Epigenetic salt accumulation and water movement in the active layer of central Yakutia in eastern Siberia
Epigenetic salt accumulation and water movement in the active layer of central Yakutia in eastern Siberia
复制标题
DOI：
10.1002/hyp.6224
复制
发表时间：
2005-12
影响因子：
3.2
通讯作者：
C. Lopez;A. Brouchkov;H. Nakayama;F. Takakai;A. Fedorov;M. Fukuda
中科院分区：
文献类型：
--
作者：
C. Lopez;A. Brouchkov;H. Nakayama;F. Takakai;A. Fedorov;M. Fukuda
在东西伯利亚的Neleger站，从5月到8月进行了土壤水分和盐分含量的观测。研究了落叶松林活动层（原状）和热岩溶洼地（扰动）土壤盐分和水分分布的季节变化。完整森林的电导率ECe显示出较高的浓度，从土壤表面到活动层和下面的永久冻土层的深度增加：在1.1 m处为1 mS cm−1，在永久冻土层160 cm处为2.6 mS cm−1。然而，在0.6 m深度处的最大值为5.4 mS cm−1，出现在阿拉斯的干燥区域。离子的浓度，特别是Na+，Mg 2+，Ca 2+，SO 42-和HCO 3-在这个长期扰动的网站的上层，表明离子与水一起向上运动。较高浓度的溶质被发现在配置文件与更深的季节性解冻。盐沼中盐分的积累从春天一直持续到生长季节。表层土壤盐分浓度低，似乎与降雨对盐分的沥滤有关。林地和林地土壤的含水量和电导率有很大差异。阿拉斯活跃层的现代盐碱化是后生的，它发生在夏季，由于泉水收集和夏季蒸发量大;与森林相比，阿拉斯的盐逐渐积累是由活跃层的水盐年度平衡控制的。目前的气候趋势表明，东西伯利亚的永久冻土持续退化，增加了地表盐碱化的风险，这已经通过阻碍森林的生长而改变了地貌。版权所有© 2006约翰威利父子有限公司。
Observations of soil moisture and salt content were conducted from May to August at Neleger station in eastern Siberia. Seasonal changes of salt and soil moisture distribution in the active layer of larch forest (undisturbed) and a thermokarst depression known as an alas (disturbed) were studied. Electric conductivity ECe of the intact forest revealed higher concentrations that increased with depth from the soil surface into the active layer and the underlying permafrost: 1 mS cm−1 at 1·1 m, to 2·6 mS cm−1 at 160 cm depth in the permafrost. However, a maximum value of 5·4 mS cm−1 at 0·6 m depth was found in the dry area of the alas. The concentration of ions, especially Na+, Mg2+, Ca2+, SO42− and HCO3− in the upper layers of this long‐term disturbed site, indicates the upward movement of ions together with water. A higher concentration of solutes was found in profiles with deeper seasonal thawing. The accumulation of salts in the alas occurs from spring through into the growing season. The low concentration of salt in the surface soil layers appears to be linked to leaching of salts by rainfall. There are substantial differences between water content and electric conductivity of soil in the forest and alas. Modern salinization of the active layer in the alas is epigenetic, and it happens in summer as a result of spring water collection and high summer evaporation; the gradual salt accumulation in the alas in comparison with the forest is controlled by the annual balance of water and salts in the active layer. Present climatic trends point to continuous permafrost degradation in eastern Siberia increasing the risk of surface salinization, which has already contributed to changing the landscape by hindering the growth of forest. Copyright © 2006 John Wiley & Sons, Ltd.