Growth Dynamics of Acacia auriculiformis under Cadmium Pollution and Its Combination with Atmospheric CO2 Enrichment and Nitrogen Addition

Abstract:

In order to understand the response of trees to elevated CO₂, N addition and Cd stress, the growth characters of Acacia auriculiformis, such as basal diameter, tree height and individual biomass, were studied using an open-top chamber (OTC). The results showed that the basal diameter, height and individual biomass of A. auriculiformis were significantly inhibited under Cd stress, and the inhibition effect was with a lag time. Both elevated CO₂ and N addition remitted the inhibition of Cd stress on A. auriculiformis growth, N addition could promote the base diameter growth of A. auriculiformis, and tree height growth was more sensitive to CO₂ enrichment. Under Cd stress, the biomass accumulation of A. auriculiformis was mainly caused by N addition. So, it was suggested that N fertilization management was an important strategy to promote phytoremediation in the early stage of heavy metal contaminated land remediation.