摘要
生物结皮是干旱和半干旱地区地表覆被的重要组成部分,可对土壤理化性状以及水土流失产生重要影响,其中土壤斥水性是一个重要方面。使用滴水穿透时间法、酒精溶液入渗法以及盘式吸渗仪法,分别测定了黄土区典型苔藓结皮和无结皮对照的斥水时间、斥水强度以及斥水系数,对比研究了苔藓结皮对土壤斥水性的影响。同时,对苔藓结皮进行了不同时间(15,30,45,60,90s)的火烧处理,分析苔藓结皮的斥水性对火烧时间的响应。结果表明:黄土区苔藓结皮的平均斥水时间为22.95s,斥水强度(酒精溶液临界浓度)为3%,斥水系数为2.66。与无结皮对照相比,苔藓结皮的斥水时间和斥水系数分别显著增加了12倍和14.6%。同时,火烧处理显著增强了苔藓结皮的斥水性,且火烧时间越长其斥水性越强。15,30,45,60,90s火烧处理后,苔藓结皮的斥水时间分别增加0.9,31.4,19.3,54.8,127.4倍,斥水系数分别增加8.9%、11.2%、21.2%、21.9%、28.9%。说明黄土区苔藓结皮具有较强斥水性,且火烧处理可使其斥水性进一步增强,因此在该地区土地利用和管理中应予以重视。
Biological soil crusts （BSCs） are very important components of land cover in arid and semiarid climate regions. Thesoil water repellency of BSCs is of great importance to their hydrological and ecological function, but have not yet sufficientlyinvestigated. On the Loess Plateau of China, the duration, intensity, and indices of soil water repellency of the typical mossdominatedBSCs, the BSCs after different burning durations （15, 30, 45, 60, 90s）, and no crust were measured by the methods ofwater-drop penetration time, molarity of ethanol droplet, and mini disk infiltrometer, respectively, to determine the effects of BSCson soil water repellency and their response to fire duration. The results showed that the duration, intensity, and indiex of soilwater repellency of the BSCs were 22.5s, 3%, and 2.66, respectively. Compared with the no crust, the duration and the index ofsoil water repellency were significantly increased by 12 times and 14.6%, respectively, due to the occurrence of BSCs. After 15,30, 45, 60 and 90s of fire, the duration times of soil water repellency indices of the BSCs were increased by 0.9, 31.4, 19.3,54.8, and 127.4, respectively, whereas the soil water repellency indices of the BSCs were increased by 8.9%, 11.2%, 21.2%,21.9%, and 28.9%, respectively. This results indicated that the soil water repellency of the BSCs was further intensified by thefire. From this study, we concluded that the moss-dominated BSCs have significant influences on soil water repellency on theLoess Plateau of China, and these influences would be further significantly strengthened by fire.
出处
《沈阳农业大学学报》
CAS
CSCD
北大核心
2016年第2期212-217,共6页
Journal of Shenyang Agricultural University
基金
国家自然科学基金项目(41001156)
黄土高原土壤侵蚀与旱地农业国家重点实验室基金项目(A314021402-1513)
关键词
生物结皮
苔藓结皮
火烧
斥水时间
斥水强度
斥水系数
microbiotic crust
moss crust
fire duration
water drop penetration time
water repellence intensity
water repellency index
