日本地球惑星科学連合2018年大会

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[JJ] ポスター発表

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-CG40] 陸域生態系の物質循環

2018年5月24日(木) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 7ホール)

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、共同)、平田 竜一(国立環境研究所)

[ACG40-P02] 沖縄の亜熱帯林常緑広葉樹林における幹枝呼吸量の解明

*塩垣 美森1松本 一穂1谷口 真吾1速水 眞誉2高嶋 敦史1 (1.琉球大学農学部、2.琉球大学大学院農学研究科)

キーワード:幹呼吸量、亜熱帯林

We measured the stem respiration of five tree species in a subtropical mature evergreen broadleaf forest in northern Okinawa Island. In August and September 2017, we measured stem respiration at 50 points on 23 trees and examined the differences along the circumference, among individuals, and among species. No significant circumferential variation in stem respiration was found in the two major species: Castanopsis sieboldii and Schima wallichii. In these species, although no significant difference was found among individuals within the same species, there was a positive correlation between stem respiration and individual radial stem growth in Castanopsis sieboldii. The inter-species difference in stem respiration was not significant. The average stem respiration at all measurement points in the summer was 1.5 µmol m-2 s-1. We estimated the total stem and branch respiration on a whole-tree scale by multiplying the average stem respiration per unit stem surface area by the total surface area of the stem and branches, estimated from forest inventory data assessed in 2016. The stand-scale stem and branch respiration per unit ground area calculated by integrating the individual whole-tree values was 3.7 µmol m-2 s-1. After the summer measurements, we continued to make monthly measurements for fewer trees. The stem respiration decreased toward winter depending on the air temperature and was 18% of the summer value in January.