Original Article Climatic Changes Indicators, Useful Tools in Emphasizing Tree Physiological Disorders ODAGIU Antonia 1 , Ioan OROIAN 1 *, Tania MIHAIESCU 1 , Claudia BALINT 1 , Cristian MĂLINAŞ 1 , Radu MIHĂIESCU 2 1 Faculty of Agriculture, University of Agricultural Sciences and Veterinary Medicine, 3-5 Calea Manastur, 400372 Cluj-Napoca, Romania 2 Babeş-Bolyai University, Faculty of Environmental Science and Engineering, Fântânele St., No 30, 400294, Cluj-Napoca, Romania Received 20 October 2015; received and revised form 29 October 2015; accepted 5 December 2015 Available online 31 December 2015 Abstract The challenging problem of climatic changes became an important reference point for various and numerous analyses fighting against this threat. In Romania, few studies concerning the climate changes evolution are conducted, and urban pollution due to greenhouse gases emissions, is not enough studied. Testing the interrelations between a climatic change indicator N2O and health status of three species of ornamental trees, Aesculus hippocastanum, Pinus nigra, and Tilia cordata, respectively, in Cluj-Napoca town, was the aim of our research. The experimental model was represented by the following tree species: Aesculus hippocastanum, Pinus nigra, Tilia cordata. Tree leaves status was weekly recorded in 2014, and climatic data were delivered by the National Agency of Environmental Protection Cluj- Napoca. Data were processed with IBM SPSS Statistics 20 for Windows. Results emphasizes, on one hand that the most important contributions of carbon dioxide and methane expressed as potential greenhouse effects (PGE), CO2 equivalent, to climatic evolutions in Cluj - Napoca. On the other hand all tree species taken into the study developed specific behavior, associated to analyzed climatic changes indicator, N2O, respectively. Keywords: nitrogen, sulphur, oxides, environment. 1. Introduction The particular situation reported for Cluj – Napoca, the second urban agglomeration according to the last national census from 2011, emphasizes an ascendant evolution tendencies of temperature (Fig. 1) and precipitation regimen (Fig. 2) during 1951 – 2011. * Corresponding author. Fax: +40-264-593792 Tel: +40-264-596384 e-mail: neluoroian@gmail.com The most important greenhouse gases in Cluj – Napoca are: CO2, N2O, and CH4. Their potential greenhouse effect is usually expressed in CO2 equivalent. According to the Agency of Environmental Protection [10], the proportion of the three greenhouse gases expressed as a percentage of CO2 equivalent was in 2010 of CO2 – 67.45%, N2O – 0.83%, CH4 –31.72 %. The most important amounts of CO2 derived from combustion in manufacturing, combustion energy and processing industries. CH4 emissions come from agriculture and waste treatment and disposal, while the largest amount of N2O emissions result from waste treatment and disposal, mobile sources or combustions in processing industry [1, 3, 5]. Available online at http://journals.usamvcluj.ro/index.php/promediu ProEnvironment ProEnvironment 8 (2015) 657 - 661 657