Chin J Plan Ecolo ›› 2010, Vol. 34 ›› Issue (10): 1155-1164.DOI: 10.3773/j.issn.1005-264x.2010.10.004

• Research Articles • Previous Articles     Next Articles

Effects of changing precipitation patterns on seedlings of Stipa grandis, a dominant plant of typical grassland of Inner Mongolia, China

ZHOU Shuang-Xi1,2, WU Dong-Xiu1*, ZHANG Lin1,2, and SHI Hui-Qiu1,2   

  1. 1State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; and
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-05-11 Revised:2010-07-28 Online:2010-10-01 Published:2010-10-31
  • Contact: WU Dong-Xiu

Abstract: Aims Stipa grandis is a dominant species of Inner Mongolia typical grassland. Our objective is to explore the responses of S. grandis seedlings to changed precipitation patterns to provide insight into responses of Inner Mongolia grassland to future global climate change. Methods A simulated experiment was conducted in 2009 to examine the effects of precipitation quantity and interval on S. grandis seedlings in open-top chambers at the Inner Mongolia Grassland Ecosystem Research Station of the Chinese Academy of Sciences. Important findings At final harvest, aboveground biomass of S. grandis seedlings was significantly increased by an average of 23% (p < 0.05) by increased precipitation quantity (+50%) and by an average of 48.8% (p < 0.001) by extending the precipitation interval from 5 to 15 days. Precipitation quantity had no significant effect on belowground biomass. When compared with that under regular precipitation interval with same precipitation quantity, belowground biomass was significantly increased 56.2% (p < 0.001) with extended precipitation interval under low precipitation quantity, but was not significantly affected by extended precipitation interval under high precipitation quantity. The effect of precipitation quantity and interval on root/shoot ratio depended greatly on each other. Root/shoot ratio was significantly decreased by 28.4% (p < 0.05) by increased precipitation quantity only under the extended precipitation interval level and significantly decreased by 28.8% (p < 0.05) by extended precipitation interval only under increased precipitation quantity. During the whole treatment period, differences in aboveground, belowground and total biomass of seedlings between treatments for seedlings treated for 30 days and 45 days were determined by total precipitation quantity, and biomass differences for seedlings treated for 75 days were determined by precipitation interval. Therefore, precipitation interval could be as important as precipitation quantity on growth of S. grandis seedlings. Effects of precipitation patterns could be complex since the effects of precipitation quantity and precipitation interval interacted greatly and changed with seedling growth period.