[A-CG40] 陸域生態系の物質循環

[ACG40-02] CO₂フラックス長期観測から見るカラマツ林での間伐が炭素収支に与える影響

*高橋 善幸¹、三枝 信子¹、平田 竜一¹、梁 乃申¹、井手 玲子¹、寺本 宗正¹ (1.国立環境研究所地球環境研究センター)

キーワード：二酸化炭素、フラックス、撹乱、長期観測

Larch forest is an important research object for evaluating CO₂ uptake by forests because it is a common tree type of plantation that has been planted widespread over northeastern Japan. Quantifying the influence of the forest management on carbon budget in larch forests have significance on the securement of forests as a source of CO₂ absorption. Thus, National Institute for Environmental Studies (NIES) has implemented long-term monitoring program of CO₂ exchange over larch forests. Fuji Hokuroku Flux Observation Site was established in the foothills of Mt. Fuji as an alternative base for monitoring, and began observations in January 2006. The site is dominated by larch trees of more than 50 year-old. 30% thinning was conducted at the site in spring of year 2014 and 2015. The characteristics of CO₂ exchange were affected from the human disturbance. Gross primary production (GPP) and ecosystem respiration (RE) of CO₂ were remarkably decreased temporarily after the thinning. Consequently, both GPP and RE has recovered gradually. Net ecosystem production (NEP) has not fully recovered at 2017 to the level before the thinning because the speed of the recovery differs for GPP and RE. We will introduce the results of carbon fluxes and related parameters for the sites.