Comparing Soil Datasets with the APEX Model: Calibration and Validation for Hydrology and Crop Yield in Whatcom County, Washington

Controlling pollution from agricultural lands is a priority for improving watershed health. Best management practices (BMPs) recommend strategies such as riparian buffers and altered fertilizer application timing and rates for reduction of nutrient and sediment export from agricultural watersheds, but BMP effectiveness in nutrient retention can vary greatly depending on differences in crops, soils, and topography. Conducting nitrogen (N) and phosphorus (P) measurements in all BMP projects is generally not feasible, so well-validated models can help estimate benefits on the watershed scale. This project uses the Agricultural Policy/ Environmental Extender (APEX) model to simulate crop yield, streamflow, and surface runoff in a small watershed in Whatcom County, Washington, to prepare the model for future use in estimating nutrient and sediment retention benefits by BMPs. The APEX model requires detailed inputs for soils, climate, cropping system, and agricultural management; outputs must be calibrated and validated against existing environmental data. No current consensus exists as to the ideal set of soil data for the APEX model. I tested the APEX model for three different soils datasets: the Soil Survey Geographic Database (SSURGO), the National Cooperative Soil Survey (NCSS), and the Nutrient Tracking Tool (NTT), to determine the best dataset to use in terms of ease of use and model fit. I modeled the northern Kamm Creek watershed, a 227 hectare watershed that contains a diverse representation of Whatcom County cropping systems. As the first APEX modelling effort in western Washington, this study investigated parameters for blueberry and raspberry, two crops new to the APEX model, while testing model performance with three different sets of soils data. I manipulated key parameters in two of the datasets to evaluate their effects on hydrology and yield. The model performed well for streamflow and surface runoff across all soils during calibration, with satisfactory validation for surface runoff, but not streamflow. Performance for crop yields, however, varied across both crop type and soil data sets. Simulated crop yields fell within 10% of county-reported average yields for four of the five soils for blueberry, raspberry, and corn silage crops, whereas NTT soils drastically underestimated yields of both berry crops. I recommend applying the SSURGO soils dataset to future APEX modelling in Whatcom County, as it had the best model fit for hydrology and crop yields. Further recommendations are made for obtaining data to parameterize, calibrate, and validate the model to assure accuracy for future APEX modelling efforts

Examining the Effect of Biochar on Invasive Typha x glauca in a Greenhouse Experiment

Invasive species in the Great Lakes pose ecological, economic, and social dilemmas as they alter and diminish the quality of ecosystems. By dominating native plant communities through efficient uptake of excess nutrients, the hybrid cattail, Typha × glauca, reduces the plant diversity of Great Lakes coastal wetlands, homogenizing habitat for many species of fish, animals, and insects. This study investigated how biochar, a charcoal-like substance, affected biomass accumulation in hybrid cattails and native wetland plants. I conducted a greenhouse experiment by growing assemblages of native wetland plants, Typha × glauca, and a combination of both native species and hybrid cattails in separate buckets with a homogenized, sand-compost mixture containing 0%, 2.5%, and 5% biochar by weight for approximately fifty days. I found that biochar reduced the overall biomass of Typha × glauca when comparing the 2.5% and 5% biochar applications to the 0% application. Biochar was also found to change the phosphorus content in Typha × glauca, a nutrient which is often found in excess in wetlands due to agricultural pollution. This preliminary study provides evidence that biochar has the potential to reduce the biomass of Typha × glauca, therefore impeding its dominance in Great Lakes coastal wetlands

Harvesting Invasive Plants to Reduce Nutrient Loads and Produce Bioenergy: An Assessment of Great Lakes Coastal Wetlands

In Laurentian Great Lakes coastal wetlands (GLCWs), dominant emergent invasive plants are expanding their ranges and compromising the unique habitat and ecosystem service values that these ecosystems provide. Herbiciding and burning to control invasive plants have not been effective in part because neither strategy addresses the most common root cause of invasion, nutrient enrichment. Mechanical harvesting is an alternative approach that removes tissue‐bound phosphorus and nitrogen and can increase wetland plant diversity and aquatic connectivity between wetland and lacustrine systems. In this study, we used data from three years of Great Lakes‐wide wetland plant surveys, published literature, and bioenergy analyses to quantify the overall areal extent of GLCWs, the extent and biomass of the three most dominant invasive plants, the pools of nitrogen and phosphorus contained within their biomass, and the potential for harvesting this biomass to remediate nutrient runoff and produce renewable energy. Of the approximately 212,000 ha of GLCWs, three invasive plants (invasive cattail, common reed, and reed canary grass) dominated 76,825 ha (36%). The coastal wetlands of Lake Ontario exhibited the highest proportion of invasive dominance (57%) of any of the Great Lakes, primarily from cattail. A single growing season\u27s biomass of these invasive plants across all GLCWs was estimated at 659,545 metric tons: 163,228 metric tons of reed canary grass, 270,474 metric tons of common reed, and 225,843 metric tons of invasive cattail, and estimated to contain 10,805 and 1144 metric tons of nitrogen and phosphorus, respectively. A one‐time harvest and utilization for energy of this biomass would provide the gross equivalent of 1.8 million barrels of oil if combusted, or 0.9 million barrels of oil if converted to biogas in an anaerobic digester. We discuss the potential for mitigating non‐point source nutrient pollution with invasive wetland plant removal, and other potential uses for the harvested biomass, including compost and direct application to agricultural soils. Finally, we describe the research and adaptive management program we have built around this concept, and point to current limitations to the implementation of large‐scale invasive plant harvesting

