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..., ,热带土壤中植物可利用硅（Si）的浓度存在显著差异，但此类差异的生态重要性在很大程度上尚未得到阐明。诸多作物的研究显示，硅有效性提升可促进植株生长并调控叶片养分状态，这提示自然生态系统中或存在类似效应。然而，植株生长、叶片硅与大量营养元素浓度，以及其化学计量比对植物可利用硅的响应规律，以及这些响应在热带树种间的差异，目前仍属未知。本实验将12种热带树种的幼苗置于梯度设置的植物可利用硅浓度环境中，该浓度梯度覆盖了巴拿马中部地区土壤硅浓度变异的85%，并评估了其地上生长与叶片养分状态的响应情况。此外，本研究还探究了更高的植物可利用硅浓度是否会提升磷（P）的有效性。植物可利用硅浓度的提升可使叶片硅浓度最高升高140%，同时还可促进地上生长，最高提升22%（原文此处内容未完整）