Preliminary results, revealed at the CalScape Expo earlier this month, are showing that a total of 216 “4-inch” plants of Ficus benjamina, pothos, philodendron, sansevieria, aglaonema, and spathiphyllum, clearly fix carbon. 

In addition, since plants absorb carbon dioxide as a molecule, there is a positive impact on the environment by the CO₂ removal, and not just carbon. The weight of elemental carbon is 12, while the weight of CO₂ is 44. Thus more than three times the amount of CO₂ is removed as just carbon.

"Project Carbon," conducted by University of Georgia researchers Drs. Bodie Pennisi and Marc van Iersel, seeks to provide the additional science that would support an expansion of the certification to indoor plants. Leadership in Energy and Environmental Design (LEED) currently does not recognize indoor plants and their role in improving indoor air quality (IAQ) as part of the LEED point system. LEED promotes a whole-building approach to sustainability in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.

A total of three phases are planned for "Project Carbon;" each phase consists of three species grown for a 10-week duration. Greenhouses are set at consistent temperatures both day and night.  After acclimatization, plants are placed in a growth chamber under three light levels, typically encountered in interiorscapes. Upon termination of the period in the growth chamber, the data is taken: dry weight of shoot, dry weight of root, total leaf area, number of leaves, vine length, and height. After experiment termination, representative dried tissue samples are sent to the lab for elemental analysis, including carbon, oxygen, hydrogen, and macro and micronutrients.

Photosynthetic measurements of plants under real interiorscape conditions (in situ) will also be taken in various accounts in the Metro Atlanta area and managed by the same company for consistency. In the process of regular maintenance, plant material (leaf clippings, stems, etc.) will be removed and preserved for dry weight analysis. Thus, the photosynthetic rate, the light level and the tissue removed, will provide an estimate of the carbon removal from interiorscape plants in situ.

More details on "Project Carbon" will be offered during the Tropical Plant Industry Exhibition, January 14-16, 2010. 

For more information about the National Foliage Foundation, visit www.nationalfoliagefoundation.org.