Chin J Plant Ecol ›› 2018, Vol. 42 ›› Issue (8): 818-830.DOI: 10.17521/cjpe.2018.0056

• Research Articles • Previous Articles     Next Articles

Response of plant biomass to nitrogen addition and precipitation increasing under different climate conditions and time scales in grassland

DIAO Li-Wei1,2,*,LI Ping2,3,*,LIU Wei-Xing2,XU Shan4,QIAO Chun-Lian5,ZENG Hui1,6,LIU Ling-Li2,3,**()   

  1. 1 School of Urban Plan and Design, Shenzhen Graduate School, Peking University, Shenzhen, Guangdong 518055, China
    2 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    3 University of Chinese Academy of Sciences, Beijing 100049, China
    4 South China Botanical Garden, Chinese Academy of Science, Guangzhou 510650, China
    5 Institute for Conservation and Utilization of Agro-bioresources in the Dabie Mountains, Xinyang Normal University, Xinyang, Henan 464000, China; and 6College of Urban and Environmental Sciences, Peking University, Beijing 100084, China
    6 College of Urban and Environmental Sciences, Peking University, Beijing 100084, China
  • Received:2018-03-07 Online:2018-08-20 Published:2018-11-03
  • Contact: Li-Wei DIAO,Ping LI,Ling-Li LIU
  • Supported by:
    Supported by the Chinese National Key Development Program for Basic Research(2014CB954003);the National Natural Science Foundation of China(31522011)

Abstract:

Aims Plant biomass accounts for the main part of grassland productivity. The productivity of grassland regarded as one of important ecosystem function is always co-limited by nitrogen and water availability, therefore, how grasslands respond to atmosphic nitrogen (N) addition and precipitation increasing need to be systematically and quantitatively evaluated at different climate conditions and temporal scales.
Methods To investigate the impact of nitrogen addition and precipitation increasing on grassland biomass over climate conditions and temproal scales, a meta-analysis was conducted based on 46 papers that were published during 1990-2017 involving 1 350 observations.
Important findings Results showed that: (1) N addtion, precipitation increasing and the combinations of these two treatments significantly increased the aboveground biomass (37%, 41%, 104%), total biomass (32%, 23%, 60%) and the ratio of aboveground biomass to belowground biomass (29%, 25%, 46%) in grassland ecosystem. Belowground biomass showed no response to single N addtion, but could be significantly enhanced together with increaseing precipitation; (2) The response of grassland biomass under these N addtion and the increasing of precipitation showed obvious spatial pattern under different climate conditions. The N addition tended to increase more aboveground biomass, total biomass and the ratio of aboveground biomass to belowground biomass under high sites with high mean annual air temperature (MAT) and mean annual precipitation (MAP) while precipitation increasing tended to simulate more belowground biomass and total biomass under low MAT and MAP sites; (3) In addition, the response of grassland biomass under these two global change index showed obvious temporal pattern. With the increase of duration of N addition, the belowgound biomass tended to decrease, while the aboveground biomass, total biomass and the ratio of aboveground biomass to belowground biomass tended to increase under N addition. With the increase of duration of precipitation manipulation, the total biomass showed no response to precipitation increasing, while aboveground biomass, belowground biomass and the ratio of aboveground biomass to belowground biomass tended to be enhanced. The results indicated that aboveground biomass was more likely to be enhanced than belowground biomass under N addition or precipitation increasing in the long term.

Key words: grassland biomass, nitrogen addition, precipitation increasing, response ratio, meta-regression, climate condition, temporal scale