Plant Impact on CO2 Consumption by Silicate Weathering: The Role of Bamboo

CO2 consumption by silicate weathering has exerted a major control on atmospheric CO2 over geologic time. In order to assess plant impact on this process, the study compared water geochemistry and CO2 consumption rates by silicate weathering in watersheds covered by bamboos and other forests. Our study showed that SiO2 concentrations (80 ~ 150 μmol/L, average 105 μmol/L) in water from pure bamboo forest watersheds were higher than that (15 ~ 85 μmol/L, average 60 μmol/L) from other watersheds. Si/(Nasilicate + Ksilicate) ratios in water draining from bamboo watersheds (2.0 ~ 4.0, average 2.9) were higher than that from other watersheds ?>(0.7 ~ 2.7, average 2.2). CO2 consumption rates by silicate weathering in bamboo watersheds (1.8 ~ 3.4 105 mol/km2/yr, average 2.5 105 mol/km2/yr) were higher than that in other watersheds (1.5 ~ 2.6 105 mol/km2/yr, average 2.0 105 mol/km2/yr). Therefore, bamboo-enhanced silicate weathering is a potential biogeochemical remediation approach for atmospheric CO2.