Carbon Sequestration Potential and Phytolith-Occluded Carbon in Two Bamboo Species

Abstract

The alarming rise in atmospheric CO₂ levels is a major driver of global warming and climate change. Bamboo, a fast-growing and renewable resource, has emerged as a promising solution due to its high carbon sequestration capacity. This study investigates the carbon storage potential, phytolith content, and phytolith-occluded carbon in different plant parts of two bamboo species Bambusa balcooa and Bambusa vulgaris grown in Coimbatore, India. The organic carbon content in the leaves of B. balcooa and B. vulgaris was 44.52% and 50.11%, respectively, while in the branches it was 49.10% and 50.94%. Phytolith content in the leaves was recorded at 174.43 mg g⁻¹ for B. balcooa and 113.03 mg g⁻¹ for B. vulgaris; in branches, the values were 105.03 mg g⁻¹ and 79.06 mg g⁻¹, respectively. Five morphotypes of phytoliths were identified in the leaves and branches of both species: (1) dumbbell or bilobate, (2) globular granulate or spherical rugose, (3) saddle-shaped, (4) elongated, and (5) square short cells. These morphotypes varied in distribution and abundance between the species and plant parts. The findings indicate that B. vulgaris has a higher organic carbon content and greater potential for PhytOC formation compared to B. balcooa, despite the latter exhibiting higher phytolith content. This suggests that B. vulgaris may be more effective in long-term carbon sequestration through PhytOC mechanisms. Given the significant role of bamboo in the global carbon cycle, promoting the cultivation of high PhytOC-producing species like B. vulgaris could serve as an effective nature-based strategy for climate change mitigation.