Environmental Geoscience

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https://hdl.handle.net/1912/1589

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Browsing Environmental Geoscience by Subject "Accretion"
  • Article
    Peat decomposition and erosion contribute to pond deepening in a temperate salt marsh
    (American Geophysical Union, 2023-01-30) Luk, Sheron ; Eagle, Meagan J. ; Mariotti, Giulio ; Gosselin, Kelsey ; Sanderman, Jonathan ; Spivak, Amanda C.
    Salt marsh ponds expand and deepen over time, potentially reducing ecosystem carbon storage and resilience. The water filled volumes of ponds represent missing carbon due to prevented soil accumulation and removal by erosion and decomposition. Removal mechanisms have different implications as eroded carbon can be redistributed while decomposition results in loss. We constrained ponding effects on carbon dynamics in a New England marsh and determined whether expansion and deepening impact nearby soils by conducting geochemical characterizations of cores from three ponds and surrounding high marshes and models of wind‐driven erosion. Radioisotope profiles demonstrate that ponds are not depositional environments and that contemporaneous marsh accretion represents prevented accumulation accounting for 32%–42% of the missing carbon. Erosion accounted for 0%–38% and was bracketed using radioisotope inventories and wind‐driven resuspension models. Decomposition, calculated by difference, removes 22%–68%, and when normalized over pond lifespans, produces rates that agree with previous metabolism measurements. Pond surface soils contain new contributions from submerged primary producers and evidence of microbial alteration of underlying peat, as higher levels of detrital biomarkers and thermal stability indices, compared to the marsh. Below pond surface horizons, soil properties and organic matter composition were similar to the marsh, indicating that ponding effects are shallow. Soil bulk density, elemental content, and accretion rates were similar between marsh sites but different from ponds, suggesting that lateral effects are spatially confined. Consequently, ponds negatively impact ecosystem carbon storage but at current densities are not causing pervasive degradation of marshes in this system.
  • Article
    Practical guide to measuring wetland carbon pools and fluxes
    (Springer, 2023-11-28) Bansal, Sheel ; Creed, Irena F. ; Tangen, Brian A. ; Bridgham, Scott D. ; Desai, Ankur R. ; Krauss, Ken W. ; Neubauer, Scott C. ; Noe, Gregory B. ; Rosenberry, Donald O. ; Trettin, Carl ; Wickland, Kimberly P. ; Allen, Scott T. ; Arias-Ortiz, Ariane ; Armitage, Anna R. ; Baldocchi, Dennis D. ; Banerjee, Kakoli ; Bastviken, David ; Berg, Peter ; Bogard, Matthew J. ; Chow, Alex T. ; Conner, William H. ; Craft, Christopher ; Creamer, Courtney ; DelSontro, Tonya ; Duberstein, Jamie A. ; Eagle, Meagan ; Fennessy, M. Siobhan ; Finkelstein, Sarah A. ; Gockede, Mathias ; Grunwald, Sabine ; Halabisky, Meghan ; Herbert, Ellen ; Jahangir, Mohammad M. R. ; Johnson, Olivia F. ; Jones, Miriam C. ; Kelleway, Jeffrey J. ; Knox, Sara H. ; Kroeger, Kevin D. ; Kuehn, Kevin A. ; Lobb, David ; Loder, Amanda L. ; Ma, Shizhou ; Maher, Damien T. ; McNicol, Gavin ; Meier, Jacob ; Middleton, Beth A. ; Mills, Christopher ; Mistry, Purbasha ; Mitra, Abhijit ; Mobilian, Courtney ; Nahlik, Amanda M. ; Newman, Sue ; Mills, Christopher ; Mistry, Purbasha ; Mitra, Abhijit ; Mobilian, Courtney ; Nahlik, Amanda M. ; Newman, Sue ; O’Connell, Jessica L. ; Oikawa, Patty ; van der Burg, Max Post ; Schutte, Charles A. ; Song, Changchun ; Stagg, Camille L. ; Turner, Jessica ; Vargas, Rodrigo ; Waldrop, Mark P. ; Wallin, Marcus B. ; Wang, Zhaohui Aleck ; Ward, Eric J. ; Willard, Debra A. ; Yarwood, Stephanie ; Zhu, Xiaoyan
    Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C. Sampling approaches range in their representation of wetland C from short to long timeframes and local to landscape spatial scales. This review summarizes common and cutting-edge methodological approaches for quantifying wetland C pools and fluxes. We first define each of the major C pools and fluxes and provide rationale for their importance to wetland C dynamics. For each approach, we clarify what component of wetland C is measured and its spatial and temporal representativeness and constraints. We describe practical considerations for each approach, such as where and when an approach is typically used, who can conduct the measurements (expertise, training requirements), and how approaches are conducted, including considerations on equipment complexity and costs. Finally, we review key covariates and ancillary measurements that enhance the interpretation of findings and facilitate model development. The protocols that we describe to measure soil, water, vegetation, and gases are also relevant for related disciplines such as ecology. Improved quality and consistency of data collection and reporting across studies will help reduce global uncertainties and develop management strategies to use wetlands as nature-based climate solutions.