McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments
McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments
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DOI：
10.5194/bg-7-3517-2010
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发表时间：
2008-04
期刊：
影响因子：
4.9
通讯作者：
F. St-Hilaire;Jianghua Wu;N. Roulet;S. Frolking;P. Lafleur;E. Humphreys;V. Arora
中科院分区：
文献类型：
--
作者：
F. St-Hilaire;Jianghua Wu;N. Roulet;S. Frolking;P. Lafleur;E. Humphreys;V. Arora
抽象的。我们开发了麦吉尔湿地模型（MWM）的泥炭地碳模拟器（PCARS）和加拿大陆地生态系统模型的基础上的一般结构。PCARS主要有三个方面的变化：（1）光合作用的光利用效率模型改为光合作用的地球化学描述;（2）自养呼吸的描述改为与光合作用的描述一致;以及（3）队列，将多层土壤呼吸模型转化为一个简单的单箱泥炭分解模型，该模型以有效地下水位划分为好氧区和缺氧区，和一年的停留时间垃圾池。通过比较MWM的输出值与位于加拿大安大略南部的Mer Bleue泥炭地的净生态系统生产力（NEP）、总初级生产力（GPP）和生态系统呼吸（ER）的估计值，对MWM进行了评估（一致性指数[无量纲]：NEP = 0.80，GPP = 0.97，ER = 0.97;系统RMSE [g C m−2 d−1]：NEP = 0.12，GPP = 0.07，ER = 0.14;非系统RMSE：NEP = 0.15，GPP = 0.27，ER = 0.23）。模拟苔藓NPP接近沼泽泥炭地的预期，但灌木NPP似乎被低估。敏感性分析表明，由于生产和呼吸的抵消响应，模型输出没有发生很大变化，由于地下水位的变化，但即使是温和的温度升高可能会导致转换沼泽从汇CO2的来源。一般的弱点和进一步发展的MWM进行了讨论。
Abstract. We developed the McGill Wetland Model (MWM) based on the general structure of the Peatland Carbon Simulator (PCARS) and the Canadian Terrestrial Ecosystem Model. Three major changes were made to PCARS: (1) the light use efficiency model of photosynthesis was replaced with a biogeochemical description of photosynthesis; (2) the description of autotrophic respiration was changed to be consistent with the formulation of photosynthesis; and (3) the cohort, multilayer soil respiration model was changed to a simple one box peat decomposition model divided into an oxic and anoxic zones by an effective water table, and a one-year residence time litter pool. MWM was then evaluated by comparing its output to the estimates of net ecosystem production (NEP), gross primary production (GPP) and ecosystem respiration (ER) from 8 years of continuous measurements at the Mer Bleue peatland, a raised ombrotrophic bog located in southern Ontario, Canada (index of agreement [dimensionless]: NEP = 0.80, GPP = 0.97, ER = 0.97; systematic RMSE [g C m−2 d−1]: NEP = 0.12, GPP = 0.07, ER = 0.14; unsystematic RMSE: NEP = 0.15, GPP = 0.27, ER = 0.23). Simulated moss NPP approximates what would be expected for a bog peatland, but shrub NPP appears to be underestimated. Sensitivity analysis revealed that the model output did not change greatly due to variations in water table because of offsetting responses in production and respiration, but that even a modest temperature increase could lead to converting the bog from a sink to a source of CO2. General weaknesses and further developments of MWM are discussed.