Tropical coral island soils suffer from high alkalinity and poor nutrient holding capacity, making nitrogen a critically limiting factor for plant life. While traditional restoration efforts often involve heavy fertilizer use, this approach risks severe nitrogen loss and environmental damage. Recently, a team from the Xiaoliang Research Station of the South China Botanical Garden utilized 15N isotope tracing to find a better solution. By testing ammonium, nitrate, and amide nitrogen on two resilient local species (Ficus microcarpa and Terminalia catappa) grown in coral sand, the researchers systematically assessed how different nitrogen forms impact plant development and the soil's ability to retain vital nutrients.Figure 1. Growth and nutrient responses of different organs in Ficus microcarpa and Terminalia catappa to various nitrogen forms.（Image by WANG et al.）Research findings highlight that nitrogen form is the key factor in determining nutrient utilization. Based on this, the team proposes revising traditional "application-heavy" methods in favor of a "form-optimization" core strategy.The study suggests that restoration efforts on coral islands (especially in dry seasons) should prioritize nitrate-based fertilizers combined with organic soil improvements and slow-release techniques. This approach not only boosts plant growth but also slashes the risk of nitrogen loss, offering a vital technical roadmap for the long-term conservation of delicate coral island environments.Figure 2. Schematic diagram of the mechanisms by which nitrogen forms regulate soil nutrients and plant uptake on coral islands.（Image by WANG et al.）These findings have been published in the Journal of Plant Ecology under the title "Nitrogen form governs nutrient retention and plant uptake in coral island soils: Evidence from a 15N-tracing experiment." CHEN Han, a PhD candidate at the South China Botanical Garden, Chinese Academy of Sciences (CAS), is the first author, and Researcher WANG Faming is the corresponding author. This research was supported by the National Key Research and Development Program of China. Article link: https://doi.org/10.1093/jpe/rtaf191