The role of biological soil crusts in soil moisture dynamics in two semiarid ecosystems with contrasting soil textures
The role of biological soil crusts in soil moisture dynamics in two semiarid ecosystems with contrasting soil textures
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DOI：
10.1016/j.jhydrol.2013.02.051
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发表时间：
2013-05-10
影响因子：
6.4
通讯作者：
Domingo, Francisco
中科院分区：
文献类型：
--
作者：
Chamizo, Sonia;Canton, Yolanda;Domingo, Francisco
在大多数干旱和半干旱生态系统中，植物间的土壤表面被生物土壤结皮（BSCs）所覆盖。这些结皮调节着土壤的水分输入和流失，并在当地水文状况中起着重要作用。近年来，生物土壤结皮在入渗和径流方面的作用日益重要，人们对其在这些过程中的影响也有了更深入的了解。然而，生物土壤结皮在水分平衡的其他重要组成部分（如蒸发或土壤湿度）中的作用却鲜有研究，因此它们对这些过程的影响仍不为人知。本研究的目的是探究生物土壤结皮对西班牙东南部两个具有不同粒径分布的半干旱生态系统中土壤表层土壤湿度状况的影响。在两个研究地点，分别在两种生物土壤结皮（一种以蓝藻为主的生物土壤结皮和一种以地衣为主的生物土壤结皮）下以及它们被移除后的相邻土壤中，对0.03米和0.10米深处的土壤湿度进行监测。我们的研究结果表明，在土壤湿润期，与有生物土壤结皮覆盖的土壤相比，移除生物土壤结皮会导致土壤湿度下降，尤其是在上层（0.03米处）。移除地衣后土壤湿度的下降比移除蓝藻生物土壤结皮更为明显，且在质地细的土壤中比在质地粗的土壤中更为显著。没有生物土壤结皮的土壤水分流失通常也比有生物土壤结皮覆盖的土壤更快。然而，在土壤干燥期，有结皮和无结皮的土壤湿度没有差异。生物土壤结皮的类型对土壤湿度的影响因土壤含水量而异。在土壤湿润期，蓝藻生物土壤结皮下的土壤水分流失更快，土壤湿度更低。相反，在土壤干燥期，地衣覆盖的土壤失水更快，湿度更低。我们的研究结果表明了生物土壤结皮的存在以及其类型在半干旱生态系统土壤含水量中所起的重要作用。（C）2013爱思唯尔公司。保留所有权利。
The interplant soil surfaces in most arid and semiarid ecosystems are covered by biological soil crusts (BSCs). These crusts regulate water inputs and losses through soils and play major roles in local hydrological regimes. In recent years, the role of BSCs in infiltration and runoff has gained increasing importance and better knowledge of their effects on these processes has been acquired. However, the role of BSCs in other important components of the water balance, such as evaporation or soil moisture has hardly been studied, so their effects on these processes remain unknown. The aim of this study was to explore the influence of BSCs on soil moisture regimes in the top layer of the soil in two semiarid ecosystems in SE Spain with different particle-size distributions. At both study sites, soil moisture was monitored at 0.03 and 0.10 m under two types of BSCs, a cyanobacteria-dominated BSC and a lichen-dominated BSC, and in adjacent soils where they had been removed. Our results showed that during wet soil periods, removal of BSCs led to decreased soil moisture, especially in the upper layer (0.03 m), compared to soils covered by BSCs. Decrease in soil moisture was more noticeable after removal of lichens than cyanobacterial BSCs, and more so in fine than in coarse-textured soils. Soil water loss was also generally faster in soils with no BSCs than in soils covered by them. However, no difference was found in soil moisture under either crusted or scalped soils during soil drying periods. The type of BSC influenced soil moisture differently depending on soil water content. During wet soil periods, soil water loss was faster and soil moisture lower under cyanobacterial than under lichen BSCs. On the contrary, during soil drying periods, soils covered by lichens lost water faster and showed lower moisture than those covered by cyanobacteria. Our results show the major role of the presence of BSCs, as well as the types, in soil water content in semiarid ecosystems. (C) 2013 Elsevier B.V. All rights reserved.