Chinese researchers tested 47 plant species using an air pollution tolerance index (APTI) that takes into account relative water content, total chlorophyll content, leaf extract pH and ascorbic acid. Leaves were gathered in Beijing from heavily trafficked roadsides and a suburban site. One of the sites was even near a steel factory.
Here’s what they found: The most tolerant species for use in sites with moderate to heavy air pollution are Magnolia denudata, Diospyros kaki, Alianthus altissima, Fraxinus chinensis and Rosa chinensis.
Other species showed varying degrees of tolerance depending on the site’s other environmental conditions. The next level of tolerance included Cotinus coggygria, Punica granatum, Robinia pseudoacacia and Syringa reticulata var. Amurensis, followed by another tier that included Curcubita moschata, Lagerstroemia indica and Populus tomentosa.
The researchers suggested that additional plant features such as physiological and biochemical properties be considered in developing an index for air pollution tolerance in the future.
(Note: This study did not consider the edibility of fruit produced by plants such as Curcubita moschata, Diospyros kaki or Punica granatum near roadsides. However, it is well known that particulate matter is deposited on plants proximate to transportation corridors, therefore fruit may not be suitable for consumption.)
Pollution resistance assessment of existing landscape plants on Beijing streets based on air pollution tolerance index method by Peng-qian Zhang, Yan-ju Liu, Xing Chen, Zheng Yang, Ming-hao Zhu and Yi-ping Li in Ecotoxicology and Environmental Safety, Volume 132, October 2016, Pages 212–223, doi.org/10.1016/j.ecoenv.2016.06.003.
May 1, 2017 NewTerrain.