Environmental impacts of ozone and climatic changes on major Brazilian crops (sugarcane and coffee cultivars)

Abstract

While public awareness for climate-change-related risks is rising rapidly, scientific evidence is missing for understanding the combined effects of elevated O3, CO2, and supra-optimal air temperature on sugarcane and coffee plantations in highly anthropized areas of São Paulo. The effects of elevated O3 in sugarcane are poorly described and in coffee are entirely unknown. The physiological and metabolic performances considering supra-optimal air temperatures associated with elevated CO2 are unknown in the case of sugarcane or poorly understood in the case of coffee. This integrated project was conceived aiming at bringing new scientific knowledge on this subject. This challenge will be overcome by: 1) synthetizing the current knowledge to comprehensively understand physiological, biochemical, metabolic, and yield responses of sugarcane and coffee to ozone and climatic change factors; 2) conducting experiments in Italy and Brazil, under the straight collaboration of both research teams. In IRET-CNR (Italy), we will employ a newly ozone FACE (free air-controlled exposure) facility, in order to achieve a realistic assessment under field conditions. In Brazil, we will employ a new walk-in growth chamber facility, to study the impacts of high atmospheric CO2 and high air temperatures on sugarcane and coffee plants. Temporal dynamics of eco-physiological traits related to plant water relations, photosynthesis, biochemistry, and plant growth will be evaluated in all experiments; 3) carrying out a field measurement campaign in Brazil to validate and update the model parameters obtained in the FACE facility and to reflect the real sugarcane and coffee stomatal responses to O3. We will use the O3 and meteorological data from the monitoring network in the area covered by sugarcane and coffee plantations in the state of São Paulo; 4) proposition of mechanistic models of sugarcane and coffee responses to O3, CO2, and air temperature. Target effect parameters will be sugarcane/coffee yield or CO2 uptake capacity. Current and future scenarios will be tested to predict how O3 could influence crop responses to CO2 and supra-optimal temperatures and O3 fluxes and associated parameters under elevated CO2 and air temperature. (AU)