Foliar elemental profiles in the ultramafic flora of Kinabalu Park (Sabah, Malaysia)

The foliar elemental profile of most plants reflects that of the soil on which plants grow in their natural habitat. The aim of this study was to elucidate foliar elemental profiles in the ultramafic flora of Kinabalu Park in Sabah, Malaysia. Kinabalu Park is ideal for studying plant elemental profiles because of its exceptionally rich flora and diversity in soil types. Foliar elemental profiles of 594 plant species in 99 families were analysed (totalling 1710 samples). This included 495 species (90 families) from ultramafic soils, and 120 species (45 families) from non-ultramafic soils (used as a comparison dataset). In general, the foliar elemental uptake ranges from exclusion of phytotoxic elements such as Ni and Mn, to a limited number of plant species characterised by extreme accumulation of specific elements, including trace elements (Co, Mn, Ni, Zn,), or non-essential elements (Al). This research identified hyperaccumulator behaviour (as defined by exceedances of established threshold foliar concentrations) in numerous plant species: Al > 1000 μg g⁻¹ (38 spp.), Mn > 10 mg g⁻¹ (7 spp.), Co > 300 μg g⁻¹ (3 spp.), Ni > 1000 μg g⁻¹ (24 spp.) and Zn > 3000 μg g⁻¹ (2 spp.). Distinct phylogenetic patterns emerged for Ni in which 18 of the identified 24 Ni hyperaccumulators were in the order Malpighiales, predominantly in the families Phyllanthaceae, Salicaceae and Violaceae.