Net ecosystem CO2 exchange over a larch forest in Hokkaido, Japan
Net ecosystem CO2 exchange over a larch forest in Hokkaido, Japan
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DOI：
10.1016/j.atmosenv.2004.02.071
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发表时间：
2004-12
影响因子：
5
通讯作者：
Huimin Wang;N. Saigusa;S. Yamamoto;H. Kondo;T. Hirano;Atsushi Toriyama;Y. Fujinuma
中科院分区：
文献类型：
--
作者：
Huimin Wang;N. Saigusa;S. Yamamoto;H. Kondo;T. Hirano;Atsushi Toriyama;Y. Fujinuma
落叶松森林广泛分布于欧亚大陆东部，在陆地生态系统碳循环过程中发挥着重要作用。鉴于这一重要生物群落的碳交换研究非常有限，自2000年以来，我们在日本北部北海道的落叶松森林生态系统中开展了长期通量观测。净生态系统co2交换（NEE）表现出较大的季节和日变化。在5 - 10月的生长季节，落叶松林生态系统在夜间释放co2，在白天吸收co2。该生态系统在5月开始成为净碳汇，6月达到最大碳吸收量186g Cm - 2month - 1。随着黄变、衰老和落叶，生态系统在11月变成了一个碳源。在非生长期，落叶松森林生态系统成为二氧化碳的净来源，平均释放16.7g Cm−2月−1。总体而言，生态系统在2001年吸收了141-240g Cm−2yr−1。环境因子对NEE有显著影响。例如，生态系统的呼吸作用指数依赖于气温，而光合作用与入射PAR的关系与Michaelis-Menten模型一致。虽然蒸汽压差（VPD）不高于15hPa，但当VPD超过10hPa时，co2吸收率也会下降。
Larch forests are distributed extensively in the east Eurasian continent and are expected to play a significant role in the terrestrial ecosystem carbon cycling process. In view of the fact that studies on carbon exchange for this important biome have been very limited, we have initiated a long-term flux observation in a larch forest ecosystem in Hokkaido in northern Japan since 2000. The net ecosystem CO2exchange (NEE) showed large seasonal and diurnal variation. Generally, the larch forest ecosystem released CO2in nighttime and assimilated CO2in daytime during the growing season from May to October. The ecosystem started to become a net carbon sink in May, reaching a maximum carbon uptake as high as 186g Cm−2month−1in June. With the yellowing, senescing and leaf fall, the ecosystem turned into a carbon source in November. During the non-growing season, the larch forest ecosystem became a net source of CO2, releasing an average of 16.7g Cm−2month−1. Overall, the ecosystem sequestered 141–240g Cm−2yr−1in 2001. The NEE was significantly influenced by environmental factors. Respiration of the ecosystem, for example, was exponentially dependent on air temperature, while photosynthesis was related to the incident PAR in a manner consistent with the Michaelis–Menten model. Although the vapor pressure deficit (VPD) was scarcely higher than 15hPa, the CO2uptake rate was also depressed when VPD surpassed 10hPa.