JpGU-AGU Joint Meeting 2020

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG54] Biogeochemical cycles in Land Ecosystem

convener:Tomomichi Kato(Research Faculty of Agriculture, Hokkaido University), Kazuhito Ichii(Chiba University), Takeshi Ise(FSERC, Kyoto University), Munemasa Teramoto(Arid Land Research Center, Tottori University)

[ACG54-09] Soil organic carbon and its water-extractable fraction in volcanic ash soils in a Japanese temperate forest: relations to phosphate absorption coefficient and their implication

*Hirohiko Nagano1, Sota Tanaka1, Mariko Atarashi-Andoh1, Jun Koarashi1 (1.Japan Atomic Energy Agency)

Keywords:Soil organic carbon, Stability, Vulnerability, Volcanic ash soil

Soil organic carbon (SOC) is a key component in global carbon cycling, while water-extractable organic carbon (WEOC) in soils is a proxy of soil carbon available to the living microbial community. Volcanic ash soils, a soil type dominant in Japan, are known to have a very high ability to stabilize soil carbon, and SOC content often correlates with phosphate absorption coefficients (PAC) in soils. In this study, we compared the SOC-PAC relationship and the WEOC-PAC relationships using 42 volcanic ash soils (0-6 cm depth) collected from a Japanese temperate forest. SOC showed a very strong correlation with PAC (r = 0.72). Correlation between SOC and WEOC was also strong (r = 0.84). Correlation between WEOC and PAC was, however, weak (r = 0.42). Thus, water destabilized carbon likely originated from residual carbon sources other than the primary carbon that is highly stabilized in volcanic ash soils.