Biochar application increased ecosystem carbon sequestration capacity in a Moso bamboo forest

Abstract

Biochar application has been considered as one of approaches to mitigate climate change, however, most of existing studies only focus on its effects on soil carbon pools, rather than the ecosystem level carbon sequestration capacity in forests. Moso bamboo (Phyllostachys heterocycla var. pubescens) has a uniquely growth and development pattern, which can provide a possibility for exploring the short-term effects of biochar application on ecosystem carbon sequestration. We conducted a 24-month field experiment in a Moso bamboo forest to investigate the effects of different biochar application rates (0(CK), 5 (B5) and 15 (B15) Mg ha−1) on soil greenhouse gas emissions, soil organic carbon (SOC) stocks and vegetation carbon stocks. In comparison to CK, SOC stocks for B5 and B15 treatments increased by 26.60% and 7.07%, respectively. Similarly, the vegetation carbon stocks for B5 and B15 treatments increased by 66.79% and 59.85%, respectively. The total greenhouse gases emission increased by 19.70% and 21.23% in B5 and B15, respectively. In terms of non-CO2 greenhouse gases, biochar application significantly decreased N2O emissions in B5 and B15 by 18.02% and 24.42% (P < 0.05), and increased CH4 uptakes by 16.22% and 8.11%, respectively. In summary, biochar applications increased total ecosystem carbon stocks in Moso bamboo forest by 486.31% and 252.98% under B5 and B15 treatments, respectively. This implied that biochar amendment can significantly promote the carbon sequestration capacity in Moso bamboo forest ecosystems; therefore, it is an effective forest management option to increase carbon stocks and reduce non-CO2 greenhouse gas emissions in Moso bamboo forests.