Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (3): 274-285.DOI: 10.17521/cjpe.2020.0344

• Research Articles • Previous Articles     Next Articles

Pressure-volume curve analysis of epiphytic lichens and its applicability in subtropical forests

DONG Lin-Lin1, PU Xiao-Yan2, ZHANG Lu-Lu1,*(), SONG Liang2, LU Zhi-Yun2,3, LI Su2,*()   

  1. 1Institute of Environment and Ecology, Shandong Normal University, Jinan 250358, China
    2CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China
    3Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences, Jingdong, Yunnan 676209, China
  • Received:2020-10-20 Accepted:2021-01-02 Online:2021-03-20 Published:2021-05-17
  • Contact: ZHANG Lu-Lu,LI Su
  • Supported by:
    National Natural Science Foundation of China(31770494);National Natural Science Foundation of China(3175001);Youth Innovation Promotion Association of the Chinese Academy of Sciences (CAS)(2017441);CAS “Light of West China” Program, and the CAS 135 Program(2017XTBG-T01)


Aims Epiphytic lichens are a widespread and significant component of forest ecosystems, and play an important role in biodiversity maintaining and water and nutrient cycling. This study aims to illustrate the water potential characteristics of the epiphytic lichen group and to assess whether the pressure-volume (PV) curve and relative parameters are suitable for exploring the response of lichens to drought stress.
Methods The water potential parameters and PV curves of 15 epiphytic lichen species from five functional groups were measured in the subtropical forests in the Ailao Mountains, Yunnan Province.
Important findings The internal water content (WCinternal) and symplast water content (Rs) of cyanolichens were significantly higher than those of chlorolichens, while other parameters showed no significant differences. We only observed significant differences in WCinternal, Rs and relative water content at turgor loss point (RWCTLP) among different functional groups of lichens. All parameters differed significantly among species. Results of principal component analysis (PCA) further indicated that there are extensive limitations for PV curves and water potential parameters in evaluating the overall response of lichen species to water stress and in revealing the selection strategy of water-related habitats, largely due to the influence of the photobiont type and growth form. However, the adaptation strategies of cyanolichens to habitat could be explained by the maximum internal water holding capacity, while the adaptation to water conditions could be explained by the saturated water osmotic potential (Ψsat) in narrowly lobed foliose lichens, and by the RWCTLP in broadly lobed foliose and fruticose lichens. Our study suggests that PV curves and water potential parameters are not suitable for the general evaluation of the drought resistance of lichen communities, and should be used carefully in comparing the drought resistances between lichens and other plant groups.

Key words: epiphytic lichen, water potential, internal water content, pressure-volume curve, principal component analysis, poikilohydric plant