the resilience of these restored ecosystems in the face of accelerated sea-level rise (SLR) remains uncertain. We implemented a Monitoring-based Simulation of Accretion in Coastal Estuaries (MOSAICS) in R statistical software to address uncertainty in the resilience of modified estuarine habitats, using the Nisqually River Delta in the Pacific Northwest USA as a case study. MOSAICS is a spatially explicit model with a numerical foundation that uses empirical monitoring datasets to forecast habitat change in response to rising tidal levels. Because it accounts for the crucial ecomorphodynamic feedbacks between tidal inundation, vegetative growth, and sediment accretion, MOSAICS can be used to determine whether alternative management scenarios, such as enhanced sediment inputs, will bolster estuarine resilience to SLR. Under moderate SLR (0.62 m), the model predicted that a two-fold increase in mean daily suspended sediment during the rainy season was sufficient to maintain Nisqually’s emergent marshes through 2100, but under high SLR (1.35 m) MOSAICS indicated that greater sediment additions would be necessary to prevent submergence. A comparison between a restored marsh with subsided and high-elevation areas and a relict marsh demonstrated that the subsided restoration area was highly susceptible to SLR. Findings from the MOSAICS model highlight the importance of a site’s initial elevation, capacity for producing above and belowground biomass, and suspended sediment availability when considering management actions in estuaries and other coastal ecosystems.

The effects of changing climate on estuarine water levels: a United States Pacific Northwest case study

Abstract. Climate change impacts on extreme water levels (WLs) at two United States Pacific Northwest estuaries are investigated using a multicomponent process-based modeling framework. The integrated impact of climate change on estuarine forcing is considered using a series of sub-models that track changes to oceanic, atmospheric, and hydrologic controls on hydrodynamics. This modeling framework is run at decadal scales for historic (1979–1999) and future (2041–2070) periods with changes to extreme WLs quantified across the two study sites. It is found that there is spatial variability in extreme WLs at both study sites with all recurrence interval events increasing with further distance into the estuary. This spatial variability is found to increase for the 100-year event moving into the future. It is found that the full effect of sea level rise is mitigated by a decrease in forcing. Short-recurrence-interval events are less buffered and therefore more impacted by sea level rise than higher-return-interval events. Finally, results show that annual extremes at the study sites are defined by compound events with a variety of forcing contributing to high WLs.

The Stratigraphy of Compound Sand Blows at Sites of Recurrent Liquefaction: Implications for Paleoseismicity Studies

Paleoliquefaction studies provide valuable information for seismic hazard analyses in areas where the return period of moderate to large events is longer than the duration of the historical earthquake catalog (e.g., Central-Eastern and Pacific Northwest United States). Toward this end, paleoliquefaction studies require accurate and detailed assessments of individual features and of the extent of the paleoliquefaction field for the event, with the difficulty of accurately interpreting field observations increasing in areas where recurrent liquefaction was triggered by spatiotemporally clustered paleo events. Accordingly, undisturbed features formed by recurrent liquefaction during the 2010–2011 Canterbury, New Zealand, earthquake sequence were studied to facilitate interpretation of paleoliquefaction analogs. Silt drapes demarcated multiple episodes of liquefaction in the sand blows, with the thickness of the silt drapes correlating to the fines content of the liquefied source stratum. However, no ubiquitous trends in the spatial sorting of grain sizes in the coarser fraction of the ejecta underlying silt drapes were observed. This study provides a modern analog to recurrent paleoliquefaction evidence and has important implications for interpretation of seismic hazards.

