Content of carbohydrates and proline of Oriental plane (Platanus orientalis L.) leaf in air pollution stress, case study: Urmia city

Air pollution severely damages tree growth and quality in urban areas due to constant absorption of pollutants by plants. It has been clearly substantiated that urban green landscapes considerably decrease environmental pollution. This study aimed to evaluate the effect of air pollution on carbohydrate and proline contents in oriental plane (Platanus orientalis L.) trees in Urmia city. For this purpose, five parks of supposedly different levels of pollution were sampled in two phases (i.e. August 2013 and May 2014). Five plane trees of relatively the same age were selected in each park. Leaf samples were collected from the outer branches of trees at three height levels. The carbohydrate and proline contents of the leaves, measured in two steps, were correlated with the level of O3, NH3, SO2, CO and PM10. The results indicated that, except for proline with NH3 in August 2013, the amounts of carbohydrates and proline were significantly (α=1%) higher with increasing air pollution.