Browsing by Author "Johnson, Nathan W"

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    Supporting data for "Sulfur geochemistry impacts population oscillations of wild rice (Zizania palustris)"
    (2020-07-10) LaFond-Hudson, Sophia; Johnson, Nathan W; Pastor, John; Dewey, Brad; lafo0062@d.umn.edu; LaFond-Hudson, Sophia
    Wild rice populations decline with exposure to elevated sulfate due to production of sulfide in anoxic sediment. Using self-sustaining wild rice mesocosms, we collected data on the population response to sulfate, as well as iron and litter, which both may modify the production and availability of sulfide to plants. Wild rice also experiences natural population oscillations due to delays in release of nitrogen from decomposing litter. We use this data to investigate how sulfate-induced population declines interact with stable litter-driven population cycles. Population data was collected 2014-2019, and geochemical data (iron, sulfide, pH) was collected in 2019, after 5 years of of a factorial design treatment (sulfate, iron, litter).
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    Wild rice geochemistry and reproductive life stage data from experimental pots amended with sulfate, 2016
    (2019-10-24) LaFond-Hudson, Sophia L; Johnson, Nathan W; Pastor, John; Dewey, Brad; lafo0062@d.umn.edu; LaFond-Hudson, Sophia L
    Wild rice, an annual aquatic plant produces fewer, smaller seeds with less nitrogen when exposed to sulfide, but does not produce decreased vegetative biomass. We compared the timing and duration of reproductive life stages in sulfate-amended plants to unamended plants to see how sulfide affects reproductive phenology. We recorded the life stage of plants starting with initiation of reproduction until senescence and measured seed count, mass and nitrogen content. Additionally, we sampled the geochemistry of porewater, sediment, and root surfaces to understand how plant life stage may control sediment redox conditions relevant to sulfide.