Trace element partitioning in a poplar phytoextraction stand in relation to stem size

Area of Science:

• Environmental Science
• Phytoremediation
• Plant Biology

Background:

• Phytoextraction uses plants to remove toxic trace elements (TEs) from soil.
• Optimizing phytoextraction efficiency involves managing plant biomass and uptake capacity.
• Fast-growing trees like poplar are candidates for phytoremediation.

Purpose of the Study:

• To determine the efficiency of poplar phytoextraction based on TEs uptake, bioavailability, and biomass yield.
• To investigate how plant size (diameter at breast height - DBH) influences TE concentration in poplar biomass.
• To explore strategies for managing poplar stands to enhance phytoextraction of specific TEs.

Main Methods:

• Field testing at an Italian site to assess phytoextraction efficiency.
• Analysis of trace element concentrations in poplar bark and wood across different plant diameters (40, 50, 60 mm DBH).
• Evaluation of biomass yield and TEs accumulation in relation to plant size.

Main Results:

• Trace element concentration in poplar biomass varies with plant size (DBH).
• Zinc (Zn) accumulation was highest in the largest poplar plants (60 mm DBH).
• Cadmium (Cd), Copper (Cu), and Nickel (Ni) were more concentrated in smaller plants (50 mm DBH), while Lead (Pb) was highest in even smaller plants (40 mm DBH).

Conclusions:

• Plant size is a critical factor influencing the phytoextraction of specific trace elements by poplar.
• Managing poplar stands through adjusted coppicing and planting cycles can enhance targeted TEs removal.
• These findings offer new strategies for optimizing poplar-based phytoremediation for diverse soil contaminants.