Li Rencheng, Gu Zhitao, Vachula Richard S, Dong Haiyan, Xu Mengtong, Chen Xiaofang, Xu Bin, Sun Yunwu
College of Earth Science, Guilin University of Technology, Guilin, 541004, China.
Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration, Guilin, 541004, China.
Sci Rep. 2024 Dec 3;14(1):30009. doi: 10.1038/s41598-024-81246-9.
Phytolith have been recognized as an important soil bioavailable Si source for plants, as well as a sink of C and heavy metals in soils. Though the impacts of fire and heat on phytolith sequestration of some nutrients (phosphorus, potassium) and heavy metals have been addressed, little attention has been paid to fire's effects on phytolith carbon sequestration. In this study, the carbon and dissolved Si content of phytoliths extracted from 6 common grass species and their burned ashes, as well as phytoliths collected from different areas (burned, transitional, and unburned) of a pine forest, were compared to characterize the effects of open fire on phytolith carbon content, solubility, and carbon sequestration. The carbon content and Si dissolution of ashed phytoliths varied between plant species, and differed with phytoliths from modern plants. The topsoil phytoliths had increased carbon content, and generally decreased solubility across the gradient of unburned, transitional, and burned pine forest. We therefore conclude that open fire can cause changes in phytolith related carbon content and solubility, as well as its preservation in soils. This study provides new perspective on the effects of open fire on phytolith carbon sequestration and its estimation.
植物硅酸体已被认为是植物重要的土壤生物可利用硅源，也是土壤中碳和重金属的汇。尽管火灾和高温对某些养分（磷、钾）和重金属在植物硅酸体中的固存影响已得到研究，但火灾对植物硅酸体碳固存的影响却很少受到关注。在本研究中，比较了从6种常见草种及其燃烧灰烬中提取的植物硅酸体的碳和溶解硅含量，以及从一片松林的不同区域（燃烧区、过渡区和未燃烧区）收集的植物硅酸体，以表征明火对植物硅酸体碳含量、溶解度和碳固存的影响。灰化植物硅酸体的碳含量和硅溶解度因植物种类而异，与现代植物的植物硅酸体也有所不同。在未燃烧、过渡和燃烧的松林梯度中，表层土壤植物硅酸体的碳含量增加，溶解度普遍降低。因此，我们得出结论，明火可导致植物硅酸体相关碳含量和溶解度的变化，以及其在土壤中的保存情况。本研究为明火对植物硅酸体碳固存及其估算的影响提供了新的视角。
