Biological soil crusts cause subcritical water repellency in a sand dune ecosystem located along a rainfall gradient in the NW Negev desert, Israel
Biological soil crusts cause subcritical water repellency in a sand dune ecosystem located along a rainfall gradient in the NW Negev desert, Israel
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DOI：
10.1515/johh-2016-0001
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发表时间：
2016-06-01
影响因子：
1.9
通讯作者：
Felix-Henningsen, Peter
中科院分区：
文献类型：
--
作者：
Keck, Hannes;Felde, Vincent John Martin Noah Linus;Felix-Henningsen, Peter
内盖夫西北部的生物土壤结皮（BSC）通过增加地表径流引起当地水的重新分布。在早期的研究中，对有机和无机结壳成分的孔隙堵塞和膨胀的影响进行了深入研究。然而，拒水性（WR）的影响还没有得到系统的解决。本研究调查了次临界WR的BSC在三个不同的研究地点在西北内盖夫。为此，使用了三种常用的方法来确定土壤WR：（i）排斥指数（RI）方法，（ii）水滴渗透时间（WDPT）测试和（iii）威廉米平板法（WPM）。此外，还讨论了水资源分配对当地水资源再分配的潜在影响，并对各种方法进行了比较。我们发现BSC是亚临界防水的。水分亏缺程度可能只在微观尺度上影响水分再分配，对整个生态系统的影响不大。RI方法显然是最适合使用的，而WDPT和WPM未能检测亚临界WR。
The biological soil crusts (BSCs) in the NW Negev cause local water redistribution by increasing surface runoff. The effects of pore clogging and swelling of organic and inorganic crust components were intensively investigated in earlier studies. However, the effect of water repellency (WR) was not addressed systematically yet. This study investigates subcritical WR of BSCs in three different study sites in the NW Negev. For this purpose, three common methods to determine soil WR were used: (i) the repellency index (RI) method (ii) the water drop penetration time (WDPT) test and (iii) the Wilhelmy plate method (WPM). Furthermore, the potential influence of WR on local water redistribution is discussed and the applied methods are compared. We found the BSC to be subcritically water repellent. The degree of WR may only affect water redistribution on a microscale and has little influence on the ecosystem as a whole. The RI method was clearly the most appropriate to use, whereas the WDPT and the WPM failed to detect subcritical WR.