47 research outputs found

    Separating the Influences of Diagenesis, Productivity and Anthropogenic Nitrogen Deposition on Sedimentary δ15N Variations

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    The stable isotopic composition of nitrogen (δ15N) in organic lake sediments is frequently used to infer changes in the source or cycling of N prior to sedimentation. However, diagenetic processes that occur after sedimentation can systematically alter the primary isotopic signal recorded in sedimentary organic matter and must be accounted for in order to detect changes in the δ15N of nitrogen inputs to the sediment surface. Here we present a null model that estimates the diagenetic effect on sedimentary lake δ15N records. The model was tested using lake sediment cores from relatively pristine alpine lakes in the Wind River and Teton Ranges of Wyoming, USA. Model-inferred increases in productivity were tested against independent productivity proxies (diatom accumulation rates and the planktonic to benthic ratio), and inferred changes in anthropogenic nitrogen contribution were validated with records of atmospheric nitrogen deposition from the nearby Fremont Glacier, Wyoming. Diagenetic overprinting significantly altered sediment δ15N profiles, and the degree of alteration was not constant through time. Of the cores analyzed, ∼30–70% of the variability can be explained by diagenesis alone, with the remainder explained by either a change in productivity or a change in the isotopic composition of the source material. Our null model of isotopic fractionation proved to be successful at separating the diagenetic overprinting from other causes of isotopic shifts, thereby providing environmental scientists with an analytical tool to partition the effects of diagenesis and environmental change on sedimentary δ15N values

    Holocene Earthquakes and Right-lateral Slip on the Left-lateral Darrington-Devils Mountain Fault Zone, Northern Puget Sound, Washington

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    Sources of seismic hazard in the Puget Sound region of northwestern Washington include deep earthquakes associated with the Cascadia subduction zone, and shallow earthquakes associated with some of the numerous crustal (upper-plate) faults that crisscross the region. Our paleoseismic investigations on one of the more prominent crustal faults, the Darrington–Devils Mountain fault zone, included trenching of fault scarps developed on latest Pleistocene glacial sediments and analysis of cores from an adjacent wetland near Lake Creek, 14 km southeast of Mount Vernon, Washington. Trench excavations revealed evidence of a single earthquake, radiocarbon dated to ca. 2 ka, but extensive burrowing and root mixing of sediments within 50–100 cm of the ground surface may have destroyed evidence of other earthquakes. Cores in a small wetland adjacent to our trench site provided stratigraphic evidence (formation of a laterally extensive, prograding wedge of hillslope colluvium) of an earthquake ca. 2 ka, which we interpret to be the same earthquake documented in the trenches. A similar colluvial wedge lower in the wetland section provides possible evidence for a second earthquake dated to ca. 8 ka. Three-dimensional trenching techniques revealed evidence for 2.2 ± 1.1 m of right-lateral offset of a glacial outwash channel margin, and 45–70 cm of north-side-up vertical separation across the fault zone. These offsets indicate a net slip vector of 2.3 ± 1.1 m, plunging 14° west on a 286°-striking, 90°-dipping fault plane. The dominant right-lateral sense of slip is supported by the presence of numerous Riedel R shears preserved in two of our trenches, and probable right-lateral offset of a distinctive bedrock fault zone in a third trench. Holocene north-side-up, right-lateral oblique slip is opposite the south-side-up, left-lateral oblique sense of slip inferred from geologic mapping of Eocene and older rocks along the fault zone. The cause of this slip reversal is unknown but may be related to clockwise rotation of the Darrington–Devils Mountain fault zone into a position more favorable to right-lateral slip in the modern N-S compressional stress field

    An Adaptive Framework for Selecting Environmental Monitoring Protocols to Support Ocean Renewable Energy Development

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    Offshore renewable energy developments (OREDs) are projected to become common in the United States over the next two decades. There are both a need and an opportunity to guide efforts to identify and track impacts to the marine ecosystem resulting from these installations. A monitoring framework and standardized protocols that can be applied to multiple types of ORED would streamline scientific study, management, and permitting at these sites. We propose an adaptive and reactive framework based on indicators of the likely changes to the marine ecosystem due to ORED. We developed decision trees to identify suites of impacts at two scales (demonstration and commercial) depending on energy (wind, tidal, and wave), structure (e.g., turbine), and foundation type (e.g., monopile). Impacts were categorized by ecosystem component (benthic habitat and resources, fish and fisheries, avian species, marine mammals, and sea turtles) and monitoring objectives were developed for each. We present a case study at a commercial-scale wind farm and develop a monitoring plan for this development that addresses both local and national environmental concerns. In addition, framework has provided a starting point for identifying global research needs and objectives for understanding of the potential effects of ORED on the marine environment

