Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (7): 557-565.DOI: 10.17521/cjpe.2018.0230

• Research Articles •     Next Articles

Temporal changes in precipitation altered aboveground biomass in a typical steppe in Nei Mongol, China

MIAO Bai-Ling1,2,LIANG Cun-Zhu1,*(),SHI Ya-Bo1,LIANG Mao-Wei1,LIU Zhong-Ling1   

  1. 1School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
    2Inner Mongolia Meteorological Institute, Hohhot 010051, China
  • Received:2018-09-18 Accepted:2019-06-21 Online:2019-07-20 Published:2019-12-12
  • Contact: LIANG Cun-Zhu
  • Supported by:
    Supported by the National Key R&D Program of China(2016YFC0500503);the Science and Technology Project of Nei Mongol Autonomous Region(20140409)

Abstract:

Aims Precipitation and its spatiotemporal changes are crucial for determining the effects of climate on plant community assembly and functioning of ecosystem (CAFE) in arid and semi-arid regions. Plant functional groups (PFGs) - an effective representation of CAFE—have been widely reported for their identity-dependent response to the changing climate. Here, we examine the responses of different PFGs to the temporal changes in precipitation by using aboveground biomass (AGB) as the dependent variable.
Methods We conducted a long-term ecological research of AGB since 1982 in a typical steppe grassland of Nei Mongol, China. We used the monthly-observation dataset from 1982 through 2015 to quantify the empirical relationships between AGB of different PDFs and precipitation.
Important findings We found that: 1) the decline in precipitation-concentration degree (PCD) was coupled with an increase in small rainfall events (≤5 mm) during the 35-year study period; 2) temporal changes in precipitation resulted in AGB decreases of annuals and biennials (AB), perennial forbs (PF) and perennial rhizome grass (PR), whereas AGB increased for perennial bunchgrasses (PB); 3) AGB, PF and semi-shrubs (SS) were positively correlated with growing season rainfall with AGB positively correlated with PCD while AGB of the shrubs (S) was negatively correlated with PCD; 4) AGB showed no significant correlation with precipitation frequency, but a significant negative correlation for type I to II precipitation 0.1-10 mm; 5) AGB had negative correlations with frequency and amount of type I (0.1-5.0 mm) and type VI (20-25 mm) precipitation. We concluded that the increase in small precipitation events will significantly reduce the AGB. These small precipitation events should be further explored for their ecological significances in the arid and semi-arid regions.

Key words: precipitation dynamics, precipitation-concentration degree, typical steppe, aboveground biomass, plant functional groups