Plant Physiological Responses in Relation to Temperature, Light Intensity, and CO2 Concentration for the Selection of Efficient Foliage Plants on the Improvement of Indoor Environment

This study was conducted to select efficient foliage plants for improving indoor environment conditions through the investigation of physiological responses including photosynthetic rate according to temperature, light intensity, and CO2 level. Eight popular foliage plants used in this study were Hedera helix L., Cissus rhombifolia Vahl, Ficus benjamina L. 'Hawaii', Syngonium podophyllum Schott 'Albo-Virens', Dieffenbachia sp. 'Marrianne', Pachira aquatica Aubl., Spathiphyllum wallisii Regel, and Scindapsus aureus Engler. Photosynthetic rate and transpiration rate of the plants subjected to various light intensities (0, 25, 50, 75, 100, 150, 300, and 600 mu mol.m(-2).s(-1) PPFD), CO2 levels (0, 50, 100, 200, 400, 700, and 1,000 mu molCO(2).mol(-1)), and two different temperatures (16 and 22 degrees C) were measured. In addition, various parameters in relation to photosynthesis were calculated from the measured data. As a result, the patterns of photosynthesis varied among 8 foliage plants according to light intensity, CO2 level, and temperature. Most foliage plants except Dieffenbachia had high levels of apparent quantum yield, which represents the photosynthetic rate under low light intensity (PPFD 0-100 mu mol.m(-2).s(-1)). Hedera helix, Ficus benjamina, Pachira aquatica, and Spathiphyllum wallisii exposed to high light intensity (PPFD 200-600 mu mol.m(-2).s(-1)) showed high levels of photosynthesis. Cissus rhombifolia and Syngonium podophyllum were low in CO2 fixation efficiency compared to the other 6 foliage indoor plants. Hedera helix and Spathiphyllum wallisii showed high photosynthetic rate under high CO2 level and vigorous photosynthesis was also observed in Ficus benjamina and Pachira aquatica grown under 22 degrees C. Considering characteristics of indoor environment such as low light, high CO2 level, and low relative humidity, therefore, Hedera helix, Spathiphyllum wallisii, Ficus benjamina, and Pachira aquatica were efficient indoor foliage plants to improve indoor environmental conditions.