Chin J Plant Ecol ›› 2010, Vol. 34 ›› Issue (9): 1117-1124.DOI: 10.3773/j.issn.1005-264x.2010.09.012

• Research Communications • Previous Articles    

Effects of acid rain stress on gas exchange and chlorophyll fluorescence of Castanopsis sclerophylla seedlings

JIN Qing1, JIANG Hong1,2,*(), YU Shu-Quan1, YIN Xiu-Min1   

  1. 1International Research Center of Spatial Ecology and Ecosystem Ecology, Zhejiang Agriculture & Forestry University, Hangzhou 311300, China
    2International Institute for Earth System Science, Nanjing University, Nanjing 210093, China
  • Received:2009-11-12 Accepted:2010-01-22 Online:2010-11-12 Published:2010-10-08
  • Contact: JIANG Hong


Aims Castanopsis sclerophylla is a constructive species in the zonal climax community of the subtropics. It is important for regional forest resource protection and sustainable use. With serious acid rain in this region, studies of physiological and ecological responses of C. sclerophylla to acid rain have important theoretical and practical value. My objective was to determine the effects of acid rain stress on photosynthetic and physiological characters of C. sclerophylla.

Methods Three gradients of simulated acid rain treatments were applied to the species: pH = 2.5, 4.0 and 5.6. Tests were done in April, July and October of both 2007 and 2008.

Important findings In the pH 2.5 treatment, the relative chlorophyll content of C. sclerophylla seedlings was lowest during a short time, and there were significant differences between the pH 2.5 and 5.6 treatments (p < 0.05). After a period of time for acid rain treatment processing, the relative chlorophyll content of C. sclerophylla seedlings was highest with pH 4.0, indicating that acid rain of low concentrations would increase the relative chlorophyll content. In April 2007, the net photosynthetic rate (Pn), maximal photochemical efficiency of photosystem II (Fv/Fm) and potential activity of photosystem II (Fv/F0) were almost unchanged under different acid rain treatments. With the extension of acid rain treatment, Pn, light compensation point (LCP), light saturation point (LSP) and dark respiration rate (Rd) were greatly reduced in the treatments with pH 2.5, and there were significant differences between the treatments with pH 2.5 and pH 5.6 (p < 0.05). The differences of Fv/Fm and Fv/F0 between pH 2.5 and 5.6 were smaller than before. The changes of stomatal conductance (Gs) and apparent quantum yield (AQY) were not obvious. In the early phase of acid rain treatments, the high concentrations of acid rain stress significantly affected the relative chlorophyll content and photosynthetic physiological parameters, but with the processing of treatment, the effects of acid rain stress on C. sclerophylla seedlings reduced gradually, which showed that the seedlings have some resistance and adaptability to the detrimental environment stresses.

Key words: acid rain stress, Castanopsis sclerophylla seedlings, chlorophyll fluorescence, gas exchange