Evaluation of the Impacts of Marine Salts and Asian Dust on the Forested Yakushima Island Ecosystem, a World Natural Heritage Site in Japan

Yakushima Island experiences significant ecological impacts from marine salts and Asian dust. Research reveals that streamwater chemistry is heavily influenced by sea salt aerosols, contributing to high Na and Cl concentrations while depleting Ca and HCO3 levels. The study found that rain-derived cations account for 81% of Na and 83% of Mg in streamwater, with Sr isotope ratios indicating substantial leaching from bedrock due to acidic precipitation. Soils on Yakushima are depleted in Ca, Na, P, and Sr compared to parent materials, suggesting chemical weathering processes driven by sea salt-enriched rain. Additionally, Asian dust-derived apatite serves as a crucial phosphorus source in base cation-depleted soils. The study employed elemental composition analysis and Sr/Nd isotope ratios to trace the origins and impacts of these airborne materials on the island's ecosystem.

Nakano, T., Yokoo, Y., Okumura, M., Jean, S.-R., & Satake, K. (2012). Evaluation of the Impacts of Marine Salts and Asian Dust on the Forested Yakushima Island Ecosystem, a World Natural Heritage Site in Japan. Water, Air, & Soil Pollution, 223(9), 5575–5597. https://doi.org/10.1007/s11270-012-1297-z