Boron accumulation and tolerance of hybrid poplars grown on a B-laden mixed paper mill waste landfill

Abstract

Paper mill wastes are a mixture of by-products from pulp production and on-site energy production, consisting of paper mill sludge, ash and cinders. Landfilling of these highly boron (B) and heavy metal laden waste products carries environmental risks. Poplars have been successfully employed in the phytomanagement and hydraulic control of B contaminated sites. Here, we assess the performance of hybrid poplars on a paper-mill waste landfill, investigate the accumulation of B by the trees and explore the relationship between local-scale root growth and substrate properties. Leaf and root tissue samples were collected on three plots and analyzed for their chemical properties and root traits. Additionally, we sampled four soil cores in the vicinity of each of the trees and determined chemical and physical properties. Using a principal component analysis followed by a cluster analysis, we identified three substrate types. This method delineated the soil effects on tree survival and growth, although correlations with individual soil element concentrations were weak. Despite signs of B toxicity in some leaves, B was not the key limiting factor for poplar growth. Instead, Ca deficiency caused by a Mg:Ca imbalance was the primary reason for the poor performance of some trees. Root growth was not limited by toxicity effects of soil contaminants. Our results show that hybrid poplars perform well under the harsh growing conditions on a multi-contaminated, B-laden substrate in a hemiboreal climate. Exploiting the differences in the performance of the four clones in relation to the soil types, could increase the success of revegetation on this and other landfills.

Two Poplar Hybrid Clones Differ in Phenolic Antioxidant Levels and Polyphenol Oxidase Activity in Response to High Salt and Boron Irrigation

“…Ideally, a poplar plantation could be used to recycle salt and B laden waters (e.g., drainage or groundwater), while the harvested tree products could provide an economical resource . Several poplar species have already been identified with the ability to grow under high salt irrigation, , while others have demonstrated that poplar clones can tolerate B-contaminated soils and accumulate B …”

“…6 Several poplar species have already been identified with the ability to grow under high salt irrigation, 7,8 while others have demonstrated that poplar clones can tolerate B-contaminated soils and accumulate B. 9 The combined stress of high salinity and B exposure to plants can lead to a wide range of effects, including elevating phenolic levels 11 and affecting (synergestic or antagonistic) the uptake of other ions. 10,11 Typically, excessive salinity results in an increase of plant phenolic levels.…”

Minería de rellenos sanitarios como alternativa de gestión para residuos sólidos

“…Su fin es reducir la huella ecológica de forma significativa (Hrad et al, 2013;Rees et al, 2013;Kumar & Sharma, 2014).…”

Intenzív üzemű halnevelő-telepről származó szennyvíz mezőgazdasági elhelyezésének és hasznosításának vizsgálata energiafűz kísérletben

“…Lack of enough water often limits willow growth, the extra water may enhance its growth (Lindroth és Bath 1999). Energy willow and poplar have many advantages compared to other plants: long growing season, high evapotranspiration rate, ability to take up nutrients and toxic elements with minimum leaching potential (Arronson 2001, Patterson et al 2009, Rees et al 2013.…”