[A-CG37] Biogeochemical Cycles in Land Ecosystem

[ACG37-02] Nine years of continuous observation on soil carbon fluxes in a cool temperate forest following a massive windthrow disturbance

*Sun Lifei¹, Naishen Liang¹, Takashi Hirano², Yoshiyuki Takahashi¹, Kentaro Takagi², Munemasa Teramoto³, Sachinobu Ishida⁴, Masahiro Takagi⁵, Toshiaki Kondo⁶, Jun koarashi⁷, Atarashi Atarashi-Andoh⁷, Tomotsugu Yazaki⁸ (1.National Institute for Environmental Studies Japan, 2.Hokkaido University, 3.Tottori University, 4.Hirosaki University, 5.University of Miyazaki, 6.Japan International Research Center for Agricultural Sciences, 7.Japan Atomic Energy Agency, 8.Meji University)

Keywords:soil carbon fluxes, disturbance, automatic chamber, continuous observation, early succession stage

Forests constitute approximately 30% of terrestrial ecosystems, thus playing a significant role as a carbon sink. Windthrow is a typical disturbance affecting the monsoon Asian forest carbon balance. Both frequency and intensity of windthrow have increased in recent years caused by climate extreme. Therefore, clarifying the response of the carbon budget of forest ecosystems to the impacts of windthrow disturbance, particularly the post-disturbance with vegetation variation, is essential for accurately predicting the global carbon budget and forest management strategies under climate change. Tomakomai Flux research site was a 45-year-old larch plantation that was severely disturbed by Typhoon Songda in 2004, resulting in the blowdown of over 90% of overstory trees. Subsequently, the site underwent natural regeneration. Previous studies in this site have investigated the effects of windthrow disturbance on the ecosystem carbon balance and demonstrated that the forest ecosystem transits from a carbon sink to a source before and after the typhoon. To assess the variation of soil carbon fluxes during the early succession stage, we continuously measured soil respiration and understory fluxes during snow-free periods using an automatic chamber system from 2010 to 2019. Simultaneously, some biological and environmental variables such as vegetation biomass, soil temperature, and soil moisture were observed throughout the entire observation period. In this presentation, we will clarify how soil carbon fluxes varied, and what environmental factors controlled the changes in soil carbon fluxes during the early succession stage after windthrow disturbance.