Plant Diversity ›› 2014, Vol. 36 ›› Issue (05): 603-610.doi: 10.7677/ynzwyj201413231

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Photosynthetic Characteristics of Three Epiphytic Lichens under Different Water Conditions

CHEN Ke-1、2, LIU Wen-Yao-1, LI Su-1, SONG Liang-1   

  1. 1 Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650224, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2013-11-30 Online:2014-09-25 Published:2014-07-14
  • Supported by:

    国家自然科学NSFC—云南联合基金项目 (U1133605)

Abstract:

Epiphytic lichen is one of the important structural components of montane moist evergreen broadleaved forest ecosystem in Ailao Mts. The photosynthesis light response curves of three dominant epiphytic lichens Sticta nylanderiana, Lobaria retigera and Cetrelia olivetorum, were determined in the region under different water conditions. The results showed that the three epiphytic lichens had high light compensation points (LCP) and light saturation points (LSP). The epiphytic lichens were able to adapt to strong light conditions. The maximum net photosynthetic rates (Pmax) of three epiphytic lichens were low, with the range of 17~50nmol·g-1·s-1, under water stress (water content of 5%~10%). With the increasing water content, the Pmax, respiration rate (Rday), the LSP of three lichens increased while the LCP decreased. These epiphytic lichens have the characteristics of “sun plants”, and they are able to adapt to the strongilluminated shrubs and branches. The initial chlorophyll fluorescence (F0) and maximum photochemical efficiency parameter (Fv/Fm) were deceased with water content decreasing, indicating the photosynthetic reaction center of lichens had a strong sensitivity to water condition. The photosynthetic reaction center would recover into an active physiological state with the improvement of the water condition.

Key words: Epiphytic lichens, Water content, Photosynthesis, Light response, Fluorescence characteristics

CLC Number: 

  • Q 945