Effects of plant-available soil silicon on seedling growth and foliar nutrient status across tropical tree species

Plant-available silicon (Si) concentrations vary considerably across tropical soils, yet the ecological importance of that variation remains largely unresolved. Increased Si availability can enhance growth and modulate foliar nutrient status in many crop species suggesting similar effects might occur in natural systems. However, how growth, foliar Si, and macronutrient concentrations, as well as their stoichiometry, respond to plant-available Si and how these responses differ across tropical tree species is unknown.
We experimentally exposed seedlings of 12 tropical tree species to a gradient of plant-available Si concentrations, representing 85% of the variation found across Central Panama, and assessed responses in aboveground growth and foliar nutrient status. Furthermore, we assessed whether higher plant-available Si increases P availability.
Increasing plant-available Si led to increased foliar Si concentrations (by up to 140%). It also led to higher aboveground growth (by up to 22..., ,