Variation in rare earth element (REE), aluminium (Al) and silicon (Si) accumulation among populations of the hyperaccumulator Dicranopteris linearis in southern China

Abstract

Dicranopteris linearis is a rare earth element (REE), aluminium (Al) and silicon (Si) hyperaccumulator plant which occurs in southern China. To date, there have been no studies on the variation in elemental accumulation among populations of Dicranopteris linearis occurring on REE-enriched and non-REE enriched soils. In total 43 Dicranopteris linearis individuals and the corresponding rhizosphere soils from 7 populations in southern China were sampled and the plant material and soil composition were chemically analysed for REE and other elements. Dicranopteris linearis populations from REE-enriched soils and non-REE enriched soils both have the ability to accumulate high concentrations of REE (> 1000 mg kg− 1), Al (> 1000 mg kg− 1) and Si (> 10 000 mg kg− 1). The ratios of light REEs (LREEs) to heavy REEs (HREEs) in Dicranopteris linearis pinnae are consistently > 1, regardless of their ratios in the corresponding soils. Concentrations of REE in Dicranopteris linearis pinnae vary significantly among populations and have positive correlations with total and extractable soil REE concentrations. The plant Al and Si concentrations in Dicranopteris linearis populations are uncoupled from variations in soil Al and Si concentrations. The plant REE concentrations have no obvious relationships with the prevailing Al concentrations, but are positively correlated with plant Si and Mn, and negatively correlated with soil extractable P concentrations. The hyperaccumulation of REEs (LREE > HREE), Al and Si in non-REE enriched soils is a species-wide trait. The accumulation of REEs is highly variable and associated with soil REE concentrations, nutrients status, and other soil properties.