Aspect influences on soil water retention and storage
Aspect influences on soil water retention and storage
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DOI：
10.1002/hyp.8281
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发表时间：
2011-12-15
影响因子：
3.2
通讯作者：
McNamara, J. P.
中科院分区：
文献类型：
--
作者：
Geroy, I. J.;Gribb, M. M.;McNamara, J. P.
许多流域水文生态过程都受到土壤贮水能力的影响，而土壤贮水能力又取决于土壤剖面厚度和土壤的持水特性。土壤持水特性主要受土壤质地控制，而土壤质地又因小气候引起的日照、湿度和温度差异而在空间上发生变化。所有这些变量都可以通过坡度方面进行强烈区分。在这项研究中，我们比较了土壤持水能力的定量措施，在美国西南部爱达荷州的半干旱集水区的两个相对的斜坡。采用原状土柱，从南北两个方向进行连续排水试验，估算每个样点的土壤持水曲线。相对较大的样本量（35）支持统计分析的土壤持水率相对方面之间的坡度尺度差异。在任何给定的土壤水压力下，北面的土壤比南面斜坡的土壤多保留25%的水分。土壤孔隙度、土壤有机质和粉粒含量均以北侧为最大，且均对土壤持水能力有较大贡献。这些结果，沿着观察，北山坡上的土壤往往更深，表明北山坡可以存储更多的水分从潮湿的冬季到干燥的夏季在该地区，观察与生态功能和景观演变的潜在影响。版权所有（c）2011约翰威利父子有限公司
Many catchment hydrologic and ecologic processes are impacted by the storage capacity of soil water, which is dictated by the profile thickness and water retention properties of soil. Soil water retention properties are primarily controlled by soil texture, which in turn varies spatially in response to microclimate-induced differences in insolation, wetness and temperature. All of these variables can be strongly differentiated by slope aspect. In this study, we compare quantitative measures of soil water retention capacity for two opposing slopes in a semi-arid catchment in southwest Idaho, USA. Undisturbed soil cores from north and south aspects were subjected to a progressive drainage experiment to estimate the soil water retention curve for each sample location. The relatively large sample size (35) supported statistical analysis of slope scale differences in soil water retention between opposing aspects. Soils on the north aspect retain as much as 25% more water at any given soil water pressure than samples from the south aspect slope. Soil porosity, soil organic matter and silt content were all greater on the north aspect, and each contributed to greater soil water retention. These results, along with the observation that soils on north aspect slopes tend to be deeper, indicate that north aspect slopes can store more water from the wet winter months into the dry summer in this region, an observation with potential implications on ecological function and landscape evolution. Copyright (c) 2011 John Wiley & Sons, Ltd.