Elevated Ozone Concentration Reduces Photosynthetic Carbon Gain but Does Not Alter Leaf Structural Traits, Nutrient Composition or Biomass in Switchgrass

Shuai Li, Galatéa Courbet, Alain Ourry, Elizabeth Ainsworth

Research output: Contribution to journalArticle


Elevated tropospheric ozone concentration (O3) increases oxidative stress in vegetation and threatens the stability of crop production. Current O3 pollution in the United States is estimated to decrease the yields of maize (Zea mays) up to 10%, however, many bioenergy feedstocks including switchgrass (Panicum virgatum) have not been studied for response to O3 stress. Using Free Air Concentration Enrichment (FACE) technology, we investigated the impacts of elevated O3 (~100 nmol mol 1) on leaf photosynthetic traits and capacity, chlorophyll fluorescence, the Ball–Woodrow–Berry (BWB) relationship, respiration, leaf structure, biomass and nutrient composition of switchgrass. Elevated O3 concentration reduced net CO2 assimilation rate (A), stomatal conductance (gs), and maximum CO2 saturated photosynthetic capacity (Vmax), but did not affect other functional and structural traits in switchgrass or the macro- (except potassium) and micronutrient content of leaves. These results suggest that switchgrass exhibits a greater O3 tolerance than maize, and provide important fundamental data for evaluating the yield stability of a bioenergy feedstock crop and for exploring O3 sensitivity among bioenergy feedstocks.

Original languageEnglish (US)
Article number85
Issue number4
StatePublished - Apr 2 2019



  • Biomass
  • Chlorophyll fluorescence
  • Leaf anatomy
  • Ozone
  • Photosynthesis
  • Stomatal conductance
  • Switchgrass

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Plant Science

Cite this