Heavy metal uptake by plant parts of willow species: A meta-analysis

Abstract

Previous studies on phytoremediation reported contradictory or inconsistent results on the Cd, Pb, and Zn accumulation in and among plant parts of willow (Salix) species. We hypothesized that metals could accumulate in all plant organs in different concentrations and the metal accumulation in tissues would be increased with exposure time. Furthermore, we analysed the effect of soil pH on metal accumulation, and the correlation between metals. We evaluated published information on Cd, Pb, and Zn accumulation in root, stem, twig, and leaf of willow species using meta-analysis. Results showed that all parts of willow species accumulated significantly more Cd, Pb, and Zn in contaminated soils than in uncontaminated soils. However, the metal accumulation was significantly different among plant parts. We concluded that willow species were proven to be prosperous accumulators of Cd (twigs and leaves), Pb (roots and twigs) and Zn (twigs). We found that Cd accumulation rate in stems is higher in soils with lower pH. Significant positive correlation was found between the accumulations of Cd and Zn in stems. Accumulation rates of Cd (both in leaves and twigs) and Zn (in twigs) were increased significantly with exposure time and the accumulation was successful for at least 3 years.

Negative Effects on Photosynthesis and Chloroplast Pigments Exposed to Lead and Aluminum: A Meta-Analysis

“…These models were used because they attribute the effect size distribution to the actual differences among the cases and do not assume that the sampling error is the only source of differences among them. A Z test was performed with a 95% confidence interval and the maximum and minimum values were calculated to determine if the effect size differed from a normal distribution (Tozsér et al, 2017;Gurevitch et al, 2018). Moreover, the heterogeneity was assessed in order to identify moderators that would explain potential differences among the cases.…”

“…However, untreated effluent is sometimes released, harming ecosystems, biodiversity and human health. The destruction of vegetation cover and the degradation of soil are consequences of the leaching of these metals, which is the main route of contamination of water sources, rivers and groundwater (Tozsér et al, 2017).…”

Lignocellulosic‐based bioenergy and water quality parameters: a review

“…In a recent meta‐analysis, Tőzsér et al . () reported that growing willow can remediate Cd‐, Pb‐, and Zn‐contaminated soils. Research has suggested that SRWCs (i) adsorb and immobilize contaminants through plant uptake (ii) convert organic contaminants to nontoxic forms via microbial activities, (iii) degrade contaminants by synthesizing enzymes, (iv) transform contaminants into volatile compounds and release into atmosphere through evaporation (phytovolatilization), and (v) improve soil physical properties (Mirck et al ., ; Volk et al ., ; Brunner et al ., ).…”

Sexual Differences in Physiological and Transcriptional Responses to Salinity Stress of Salix linearistipularis

“…Because of their rapid growth, high biomass yield, and ease of propagation, willows are important wood resources for both bioenergy production and afforestation (Greger and Landberg, 1999;Karp et al, 2011). Furthermore, willow species are extensively used in phytoremediation activities (Tozser et al, 2017). Salix linearistipularis (Franch.)…”