Chinese Journal of Agrometeorology ›› 2015, Vol. 36 ›› Issue (06): 746-754.doi: 10.3969/j.issn.1000-6362.2015.06.012

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Effects of Simulated Warming and Precipitation Enhancement on Litter Decomposition of Stipa krylovii Steppe

DAN Mu-chun, YANG Jie, HOU Hong, ZHANG Li-xing, SONG Bing-yu   

  1. School of Life Science,Inner Mongolia University,Hohhot 010021,China
  • Received:2015-02-11 Online:2015-12-20 Published:2015-12-17

Abstract: In this study, open top chambers (OTCs) were used to simulate warming. Three treatments, warming (W), precipitation enhancement(P), warming combine with precipitation enhancement(WP) were set in comparison with natural state to investigate the litter decomposition rate of main species in Stipa krylovii steppe including Stipa krylovii, Cleistogenes squarrosa, Artemisia frigida and the community littlers. The results showed that: (1) after one year of decomposition, the fraction of mass remaining of all litter types in warming treatment were higher than those of control, so warming slowed down the decomposition rate of the litters. The interactive effect of warming and precipitation enhancement on the mass remaining fraction of all litter types was consistent with that of warming tratment, but the influence of warming on the the litter decomposition was greater. However, enhanced precipitation had no significant influence on the litter mass remaining faction. (2)Warming did not influence the litter decomposition process of different litter types, while enhanced precipitation significantly accelerated the decomposition processes of Cleistogenes squarrosa. Warming combining with enhanced precipitation influenced decomposition of Artemisia frigida strongly. (3)Analysis of variance showed that the effects of warming and enhanced precipitation on litter decomposition were mainly related to the litter types and the duration of decompostion. (4) Olso negative index model was used to simulate the litter mass loss processs, which showed that under warming treatment the k values (characterization of decomposition rate) of all the litter types except for Artemisia frigida were lower than the control, while in enhanced precipitation treatment the k values were higher for Stipa krylovii and Cleistogenes squarrosa but lower for Artemisia frigida and coummity litters compared to the control. The interactive effect of warming and enhanced precipitation on k values of all the litter types was consistent with that of warming, but the k values under warming and precipitation enhancement treatment were higer than those of warming. Our results suggested that the litter decomposition rate of Stipa krylovii steppe in Inner Mongolia would tend to slow down under future climate change. Warming and precipitation variation due to climate change have important influence on litter decomposition,but few researches focused on the interactive effect of warming and precipitation variation on the litter decomposition.

Key words: Climate change, Stipa krylovii steppe, Litter decomposition, Olso negative index model