Development of a model for evaluation of biogeochemical interactions between the atmosphere and terrestrial ecosystems

本研究建立了一个模拟大气与生物圈之间的地球化学相互作用，特别是温室气体交换的模式。二氧化碳（CO_2）、甲烷（CH_4）和一氧化二氮（N_2O）是陆地生态系统中重要的温室气体，在陆地生态系统中的交换是研究的重点。本文介绍了基于过程的陆地生态系统模式（Sim-CYCLE）模拟CH_4氧化和N_2O排放的几种方案。对Ridgewell等（1999）和Potter等（1996 a）提出的两种CH_4氧化方案以及Parton等（1996）和Potter等（1996 b）提出的两种N_2O排放方案进行了试验。该模型被应用到一个冷温带落叶阔叶林和万年青针叶林在日本中部。此外，我们研究了估计的生态系统和土壤呼吸速率与通量测量数据进行比较，这意味着模型的有效性和一些问题，在夜间生态系统呼吸的短期变化。这些结果在博尔德举行的IGBP-iLEAPS会议上发表，并部分作为科学论文发表。为了研究模型估计的不确定性范围，我们比较了使用不同气候数据集（包括新的日本数据集（JRA 25））和使用不同生态系统模型的模拟结果。这项相互比较研究表明，模拟结果将强烈依赖于输入数据和生态系统模型使用。这些结果发表在几篇科学论文中。

This study constructed a model for simulating biogeochemical interactions between the atmosphere and biosphere, particularly concerning greenhouse gas exchange. We put focus of the exchange of carbon dioxide (CO_2), methane (CH_4), and nitrous oxide (N_2O), because terrestrial ecosystems exchange these important greenhouse gases. Based on a process-based terrestrial ecosystem model (Sim-CYCLE), several schemed of CH_4 oxidation and N_2O emission were introduced. Two schemed of CH_4 oxidation, by Ridgewell et al. (1999) and Potter et al. (1996a), were considered, and also two schemes of N2O emission, by Parton et al. (1996) and Potter et al. (1996b), were tried. The model was applied to a cool-temperate deciduous broad-leaved forest and an evergreen needle-leaved forest in central Japan. Also, we examined the estimated ecosystem and soil respiration rates by comparing with flux measurement data, implying model validity and some problems in retrieving short-term variability in nighttime ecosystem respiration. These results were presented at the IGBP-iLEAPS Conference at Boulder, and partly published as a scientific paper. To examine the range of uncertainty in model estimation, we compared simulation results using different climate datasets, including the new Japanese dataset (JRA25), and using different ecosystem models. This intercomparison study suggested that simulation results would be strongly dependent on input data and ecosystem model used. The results were published from a coupled of scientific papers.