Author(s): Qingqing Zhao; Junhong Bai; Wang Wei; Wang Xin; Yongchao Gao; Jianing Wang; Guanhong Chen
Linked Author(s):
Keywords: Tidal flow restoration; Freshwater inputs; Soil quality index; Soil quality assessment; Coastal wetlands
Abstract: With the degradation and loss of coastal wetlands, more and more restoration projects have been widely conducted. Tidal flow restoration and freshwater inputs have been proved to be two effective restoration ways. Soil samples were collected to a depth of 50 cm in August, 2015, in tidal flow restored salt marshes (RTSM) and corresponding degraded wetlands (DTSM), freshwater restored wetlands (FRW) and corresponding degraded wetlands (DWFI) in the Yellow River Delta, China to investigate the changes of soil properties after wetlands restoration. Our results showed that tidal flow restoration significantly lowered soil electronic conductivity (EC), salt ions, and sodicity, enhanced the levels of soil organic carbon and nitrogen, and changed soil structure (p< 0.05). Compared to DWFI soils, lower salinity, higher soil organic carbon and nitrogen contents and finer soil texture were observed in FRW soils (p< 0.05). Cluster analysis and redundancy analysis revealed that restored wetlands and degraded wetlands were clearly distinguished. Soil properties were transformed to establish a soil quality index (SQI) for the assessment of soil quality after restoration measures implemented. Lower SQI values were observed in degraded wetlands than restored wetlands.
Year: 2018