Browsing by Subject "Coastal wetlands"
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Item Habitat and landscape characteristics that influence Sedge Wren (Cistothorus platensis) and Marsh Wren (C. palustris) distribution and abundance in Great Lakes coastal wetlands(2013-08) Panci, HannahI analyzed habitat and landscape characteristics important to the Sedge Wren (Cistothorus platensis) and Marsh Wren (C. palustris) in Great Lakes coastal wetlands using breeding bird census data from two large projects in 2002-2003 and 2011-2012. Little is known about the population or distribution of these species in the Great Lakes region. For each of 840 survey points in coastal wetlands along the U.S. and Canadian shorelines, I used National Land Cover Data and Ontario Land Cover Data to calculate the percent cover of seven different land use classes within 500, 1000, and 2000 m buffers of each point. I combined these with climatic and landscape configuration variables as well as field-collected vegetation data to develop classification trees that predicted both Sedge and Marsh Wren presence and relative high abundance (≥3 wrens/site). After eliminating geographic variables, the best classification trees predicted Sedge Wrens to be present in wetlands with greater than 9% woody wetlands at the 2000 m buffer, and in high abundance in sites with less than 3% cattails and greater than 4% meadow vegetation. Marsh Wren presence was positively associated with emergent vegetation and cropland, and negatively associated with woody wetland at the 500 m buffer. Marsh Wrens were predicted to be in high abundance at sites with greater than 14% cattails. This classification tree analysis is a powerful predictive tool which significantly increases our ability to correctly predict the presence of these secretive wetland species. These results provide a basic understanding of characteristics of Great Lakes coastal wetlands important to two wetland-obligate bird species and can be useful in conservation decisions and management plans.Item Human Influences on Water Quality in Great Lakes Coastal Wetlands(2008) Morrice, John A; Danz, Nick; Regal, Ronald R; Kelly, John R; Niemi, Gerald J; Reavie, Euan; Hollenhorst, Thomas; Axler, Richard P; Trebitz, Annet; Cotter, Anne C; Peterson, Gregory SThis peer-reviewed article discusses water quality and chemistry issues with anthropogenic causes. Geographically, it covers the US coastal region of the Great Lakes. A map in the article suggests that only one sampling point was within Minnesota’s coastal region. The article focuses on water chemistry in coastal wetlands across the Great Lakes, but not specifically for Minnesota. Key points in the abstract are extracted and reproduced below. A better understanding of relationships between human activities and water chemistry is needed to identify and manage sources of anthropogenic stress in Great Lakes coastal wetlands. The objective of the study described in this article was to characterize relationships between water chemistry and multiple classes of human activity (agriculture, population and development, point source pollution, and atmospheric deposition). We also evaluated the influence of geomorphology and biogeographic factors on stressor-water quality relationships. We collected water chemistry data from 98 coastal wetlands distributed along the United States shoreline of the Laurentian Great Lakes and GIS-based stressor data from the associated drainage basin to examine stressor-water quality relationships. The sampling captured broad ranges (1.5–2 orders of magnitude) in total phosphorus (TP), total nitrogen (TN), dissolved inorganic nitrogen (DIN), total suspended solids (TSS), chlorophyll a (Chl a), and chloride; concentrations were strongly correlated with stressor metrics. Hierarchical partitioning and all-subsets regression analyses were used to evaluate the independent influence of different stressor classes on water quality and to identify best predictive models. Results showed that all categories of stress influenced water quality and that the relative influence of different classes of disturbance varied among water quality parameters. Chloride exhibited the strongest relationships with stressors followed in order by TN, Chl a, TP, TSS, and DIN. In general, coarse scale classification of wetlands by morphology (three wetland classes: riverine, protected, open coastal) and biogeography (two eco-provinces: Eastern Broadleaf Forest [EBF] and Laurentian Mixed Forest [LMF]) did not improve predictive models. This study provides strong evidence of the link between water chemistry and human stress in Great Lakes coastal wetlands and can be used to inform management efforts to improve water quality in Great Lakes coastal ecosystems.Item An organic geochemical record of inland migration in a coastal marsh, Chesapeake Bay, Maryland, USA(2017-05) Van Allen, RachelOrganic matter accumulation in marsh soils affects marsh survival under rapid sea level rise (SLR). This work describes the changing organic geochemistry of a salt marsh located in Blackwater National Wildlife Refuge on the eastern shore of Chesapeake Bay that is transgressing inland with SLR. Marsh soils and vegetation were sampled along an elevation gradient from the intertidal zone to the adjacent forest. Stable carbon isotope analysis of bulk organic matter suggests a broad transition towards C4-dominated marsh vegetation over time. Vegetative source of the organic matter shifts along a marsh-upland mixing line from herbaceous angiosperm-sourced lignin in the low marsh to a woody gymnosperm signature at the upper border of the marsh. Stable isotope and lignin chemistry results illustrate that landward encroachment of marsh grasses results in deposition of herbaceous tissues that exhibit relatively little decay. This presents a possible mechanism for organic matter stabilization as marshes migrate inland.