Transfer of arsenic and phosphorus from soils to the fronds and spores of arsenic hyperaccumulator Pteris vittata and three non-hyperaccumulators

Abstract

Concentrations of chemical analogs arsenic (As) and phosphorus (P) were measured in As-hyperaccumulator (Pteris vittata; PV) and three non As-hyperaccumulators (Thelypteris kunthii, Nephrolepsis brownii, and N. falcata) to draw inferences regarding their uptake from soils to roots and translocation to fronds and spores. Frond and root samples of 150 ferns at peak spore maturation were collected with associated soils between July 2012 and July 2014. Arsenic in PV spores (45.4–336 mg kg−1) exceeded soil As (0.60–111 mg kg−1) in all sites and at clean sites (0.60–1.17 mg kg−1) for non-hyperaccumulator spores (1.83–8.60 mg kg−1). In PV, As in fronds and spores correlated positively with soil As (r = 0.71–0.74) with bioconcentration factors (tissue As:soil As) of 14.3–654 and 3.26–53.6 compared to 0.08–0.44 and 0.03–8.37 for three non-hyperaccumulators. However, P in PV spores (1977–4832 mg kg−1) correlated negatively with frond (1028–2439 mg kg−1; r = −0.43) and soil (76.2–170 mg kg−1; r = −0.34) P. PV hyperaccumulates As into fronds and spores from soils with trace As. Since PV spores constituted ~9 % of frond biomass, the elevated spore As may deserve further investigation in their role as a potential health hazard and metal cycling.