ORCHIDEE-SOM: modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe
ORCHIDEE-SOM: modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe
复制标题
ORCHIDEE - SOM：对欧洲土壤垂直剖面中的土壤有机碳（SOC）和溶解性有机碳（DOC）动态进行建模
DOI：
10.5194/gmd-11-937-2018
复制
发表时间：
2018-03-15
影响因子：
5.1
通讯作者：
Janssens, Ivan A.
中科院分区：
文献类型：
--
作者：
Camino-Serrano, Marta;Guenet, Bertrand;Janssens, Ivan A.
目前的陆面模型（LSM）通常以非常简单的方式表示土壤，假设土壤有机碳（SOC）为主体，从而阻碍了深层土壤碳动态的正确表示。此外，LSM通常忽略了溶解有机碳（DOC）从土壤到河流的生产和输出，导致高估了陆地上的潜在固碳。这种常见的过度简化的SOC在LSM的处理是部分负责在预测土壤碳对气候变化的响应的大的不确定性。在这项研究中，我们提出了一个新的土壤碳模块，称为ORCHIDEE-SOM，嵌入在陆面模型ORCHIDEE，这是能够再现DOC和SOC动态在垂直离散土壤2米。该模型包括生物生产和消耗的SOC和DOC，DOC吸附和解吸的土壤矿物，SOC和DOC的扩散，DOC的迁移与水通过和出土壤到河流的过程。我们评估ORCHIDE-SOM对DOC浓度和SOC股票从欧洲四个网站不同的植被覆盖：针叶林，落叶林，草地和农田的观测。该模型能够再现SOC股票沿着他们的垂直剖面在四个站点和DOC浓度的测量范围内，在针叶林上层土壤中的DOC浓度除外。然而，该模型不能完全捕捉DOC浓度的时间动态。进一步的模型改进应侧重于植物和深度依赖的参数化的新的输入模型参数，如DOC的周转时间和微生物碳的利用效率。我们建议，这个新的土壤模块，参数化的全球模拟，将提高代表性的全球碳循环LSM，从而有助于限制未来SOC响应全球变暖的预测。
Current land surface models (LSMs) typically represent soils in a very simplistic way, assuming soil organic carbon (SOC) as a bulk, and thus impeding a correct representation of deep soil carbon dynamics. Moreover, LSMs generally neglect the production and export of dissolved organic carbon (DOC) from soils to rivers, leading to overestimations of the potential carbon sequestration on land. This common oversimplified processing of SOC in LSMs is partly responsible for the large uncertainty in the predictions of the soil carbon response to climate change. In this study, we present a new soil carbon module called ORCHIDEE-SOM, embedded within the land surface model ORCHIDEE, which is able to reproduce the DOC and SOC dynamics in a vertically discretized soil to 2 m. The model includes processes of biological production and consumption of SOC and DOC, DOC adsorption on and desorption from soil minerals, diffusion of SOC and DOC, and DOC transport with water through and out of the soils to rivers. We evaluated ORCHIDEE-SOM against observations of DOC concentrations and SOC stocks from four European sites with different vegetation covers: a coniferous forest, a deciduous forest, a grassland, and a cropland. The model was able to reproduce the SOC stocks along their vertical profiles at the four sites and the DOC concentrations within the range of measurements, with the exception of the DOC concentrations in the upper soil horizon at the coniferous forest. However, the model was not able to fully capture the temporal dynamics of DOC concentrations. Further model improvements should focus on a plant- and depth-dependent parameterization of the new input model parameters, such as the turnover times of DOC and the microbial carbon use efficiency. We suggest that this new soil module, when parameterized for global simulations, will improve the representation of the global carbon cycle in LSMs, thus helping to constrain the predictions of the future SOC response to global warming.