Phytolith Carbon Sequestration as a Sustainable Pathway for Climate Change Mitigation

Abstract

Phytolith carbon sequestration is one of the lesser-known long-term carbon storage mechanisms, where carbon is trapped inside the silica formed in plant tissues. Phytolith is strongly resistant to decomposition; hence, the carbon inside it can be trapped for millions of years. This process helps in a stable pathway for the reduction of the atmospheric carbon dioxide level. Phytolith formation is controlled by the uptake of monosilicic acid by plants and silica polymerization. And, the carbon occlusion depends on soil conditions, phytolith type, plant species, and environment. Phytolith contributes to carbon sequestration across ecosystems. For example, 1.7 Tg CO₂ is trapped annually in China’s forests, where bamboo is the high contributor. Wetlands, particularly peat-forming wetlands (sequestering 0.003-0.077 t CO₂ ha-¹ yr¹) and eelgrass beds, store high phytolith-occluded carbon. Phytoliths are a promising long-term carbon-capturing material. This paper provides a broader knowledge on phytolith carbon sequestration and their importance as a nature-based pathway for climate mitigation.