Occluded C in rice phytoliths: implications to biogeochemical carbon sequestration
Occluded C in rice phytoliths: implications to biogeochemical carbon sequestration
复制标题
DOI：
10.1007/s11104-013-1661-9
复制
发表时间：
2013-09-01
期刊：
影响因子：
4.9
通讯作者：
Wang, Hailong
中科院分区：
文献类型：
--
作者：
Li, Zimin;Song, Zhaoliang;Wang, Hailong
植硅体固碳是一种长期的地球化学固碳机制，在全球碳循环和气候变化中起着重要作用。在这项研究中，我们探讨了种植水稻中产生的植硅体中碳生物螯合的潜力本文采用微波消解法对水稻植硅体进行了提取，并根据植硅体-Si溶解法测定了植硅体中的包藏C。化学分析表明，水稻不同器官植硅体中包藏C（PhytOC）的含量与水稻不同器官的含量呈显著正相关。5个水稻品种（叶、茎、鞘和籽粒）的含碳量在0.4 ~ 2.8mg g（-1）之间，籽粒中植硅体的含碳量远低于叶、茎和鞘。水稻的PhytOC含量取决于水稻生长过程中植硅体的含量和植硅体中C的吸收效率。5个水稻品种植硅体的碳地球化学固定通量约为0.03-0.13 Mg CO2当量（Mg-e-CO2）ha（-1）a（-1）。从1950年到2010年，中国水稻植硅体中可能封存了约2.37 × 10（8）Mg的CO2当量。假设植硅体碳的最大生物固碳通量为0.13 Mg-e-CO2 ha（-1）year（-1），则水稻植硅体固碳的全球年潜在速率约为1.94 x 10（7）Mg。因此，水稻作物可能通过形成PhytOC在长期固碳中发挥重要作用。
Carbon (C) bio-sequestration within the phytoliths of plants, a mechanism of long-term biogeochemical C sequestration, may play a major role in the global C cycle and climate change. In this study, we explored the potential of C bio-sequestration within phytoliths produced in cultivated rice (Oryza sativa), a well known silicon accumulator.The rice phytolith extraction was undertaken with microwave digestion procedures and the determination of occluded C in phytoliths was based on dissolution methods of phytolith-Si.Chemical analysis indicates that the phytolith-occluded C (PhytOC) contents of the different organs (leaf, stem, sheath and grains) on a dry weight basis in 5 rice cultivars range from 0.4 mg g(-1) to 2.8 mg g(-1), and the C content of phytoliths from grains is much lower than that of leaf, stem and sheath. The data also show that the PhytOC content of rice depends on both the content of phytoliths and the efficiency of C occlusion within phytoliths during rice growth. The biogeochemical C sequestration flux of phytoliths in 5 rice cultivars is approximately 0.03-0.13 Mg of carbon dioxide (CO2) equivalents (Mg-e-CO2) ha(-1) year(-1). From 1950 to 2010, about 2.37 x 10(8) Mg of CO2 equivalents might have been sequestrated within the rice phytoliths in China. Assuming a maximum phytoliths C bio-sequestration flux of 0.13 Mg-e-CO2 ha(-1) year(-1), the global annual potential rate of CO2 sequestrated in rice phytoliths would approximately be 1.94 x 10(7) Mg.Therefore rice crops may play a significant role in long-term C sequestration through the formation of PhytOC.