Analyzing the Effects of Urban Photopollution on Photosynthetic Efficiency of Certain Trees through Chlorophyll Fluorescence OJIP Transient

Abstract

Trees in urban areas provide important ecosystem services and are an essential element of urban green space. The constant increase in artificial light from anthropogenic activities around the world creates photopollution that affects the phenology and physiology of plants. Here we conducted a field study to investigate the anthropogenic impacts on six urban trees (Saraca asoca, Terminalia catappa, Bauhinia variegata, Holoptelea integrifolia, Ficus benjamina and Thevetia peruviana) using chlorophyll fluorescence analysis. OJIP curve, maximum quantum yield of primary photochemistry (ΦPo), quantum yield of electron transport (ΦEo), probability that an absorbed photon will be dissipated (ΦDo), photosynthetic performance index (PIcsm) and reaction center photochemistry were assessed. According to the results, various parameters of chlorophyll fluorescence showed significant and important effects on different tree species. T. peruviana and F. benjamina were found to be tolerant to street lighting, while on the other hand, S. asoca, T. catappa, B. variegata and H. integrifolia were found to be sensitive to artificial light induced by street lamps. This study clearly indicates that chlorophyll fluorescence analysis is a potent method for screening the tolerance of tree species to photopollution induced by artificial lights.

Keywords

• photopollution
• chlorophyll fluorescence
• OJIP
• tree physiology
• street light