Determinants of phytolith occluded carbon in bamboo stands across forest types in the eastern Indian Himalayas

Phytoliths are known to play a significant role in the global carbon cycle by sequestering atmospheric carbon dioxide as phytolith-occluded carbon (PhytOC) for a long time. Given the resistant nature of phytolith to decomposition, PhytOC can represent up to 82 % of total carbon in some soil and sediments even after 2000 years of litter decomposition. Hence, forests with high PhytOC sequestration rates could play a critical role in increasing terrestrial carbon storage. In this study, we quantified the variation in PhytOC concentrations in bamboo leaves, branches and culms with forest types in the Eastern Indian Himalayas as bamboos are efficient accumulator of phytolith and PhytOC due to their fast growth and high biomass accumulation rates. Using nine different machine learning techniques, we also investigated the determinants of PhytOC production in bamboo stands in the study area in India. The results revealed that the PhytOC concentrations in bamboo stands were in the order of leaf (3.0 g kg−1) > culm (1.0 g kg−1) > branch (0.2 g kg−1) across forest types. The highest PhytOC stock (53.8 kg ha−1) was found in bamboo stands in the subtropical pine forests (1900–3500 m elevation), while the lowest (28.0 kg ha−1) was in the tropical evergreen forests (