Dry aggregate stability of soils influenced by crop rotation, soil amendment, and tillage in the Columbia Plateau

Abstract Dry aggregate stability (DAS) is an important factor that influences soil erodibility. The purpose of this study was to measure DAS of soil, as well as assess the effect of crop rotation, soil amendment, and tillage on DAS in the main wind erosion area across the inland Pacific Northwest United States (iPNW). The stability of dry aggregates was measured using a commercial penetrometer and was found to be lower for soils in the iPNW than previously reported in other regions. Significant differences in DAS were found between tillage treatments at all locations. Dry aggregate stability was 24 to 114% higher for no-tillage summer fallow than tillage-based summer fallow treatments. Although not significant, DAS for a winter wheat-summer fallow (WW-SF) rotation was consistently higher than winter wheat-camelina-summer fallow (WW-C-SF) or winter wheat-safflower-summer fallow (WW-S-SF) rotations at two sites in central Washington. In contrast, when green manure or biosolids were applied as an amendment, there was no difference in DAS. Dry aggregate stability was more closely related to clay content than other soil properties (i.e. sand content and surface area of primary particles). Clay content, in the range 9 to 14%, can therefore be used to estimate DAS of soils in the iPNW. No-tillage management practices was beneficial to maintain greater DAS, thereby making soil aggregates more resistant to erosion and degradation.

Trajectories of Perceived Parental Psychological Control across Adolescence and Implications for the Development of Depressive and Anxiety Symptoms

Theory and research indicate considerable changes in parental control across adolescence (e.g., declining behavioral control), but the developmental course and significance of psychological control remains largely unknown. This study examined trajectories of adolescents' reports of mothers' and fathers' psychological control from ages 12 to 19, predictors of occupying distinct trajectories, and the developmental significance of these trajectories for adolescents' development of depressive and anxiety symptoms. It used eight waves of survey data on 500 adolescents (Mage = 11.83, SD = 1.03; 52% female; 67% White, 12% African American) and their parents from the Pacific Northwest United States. Most adolescents (about 90%) reported low but increasing levels of parental psychological control over time, with a small but significant subset (about 10%) perceiving perpetually elevated levels. Mothers' (but not fathers') depressive symptoms, reported at the age 12 assessment, predicted adolescents' membership in the elevated psychological control trajectory. Adolescents occupying these elevated trajectories showed more problematic growth in depressive and anxiety symptoms across adolescence. Taken together, the findings suggest that many adolescents experience increased parental psychological control as they age, and that variability in these trends indicates individual differences in their development of depressive and anxiety symptoms over time.

Field phenotyping using multispectral imaging in pea (Pisum sativum L) and chickpea (Cicer arietinum L)

Pea (Pisum sativum L) and chickpea (Cicer arietinum L) are important grain legumes grown in the Palouse region of the Pacific Northwest United States. The USDA-ARS grain legume breeding program in this region focuses on developing pea and chickpea varieties with high yield potential, resistance to biotic and abiotic stresses, and superior agronomic characteristics. In this study, aerial high resolution multispectral imaging was evaluated to phenotype yield potential differences among genotypes in green pea, yellow pea and chickpea. Five experiments (three field pea and two chickpea) with 10–25 varieties grown at two locations (Pullman, Washington; Genesee, Idaho) were assessed. Images were acquired approximately 60, 70 and 90 days after planting (DAP) at 110 m above ground level. Normalized difference vegetation index (NDVI), green normalized difference vegetation index, soil adjusted vegetation index (SAVI) and simple ratio (SR) image based features (SUM, MIN, MAX, MEAN) were extracted. In most cases, the MEAN NDVI data was found to be consistently correlated with dry seed yield (p < 0.05), with green pea genotypes showing strongest relationship (r = 0.64–0.93 at about 70 DAP, both during “plot-by-plot” and “by genotype” comparisons). The MEAN SAVI and SR values were also strongly correlated with yield at 61–72 DAP in most of the pea experiments. The data collected during flowering and early pod development phenological growth stages was found to be useful in yield estimation. The developed methods can be used for early generation evaluation in breeding programs, where yield cannot be estimated due to limited seed availability.

