Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (12): 1314-1328.DOI: 10.17521/cjpe.2021.0211

Special Issue: 全球变化与生态系统 青藏高原植物生态学:群落生态学

• Research Articles • Previous Articles     Next Articles

Effects of changing precipitation on litter quality and decomposition of different plant functional groups in an alpine meadow

YANG De-Chun, HU Lei, SONG Xiao-Yan, WANG Chang-Ting()   

  1. Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu 610041, China
  • Received:2021-06-03 Accepted:2021-08-18 Online:2021-12-20 Published:2021-10-15
  • Contact: WANG Chang-Ting
  • Supported by:
    National Natural Science Foundation of China(U20A2008);National Natural Science Foundation of China(31870407);Second Tibetan Plateau Scientific Expedition and Research (STEP) Program(2019QZKK0302)


Aims Litter decomposition plays a vital role in material cycling of ecosystems. However, the responses of litter decomposition to changing precipitation in alpine meadows and the mechanisms underlying these responses are still not clear. Thus this study was designed to address the effect of changing precipitation on litter decomposition of different plant functional groups in alpine meadows.

Methods We used the litter bag method to investigate changes of initial nutrient content, mass loss and nutrient release in the litter of three plant functional groups (grass, sedge and forb) and in communities in an alpine meadow of Eastern Qingzang Plateau, in response to five precipitation treatments, including 90%, 50% and 30% decrease (Pr-90, Pr-50, Pr-30), ambient control (CK) and 50% increase (Pr+50).

Important findings The results showed that: 1) Precipitation decrease (Pr-90, Pr-50, Pr-30) significantly increased the initial nitrogen (N) content, carbon (C):N and lignin:N ratios of grass litters, while precipitation increase (Pr+50) significantly increased the initial phosphorus (P) content of all litter types. 2) According to the Olson negative exponential model, under different precipitation, the forbs decomposed the fastest, with the 95% decomposition time of 3.49-7.45 a; the decomposition of the communities and of the sedge species were the second fastest, with the 95% decomposition time of 4.07-8.05 and 4.65-7.74 a, respectively; grasses decomposed most slowly, 5.84-11.18 a. 3) Extreme precipitation decrease (Pr-90) inhibited the decomposition of all litter types, while moderate precipitation change (Pr-50, Pr-30, Pr+50) inhibited the decomposition of grass litter, but had no significant effects on sedge, forb and community litter, only precipitation increase (Pr+50) promoted the decomposition of forb litter. 4) C release was inhibited under precipitation decrease (Pr-90, Pr-30) in all litter types. N and P release of grass litters were promoted under both precipitation increase and decrease. Pr-30 promoted N release, Pr-90 inhibited P release and Pr+50 promoted P release in sedge, forb and community litters. 5) Structural equation models (SEM) showed that the mass and nutrient remaining rate were directly negatively affected by precipitation, and indirectly affected by litter types through initial C, N, P, lignin, cellulose and hemicellulose content. In conclusion, both litter types and precipitation can affect the mass loss and nutrient release of litters in an alpine meadow. Decomposition was slower and the response to precipitation was more sensitive in grass than that in other litter types. In the future, we should pay attention to the effects of mass loss and nutrient release of grass litter under climate change, especially extreme precipitation decrease, on organic matter input and C, N and P cycling in an alpine meadow.

Key words: litter decomposition, precipitation, nutrient release, alpine meadow