日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

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

[A-CG39] 陸域生態系の物質循環

2019年5月28日(火) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:加藤 知道(北海道大学農学研究院)、市井 和仁(千葉大学)、伊勢 武史(京都大学フィールド科学教育研究センター)、寺本 宗正(国立環境研究所)

[ACG39-P01] 苗場山ブナ林における微生物呼吸に対する長期的な温暖化の影響

*寺本 宗正1梁 乃申1楢本 正明2曾 継業1趙 昕1冨松 元1 (1.国立環境研究所地球環境研究センター、2.静岡大学農学部)

キーワード:土壌有機炭素、地球温暖化、微生物呼吸、チャンバー、アジアモンスーン

Soil respiration is the second largest carbon flux in terrestrial ecosystems and the global soil respiration is estimated to be 98 GtC yr-1. Soil respiration consists of root respiration and heterotrophic respiration (Rh), and Rh contributes more than half of the soil respiration. It is commonly observed that Rh exponentially increases with temperature. Therefore, a small increase of temperature can result in a remarkable enhancement of Rh, indicating that it is an important positive feedback factor to accelerate global warming under a warmer environment. However, the long-term warming effect on Rh is not well understood especially in the humid Asian monsoon region.

To examine the long-term response of Rh to global warming in Asian monsoon forests, we set a multi-channel automated chamber measurement system in a beech forest on Mount Naeba in July 2007. We prepared 10 trenched chambers (90 cm × 90 cm × 50 cm) to continuously measure Rh. Half of those trenched chambers were artificially warmed by infrared heaters 1.6 m above the soil surface (+2.5ºC), and the influence of soil warming on Rh was examined by comparing control plots and warming plots. Measurements were conducted mainly during growing season from June to October.

Even though there was a large inter-annual variation, enhancement of Rh by soil warming was confirmed in all 8 years measurements. Soil temperature was the primary factor for the seasonal variation of Rh. The influence of soil moisture on seasonal variation of Rh was relatively small.