Mechanical Harvesting Effectively Controls Young Typha spp. Invasion and Unmanned Aerial Vehicle Data Enhances Post-treatment Monitoring

The ecological impacts of invasive plants increase dramatically with time since invasion. Targeting young populations for treatment is therefore an economically and ecologically effective management approach, especially when linked to post-treatment monitoring to evaluate the efficacy of management. However, collecting detailed field-based post-treatment data is prohibitively expensive, typically resulting in inadequate documentation of the ecological effects of invasive plant management. Alternative approaches, such as remote detection with unmanned aerial vehicles (UAV), provide an opportunity to advance the science and practice of restoration ecology. In this study, we sought to determine the plant community response to different mechanical removal treatments to a dominant invasive wetland macrophyte (Typha spp.) along an age-gradient within a Great Lakes coastal wetland. We assessed the post-treatment responses with both intensive field vegetation and UAV data. Prior to treatment, the oldest Typha stands had the lowest plant diversity, lowest native sedge (Carex spp.) cover, and the greatest Typha cover. Following treatment, plots that were mechanically harvested below the surface of the water differed from unharvested control and above-water harvested plots for several plant community measures, including lower Typha dominance, lower native plant cover, and greater floating and submerged aquatic species cover. Repeated-measures analysis revealed that above-water cutting increased plant diversity and aquatic species cover across all ages, and maintained native Carex spp. cover in the youngest portions of Typha stands. UAV data revealed significant post-treatment differences in normalized difference vegetation index (NDVI) scores, blue band reflectance, and vegetation height, and these remotely collected measures corresponded to field observations. Our findings suggest that both mechanically harvesting the above-water biomass of young Typha stands and harvesting older stands below-water will promote overall native community resilience, and increase the abundance of the floating and submerged aquatic plant guilds , which are the most vulnerable to invasions by large macrophytes. UAV’s provided fast and spatially expansive data compared to field monitoring, and effectively measured plant community structural responses to different treatments. Study results suggest pairing UAV flights with targeted field data collection to maximize the quality of post-restoration vegetation monitoring

Genetical genomics: spotlight on QTL hotspots

No abstract available

Attitudes Toward the Ethics of Research Using Social Media: A Systematic Review.

BACKGROUND: Although primarily used for social networking and often used for social support and dissemination, data on social media platforms are increasingly being used to facilitate research. However, the ethical challenges in conducting social media research remain of great concern. Although much debated in the literature, it is the views of the public that are most pertinent to inform future practice. OBJECTIVE: The aim of our study was to ascertain attitudes on the ethical considerations of using social media as a data source for research as expressed by social media users and researchers. METHODS: A systematic review was conducted, wherein 16 databases and 2 Internet search engines were searched in addition to handsearching, reference checking, citation searching, and contacting authors and experts. Studies that conducted any qualitative methods to collect data on attitudes on the ethical implications of research using social media were included. Quality assessment was conducted using the quality of reporting tool (QuaRT) and findings analyzed using inductive thematic synthesis. RESULTS: In total, 17 studies met the inclusion criteria. Attitudes varied from overly positive with people expressing the views about the essential nature of such research for the public good, to very concerned with views that social media research should not happen. Underlying reasons for this variation related to issues such as the purpose and quality of the research, the researcher affiliation, and the potential harms. The methods used to conduct the research were also important. Many respondents were positive about social media research while adding caveats such as the need for informed consent or use restricted to public platforms only. CONCLUSIONS: Many conflicting issues contribute to the complexity of good ethical practice in social media research. However, this should not deter researchers from conducting social media research. Each Internet research project requires an individual assessment of its own ethical issues. Guidelines on ethical conduct should be based on current evidence and standardized to avoid discrepancies between, and duplication across, different institutions, taking into consideration different jurisdictions

An Observationally Constrained Evaluation of the Oxidative Capacity in the Tropical Western Pacific Troposphere

Hydroxyl radical (OH) is the main daytime oxidant in the troposphere and determines the atmospheric lifetimes of many compounds. We use aircraft measurements of O3, H2O, NO, and other species from the Convective Transport of Active Species in the Tropics (CONTRAST) field campaign, which occurred in the tropical western Pacific (TWP) during January–February 2014, to constrain a photochemical box model and estimate concentrations of OH throughout the troposphere. We find that tropospheric column OH (OHCOL) inferred from CONTRAST observations is 12 to 40% higher than found in chemical transport models (CTMs), including CAM-chem-SD run with 2014 meteorology as well as eight models that participated in POLMIP (2008 meteorology). Part of this discrepancy is due to a clear-sky sampling bias that affects CONTRAST observations; accounting for this bias and also for a small difference in chemical mechanism results in our empirically based value of OHCOL being 0 to 20% larger than found within global models. While these global models simulate observed O3 reasonably well, they underestimate NOx (NO + NO2) by a factor of two, resulting in OHCOL ~30% lower than box model simulations constrained by observed NO. Underestimations by CTMs of observed CH3CHO throughout the troposphere and of HCHO in the upper troposphere further contribute to differences between our constrained estimates of OH and those calculated by CTMs. Finally, our calculations do not support the prior suggestion of the existence of a tropospheric OH minimum in the TWP, because during January–February 2014 observed levels of O3 and NO were considerably larger than previously reported values in the TWP