Automated- closed canopy chamber for measuring photosynthesis and transpiration responses of ornamental plants to soil aeration

Abstract

A system was developed for measuring the time course of photosynthesis and transpiration. The system was applied to ornamental plants in an office under different root environmental conditions: soil and non-soil aerations. This system composes an automated-closed chamber and a sensing unit. The shoot part of a fully grown ornamental plant enclosed by a transparent film in the chamber. Two circulation fans are installed at the center of the chamber to continuously stir the air. One ventilation fan located at the bottom of the chamber to exhaust air and create an upward airflow in the chamber. When the ventilation fan is turned off, the chamber becomes a closed space. The changes in the concentrations of CO2 and H2O during the period over which the chamber is closed are used to calculate the photosynthesis and transpiration rates of the plant. Two types of ornamental indoor plants were observed under the aforementioned root conditions. Soil aeration was found to produce an increase in the photosynthetic rate, transpiration rate, and total conductance. These results indicate that the measuring system could be a particularly helpful tool for evaluating temporal changes in the photosynthesis and transpiration of ornamental plants in an indoor environment.