The Characterization of the Selected Trees Damaged During Severe Weather Episode on the Mountain Avala (Serbia) Using IR Thermography, ICP-OES, and Microbiological Analysis

Selected plants of white fir and lime, damaged during severe weather episode on the mountain Avala (Serbia) in summer 2014, were analyzed and characterized (including their spatial soil samples) by inductively coupled plasma optical emission spectroscopy (ICP-OES), infrared (IR) thermography, and microbiological method such as enumeration of cultivable microorganisms. The results obtained from chemical and microbiological analyses provided valuable information on possible biotic and abiotic stressors such as soil fungi and heavy metals, which could affect the health status of trees, while IR thermography visualized this status in a very specific and effective way. The results of ICP-OES analysis clearly showed that the investigated heavy metals (Cu, Zn, Pb, As, Cd, and Ni) were less likely crucial factors responsible for ruined health status of damaged trees. The role of soil fungi was not clear, since the results of microbiological analysis only provided evidence that their amounts in all investigated soil samples were within normal ranges as well as that their amounts in the corresponding samples of the uprooted trees were much greater than in the case of snapped trees. Therefore, further molecular characterization of microorganisms should be performed to identify if pathogenic species are present and clarify their role. Nevertheless, all used methods, especially IR thermal imaging as a totally non-invasive, fast and very comfortable technique, can be recommended as very useful in preventive screening of the trees' health status and for early detection of tissue decay that usually hamper trees survival or resistance to extreme weather events