植物生态学报 ›› 2006, Vol. 30 ›› Issue (3): 457-464.DOI: 10.17521/cjpe.2006.0061

• 研究论文 • 上一篇    下一篇

用Minirhizotrons观测柠条根系生长动态

张志山, 李新荣, 张景光, 王新平, 赵金龙, 陈应武   

  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
  • 接受日期:2005-05-17 发布日期:2006-05-30
  • 作者简介:E-mail: zhangzhsh2002@yahoo.com.cn
  • 基金资助:
    国家自然科学基金项目(90202015.40401004);国家自然科学基金项目(40301008)

ROOT GROWTH DYNAMICS OF CARAGANA KORSHINSKII USING MINIRHIZOTRONS

ZHANG Zhi-Shan, CHEN Ying-Wu, ZHANG Jing-Guang, WANG Xin-Ping, ZHAO Jin-Long, CHEN Ying-Wu   

  1. Shapotou Desert Research and Experiment Station, Cold & Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Accepted:2005-05-17 Published:2006-05-30

摘要:

Minirhizotrons是一种非破坏性、定点直接观察和研究植物根系的新方法。该文介绍了用Minirhizotrons测定植物根系的方法,并同根钻取原状土样法进行了比较;探讨了根系生长动态同土壤含水量间的关系。试验于2004年植物生长季在沙坡头沙漠试验研究站的水分平衡观测场的人工柠条(Caragana korshinskii)林进行,结果表明:Minirhizotrons管埋入土壤后需要10个月时间允许柠条根系在其周围定居,其观测图片中的根系代表了管子周围2.6 mm土层的根系。柠条根系生长动态和土壤水分变化相关,含水量的升高导致根系的大量繁殖,而根系吸水及蒸发散又导致含水量的减少;在2004年植物生长季,土壤水分和根系的这种相互作用出现了两次,但根系生长高峰比土壤含水量高峰滞后20 d左右。

关键词: 柠条, 根系生长动态, Minirhizotrons, 根钻, 土壤含水量

Abstract:

Minirhizotrons provide a nondestructive, in situ method for directly viewing and studying fine root dyanmics. In this paper, we introduce the minirhizotron methodology for measuring root systems, compare results between the minirhizotron and the soil corer method, and compare root growth dynamics under different soil water conditions. The experiments were conducted on a re-vegetated Caragana korshinskii quadrat at the Water Balance Experimental Field (WBEF) of Shapotou Desert Research and Experimental Station, Chinese Academy of Sciences (CAS) during the growing season in 2004. Shapotou is located at 37°33' N, 105°02' E in Ningxia Hui Autonomous Region at the southeastern edge of the Tengger Desert in northern China, elevation 1 250 m with a mean annual precipitation of 186.2 mm. It is classified as a steppified desert zone and is a transitional zone between desert and oasis. In September,2003, a block of soil was excavated from the C. korshinskii quadrat and 3 minirhizotrons were placed at a 45° angle at a distance of 20, 50 and 100 cm from the sample plant and the soil repacked. Beginning on March 27,2004, root images were collected every two weeks, and the soil water content was measured by neutron probe and TDR. Roots were colleted with a soil corer each month from a depth of 0-200 cm at 10 cm depth intervals. The results indicated that 10 months were required to allow the roots to recolonize the soil following the tube installation. The 2-D minirhizotron images were equivalent to a 2.6 mm depth of field (DOF) around the tube, within which all roots were observed. The root growth dynamics of C. korshinskii supplemented with soil water resulted in a great deal of root growth; however, root water uptake and evapotranspiration by C. korshinskii subsequently would reduce the soil water content and slow growth. The interactions between root growth and soil water content went through two cycles, and the lag time between growth of root apices and reductions of soil water content was about 20 days.

Key words: Caragana korshinskii, Root growth dynamics, Minirhizotrons, Soil auger, Soil water content