Haloconduction as a remediation strategy: Capture and quantification of salts excreted by recretohalophytes

Abstract

Recretohalophytes employ specialized glands to excrete salt ions onto their tissue surfaces, which then have the potential to be transported away from the plant via wind in a process referred to as ‘haloconduction’. Spartina pectinata and Distichlis spicata were selected to investigate the potential to remediate a cement kiln dust landfill in Bath, ON via salt excretion and haloconduction. Under ideal conditions in the laboratory, measurements of salt excreted by large (>15 shoots and > 50 cm height) plants of each species were 280 ± 164 g/m2 and 164 ± 75 g/m2, respectively, resulting in potential remediation timeframes of 1.4 ± 0.9 and 2.4 ± 1.1 years. Three salt collection methods were developed and installed in the field to test their efficacy for capturing and measuring windborne salt mobilized from plant surfaces. All three methods (two ground-level and one at 260 cm height) were successful in capturing and quantifying airborne salts up to 15 m from the plots. This study is the first to collect and quantify dispersed salt from recretohalophytes and hence confirm the theory of haloconduction, a promising new remediation technology for salt-impacted soils.