A Structured Framework for Adaptive Management: Bridging Theory and Practice in the Olympic Experimental State Forest

Abstract Adaptive management is a systematic approach to learning from outcomes to improve management. Although its virtues are commonly praised, it has been implemented infrequently in natural resource management because of the challenges of developing a feasible process that can be sustained over time. Our analysis of regional experiences from private, state, and federal lands in the Pacific Northwest (United States and Canada) finds that the questions addressed by private organizations tend to be more specific, associated with a narrower scope of uncertainties, and addressed in a shorter time frame with limited stakeholder involvement. On publicly managed lands, questions tend to be more complex and open-ended, usually driven by their mandate for multiple use and high level of stakeholder engagement. We present a structured adaptive management framework that translates theory into action by describing an implementation process and organizational structure, explicitly linking learning to management planning and implementation, and integrating the technical and social aspects of adaptive management. Forest managers and policymakers can customize our example according to their mandate and management objectives. The framework is particularly relevant to land management for multiple uses, where the uncertainties are abundant and complex, and the decisionmakers increasingly use mathematical modeling to inform their decisions.

Energy technology adoption: Case of solar photovoltaic in the Pacific Northwest USA

Current political, economic, and environmental issues have made energy source selection a delicate decision. These pressures concurrent with the decrease in sustainable energy costs have increased the interest in cleaner alternative energies such as solar and wind in order to mitigate the environmental consequences. Among these energies, solar photovoltaic (PV) energy is one of the most promising sources of power with the potential of providing one fifth of the annual energy in US alone. The purpose of this study is to analyze the associations and correlations of income, education, and solar adoption through surveys and Geographic Information Systems (GIS) respectively. Results from GIS analysis and linear regression show correlations between education, income levels, and the number of solar PV adopters in Oregon census tracts. By identifying adoption hotspots, this study recommends four areas in Oregon State which are ideal for energy companies to promote, educate, and incentivize Solarize programs in order to bolster the adoption and diffusion of solar PVs. The selected areas have high income and education levels but the number of solar adoptions are not significant which makes them good candidates for more analysis and potentially incentives and education programs.

The importance of atmospheric turbulence and stability in machine-learning models of wind farm power production

Machine learning is frequently applied in the wind energy industry to build statistical models of wind farm power production using atmospheric data as input. In the field of wind power forecasting, in particular, there has been substantial research into finding the best-performing learning algorithms that improve model predictions. Overlooked in the literature, however, is the influence of atmospheric turbulence and stability measurements in improving model predictions. It has been well-established through observations and physical models that these effects can have considerable influence on wind farm power production; yet consideration of these effects in statistical models is almost entirely absent from the literature. In this work, we examine the impact of atmospheric turbulence and stability inputs on statistical model predictions of wind farm power output. Hourly observations from a wind farm in the Pacific Northwest United States located in very complex terrain are used. Five common learning algorithms and nine atmospheric variables are considered, five of which represent some measure of turbulence or stability. We find a considerable improvement in hourly power predictions when some measure of turbulence or stability is included in the model. In particular, turbulent kinetic energy was found to be the most important variable apart from wind speed and more important than wind direction, pressure, and temperature. By contrast, the choice of learning algorithm is shown to be relatively less important in improving predictions. Based on this work, we recommend that turbulence and stability variables become standard inputs into statistical models of wind farm power production.

Precipitation chemistry and deposition at a high-elevation site in the Pacific Northwest United States (1989–2015)

Emissions from fuel combustion and agricultural activities contribute significantly to the continuous atmospheric entrainment of pollutants into protected and vulnerable ecosystems where long-term monitoring is often a challenge. Here, results are presented from a 26-year study (1989–2015) of wet precipitation collected at Paradise Station (1654 m above sea level), Mount Rainier National Park, Washington, USA. Weekly samples were analyzed for pH, conductivity and major anions and cations. While precipitation concentrations for sulfate, nitrate, protons and conductivity peaked in the early 2000s, overall trends decreased by 54%, 46%, 41%, and 37%, respectively. Associated pH values increased from 5.2 to 5.6, and were largely controlled by non-sea-salt contributions of sulfate and neutralizing calcium, potassium and magnesium. Between 1999 and 2015, nitrogen (N) deposition rates from ammonium increased by a factor of 3.6, from 0.27 to 0.96 kg N ha−1 yr−1 (p = 0.02), while nitrate deposition did not change statistically (0.91–0.74 kg N ha−1 yr−1, p = 0.30). Combined, these N sources are reaching reported critical loads of 2.0 kg N ha−1 yr−1. Results indicate that emission regulations focused on stationary sources have effectively decreased apparent acid precipitation, however, increased nitrogen deposition from ammonium may lead to further fertilization and acidification of delicate soils and waters. Continued long-term monitoring is thus imperative to track continued anthropogenic inputs to vulnerable ecosystems.

