Cu isotopic compositions in Elsholtzia splendens: Influence of soil condition and growth period on Cu isotopic fractionation in plant tissue

摘要

This study investigates the magnitude and direction of Cu isotopic fractionation in the Cu-tolerant, strategy I plant, Elsholtzia splendens, considering the effect of soil condition and plant growth cycle. Uptake of Cu by E. splendens from soil was found to favor light Cu isotopic enrichment (delta Cu-65 < 0 parts per thousand) due to reduction at the soil root interface. The magnitude of fractionation between soil and plant was found to be dependent on free Cu ion species in soil solution correlated with pH value of soil other than the phytoavailable component of soil or total soil for the same parent soil.