title: Sustained acceleration of soil carbon decomposition observed in a 6-year warming experiment in a warm-temperate forest in southern Japan.
abstract: To examine global warming's effect on soil organic carbon (SOC) decomposition in Asian monsoon forests, we conducted a soil warming experiment with a multichannel automated chamber system in a 55-year-old warm-temperate evergreen broadleaved forest in southern Japan. We established three treatments: control chambers for total soil respiration, trenched chambers for heterotrophic respiration (Rh), and warmed trenched chambers to examine warming effect on Rh. The soil was warmed with an infrared heater above each chamber to increase soil temperature at 5 cm depth by about 2.5 °C. The warming treatment lasted from January 2009 to the end of 2014. The annual warming effect on Rh(an increase per °C) ranged from 7.1 to17.8% °C-1. Although the warming effect varied among the years, it averaged 9.4% °C-1over 6 years, which was close to the value of 10.1 to 10.9% °C-1that we calculated using the annual temperature-efflux response model of Lloyd and Taylor. The interannual warming effect was positively related to the total precipitation in the summer period, indicating that summer precipitation and the resulting soil moisture level also strongly influenced the soil warming effect in this forest.
authors.affiliation: Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan.
authors.forename: Munemasa
authors.initials: M
authors.lastname: Teramoto
authors.affiliation: Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan.
authors.forename: Naishen
authors.initials: N
authors.lastname: Liang
authors.affiliation: Faculty of Agriculture, University of Miyazaki, 11300 Tano-cho, Miyazaki 889-1702, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takagi
authors.affiliation: Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan.
authors.forename: Jiye
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Institute of Ecology and Resource Management, University of Edinburgh, Edinburgh EH9 3JU, UK.
authors.forename: John
authors.initials: J
authors.lastname: Grace