[A-HW29_2PM1] JapanFlux：水・物質循環における陸域生態系の役割

[AHW29-07] 富士北麓カラマツ林における林床部CO2フラックスの連続測定

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

キーワード：土壌呼吸, チャンバー, 林床植生, 光合成

Carbon fluxes of forest floor are thought to be important part of forest carbon dynamics. Multi-channel automated chamber system was installed to a larch forest site on the base of Mount Fuji in 2006 for continuous measurement of forest floor CO₂ fluxes. We prepared soil chambers for measuring soil respiration (Rs) and heterotrophic respiration (Rh). Root trenching was applied to separate Rs and Rh. Net ecosystem exchange (NEE) on the forest floor was measured with plant chambers. In 2013, the average efflux of CO₂ was 2.24, 1.81 and 2.11 μmol CO₂ m^-2 s^-1 in Rs, Rh and NEE, respectively. Root respiration was estimated to occupy 80.7% of Rs. Plants of forest floor was suggested to absorb about 5.9% of CO₂ in Rs, and it meant that the amount of carbon fixed by those plants was relatively low. There was little rain in summer time (July-August), and forest floor CO₂ fluxes were decreased due to decreased soil moisture. Q₁₀ was 2.49 and 2.87 in Rs and Rh, respectively. Soil respiration was estimated to be 8.48 tC ha^-1 yr^-1, and the forest floor was seen as 7.98 tC ha^-1 yr^-1 carbon source.