Effects of surface characteristics on infiltration patterns in an arid shrub desert
Effects of surface characteristics on infiltration patterns in an arid shrub desert
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DOI：
10.1002/hyp.6185
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发表时间：
2007-01
影响因子：
3.2
通讯作者：
Xin‐ping Wang;Xin‐rong Li;Honglang Xiao;R. Berndtsson;Yan-xia Pan
中科院分区：
文献类型：
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作者：
Xin‐ping Wang;Xin‐rong Li;Honglang Xiao;R. Berndtsson;Yan-xia Pan
降水通常是干旱和半干旱地区唯一的水补充来源，因此在维持沙漠生态系统方面发挥着重要作用。在中国兰州附近的沙坡头沙漠试验研究站，主要使用油蒿和柠条进行了40多年的植被重建，在稳定的沙丘上建立了矮灌木和微生物土壤结皮覆盖。渗透水分的再分配通过渗滤，根提取，和蒸散途径进行了研究。将三组时域反射仪（TDR）探头水平插入土壤坑中地面以下5、10、15、20、30和40 cm深度处。三套TDR探头分别安装在A. ordosica和C. korshinskii群落，有和没有微生物土壤结皮覆盖，另一组被放置在一个裸露的沙丘地区，既没有植被，也没有微生物土壤结皮存在。每小时记录一次土壤体积含水量，并用于评估不同地表覆盖物的渗透情况。入渗量变化很大，从7.5 cm到45 cm以上，取决于降雨量和土壤表面条件。在灌木群落区没有微生物土壤结皮覆盖，渗透增加，由于优先流与根隧道。微生物土壤结皮覆盖对小降雨事件（10 mm）的入渗有显着的负面影响，限制入渗深度小于20 cm，增加土壤水分含量仅低于10 cm的土壤剖面，而它不是强大的或明显的较大的降雨事件（10 mm）。在小降雨过程中，3种地表覆盖的湿润锋深度大小为：无生物结皮灌木群落>裸地>有生物结皮灌木群落。相比之下，对于大的降雨事件，在灌木群落中的渗透率是相似的，没有微生物土壤结皮覆盖，但显着高于在裸露地区测量。土壤水分提取与蒸发蒸腾限制湿润锋渗透后1至3小时的降雨。版权所有© 2006约翰威利父子有限公司。
Precipitation is often the sole source of water replenishment in arid and semi‐arid areas and, thus, plays a pertinent role in sustaining desert ecosystems. Revegetation over 40 years using mainly Artemisia ordosica and Caragana korshinskii at Shapotou Desert Experimental Research Station near Lanzhou, China, has established a dwarf‐shrub and microbiotic soil crust cover on the stabilized sand dunes. The redistribution of infiltrated moisture through percolation, root extraction, and evapotranspiration pathways was investigated. Three sets of time‐domain reflectometry (TDR) probes were inserted horizontally at 5, 10, 15, 20, 30 and 40 cm depths below the ground surface in a soil pit. The three sets of TDR probes were installed in dwarf‐shrub sites of A. ordosica and C. korshinskii community with and without a microbiotic soil crust cover, and an additional set was placed in a bare sand dune area that had neither vegetation nor a microbiotic soil crust present. Volumetric soil moisture content was recorded at hourly intervals and used in the assessment of infiltration for the different surface covers. Infiltration varied greatly, from 7·5 cm to more than 45 cm, depending upon rainfall quantity and soil surface conditions. In the shrub community area without microbiotic soil crust cover, infiltration increased due to preferential flow associated with root tunnels. The microbiotic soil crust cover had a significant negative influence on the infiltration for small rainfall events (∼10 mm), restricting the infiltration depth to less than 20 cm and increasing soil moisture content just beneath the soil profile of 10 cm, whereas it was not as strong or clear for larger rainfall events (∼60 mm). For small rainfall events, the wetting front depth for the three kinds of surface cover was as follows: shrub community without microbiotic soil crust > bare area > shrub community with microbiotic soil crust. In contrast, for large rainfall events, infiltration was similar in shrub communities with and without microbiotic soil crust cover, but significantly higher than measured in the bare area. Soil water extraction by roots associated with evapotranspiration restricted the wetting front penetration after 1 to 3 h of rainfall. Copyright © 2006 John Wiley & Sons, Ltd.