中国沙漠 ›› 2001, Vol. 21 ›› Issue (3): 217-222.

• 研究论文 •    下一篇


李新荣, 马凤云, 龙立群, 贾晓红   

  1. 中国科学院寒区旱区环境与工程研究所沙坡头沙漠试验研究站, 甘肃兰州 730000
  • 收稿日期:2000-08-10 修回日期:2000-12-20 出版日期:2001-09-20 发布日期:2001-09-20
  • 作者简介:李新荣(1966-),男(汉族),甘肃武山人,博士,研究员,从事干旱区植物生态学研究。
  • 基金资助:

Soil Water Dynamics under Sand-fixing Vegetation in Shapotou Area

LI Xin-rong, MA Feng-yun, LONG Li-qun, JIA Xiao-hong   

  1. Shapotou Desert Research & Experiment Station, Cold and Arid Regions Environmental & Engineering Research Institute, CAS, Lanzhou 730000, China
  • Received:2000-08-10 Revised:2000-12-20 Online:2001-09-20 Published:2001-09-20

摘要: 沙坡头地区始建于1956年的无灌溉人工固沙植被,是我国交通干线防沙体系的成功模式。利用40余年的土壤水分定位观测数据,分析了不同期间建立的固沙植被土壤水分的时空变化特征及对植被的影响。结果表明,固沙植被发展至9~10a后土壤含水量开始明显下降,特别是较深层(>100cm)的含水量下降明显;0~40cm层土壤水分含量与降水相关显著,而降水对40~300cm层土壤水分的含量影响不显著;深根系固沙植物对根际区域水分的利用,进一步恶化了固沙区土壤深层的水分状况,进而抑制了这些植物的生长和生存,间接地影响了原有固沙植被组成和稳定性;经过40多年的演变,固沙植被中优势灌木种的盖度从最大盖度47.6%降至6%~9%,群落中草本和微生物结皮层得到发育。当深根系灌木的盖度降低至6%~9%时,深层土壤可维持一个相对稳定的低含水量。

关键词: 沙坡头地区, 固沙植被, 土壤水分动态

Abstract: The artificial sand-fixing vegetation under no-irrigation condition was established in 1956, which is a successful model of protective system for railway communication in China. In this paper, based on observation data during about 40 yea rs, the characteristics of soil water changes in time and in spatial and its effects on vegetation in different sand-fixing areas were analyzed. The results showed that soil water obviously decreased after 9~10 years since vegetation was planted. Especially, the soil water in deeper soil layer remarkably reduced. There is a good corrective relationship between precipitation and soil water in 0~40 cm layer, but we failed to find the relationship between precipitation and soil water in deeper layer (from 40 to 300 cm). The soil moisture in deeper layer further worsened resulted from plants with deep roots system absorbing water around roots, which restrained the plant growth and existing and affected directly on the composition and stability of sand-fixing vegetation. After 40 years, the shrubby coverage in sand-fixing vegetation decreased from maximum 47.6% to 6%~9% presently. The soil moisture content will keep a constant value (1%~1.5%) when shrubby coverage reduced to 6%~9%.

Key words: Shapotou area, sand-fixing vegetation, soil water dynamics