Carbon Dioxide Uptake of Six Plant Species Under Different Light Intensities

Background and objective: Carbon dioxide (CO₂) is a common indoor air pollutant that can lead to respiratory issues, impaired cognitive function, and increased absenteeism. Plants play a key role in CO₂ absorption through the process of photosynthesis, which is influenced by light intensity. This study aimed to assess the potential of plant species for CO₂ reduction under different light conditions, providing baseline data to optimize their effectiveness in improving indoor air quality.Methods: Six plant species, including three evergreen broad-leaved plants (Pittosporum tobira (Thunb.) W.T.Aiton, Camellia japonica L., Viburnum odoratissimum Ker Gawl. ex Rümpler var. awabuki (K.Koch) Zabel ex Rümpler) and three foliage house plants (Alocasia sinuata, Monstera deliciosa, and Epipremnum aureum) were selected to evaluate their CO₂ reduction ability under four different light intensities (10, 40, 80, and 160 μmol m⁻² s⁻¹). The plants were exposed to light for 11 hours, followed by a 11 hour dark period. A CO₂ cylinder was used to introduce CO₂ into the test chamber, and the CO₂ concentration inside the test chamber was recorded every 10 minutes over a 22-hour period. Net photosynthesis was also measured for each plant species.Results: The CO₂ reduction capacity varied among plant species and light intensities. All six plant species exhibited the highest CO₂ uptake at 160 μmol m⁻² s⁻¹, with uptake decreasing as light intensity decreased. Light intensity had a significant impact on the plants’ CO₂ reduction ability, and CO₂ absorption continued during the dark period. Among the six species, Monstera deliciosa and Epipremnum aureum demonstrated the highest CO₂ uptake.Conclusion: Plants require adequate light intensity for effective CO₂ uptake, making it crucial to examine their ability to assimilate CO₂, as plant species that emit CO₂ can have a negative impact on health. This will help identify which plant species can absorb CO₂ without raising CO₂ levels, especially in indoor environments where low light conditions are common. This study offers additional insights into the CO₂ absorption capacity of plants, enabling landscape researchers to select suitable species that contribute to balancing and reducing CO₂ concentrations in indoor environments. Further research is necessary to determine the optimal light levels and the right plant species for enhancing CO₂ reduction effects in plants.