The extent and applications of metal accumulation and hyperaccumulation in Philippine plants

To examine the potential applications of hyperaccumulator plants in the Philippines, we reviewed current data on the extent of metal hyperaccumulation in native species and partitioning of metals within the plant tissue. Twenty-eight species had reported tissue concentrations above the hyperaccumulator threshold, 11 species were endemic to the Philippines. Nickel was present in higher concentrations in the aboveground tissue than in the belowground tissue, but the reverse was found for copper, aluminium and chromium. The fact that copper accumulates belowground rather than above, and most hyperaccumulators of nickel identified were trees, has implications for the potential of phytoextraction using native Philippines flora. Soils of the Philippines often have high concentrations of heavy metals and low nutrient concentrations, which are conditions that are normally unfavourable for plant growth. However, many plants in the area have adapted to these conditions and can grow well. Here we have compiled data currently available on Philippine plants that can accumulate metals in their tissue, and the potential applications of these plants in restoration efforts. Photograph by Edwino S. Fernando.