Nutrient Budgets Calculated in Floodwaters Using a Whole‐Ecosystem Reservoir Creation and Flooding Experiment

Abstract

When terrestrial areas are inundated stored organic matter in soils and vegetation may be exported laterally to aquatic ecosystems during event-based floods and/or decompose and become a source of nutrients (

Role of Lakes, Flood, and Low Flow Events in Modifying Catchment‐Scale DOC:TN:TP Stoichiometry and Export

“…Furthermore, both direct and indirect flow paths may shift during storms, connecting less depleted or more distant soils, contributing C, N, and P to aquatic ecosystems during flow events and ultimately altering C:N:P ratios (Fasching et al., 2018; Inamdar et al., 2011). For example, flooding of forested areas can increase N and P release, while decreasing TN:TP ratios in reservoirs (Talbot et al., 2021). In forested landscapes, nutrient and DOC concentrations may decrease with stream discharge, due to a limited pool of readily mobilizable solutes (Basu et al., 2010; D’Amario et al., 2021; Fasching et al., 2018; Moatar et al., 2017), especially during snowmelt in northern landscapes influencing N export to streams (Sebestyen et al., 2009).…”

“…The amount and ratios of C, N and P exported from terrestrial to aquatic environments are largely influenced by land use, catchment geology and climate (e.g., Frost et al, 2009;Prater et al, 2017). Intense rainfall and floods contribute significantly to the transport of terrestrial dissolved organic carbon (DOC) to aquatic systems (Fasching et al, 2016;Raymond & Saiers, 2010;Strohmeier et al, 2013;Xenopoulos et al, 2021), while simultaneously increasing nutrients (Sebestyen et al, 2008(Sebestyen et al, , 2014, although not necessarily at the same rate (e.g., Sebestyen et al, 2008;Strohmenger et al, 2020;Talbot et al, 2021). Due to varying affinities in the soil matrix, nitrogen and phosphorus accumulate and transport differently through catchments.…”

Impacts of harvesting practices on nutrient balances of forests under high nitrogen deposition

“…Sustainable biomass harvest implies that the nutrient output via harvest and leaching should not exceed the nutrient input via deposition and weathering to avoid that nutrient stocks of the forest decline over subsequent rotations. Other nutrient inputs and outputs that can play a role in the nutrient balance are the supply of nutrients through groundwater (Hayes et al, 2019) and biological fixation and denitrification of nitrogen (N) from and to the atmosphere (Boring et al, 1988;Pare and Thiffault, 2016) and the loss of nutrients via runoff (Suescún et al, 2017) while flooding can be both a nutrient input as a nutrient output (Vourlitis et al, 2017;Talbot et al, 2021).…”