Potential adsorption of dissolved organic matter in poorly podzolised, high-latitude soils
Potential adsorption of dissolved organic matter in poorly podzolised, high-latitude soils
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DOI：
10.1016/j.geoderma.2014.02.027
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发表时间：
2014-08
期刊：
影响因子：
6.1
通讯作者：
A. Pengerud;L. Johnsen;J. Mulder;L. Strand
中科院分区：
文献类型：
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作者：
A. Pengerud;L. Johnsen;J. Mulder;L. Strand
溶解有机质（DOM）在土壤和水体中的许多生态地球化学过程中起着重要作用，土壤中DOM的滞留影响着DOM从陆地生态系统向水生生态系统输出的数量和组成。土壤矿物层的吸附作用被认为是DOM在土壤中保持和稳定的主要机制，灰壤由于其在矿物层B中保持DOM的能力而受到关注。随着高纬度地区气温和降水量的增加，有机质的运输预计会增加，但很少有研究调查了高纬度地区灰化土壤中DOM的吸附。在这项研究中，我们使用了一批平衡实验，以探讨潜在的DOM吸附在B层的灰化土壤从一个封闭的区域内，北方挪威。用初始质量（IM）等温线描述了土壤从溶液中去除或释放溶解有机碳（DOC）的量与添加到土壤-水悬浮液中的DOC量的线性函数关系，结果表明，在灰化不良的高纬度土壤中，B层对DOC的亲合力主要取决于无定形Fe和Al氧化物的含量，其中吸附受到有机质对无定形Fe和Al的饱和度的限制。B层位的DOC吸附特性的变化相对较大，与整体较低的潜力，吸附增加DOC在现场相关的DOC浓度。12个B层中有6个在整个DOC添加范围内（0-480 mg C kg− 1土壤）表现出DOC净解吸。这些研究结果表明，在较高纬度的温暖和潮湿的气候条件下，在灰化较差的土壤中，DOM的保留和稳定潜力有限。
Dissolved organic matter (DOM) plays an essential role in many biogeochemical processes in soil and water, and the retention of DOM in soils influences the amount and composition of DOM exported from terrestrial to aquatic ecosystems. Adsorption in soil mineral horizons is considered a main mechanism by which DOM is retained and stabilised in soils, and podzol soils have received attention due to their capacity to retain DOM in the mineral B horizon. With the projected increase in temperature and precipitation at higher latitudes, the transport of organic matter is expected to increase, but few studies have investigated the adsorption of DOM in poorly podzolised soils at higher latitudes. In this study, we used batch equilibrium experiments to investigate the potential for DOM adsorption in the B horizon of poorly podzolised soils from a confined area in Neiden, northern Norway. We used the Initial Mass (IM) isotherm to describe the amount of dissolved organic carbon (DOC) removed from or released to solution by the soil as a linear function of the amount of DOC added to the soil–water suspension.Our results suggest that the affinity for DOC of B horizons in poorly podzolised high-latitude soils is largely determined by the content of amorphous Fe and Al oxides, where adsorption is limited by the saturation of amorphous Fe and Al with organic matter. The B horizons show a relatively large variation in DOC sorption characteristics, with an overall low potential to adsorb added DOC at field relevant DOC concentrations. Six out of twelve B horizons show a net DOC desorption over the whole range of added DOC (0–480 mg C kg− 1soil). These findings indicate a limited potential for retention and stabilisation of DOM in poorly podzolised soils at higher latitudes in a warmer and wetter climate.