Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (3): 321-329.DOI: 10.17521/cjpe.2021.0295

• Research Articles • Previous Articles     Next Articles

Response of key parameters of leaf photosynthetic models to increased ozone concentration in four common trees

MA Yan-Ze, YANG Xi-Lai, XU Yan-Sen, FENG Zhao-Zhong*()   

  1. School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
  • Received:2021-08-16 Accepted:2021-11-24 Online:2022-03-20 Published:2021-12-13
  • Contact: FENG Zhao-Zhong
  • Supported by:
    National Natural Science Foundation of China(41771034);National Natural Science Foundation of China(42061160479)


Aims With fast urbanization in China, ground-level ozone (O3) has become the major atmospheric pollutant in summer. It was documented that O3 enters leaves through stomata, inhibits photosynthesis, and alters the carbon and water cycles in terrestrial ecosystems. However, few studies have investigated the key parameters of photosynthetic and stomatal conductance models in response to elevated O3 concentration.
Methods In this study, plants of four common tree species (Camellia sinensis, Acer negundo, Koelreuteria paniculata and Quercus mongolica) were exposed to two O3 treatments (CF, charcoal-filtered air; E-O3, ambient air + 60 nmol·mol-1 O3) in open top chambers. The effects of elevated O3 concentration on key parameters of photosynthetic and stomatal conductance models were explored using data from leaf gas exchange measurements.
Important findings Our results indicated that elevated O3 concentration significantly decreased the light-saturated photosynthesis and mesophyll conductance in the four species. However, species showed distinct responses of the maximum rate of Rubisco carboxylation and the maximum rate of electron transport to elevated O3 concentration. The response of stomatal conductance to O3 was also different among species. We found that elevated O3 concentration significantly increased the slope parameters (g1) of Q. mongolica and A. negundo; however, the intercept parameter of stomata model in C. sinensis was decreased in A. negundo. The intrinsic water- use efficiency of the four species was negatively correlated with g1 across O3 treatments. All in all, elevated O3 concentration significantly affected key parameters of the photosynthetic and stomatal conductance models. This study could provide the foundation and support for improving the accuracy of terrestrial ecosystem models under elevated O3 concentration.

Key words: ozone, woody plant, photosynthetic model, stomatal conductance model