Carbon Accumulation and Storage in Mineral Subsoil beneath Peat
Carbon Accumulation and Storage in Mineral Subsoil beneath Peat
复制标题
DOI：
10.2136/sssaj2004.6900
复制
发表时间：
2002-12
影响因子：
2.9
通讯作者：
T. Moore;J. Turunen
中科院分区：
文献类型：
--
作者：
T. Moore;J. Turunen
结果表明，在密歇根州拉姆齐湖附近泥炭下的桑迪底土中，70 cm深度处有机C（OC）的含量为7.5 ~ 8.0 kg/m-2，而邻近的森林土壤中有机C（OC）的含量为1.6 ~ 3.6 kg/m-2，泥炭地是从森林土壤中通过沼泽化而形成的。与森林下的土壤相比，泥炭下的土壤中含有类似量的铝（Al 0）和较少的铁，由于铁的损失下减少沥滤条件下的泥炭。泥炭下矿物层中的可提取铝大部分是有机结合的。原子焦磷酸盐可提取的（Fep + Alp）Fe + Al/C的比例较小（0.2：1），表明较大的输入和保留在泥炭下的矿物底土。土壤有机碳含量与Al、溶解有机碳（DOC）和粘粒含量呈显著正相关（r2 = 0.58，p < 0.001）。用0 ~ 117 mgDOC L-1泥炭孔隙水对DOC的吸附研究表明，土壤中DOC的零值浓度（DOC np）在<1 ~ 417 mgDOC L-1之间变化，主要与Fe 0（负相关）、Al 0（负相关）和C（正相关）相关。我们认为，泥炭下的矿物底土OC的增加与DOC的吸附通过矿物底土的孔隙水蒸发，结合缺氧条件下吸附DOC的矿化速率慢。
We showed that sandy subsoils beneath peat near Ramsey Lake, MI, contained 7.5 to 8.0 kg organic C (OC) m -2 to a depth of 70 cm, compared with 1.6 to 3.6 kg m -2 in adjacent forest soils, from which the peatland had evolved through paludification. Compared with the soils beneath the forest, those beneath the peat contained similar amounts of oxalate-extractable Al (Al 0 ) and less Fe, owing to loss of Fe under reduced leached conditions beneath the peat. Most of the extractable Al in the mineral horizons beneath peat was organically bound. Atomic pyrophosphate-extractable (Fe p + Al p ) Fe + Al/C ratios were smaller ( 0.2:1), indicating larger inputs and retention in the mineral subsoils beneath peat. Concentration of OC in subsoil samples was strongly (r 2 = 0.58, p < 0.001) related to the subsoil Al, null-point dissolved organic C (DOC) and clay concentrations. A DOC sorption study using peat pore water ranging from 0 to 117 mg DOC L -1 revealed null-point DOC (DOC np ) concentrations (at which there is neither gain nor loss of OC by the soil) varied from <1 to 417 mg DOC L -1 and was primarily related to Fe 0 (negatively), Al 0 (negatively), and C (positively). We suggest that the increase in mineral subsoil OC beneath peat is related to the sorption of DOC carried by pore water percolating through the mineral subsoil, combined with slow rates of mineralization of sorbed DOC under anoxic conditions.