Continuing professional education for green infrastructure: Fostering collaboration through interdisciplinary trainings

The practice of green infrastructure is an evolving field of sustainable planning that often requires collaborative partnerships at the municipal and state levels. Expertise from engineers, land care professionals, planners, and natural resource consultants are often required for successful project implementation. Traditionally, these professionals perform their responsibilities in their disciplinary “silos,” however green infrastructure development is creating a demand for professionals who can think analytically and work across disciplinary boundaries. Interdisciplinary Continuing Professional Education (CPE) trainings provide opportunities for professionals to learn alongside one another, conversing and negotiating new knowledge about emerging practices. This case study applies a qualitative approach to explore the motivations and instructional design processes of interdisciplinary green infrastructure CPE trainings. A variety of green infrastructure CPE providers in the Pacific Northwest United States participated in the study, offering perspectives from agencies, nonprofits, consulting firms and academic institutions. Findings suggest that CPE provider organizations aim to increase worker competency and advance the field of green infrastructure by designing trainings that facilitate communication skills, enhance networking opportunities, and exploit social learning activities.

Using photovoice to foster a student vision for natural spaces on a college campus in the Pacific Northwest United States

ABSTRACTUndergraduate students face a host of stressors and may be particularly susceptible to encountering health-related challenges throughout college life. Seventy-two (N = 72) undergraduate students enrolled at a newly developed university campus located in the pacific northwest United States used the photovoice research method in crafting a vision for how natural spaces on campus might be maintained and minimally developed to promote student health. Five student-created themes emerged: 1) mental and physical health, 2) developing community spaces, 3) sustainable infrastructure design, 4) preserving natural habitat and history of the region, and 5) addressing issues related to homelessness. Initial evidence suggests that many aspects of the student vision may be incorporated into future campus environmental planning efforts. Additional research is needed in determining whether community-based greenspace planning on college campuses can positively impact the extent to which students access natural spaces for the purposes of alleviating stress and promoting health.

Effects of imidacloprid seed treatments on crop yields and economic returns of cereal crops

In the Pacific Northwest United States, cereal crops (barley, oats, wheat) are the foundation of most dryland crop rotations. Nearly 100% of cereal producers use neonicotinoid seed treatments to manage wireworms, regardless of crop and pest density. However, wireworms cause variable damage to different crops, and whether neonicotinoids boost yield and economic returns across crops remains largely unknown. In a field experiment conducted on one commercial farm over two years, we examined effects of imidacloprid seed treatments on wireworm density, yield, and economic returns for barley, oat, and wheat crops. Wheat plots with imidacloprid seed treatments produced greater yields and economic returns over costs than untreated plots, even though wireworm densities were largely unaffected by treatments. However, no differences in yield and economic returns were observed between treatments in barley or oats. Wireworm densities were markedly lower in oats compared to barley and wheat, indicating not all crops provided a permissive environment for wireworms. Our results support the hypothesis that growers may benefit from moving away from applying seed treatments in all cereal crops, but rather targeting management to specific crops, although research at more commercial farm sites remains needed to test the generality of this conclusion. Our results also support the hypothesis that incorporating more tolerant cereal crops (barley and oats) into rotations to replace spring wheat may be a promising option for growers in areas with high wireworm pressure.

Mating Disruption for Managing Prionus californicus (Coleoptera: Cerambycidae) in Hop and Sweet Cherry.

