Partitioning of Major and Trace Elements in a Stand of the Nickel Hyperaccumulator Rinorea cf. bengalensis in Borneo

Rinorea cf. bengalensis is a tropical nickel hyperaccumulator plant known to have very high nickel concentrations, with up to 7.9 wt% nickel in its phloem tissue. We investigated the partitioning of major and trace elements in a stand of R. cf. bengalensis in Borneo. We established two 3 × 3 m² (18 m²) plots with 1 × 1 m² subplots and sampled all plant species (grouped into Rinorea and non-Rinorea) along with six representative soil cores to a depth of 30 cm. The total biomass of the vegetation in the plot was 17.4 kg (mean: 966 g m⁻²), with elemental budgets (g m⁻²) of 1.31 magnesium, 0.30 phosphorus, 0.78 sulfur, 6.25 potassium, 12.5 calcium, 0.11 manganese, 0.86 iron, 0.06 cobalt, 0.21 nickel, and 0.09 zinc. Rinorea cf. bengalensis made up 83% of the total biomass stand, containing > 75% of the respective major and trace elemental budget, reaching 94% and 99% for calcium and nickel, respectively. In the biomass stand of both Rinorea and non-Rinorea, stems were a major reservoir for all the elements, except for manganese, iron, and nickel in non-Rinorea and iron in Rinorea, which were primarily stored in the roots (> 50%). Hyperaccumulators have a large impact on the cycling of nickel and other elements in their ecosystem.