Chin J Plan Ecolo ›› 2010, Vol. 34 ›› Issue (5): 488-497.DOI: 10.3773/j.issn.1005-264x.2010.05.002

• Research Articles • Previous Articles     Next Articles

Responses of plant growth and substance allocation of three dominant plant species to experimental warming in an alpine grassland, Northwestern Sichuan, China

SHI Fu-Sun; WU Ning*; and WU Yan   

  1. Key Laboratory of Ecological Restoration, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
  • Received:2009-09-14 Online:2010-05-01 Published:2010-05-01
  • Contact: WU Ning

Abstract: Aims Plant growth and substance allocation are greatly affected by temperature change, and the response modes have been shown to vary for different functional groups (graminoids and forbs). Our main objective was to assess how experimental warming affects growth in different functional groups and how they adapt to experimental warming by different substance allocation and structural adjustment.
Methods We selected three dominant plant species, graminoid Elymus nutans and forbs Rumex acetosa and Potentilla anserina, in an alpine meadow in Northwestern Sichuan, and adapted open-top chambers as passive warming devices to generate an artificially warmed environment. After three years of warming, we measured biomass accumulation and substance allocation of the three species.
Important findings Compared to the control, experimental warming significantly increased SLA (specific leaf area) and biomass accumulation of E. nutans and R. acetosa and significantly decreased SLA and biomass accumulation of P. anserine. Warming significantly increased leaf biomass of R. acetosa, but its root biomass significantly decreased; however, warming significantly decreased leaf biomass and stem biomass of P. anserine and its root biomass significantly increased. Warming significantly increased root C concentration of R. acetosa, but decreased root N concentration. Warming significantly increased the LMR (leaf mass ratio), RMR (root mass ratio) and R/S (shoot/root biomass ratio) of R. acetosa, but its SMR (stem mass ratio) significantly decreased. For P. anserina, warming significantly increased its RMR and R/S, but its SMR and LMR significantly decreased. Warming significantly increased C and N allocation in leaves of R. acetosa, and also significantly increased C allocation in its roots, but C and N allocations in its stem were significantly decreased. For P. anserina, warming significantly decreased C allocation in its leaves, but C and N allocations in its roots were significantly increased.