Water level regulates the rhizosphere priming effect on SOM decomposition of peatland soil

• Published in: Rhizosphere
• Main Authors: Yan, Wenchao, Wang, Yuanyun, Ju, Peijun, Huang, Xinya, Chen, Huai
• Format: Report
• Language: English
• Published: ELSEVIER 2022
• Subjects: Rhizosphere priming effect; CO2; Water level; Peatland; ORGANIC-MATTER DECOMPOSITION; TEMPERATURE SENSITIVITY; CARBON DECOMPOSITION; ROOT; RESPIRATION; MINERALIZATION; INPUT; MICROORGANISMS; PERMAFROST; Agriculture; Plant Sciences; Agronomy; Soil Science; permafrost
• Online Access: http://ir.imde.ac.cn/handle/131551/56551; https://doi.org/10.1016/j.rhisph.2021.100455

The rhizosphere priming effect (RPE) is vital in soil organic matter turnover,but its role in peatlands remains unclear, especially when considering different water levels. In this study, we measured the CO2 emission rate from rhizosphere and bulk soil of peatland at different water levels, together with isotope of C-13, to evaluate the RPE in peatland. Results showed that the decomposition of SOM was significantly affect by RPE, and the RPE varied significantly among water levels (p < 0.05). Positive RPE was observed at-40 cm which soil CO2 emission increased by 59%, with rate increased 0.04 g CO2 pot(- 1 )d(-1). And negative RPE was observed at-20 cm and 0 cm, which soil CO2 emission decreased by-92% and-83%, with rate decreased 2.01 and 1.94 g CO2 pot(-1) d(-1), respectively. Positive RPE at-40 cm and negative RPE at-20 cm and 0 cm, suggested the RPE enhanced soil carbon accumulation at higher water level, and the RPE threat the carbon sink when water level further reduced. Our results showed that the RPE was a nonnegligible process in predicting peatlands carbon dynamic, especially with intensified climate change and peatlands degraded condition.