Element composition of soils to assess the success of wetland restoration

Abstract

The main purpose of this study is to assess if wetland restoration is associated with a directional shift in soil element concentration toward the original prefarming status in the peatlands of northeastern China. The concentrations of 55 soil elements and related environmental factors including organic matter content, electrical conductivity, and pH were investigated in natural, restored, and farmed wetlands in the Xingkai Lake Watershed of northeastern China. All but four of the soil element concentrations varied by wetland type (natural, restored, and farmed wetlands), and the soil concentrations of 41 elements increased from natural to restored to farmed wetlands. Soil organic matter and electrical conductivity explained 87.8% and 3.3% of the variation in element concentration based on ordination analysis using redundancy analysis. Both nonmetric multidimensional scaling analysis and cluster analysis indicated that the restored wetlands had a higher similarity with the farmed wetlands than the natural wetlands. Our findings suggest that restoration led to an increase in soil organic matter content and shifts in level of element concentration that was more similar to natural wetlands. However, differences remained so that the biogeochemistry of restored wetlands was not the same as the original prefarming level. This information is very important for wetland restoration, because to be successful, not only biodiversity and hydrology, but also the soil element composition and biogeochemistry need to be restored. Our approach can be used to assess the success of wetland restoration.

Coastal salt marsh restoration drives element composition of soils toward its original state by recovering soil organic matter

“…We found different relationships between organic matter and element composition of soils in coastal salt marshes and inland freshwater marshes. Soil organic matter correlated negatively with most metals in freshwater wetlands in Northeast of China (Wang et al, 2020) and North Dakota (Yellick et al, 2016; Zhu et al, 2019), but they correlated positively in coastal salt marshes on the Dutch coast, the Netherlands (Otte et al, 1993), the Yellow River Delta in China (Yu et al, 2011), and in our study site. The most likely explanation is that the metals in inland freshwater wetlands were bound to inorganic matter, which eroded from rocks due to glacial action thousands of years ago (Yellick et al, 2016).…”

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 ).…”

Phosphorus dynamics in litter–soil systems during litter decomposition in larch plantations across the chronosequence

“…This region was originally occupied by a mixed Korean pine broad-leaved forest, and it was converted to a secondary broadleaved forest because of a fire in the early 1950s. Since the 1960s, the natural secondary forest was replaced by larch plantations (Wang et al, 2020).…”