[A-CG37] 陸域生態系の物質循環

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

*孫 力飛¹、梁 乃申¹、平野 高司²、高橋 善幸¹、高木 健太郎²、寺本 宗正³、石田 祐宣⁴、高木 正博⁵、近藤 俊明⁶、小嵐 淳⁷、安藤 麻里子⁷、矢崎 友嗣⁸ (1.国立環境研究所、2.北海道大学、3.鳥取大学、4.弘前大学、5.宮崎大学、6.国際農林水産業研究センター、7.日本原子力研究開発機構、8.明治大学)

キーワード：土壌炭素フラックス、攪乱、自動開閉チャンバー、連続観測、遷移の初期段階

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.