Multi-element fingerprinting of waters to evaluate connectivity among depressional wetlands

Abstract

Establishing the connectivity among depressional wetlands is important for their proper management, conservation and restoration. In this study, the concentrations of 38 elements in surface water and porewater of depressional wetlands were investigated to determine chemical and hydrological connectivity of three hydrological types: recharge, flow-through, and discharge, in the Prairie Pothole Region of North America. Most element concentrations of porewater varied significantly by wetland hydrologic type (p < 0.05), and increased along a recharge to discharge hydrologic gradient. Significant spatial variation of element concentrations in surface water was observed in discharge wetlands. Generally, higher element concentrations occurred in natural wetlands compared to wetlands with known disturbances (previous drainage and grazing). Electrical conductivity explained 42.3% and 30.5% of the variation of all element concentrations in porewater and surface water. Non-metric multidimensional scaling analysis showed that the similarity decreased from recharge to flowthrough to discharge wetland in each sampling site. Cluster analysis confirmed that element compositions in porewater of interconnected wetlands were more similar to each other than to those of wetlands located farther away. Porewater and surface water in a restored wetland showed similar multi-element characteristics to natural wetlands. In contrast, depressional wetlands connected by seeps along a deactivated drain-tile path and a grazed wetland showed distinctly different multi-element characteristics compared to other wetlands sampled. Our findings confirm that the multi-element fingerprinting method can be useful for assessing hydro-chemical connectivity across the landscape, and indicate that element concentrations are not only affected by land use, but also by hydrological characteristics.

Fingerprinting sources of salinity in a coastal chalk aquifer in Denmark using trace elements

“…Abstraction from UB2 was increased from 4.9 to 9.1 m 3 /h during the second tracer test resulting in a faster breakthrough. www.geusbulletin.org Yuan et al (2019) found that multi-element fingerprinting can be useful for assessing hydrological connectivity across the landscape and indicate that element concentrations are affected not only by land use but also by hydrogeological characteristics.…”

Practical Guide to Measuring Wetland Carbon Pools and Fluxes

“…Variation in elements among wetlands occurs from differences in biogeochemical activity and hydrology. Multi-element analysis has been used to assess the condition of restored wetlands (Wang et al 2019a , 2020 ; Zhu et al 2021 ), characterize vegetation change (e.g., Jacob and Otte 2004 ), identify sources of water and sediments (e.g., Rauch et al 2000 ; Stutter et al 2009 ), and assess hydrochemical connectivity of wetlands (e.g., Yuan et al 2019 ; Zhu et al 2019b ). For example, distributions of elements La, praseodymium [Pr], terbium [Tb], bismuth [Bi], thallium [Tl], and thorium [Th] provide evidence of disturbance from agricultural activities at depths greater than 1 m (Yellick et al 2016 ; Werkmeister et al 2018 ), while Co and Ni provide information about conversion of wetlands to croplands (Zhu et al 2021 ).…”