The aim of this thesis was to determine the response of trees to air pollution in the city. For this purpose, APTI index (Air pollution tolerance index), the measurement of chlorophyll fluorescence and the analysis of the content of photosynthetic pigments were used. The examined trees were Platanus acerifolia and Prunus subhirtella v. autumnalis rosea growing in Lannova třída in České Budějovice. For evaluation of APTI index, four parameters are required. These are the quantity of ascorbic acid and the photosynthetic pigments in the leaves, the relative water content in the leaves and the leaf extract pH. The samples of leaves were taken in August 2015. From Lannova třída, three trees of each species were chosen. This research has showed that in terms of evaluation APTI index of Platanus acerifolia is more tolerant and less sensitive to air pollution than Prunus subhirtella. The value of the APTI index at the Platanus acerifolia was 9,33, at the Prunus subhirtella APTI index was 7,84. During the evaluation of the maximum photochemical efficiency of photosystem II, statistically significant differences between the trees were not found. The values obtained via the method of chlorophyll fluorescence at both tree species were low, at the Platanus acerifolia it was 0,65, at the Prunus subhirtella it was 0,68. In terms of content of photosynthetic pigments, Prunus subhirtella has come out better. In almost all, it had greater content of pigments than the Platanus acerifolia. The results of the research were used in the draft for excursions for students of 7th grades of elementary schools to this area.

The aim of this diploma thesis was to find out the seasonal changes of the air pollution tolerance index (APTI) in London planetree (Platanus acerifolia) and small-leaved lime tree (Tilia cordata), which grow in Jiráskovonábřeží in České Budějovice near the busy urban roads. The research was conducted in August, 2015. The complete results of this research were summarized into a teaching presentation for pupils at primary schools, which shall show them the issues of urban stress for these two tree species, which are very often planted in cities. The APTI index consists of four parameters, which were needed to be found out for the APTI index could be established. These parameters for the APTI are: the content of chlorophylls in a leaf, the content of the ascorbic acid in a leaf, the relative water content in a leaf and the pH of the extract from a leaf. By the discovering ofthe values of these parameters, the APTI was counted and thanks to this APTI it was easier to determine, which of these two tree species is less or more stressed by air pollution on the particular location. Further, the fluorescence of chlorophyll, which is -next to the APTI index- another indicator of effect of stress on the physiological processes in a plant and measured fluorescence values were compared with values from the previous measuring in 2013. The results were statistically evaluated and processed into the tables and graphs. According to the results of the APTI index, the small-leaved lime tree has proved as more sensitive to air pollution in Jiráskovo nábřeží, the London planetree was more resilient from this point of view. By the comparison of the results of chlorophyll content and fluorescence from 2013 and 2015, it was found out that the year 2015 has proved as less favourable for both species.