Biomonitoring Air Pollution in Carob Leaves

Papadopoulou S. *(1), Stratakis E. (2), Meletiou-Christou M.S. (1), Rhizopoulou S. (1)

(1) Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens,Panepistimiopolis, 15784 Athens, (2) IESL, FORTH, Heraklio, Crete

*sopapad@biol.uoa.gr

The optical properties and ecophysiological parameters of carob leaves, Ceratonia siliqua L., expanded in more and less polluted habitats [3], were compared, in order to evaluate the effect of air quality in leaf development [2]. The accumulation of pigments (chlorophylls a and b, and carotenoids) and specific leaf area (SLA, cm² g^-1) were seasonally determined during leaf development (i.e. in nine successively grown leaves along shoots). Leaf transmittance (T) and reflectance (R) spectra for both adaxial and abaxial leaf surfaces were measured between 250 and 2500 nm wavelengths, using a UV-VIS spectrophotometer and leaf absorbance [(Abs = 100 – (R + T)] is used to assess the effect of environmental quality of the two contrasting habitats in Athens, on carob leaf physiology. An increase, in the studied leaf parameters, was observed, for carob trees grown in the urban site. There was an increase in SLA from spring to late summer and a decrease in late autumn. Leaves of the less polluted site, regardless of the developmental stage exhibited greater water absorption, while the adaxial surface absorbed more radiation in both categories of plants. It seems likely that differences in optical properties and pigment accumulation have important implications for model simulation purposes [4] and may be used for air pollution biomonitoring [1].

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[2] Zadeh AR et al. Environmental pollution 178, 7-14 (2013)

[3] Brackx et al. Environmental Pollution 220, 159-167 (2016)

[4] Féret, J-B. et al. Remote Sensing of Environment 193, 204-215 (2017)