Factors controlling the spatial patterns of soil moisture in a grazed semi-arid steppe investigated by multivariate geostatistics
Factors controlling the spatial patterns of soil moisture in a grazed semi-arid steppe investigated by multivariate geostatistics
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DOI：
10.1002/eco.121
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发表时间：
2011-01-01
期刊：
影响因子：
2.6
通讯作者：
Horn, Rainer
中科院分区：
文献类型：
--
作者：
Zhao, Ying;Peth, Stephan;Horn, Rainer
土地利用对土壤水分的空间格局有重大影响，特别是在敏感和管理不善的地区。本文以内蒙古半干旱草原放牧区为研究对象，研究了土壤、植被和地形在控制水分空间格局中的相对重要性。在2004-2006年期间调查了五个田地：两个自1979年以来未放牧的地块（UG 79）和1999年以来未放牧的地块（UG 99）;三个放牧地块在冬季放牧（WG），连续放牧（CG）和重度放牧（HG），分别为0.5，1.2和2.0羊单位公顷（-1）年（-1）。使用相关性和地质统计学分析的数据进行了分析。结果表明：（1）放牧降低了土壤0-6 cm体积含水量及其空间异质性;（2）土壤水分空间格局具有弱到中等的空间结构;（3）土壤和植物特性，尤其是土壤物理特性是控制土壤水分空间格局的主要因素。多变量地质统计学进一步表明，这些控制参数取决于治疗的规模依赖相关性。随着放牧强度的增加，土壤和植物性状的异质性从斑块状分布逐渐降低到均匀分布。在短尺度（45 m）下，土壤和植物性状对UG 99土壤水分的变化有较强的控制作用，在长尺度（90 m）下，对CG和HG土壤水分的变化有较强的控制作用，而对UG 79和WG土壤水分的变化有较弱的控制作用。我们的研究结果对于了解半干旱草原的生态水文过程以及模型参数化具有重要意义。我们建议，牧场管理强烈修改土壤水分模式，这应该考虑在多个空间尺度的水文模型。版权所有（C）2010约翰威利父子有限公司
Land use has a significant impact on spatial patterns of soil moisture, particularly in sensitive and poorly managed regions. This study evaluated the relative importance of soil, vegetation and topography in controlling the spatial moisture patterns in a grazed semi-arid steppe of Inner Mongolia. Five fields were investigated during 2004-2006: two ungrazed plots since 1979 (UG 79) and 1999 (UG 99); three grazed plots in winter grazed (WG), continuously grazed (CG) and heavily grazed (HG) with 0.5, 1.2 and 2.0 sheep units ha(-1) year(-1), respectively. The data were analysed using correlation and geostatistical analysis. Results showed that (1) grazing reduced the volumetric moisture contents (0-6 cm) and their spatial heterogeneity; (2) soil moisture patterns had weak to moderate spatial structures and (3) soil and plant properties, especially soil physical properties, were the main factors controlling spatial moisture patterns. Multivariate geostatistics further showed scale-dependent correlation for these controlling parameters depending on treatments. With increasing grazing intensity, heterogeneity of soil and plant properties decreased from a patchy to a homogeneous distribution. Specifically, the soil and plant properties strongly controlled the variation of soil moisture for UG 99 at short scale (45 m), and for CG and HG at long scale (90 m), however, weakly controlled the variation of soil moisture for UG 79 and WG. Our results have implications for the understanding ecohydrological processes of semi-arid steppe as well as model parameterization. We suggest that pasture management strongly modified soil moisture patterns, which should be considered in the hydrological models at multiple spatial scales. Copyright (C) 2010 John Wiley & Sons, Ltd.