Data from: Impacts of silicon-based grass defences across trophic levels under both current and future atmospheric CO2 scenarios

Silicon (Si) has important functional roles in plants, including resistance against herbivores. Environmental change, such as increasing atmospheric concentrations of CO2, may alter allocation to Si defences in grasses, potentially changing the feeding behaviour and performance of herbivores, which may in turn impact on higher trophic groups. Using Si-treated and untreated grasses (Phalaris aquatica) maintained under ambient (400 ppm) and elevated (640 and 800 ppm) CO2 concentrations, we show that Si reduced feeding by crickets (Acheta domesticus), resulting in smaller body mass. This, in turn, reduced predatory behaviour by praying mantids (Tenodera sinensis), which consequently performed worse. Despite elevated CO2 decreasing Si concentrations in P. aquatica, this reduction was not large enough to affect the feeding behaviour of crickets or their predator. Our results suggest that Si-based defences in plants have adverse impacts on both primary and secondary trophic taxa, and these are not likely to decline under future climate change scenarios.

硅（Silicon, Si）在植物中发挥关键功能作用，包括抵御植食性动物。诸如大气二氧化碳（CO₂）浓度升高这类环境变化，可能改变草本植物对硅基防御的资源分配策略，进而影响植食性动物的取食行为与生存表现，最终可能波及更高营养级类群。本研究以经硅处理与未处理的球茎虉草（Phalaris aquatica）为实验材料，设置环境二氧化碳浓度（400 ppm）与升高的二氧化碳浓度（640 ppm、800 ppm）的培养条件，结果显示硅可降低家蟋蟀（Acheta domesticus）的取食活动，导致其体质量更低。这进而抑制了中华大刀螳（Tenodera sinensis）的捕食行为，使其生存表现更差。尽管升高的二氧化碳浓度降低了球茎虉草体内的硅含量，但该降幅并未达到足以影响家蟋蟀及其捕食者取食行为的程度。本研究结果表明，植物的硅基防御对初级与次级营养级类群均具有不利影响，且在未来气候变化情景下，这类影响不太可能减弱。