Vegetation controls on soil moisture distribution in the Valles Caldera, New Mexico, during the North American monsoon
Vegetation controls on soil moisture distribution in the Valles Caldera, New Mexico, during the North American monsoon
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DOI：
10.1002/eco.11
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发表时间：
2008-09-01
期刊：
影响因子：
2.6
通讯作者：
Wyckoff, Robert L.
中科院分区：
文献类型：
--
作者：
Vivoni, Enrique R.;Rinehart, Alex J.;Wyckoff, Robert L.
土壤水分分布预计将密切联系在美国西南部的水有限的环境中的生态系统过程。然而，很少有研究涉及土壤水分如何变化，经常观察到在半干旱山区设置从草原到森林的过渡。在这项研究中，我们量化的植被控制表层土壤水分采样的一系列不同的生态系统存在于山谷火山口，新墨西哥州。土壤和大气变量进行了测量，在2005年7月下旬至8月初在北美季风进行了为期2周的实地活动。实地观察得到了一个连续仪器网络的补充，该网络用于评估取样活动前后的情况。结果表明，土壤水分直接响应于夏季降水事件和介导的植物截留，这在整个草原森林连续体不同。土壤水分的时空变化的性质在不同的采样生态系统中发生变化：湿地、河岸森林、草地、黄松、落叶林和针叶混交林。特别是，土壤水分分布的统计分析表明，不同的制度（如概率密度函数）存在沿着半干旱植被梯度，这可能无法通过简单的指标，如生态系统的平均值。生态系统的差异进一步阐明了通过比较的空间变异ill每种植被类型，表明湿地和草地网站更高的变异性。版权所有（C）2008约翰威利父子有限公司
Soil moisture distributions are expected to be closely tied to ecosystem processes in water-limited environments of the southwest United States. Nevertheless, few studies have addressed how soil moisture varies across grassland to forest transitions frequently observed in semiarid mountain settings. In this study, we quantify the vegetation controls on surface soil moisture by sampling a range of different ecosystems present in the Valles Caldera, New Mexico. Soil and atmospheric variables were measured during a 2-week field campaign conducted in late July to early August 2005 during the North American monsoon. Field observations were supplemented by a network of continuous instruments used to assess conditions prior to and after the sampling campaign. Results reveal that soil moisture responds directly to summer precipitation events and is mediated by plant interception, which differs across the grassland-forest continuum. The nature of the spatial and temporal variations in soil moisture changes across the different sampled ecosystems: wetlands, riparian forests, grasslands, ponderosa, deciduous and mixed conifer forests. In particular, statistical analyses of soil moisture distributions indicate that distinct regimes (e.g. probability density functions) exist along the semiarid vegetation gradient, which may not be revealed through simple metrics such as the ecosystem average. Ecosystem differences are further elucidated through comparison of the spatial variations ill each vegetation type, indicating higher variability in wetland and grassland sites. Copyright (C) 2008 John Wiley & Sons, Ltd.