Simulation of carbon cycling, including dissolved organic carbon transport, in forest soil locally enriched with 14C
Simulation of carbon cycling, including dissolved organic carbon transport, in forest soil locally enriched with 14C
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DOI：
10.1007/s10533-011-9575-1
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发表时间：
2011
期刊：
影响因子：
4
通讯作者：
E. Tipping;P. Chamberlain;M. Fröberg;P. Hanson;P. Jardine
中科院分区：
文献类型：
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作者：
E. Tipping;P. Chamberlain;M. Fröberg;P. Hanson;P. Jardine
采用DyDOC模型对美国田纳西州橡树岭自然保护区落叶森林的土壤碳循环进行了模拟。该模型应用依赖于富集背景同位素研究（EBIS）的大量数据，该研究利用短期的局部大气放射性碳富集，建立了一个大规模的操作实验，从地上和地下凋落物中输入不同的14c。该模型首先拟合水文数据，然后利用观测到的碳库和碳通量和碳14c数据拟合描述土壤有机质（SOM）组分代谢转化和溶解有机质（DOM）运输和吸收的参数。这对土壤剖面的三个层位（O、a、B）的土壤C循环进行了详细的定量描述。根据参数化模型，薄o层内的SOM周转迅速产生DOM (46 gC m−2a−1)，主要是疏水性的。这些DOM几乎全部被吸附在A层和b层，虽然大多数相对较快地矿化，但11 gC m−2a−1经历了“成熟”反应，产生了与矿物相关的稳定SOM池，平均停留时间为100-200年。亲水DOM只有一小部分通量（~1 gC m−2a−1）离开b -视界。与矿物质无关的SOM被认为来自于凋落根，并且周转相当快（平均停留时间20-30年）。虽然DyDOC成功地拟合了C池、年通量和14c数据，但它不能很好地解释DOC浓度的短期变化。
The DyDOC model was used to simulate the soil carbon cycle of a deciduous forest at the Oak Ridge Reservation (Tennessee, USA). The model application relied on extensive data from the Enriched Background Isotope Study (EBIS), which exploited a short-term local atmospheric enrichment of radiocarbon to establish a large-scale manipulation experiment with different inputs of14C from both above-ground and below-ground litter. The model was first fitted to hydrological data, then observed pools and fluxes of carbon and14C data were used to fit parameters describing metabolic transformations of soil organic matter (SOM) components and the transport and sorption of dissolved organic matter (DOM). This produced a detailed quantitative description of soil C cycling in the three horizons (O, A, B) of the soil profile. According to the parameterised model, SOM turnover within the thin O-horizon rapidly produces DOM (46 gC m−2a−1), which is predominantly hydrophobic. This DOM is nearly all adsorbed in the A- and B-horizons, and while most is mineralised relatively quickly, 11 gC m−2a−1undergoes a “maturing” reaction, producing mineral-associated stable SOM pools with mean residence times of 100–200 years. Only a small flux (~1 gC m−2a−1) of hydrophilic DOM leaves the B-horizon. The SOM not associated with mineral matter is assumed to be derived from root litter, and turns over quite quickly (mean residence time 20–30 years). Although DyDOC was successfully fitted to C pools, annual fluxes and14C data, it accounted less well for short-term variations in DOC concentrations.