Silicon Dynamics During 2 Million Years of Soil Development in a Coastal Dune Chronosequence Under a Mediterranean Climate
Silicon Dynamics During 2 Million Years of Soil Development in a Coastal Dune Chronosequence Under a Mediterranean Climate
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DOI：
10.1007/s10021-020-00493-9
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发表时间：
2020-02
期刊：
影响因子：
3.7
通讯作者：
F. Tombeur;B. Turner;E. Laliberté;H. Lambers;J. Cornelis
中科院分区：
文献类型：
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作者：
F. Tombeur;B. Turner;E. Laliberté;H. Lambers;J. Cornelis
植物中的硅（Si）具有许多益处，包括对食草动物和水分或营养胁迫的抗性。然而，在长期的生态系统发展过程中，硅的动态仍然很少记录，特别是在土壤中的植物可用性方面的变化。我们研究了200万年的土壤时序，以研究土壤性质的长期变化如何影响土壤硅库。年代序列表现出极端的矿物学变化-从富碳酸盐到富石英土壤-碳酸盐风化域被硅酸盐风化域所取代。植物有效硅浓度最低的年轻的土壤（全新世，< 6.5 ka），增加中更新世（中更新世，120 ka），最后下降到最古老的，富含石英的土壤（早更新世，2马）。硅的有效性可能较低，在年轻的土壤中相对稳定，因为（1）碳酸盐风化消耗质子，因此减少了硅酸盐矿物的风化，（2）碱性土壤中次生矿物对硅的吸附较高。在中年站点，硅的可用性上升，碳酸盐的损失和高岭石的形成，似乎驱动其浓度，然后福尔斯在最古老的网站与石英富集。随着碳酸盐的消耗，生物硅的积累增加，表明随着生态系统的发展，土壤-植物硅循环增强。文献分析证实了控制硅的碳酸盐和硅酸盐风化域之间的可用性的过程的转变。总的来说，我们的研究结果表明，植物有效硅的非线性响应长期成土作用，与陆地生态系统的硅相关的功能可能具有重要意义。
Silicon (Si) in plants confers a number of benefits, including resistance to herbivores and water or nutrient stress. However, the dynamics of Si during long-term ecosystem development remain poorly documented, especially the changes in soils in terms of plant availability. We studied a 2-million-year soil chronosequence to examine how long-term changes in soil properties influence soil Si pools. The chronosequence exhibits extreme mineralogical changes—from carbonate-rich to quartz-rich soils—where a carbonate weathering domain is succeeded by a silicate weathering domain. Plant-available Si concentrations were lowest in young soils (Holocene, < 6.5 ka), increased in intermediate soils (Middle Pleistocene, 120 ka), and finally decreased toward the oldest, quartz-rich soil (Early Pleistocene, 2 Ma). Silicon availability is likely low and relatively constant in the young soils because (1) carbonate weathering consumes protons and therefore reduces weathering of silicate minerals and (2) Si adsorption by secondary minerals is high in alkaline soils. In the middle-aged sites, Si availability rises with the loss of carbonates and the formation of kaolinite that appears to drive its concentration, and then falls in the oldest sites with quartz enrichment. The increasing accumulation of biogenic silica following carbonate depletion indicates stronger soil–plant Si cycling as ecosystem development proceeds. A literature analysis confirms the shift in processes controlling Si availability between the carbonate and silicate weathering domains. Overall, our results show a nonlinear response of plant-available Si to long-term pedogenesis, with likely important implications for the Si-related functioning of terrestrial ecosystems.