    Standardized NEON organismal data for biodiversity research

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    Understanding patterns and drivers of species distribution and abundance, and thus biodiversity, is a core goal of ecology. Despite advances in recent decades, research into these patterns and processes is currently limited by a lack of standardized, high-quality, empirical data that span large spatial scales and long time periods. The NEON fills this gap by providing freely available observational data that are generated during robust and consistent organismal sampling of several sentinel taxonomic groups within 81 sites distributed across the United States and will be collected for at least 30 years. The breadth and scope of these data provide a unique resource for advancing biodiversity research. To maximize the potential of this opportunity, however, it is critical that NEON data be maximally accessible and easily integrated into investigators\u27 workflows and analyses. To facilitate its use for biodiversity research and synthesis, we created a workflow to process and format NEON organismal data into the ecocomDP (ecological community data design pattern) format that were available through the ecocomDP R package; we then provided the standardized data as an R data package (neonDivData). We briefly summarize sampling designs and data wrangling decisions for the major taxonomic groups included in this effort. Our workflows are open-source so the biodiversity community may: add additional taxonomic groups; modify the workflow to produce datasets appropriate for their own analytical needs; and regularly update the data packages as more observations become available. Finally, we provide two simple examples of how the standardized data may be used for biodiversity research. By providing a standardized data package, we hope to enhance the utility of NEON organismal data in advancing biodiversity research and encourage the use of the harmonized ecocomDP data design pattern for community ecology data from other ecological observatory networks

    Characterizing benthic macroinvertebrate and algal biological condition gradient models for California wadeable Streams, USA

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    The Biological Condition Gradient (BCG) is a conceptual model that describes changes in aquatic communities under increasing levels of anthropogenic stress. The BCG helps decision-makers connect narrative water quality goals (e.g., maintenance of natural structure and function) to quantitative measures of ecological condition by linking index thresholds based on statistical distributions (e.g., percentiles of reference distributions) to expert descriptions of changes in biological condition along disturbance gradients. As a result, the BCG may be more meaningful to managers and the public than indices alone. To develop a BCG model, biological response to stress is divided into 6 levels of condition, represented as changes in biological structure (abundance and diversity of pollution sensitive versus tolerant taxa) and function. We developed benthic macroinvertebrate (BMI) and algal BCG models for California perennial wadeable streams to support interpretation of percentiles of reference-based thresholds for bioassessment indices (i.e., the California Stream Condition Index [CSCI] for BMI and the Algal Stream Condition Index [ASCI] for diatoms and soft-bodied algae). Two panels (one of BMI ecologists and the other of algal ecologists) each calibrated a general BCG model to California wadeable streams by first assigning taxa to specific tolerance and sensitivity attributes, and then independently assigning test samples (264 BMI and 248 algae samples) to BCG Levels 1–6. Consensus on the assignments was developed within each assemblage panel using a modified Delphi method. Panels then developed detailed narratives of changes in BMI and algal taxa that correspond to the 6 BCG levels. Consensus among experts was high, with 81% and 82% expert agreement within 0.5 units of assigned BCG level for BMIs and algae, respectively. According to both BCG models, the 10th percentiles index scores at reference sites corresponded to a BCG Level 3, suggesting that this type of threshold would protect against moderate changes in structure and function while allowing loss of some sensitive taxa. The BCG provides a framework to interpret changes in aquatic biological condition along a gradient of stress. The resulting relationship between index scores and BCG levels and narratives can help decision-makers select thresholds and communicate how these values protect aquatic life use goals

    Selected abstracts from the Breastfeeding and Feminism International Conference 2016