Larvae of Prionus californicus Motschulsky feed on the roots of many woody perennial plants and are economically important pests of hop Humulus lupulus L. (Urticales: Cannabaceae) and sweet cherry Prunus avium (L.) (Magnoliopsida: Rosaceae) in the United States Pacific Northwest and Intermountain West. Adult males are strongly attracted to a volatile sex pheromone, (3R,5S)-3,5-dimethyldodecanoic acid, produced by females. Here, we summarize the results of field experiments evaluating the synthetic pheromone in a blend of all four possible stereoisomers as a means for managing P. californicus in hop yards and sweet cherry orchards by mating disruption (MD). Mean capture of male beetles was lower, in all 3 yr of the study, from plots in commercial hop yards and sweet cherry orchards treated with synthetic P. californicus pheromone than from similar, untreated plots. Although trap catch was lower in sweet cherry, relative differences between trap catches from MD and nonmating disruption plots were similar to that seen in hop yards. The number of P. californicus larvae recovered from plots in hop yards treated for three consecutive growing seasons with synthetic pheromone was lower than in similar plots that were not treated with the pheromone or treated with the soil fumigant ethoprop. Our research demonstrates that deployment of synthetic P. californicus pheromone effectively reduces mate-finding by males, can effectively reduce larvae populations in pheromone-treated hop yards, and thus, has excellent potential for managing P. californicus in hop, sweet cherry, and perhaps in other crops where it or Prionus species are pests.

Catchment characteristics, water quality, and cyanobacterial blooms in Washington and Oregon Lakes

Rose VJ, Forney WM, Norton RA, Harrison JA. 2018. Catchment characteristics, water quality, and cyanobacterial blooms in Washington and Oregon Lakes. Lake Reserve Manage. 35:51–63A cyanobacterial bloom (CB) model specifically developed as a screening tool for at-risk and affected lakes would benefit natural resource managers and scientists seeking cost-effective monitoring and mitigation measures to prevent blooms. We tested whether water quality, land use/land cover (LULC), and lake morphometry data could explain CB occurrence in a dataset containing 60 lakes and reservoirs in the Pacific Northwest United States using univariate and multiple logistic regressions. Of the explanatory variables evaluated by univariate regression, chlorophyll a concentration was most strongly associated with CB occurrence (pseudo-r2 = 0.39). Other factors significantly related to CB occurrence included modeled dissolved inorganic phosphorus (DIP) yield, total phosphorus concentration (TP), “mixed forest,” “developed – open space,” and “developed – low intensity” (positive correlations), and water clarity, “evergreen forest,” and “barren land” (negative correlations). The best multiple regression model evaluated included the following independent variables: TP, “drainage area,” and “developed – open space” (AIC = 47.67, modified R2 = 0.53). We selected the best performing univariate model to test for lakes at risk of developing CBs to highlight how simple models based on water quality and LULC factors may be valuable tools for conducting preliminary screenings as part of a monitoring program. Consistent with other studies, our findings suggest an important role for phosphorus in controlling CBs in the Pacific Northwest. Our study indicates that, in addition to more traditionally used water quality data, LULC variables and modeled DIP yield are strongly associated with CBs and may be valuable in the development of predictive models.

A qualitative exploration of the barriers and bridges to accessing community-based K-12 outdoor environmental education programming

The purpose of this study was to explore factors impeding or enabling 4th grade access to a community-based outdoor environmental education (OEE) organization located in the pacific northwest United States called the Children’s Forest, an initiative of the United States Forest Service. Qualitative findings indicated that teachers and administrators face significant dilemmas when having to make OEE curricular decisions in the context of broader educational mandates. Key findings suggest that OEE program staff can utilize policy-driven mandates to facilitate OEE participation and that savvy individual teachers can potentially help schools overcome policy-related, institutional, and interpersonal barriers to OEE participation. Further research is needed to corroborate and identify additional bridges and barriers that might impact diverse K-12 educator access to community-based OEE. Nonetheless, key learnings emerged from this study echoing past research and providing additional implications for future OEE practice and research.