Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (12): 1091-1100.DOI: 10.3724/SP.J.1258.2013.00112

Special Issue: 稳定同位素生态学 青藏高原植物生态学:生理生态学

• Research Articles • Previous Articles     Next Articles

Study on plant water use in Myricaria squamosa with stable hydrogen isotope tracer in Qinghai Lake basin

ZHAO Guo-Qin1,2, LI Xiao-Yan1,2,*(), WU Hua-Wu2, ZHANG Si-Yi2, LI Guang-Yong2   

  1. 1State Key Laboratory of Earth Surface Process and Resource Ecology, Beijing 100875, China
    2College of Resources Sciences and Technology, Beijing Normal University, Beijing 100875, China
  • Received:2013-08-12 Accepted:2013-10-28 Online:2013-08-12 Published:2013-12-04
  • Contact: LI Xiao-Yan

Abstract:

Aims Little study has been conducted to quantify plant water sources for Myricaria squamosa, which is a dominant alpine riparian shrub in the Qinghai Lake basin and plays a key role in maintaining riverine wetland system. The objective of this study was to quantify water sources for M. squamosa growing under different hydrological conditions.
Methods We collected the water samples from the xylem of M. squamosa, groundwater, river, and soils in the Qinghai Lake basin from June through September, and analyzed the seasonal variation of hydrogen stable isotope ratio (δD) in the xylem and potential water sources using stable hydrogen isotope tracer method. We then compared the differences in water sources for M. squamosa growing under two contrasting hydrological conditions.
Important findings Myricaria squamosa plants growing on the river bank mainly used groundwater and water from the river stream in June and July, with groundwater contributing up to 89% of water use in June and 55% in July and river stream contributing up to 86% in June and 65% in July, respectively; whilst in August, they used water mainly from the 0-20 cm soil layer; the water source in September was identifiable. In contrast, Myricaria squamosa plants growing approximately about 100 m away from the river bank mainly accessed the groundwater and river water in June (91% and 70%, respectively), and used water from the 0-60 cm soil layer during the rainy months July, August and September. Results suggest that M. squamosa plants on the river bank use mainly groundwater and river water; soil water was more important for those far away from the river bank. These are resulted from the responses of this shrub species to specific water conditions when growing under contrasting water regimes.

Key words: deuterium isotope, Myricaria squamosa, plant water use, Qinghai Lake basin, riparian shrub