最新研究表明植物能够维持陆地硅循环

来源：农环视界

生物地球化学硅循环影响全球初级生产力和碳循环，但人们对陆地生态系统长期发展过程中硅资源和硅循环的变化仍知之甚少。

近日，比利时列日大学F. de Tombeur研究组取得最新进展。他们表明植物在生态系统退化期间维持陆地硅循环。相关论文于2020年9月4日以“Plants sustain the terrestrial silicon cycle during ecosystem retrogression”为题发表在Science 上。

研究组揭示了在长期的生态系统发展过程中，沿着澳大利亚西部200万年的土壤时间序列，陆地硅循环从土壤控制转变为生物控制。

硅的可用性是由新生土壤中的成土硅，以及当成土池枯竭时旧土壤中植物来源硅的循环利用决定的。不同于主要营养成分浓度在强风化土壤中显著下降，叶面硅浓度随着土壤年龄的增长而持续增加。

研究结果表明，在生态系统退化过程中，植物对硅的保留维持了硅在陆地上的循环。这表明在营养不良环境中，植物对保留硅元素有重要益处。

论文信息：

Title: Plants sustain the terrestrial silicon cycle during ecosystem retrogression

Author: F. de Tombeur, B. L. Turner, E. Laliberté, H. Lambers, G. Mahy, M.-P. Faucon, G. Zemunik, J.-T. Cornelis

Issue&Volume: 2020/09/04

Abstract:The biogeochemical silicon cycle influences global primary productivity and carbon cycling, yet changes in silicon sources and cycling during long-term development of terrestrial ecosystems remain poorly understood. Here, we show that terrestrial silicon cycling shifts from pedological to biological control during long-term ecosystem development along 2-million-year soil chronosequences in Western Australia. Silicon availability is determined by pedogenic silicon in young soils and recycling of plant-derived silicon in old soils as pedogenic pools become depleted. Unlike concentrations of major nutrients, which decline markedly in strongly weathered soils, foliar silicon concentrations increase continuously as soils age. Our findings show that the retention of silicon by plants during ecosystem retrogression sustains its terrestrial cycling, suggesting important plant benefits associated with this element in nutrient-poor environments.

DOI: 10.1126/science.abc0393