Quantification of carbon assimilation of plants in simulated and in situ interiorscapes

Abstract

Interiorscape plants have many documented benefits, but their potential for carbon sequestration is not clear. This study was undertaken to quantify the amount of carbon assimilation under growth chamber conditions designed to mimic the photosynthetic photon flux (PPF) levels and temperatures of typical indoor environments and to quantify the amount of carbon assimilation in situ in a representative interiorscape composed of a variety of plant species and sizes. Quantitative data were obtained in 1) growth chambers with a typical range of PPF levels encountered indoors (≈10, 20, and 30 μmol·m-2·s-1); and 2) in situ conditions in an interiorscape. Under growth chamber conditions, most species exhibited positive dry mass accumulation and carbon sequestration but Sanseveria and Dracaena 'Janet Craig' exhibited consistent dry mass loss throughout the 10 weeks under simulated conditions. Carbon content was lower in herbaceous species (e.g., Scindapsus aureus, 38% of dry mass) compared with woody ones (e.g., Ficus benjamina, 43%). PPF-saturated net photosynthetic rates of plants were low, ranging from 3.4 to 7.0 μmol·m-2·s-1, whereas their light compensation points ranged from 8 to 78 μmol·m-2·s-1. In situ, plants exhibited varying dry mass gain, largely dependent on size. In general, a large plant and/or species with a higher amount of woody tissue in their above- or belowground organs (e.g., 4.6mhigh arboreal plant) sequestered more carbon than small and/or herbaceous species. This study is the first to provide quantitative data of carbon sequestration in interiorscape environments.