Elevated Cd and Zn uptake by aspen limits the phytostabilization potential compared to five other tree species

Abstract

Phytostabilization of metals using trees is often promoted although the influence of different tree species on the mobilization of metals is not yet clear. This study examined effects of six tree species on the soil characteristics pH, organic carbon (OC) content and cation exchange capacity (CEC) and on the redistribution of cadmium (Cd) and zinc (Zn) on a polluted sandy soil. Soil and biomass were sampled in 10-years-old stands growing on former agricultural land. The tree species included were silver birch (Betula pendula), oak (Quercus robur and Q. petraea), black locust (Robinia pseudoacacia), aspen (Populus tremula), Scots pine (Pinus sylvestris) and Douglas fir (Pseudotsuga menziesii). In the short period of ten years, only aspen caused significant changes in the soil characteristics. Due to accumulation of Cd and Zn in its leaf litter, aspen increased the total as well as the NH 4 OAc-EDTA-extractable Cd and Zn concentrations in the topsoil compared to deeper soil layers and to other tree species. Also topsoil pH, OC content and CEC were significantly higher than under most of the other species. This caused rather low 'bio-available' CaCl 2 -extractable concentrations under aspen. Nevertheless, given the risks of aboveground metal dispersion and topsoil accumulation, it is recommended that aspen should be avoided when afforesting Cd and Zn contaminated lands.

Copper Phytoextraction and Phytostabilization by <i>Brachiaria decumbens</i> Stapf. in Vineyard Soils and a Copper Mining Waste

“…For our purposes, we calculated the potential of copper phytoextraction by Brachiaria decumbens with a mean value of 5000 kg·ha −1 of phytomass production. Phytostabilization of metals using trees or other perennial species is often promoted and can be an important strategy to control heavy metals polluted sites [20]. Thereby, phytostabilization use plants to reduce the bioavailability of pollutants in the environment and stabilize pollutants in soils, thus rendering their harmless and reducing the risk of further environmental degradation by leaching of pollutants into the ground water or by airborne spread [5].…”

“…This technique is used successfully for heavy metals [17][18][19][20] and organic amendments [21]. This process can play an important role in the vineyard soils contaminated with copper, due to these areas are usually located in steep mountains with sandy soils, subjected to erodibility, promoting high soil losses by surface runoff.…”

Influence of Soil Chemistry and Plant Physiology in the Phytoremediation of Cu, Mn, and Zn

“…Phytostabilization, another phytotechnology, uses plants to stabilize pollutants in soil, preventing erosion, leaching or runoff, or by converting pollutants to less bioavailable forms. In this process, plants act as a ground cover, reducing animal contact with contaminants present in soil (Dasgupta-Schubert et al, 2011;Pignattelli et al, 2012;Van Nevel et al, 2011).…”

“…For example, the perennial shrub Sesbania virgata is an excellent species for use in Zn contaminated soils (Branzini et al, 2012). Other plant species that are good candidates for phytostabilization are Quercus robur, Quercus petraea, Pinus sylvestris, Pseudotsuga menziesii (Van Nevel et al, 2011) and S. paradoxa .…”

Influence of organic amendments on phytostabilization of Cd-contaminated soil by Eucalyptus camaldulensis

“…However, proper selection of plants is critical in phytostabilization, as the species plays a key role with respect to the metal stabilizing potential of the root system and the quantity of vegetative cover for protection of soil from the effects of wind and water 8 . Excluder tree species used elsewhere include birch (Betula pendula), black locust (Robinia pseudoacacia), oak (Quercus robur, Q. petraea), Scots pine (Pinus sylvestris), and Douglas fir (Pseudotsuga menziesii) 9 . However, few reports exist regarding the utilization of excluder tree species in Thailand.…”