JpGU-AGU Joint Meeting 2017


[EJ] 口頭発表

セッション記号 A (大気水圏科学) » A-CG 大気水圏科学複合領域・一般

[A-CG47] [EJ] 陸域生態系の物質循環

2017年5月25日(木) 09:00 〜 10:30 303 (国際会議場 3F)

コンビーナ:加藤 知道(北海道大学農学研究院)、平野 高司(北海道大学大学院農学研究院)、佐藤 永(海洋研究開発機構 地球表層物質循環研究分野)、平田 竜一(国立環境研究所)、座長:平野 高司(北海道大学大学院農学研究院)

09:00 〜 09:15

[ACG47-01] 富士北麓カラマツ林の林床炭素収支に対する間伐の影響

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


Forest ecosystem is the major carbon stock in terrestrial ecosystems. Elucidating the mechanism of the response of forest carbon budget against the global climate change is critical for predicting future carbon budget. Forest understory is very important component of forest carbon cycle, and it is vital to obtain detailed information about the dynamics of understory carbon budget to understand the whole response of forest carbon cycle to climate change. Forest management is thought to cause drastic change of understory environment, and we examined the influence of tree thinning on understory carbon budget using long-term chamber measurement data.
Multi-channel automated chamber measurement system was installed in a larch forest on the northern foot of Mount Fuji in 2006. We set 16 soil chambers (90 cm × 90 cm × 50 cm) for soil CO2 flux measurement. The half of those soil chambers were trenched with root cut chainsaw to the depth of 30 cm to measure heterotrophic respiration (Rh). The remaining 8 chambers were used to measure soil respiration (Rs). We set 8 of plant chambers (90 cm × 90 cm × 100 cm) that included understory vegetation to measure understory net CO2 exchange (NUE). From the NUE data, understory respiration (Ru) and understory gross primary production (GPP_u) were calculated. Stepwise tree thinning was applied to this larch forest in 2014 and 2015, and 30% of larch trees were cut down in March of 2015 in the end.
When we compared the data before (2006 to 2013) and after (2015 to 2016) tree thinning, the change of understory light environment and soil temperature resulted in increase of GPP_u and Ru, respectively. As a result, NUE did not changed remarkably.