Five state factors control progressive stages of freshwater salinization syndrome

Abstract

Factors driving freshwater salinization syndrome (FSS) influence the severity of impacts and chances for recovery. We hypothesize that spread of FSS across ecosystems is a function of interactions among five state factors: human activities, geology, flowpaths, climate, and time. (1) Human activities drive pulsed or chronic inputs of salt ions and mobilization of chemical contaminants. (2) Geology drives rates of erosion, weathering, ion exchange, and acidification‐alkalinization. (3) Flowpaths drive salinization and contaminant mobilization along hydrologic cycles. (4) Climate drives rising water temperatures, salt stress, and evaporative concentration of ions and saltwater intrusion. (5) Time influences consequences, thresholds, and potentials for ecosystem recovery. We hypothesize that state factors advance FSS in distinct stages, which eventually contribute to failures in systems‐level functions (supporting drinking water, crops, biodiversity, infrastructure, etc.). We present future research directions for protecting freshwaters at risk based on five state factors and stages from diagnosis to prognosis to cure.

Stormwater best management practices: Experimental evaluation of chemical cocktails mobilized by freshwater salinization syndrome

“…Our results suggest that FSS can alter organic matter in stormwater BMPs similar to other studies (Kaushal et al, 2022a;Kaushal et al, 2022b); this may have implications for changes in soil aggregate structure, erosion potential, and infiltration rates. Our study found that concentrations of DOC increased in response to initial stages of salinization, significantly from salinization with Na + , consistent with changes in solubility and destruction of soil aggregates due to Na + dispersion and loss of cation bridging from Ca 2+ and Mg 2+ in sodic soils (Figure 3; Table 4) (Green et al, 2008a, c;Abolfazli and Strom 2022;Norrstrom and Bergstedt, 2020).…”

“…Stormwater ponds were also found to mobilize base cations after road salting events (Barbier et al, 2018). Though stormwater BMPs do offer excellent conditions for decreasing peak discharge and organic matter and nutrient pollution, stormwater BMPs may be sources rather than sinks of metals and cations during road salting events (Kaushal et al, 2022a;Kaushal et al, 2022b), potentially leading to increased salt and chemical cocktail contamination of surface and groundwater (Kaushal et al, 2019;Burgis et al, 2020;Maas et al, 2021).…”

“…Accidental and designed wetlands may decrease peak salinity downstream but may also funnel surficial water contamination directly into groundwater aquifers (Palta et al, 2017;Maas et al, 2021). Stormwater BMPs offer more environmental benefits than cement culverts and buried streams, but further study must be conducted regarding risks associated with freshwater salinization (Kaushal et al, 2021(Kaushal et al, , 2022a. If salt use continues or increases, the quantity of metals released may begin to decrease as colloids become depleted of metals with constant base cation exchange and flushing downstream (Fernandez et al, 2003).…”

“…Ion exchange in soils and sediments is a major driver of chemical cocktail mobilization during FSS, but changes in redox conditions, pH, and solubility, enhanced microbial activity, complexation, and others process likely play a role (Kaushal et al, 2018b(Kaushal et al, , 2020(Kaushal et al, , 20212022a). Anthropogenic inputs of Na + , Ca 2+ , Mg 2+ , and K + ions contribute to freshwater salinization across land uses (Kaushal et al, 2017;Moore et al, 2017).…”

Can Common Pool Resource Theory Catalyze Stakeholder-Driven Solutions to the Freshwater Salinization Syndrome?

“…Fourth, can the knowledge coproduction frameworks, approaches, and tools being trialed in the Occoquan system (i.e., Ostrom’s SES, JFF, and FCMs) be scaled-up to address the FSS in other regions and contexts? For example, given the site-specific nature of the FSS (including potential salt sources and their human and ecosystem impacts 91 ) and the limited and patchy nature of enforceable ion-specific thresholds across the United States and globally, 16 could these transdisciplinary methods be applied more generally to foster local consensus around ion-specific thresholds, in support of polycentric governance of the FSS?…”