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

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

lin song1, 2,wang ma1,peng he3,xiao saliang1,Zhengwen Wang1   

  1. 1. Institute of Applied Ecology, Chinese Academy of Sciences
    3. College of Life Sciences, Tianjin Normal University
  • Received:2019-11-30 Revised:2020-03-23 Online:2020-06-20 Published:2020-03-26

Abstract: Aims Plant nonstructural carbohydrates (NSCs) produced by photosynthesis can reflect the responses of plant and/or ecosystem to environmental changes. Recently, climate change was predicted to increase the frequency and duration of extreme drought events in grasslands, exerting a profound impact on ecosystem structure and functions. Methods To explore the effects of extreme drought on the NSCs of dominant species and different functional groups in grasslands, we experimentally reduced precipitation amounts by 66% during four consecutive growing seasons in a meadow steppe in Hulunbier of China. Important findings Our results showed that 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. The six plants are divided into two functional groups (i.e., grasses and non-grasses). For grasses, extreme drought significantly increased the starch concentrations, and had non-significant effect on the soluble sugar concentrations. For non-grasses, however, extreme drought significantly increased the soluble sugar concentrations, and had non-significant effects on the starch concentrations. The grasses preferred to store photosynthate to cope with drought stress, thus the biomass of this functional group was less sensitive, while the non-grasses preferred to directly use soluble sugar for plant growth, defense and reproduction, so the biomass of this functional group was more sensitive. This study could provide scientific data for predicting future ecosystem responses to extreme drought in the context of global climate change.

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