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    Table of contents A1. Infant feeding and poverty: a public health perspective in a global context Lisa H. Amir A2. Mothers’ experiences with galactagogues for lactation: an exploratory cross sectional study Alessandra Bazzano, Shelley Thibeau, Katherine P. Theall A3. The motherhood journey and breastfeeding: from self-efficacy to resilience and social stigma Anna Blair, Karin Cadwell A4. Breastfeeding as an evolutionary adaptive behavior Emily A. Bronson A5. Conflict-of-interest in public health policy: as real as that logo on your website Elizabeth C. Brooks A6. Co-opting sisterhood and motherhood: behind the scenes of Similac’s aggressive social media campaigns Jodine Chase A7. The exclusion of women from the definition of exclusive breastfeeding Ellen Chetwynd, Rebecca Costello, Kathryn Wouk A8. Healthy maternity policies in the workplace: a state health department’s experience with the “Bring Your Infant to Work” program Lindsey Dermid-Gray A9. Implications for a paradigm shift: factors related to breastfeeding among African American women Stephanie Devane-Johnson, Cheryl Woods Giscombe, Miriam Labbok A10. Social experiences of breastfeeding: building bridges between research and policy: an ESRC-funded seminar series in the UK Sally Dowling A11. Manager’s perspectives of lactation breaks Melanie Fraser A12. The challenging second night: a dialogue from two perspectives Jane Grassley, Deborah McCarter-Spaulding, Becky Spencer A13. The role of lactation consultants in two council breastfeeding services in Melbourne, Australia – some preliminary impressions Jennifer Hocking, Pranee Liamputtong A14. Integrating social marketing and community engagement concepts in community breastfeeding programs Sheree H. Keitt, Harumi Reis-Reilly A15. What happens before and after the maternity stay? Creating a community-wide Ten Steps approach Miriam Labbok A16. #RVABREASTFEEDS: cultivating a breastfeeding-friendly community Leslie Lytle A17. Public health vs. free trade: a longitudinal analysis of a global policy to protect breastfeeding Mary Ann Merz A18. Legislative advocacy and grassroots organizing for improved breastfeeding laws in Virginia Kate Noon A19. Breastfeeding and the rights of incarcerated women Krista M Olson A20. Barriers and support for Puerto Rican breastfeeding working mothers Ana M. Parrilla-Rodríguez, José J. Gorrín-Peralta Melissa Pellicier, Zeleida M. Vázquez-Rivera A21. Pumping at work: a daily struggle for Puerto Rican breastfeeding mothers in spite of the law Melissa Pellicier A22. “I saw a wrong and I wanted to stand up for what I thought was right:” a narrative study on becoming a breastfeeding activist Jennifer L. Pemberton A23. Peer breastfeeding support: advocacy and action Catherine McEvilly Pestl A24. Good intentions: a study of breastfeeding intention and postpartum realities among first-time Central Brooklyn mothers Jennifer Pierre, Philip Noyes, Khushbu Srivastava, Sharon Marshall-Taylor A25. Women describing the infant feeding choice: the impact of the WIC breastfeeding classes on infant feeding practices in Ionia, Michigan Jennifer Proto, Sarah Hyland Laurie Brinks A26. Local and state programs and national partnership to reduce disparities through community breastfeeding support Harumi Reis-Reilly, Martelle Esposito, Megan Phillippi A27. Beyond black breastfeeding week: instagram image content analysis for #blackwomendobreastfeed/#bwdbf Cynthia L. Sears, Delores James, Cedric Harville, Kristina Carswell A28. Stakeholder views of breastfeeding education in the K-12 environment: a review of the literature Nicola Singletary, L. Suzanne Goodell, April Fogleman A29. “The Breastfeeding Transition”: a framework for explaining changes in global breastfeeding rates as related to large-scale forces shaping the status of women Paige Hall Smith A30. Breastfeeding, contraception, and ethics, oh my! Advocacy and informed decision-making in the post-partum period Alison M. Stuebe, Amy G. Bryant, Anne Drapkin Lyerly A31. A hard day’s night: juggling nighttime breastfeeding, sleep, and work Cecilia Tomori A32. Empowering change in Indian country through breastfeeding education Amanda L. Watkins, Joan E. Dodgson A33. Servants and “Little Mothers” take charge: work, class, and breastfeeding rates in the early 20th-century U.S. Jacqueline H. Wol

    Harnessing the NEON data revolution to advance open environmental science with a diverse and data-capable community

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    It is a critical time to reflect on the National Ecological Observatory Network (NEON) science to date as well as envision what research can be done right now with NEON (and other) data and what training is needed to enable a diverse user community. NEON became fully operational in May 2019 and has pivoted from planning and construction to operation and maintenance. In this overview, the history of and foundational thinking around NEON are discussed. A framework of open science is described with a discussion of how NEON can be situated as part of a larger data constellation—across existing networks and different suites of ecological measurements and sensors. Next, a synthesis of early NEON science, based on >100 existing publications, funded proposal efforts, and emergent science at the very first NEON Science Summit (hosted by Earth Lab at the University of Colorado Boulder in October 2019) is provided. Key questions that the ecology community will address with NEON data in the next 10 yr are outlined, from understanding drivers of biodiversity across spatial and temporal scales to defining complex feedback mechanisms in human–environmental systems. Last, the essential elements needed to engage and support a diverse and inclusive NEON user community are highlighted: training resources and tools that are openly available, funding for broad community engagement initiatives, and a mechanism to share and advertise those opportunities. NEON users require both the skills to work with NEON data and the ecological or environmental science domain knowledge to understand and interpret them. This paper synthesizes early directions in the community’s use of NEON data, and opportunities for the next 10 yr of NEON operations in emergent science themes, open science best practices, education and training, and community building

    Phytoplankton Dynamics in Three Rocky Mountain Lakes, Colorado, U.S.A.

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    In 1984 and 1985 seasonal changes in phytoplankton were studied in a system of three lakes in Loch Vale, Rocky Mountain National Park, Colorado. Three periods were evident: (1) A spring bloom, during snowmelt, of the planktonic diatom Asterionella Formosa, (2) a mid- summer period of minimal algal abundance, and (3) a fall bloom of the blue-green alga Oscillatoria limnetica. Seasonal phytoplankton dynamics in these lakes are controlled partially by the rapid flushing rate during snowmelt and the transport of phytoplankton from the highest lake to the lower lakes by the stream, Icy Brook. During snowmelt, the A. formosa population in the most downstream lake has a net rate of increase of 0.34 d-1, which is calculated from the flushing rate and from the A. formosa abundance in the inflow from the upstream lake and in the downstream lake. Measurement of photosynthetic rates at different depths during the three periods confirmed the rapid growth of A. formosa during the spring. The decline in A. formosa after snowmelt may be related to grazing by developing zooplankton populations. The possible importance of the seasonal variations in nitrate concentrations were evaluated in situ enrichment experiments. For A. formosa and O. limnetica populations, growth stimulation resulted from 8- or 16-micromolar amendments of calcium nitrate and sulfuric acid, but the reason for this stimulation could not be determined from these experiments
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