Effects of Periodic Mulching on Temperature Sensitivity of CO2 Emissions in a Lei bamboo forest

Lei Bamboo ( Phyllostachys violascens ), a prevalent economic bamboo species in subtropical China, is subjected to periodic mulching practices (hereinafter ”mulching”) to increase the soil temperature and increase bamboo shoot production. While increasing yield, these practices may contribute to bamboo forest degradation in soil quality and substantial greenhouse gas emissions from the soil. Research on the temperature sensitivity of soil CO 2 emissions from bamboo forests subjected to various mulching treatments remains scarce. This study focused on four bamboo forest stands under different mulching histories in Nanjing China: S1 (abandoned after 8 years of winter rice husk mulching and 2 years without), S2 (10 years of continuous mulching), S3 (5 years of mulching followed by 5 years without), and CK (no mulching). Soil samples from various depths(0-10cm,10-20cm,20-30cm) were incubated at different temperatures(5-35℃) to assess the effects of mulching on soil CO 2 emissions, temperature sensitivity ( Q 10 ), and soil properties, including organic carbon (SOC), nitrogen (N), phosphorus (P), potassium (K), and water content (SWC).. The findings revealed the following: Mulching notably increased the soil temperature, fertility, and CO 2 emissions, with S3 resulting in the greatest improvement in fertility and S1 resulting in the highest CO 2 emission flux and soil CO 2 production response ( Q 10 ); Q 10 decreased with increasing soil depth, with S1’s Q 10 in the 0–10 cm layer significantly elevated by 72.91%, 66.41%, and 82.56% compared to S2, S3, and CK, respectively, and mulch treatment interacting with soil depth to cause greater Q 10 increases in shallower layers; Mulching altered the Q 10 by modifying the annual average soil temperature, SOC, TN, and SWC, thereby increasing CO 2 emissions. Among the treatments, S2 minimized CO 2 emissions, whereas S3 maximized them. In conclusion, relative short periodic mulching in bamboo forests significantly increased more soil CO 2 emissions and temperature sensitivity than long-term mulching by altering the soil temperature, SOC, TN, and SWC. This study provides new references and data support for the sustainable and environmentally friendly management of bamboo forests in the context of future global warming and anthropogenic N loads