Chin J Plant Ecol ›› 2020, Vol. 44 ›› Issue (6): 669-676.DOI: 10.17521/cjpe.2019.0331

• Research Articles • Previous Articles     Next Articles

Extreme drought effects on nonstructural carbohydrates of dominant plant species in a meadow grassland

SONG Lin1,2, LUO Wen-Tao1,*(), MA Wang1,2, HE Peng3, LIANG Xiao-Sa1, WANG Zheng-Wen1   

  1. 1Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
    2College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
    3College of Life Sciences, Tianjin Normal University, Tianjin 300387, China
  • Online:2020-06-20 Published:2020-03-26
  • Contact: LUO Wen-Tao
  • Supported by:
    National Natural Science Foundation of China(31971465);National Natural Science Foundation of China(41603080);Strategic Priority Research Program of Chinese Academy of Sciences(XDA23080401)


Aims Plant nonstructural carbohydrates (NSCs) produced by photosynthesis can reflect the responses of plants and/or ecosystem to environmental changes. Climate models recently predicted an increase in the frequency and duration of extreme drought (ED) events that could profoundly impact ecosystem structure and functions. Yet, less is understood about the response patterns of different plant species and functional groups to extreme drought.
Methods Here we studied the effects of extreme drought on the NSCs of dominant species belonging to different functional groups in grasslands. To achieve ED, we experimentally reduced precipitation amounts by 66% during four consecutive growing seasons in a meadow steppe in Hulunbeier, North China. The NSCs of six plants grouped into two functional groups (i.e., grass and non-grass) were examined.
Important findings We found different species responded differently to drought, due to their differences in plant biological characteristics, photosynthetic characteristics and physiological ecology. This result implied that different species used different NSC-use strategies to cope with drought stress, resulting in different responses of their biomass to extreme drought. Extreme drought significantly increased the starch concentrations, and had no effect on the soluble sugar concentrations of the grass functional group. Contrarily, ED significantly increased the soluble sugar concentrations, and had no significant effects on the starch concentrations of the non-grass functional group. These results indicate that grasses moderately use and store photosynthate to cope with drought stress, hence their biomass was less sensitive. The biomass of the non-grasses was more sensitive perhaps because they maximally utilize soluble sugar for plant growth, defense and reproduction. Our results showed that different species or functional groups exhibit different NSC-use strategies to cope with drought stress. This study could provide scientific data for predicting future ecosystem responses to extreme drought.

Key words: extreme drought, nonstructural carbohydrates, grassland plants, functional groups, biomass, response ratio