Phytolith carbon sequestration in bamboos of different ecotypes: a case study in China

Abstract

Occlusion of carbon (C) within phytoliths (PhytOC) is becoming one of the most promising terrestrial C sequestration mechanisms. This study explored the production of PhytOC within 35 bamboo species belonging to three ecotypes using methods of microwave digestion. The aim of this study is to explore the present and potential C sequestration rate within phytoliths of bamboo species from three ecotypes. PhytOC content in bamboos of three ecotypes ranges from 0.07 % to 0.42 %. The mean PhytOC production flux decreases as: clustered bamboo (0.050 ± 0.016 t CO2 ha−1 a−1) ≈ mixed bamboo (0.049 ± 0.016 t CO2 ha−1 a−1) > scattered bamboo (0.038 ± 0.020 t CO2 ha−1 a−1). The phytolith carbon sequestration in Chinese bamboo is estimated to be 0.293 ± 0.127 Tg (1 Tg = 1012 g) CO2 a−1; approximately 75 %, 3 %, and 22 % of which is contributed from scattered, mixed and clustered bamboo, respectively. Taking the PhytOC production flux of 0.18 ± 0.12 t CO2 ha−1 a−1 and current annual area increasing rate of 3 %, global bamboo phytoliths would sequester 11.9 ± 7.9 Tg CO2 a−1 by 2050. Consequently, bamboo forests have significant potential to mitigate the increasing concentration of atmospheric CO2 by maximizing PhytOC production flux and expanding bamboos.