How does the content of nutrients in soil affect the health status of trees in city parks?

Abstract

Trees have multi-aspect influence on the microclimate in urbanised areas. Therefore, it is important to investigate the biotic and abiotic factors affecting their health. The aim of the conducted study was to assess the chemical composition of soils and the nutritional status of lime and horse chestnut trees in selected sites and the influence of these factors on the condition and health of these tree species in urbanised areas. The research was conducted on selected trees (n = 643) growing in different parts of the city. The soils and plants were analysed for the content of macro- and microelements, sodium and heavy metals. A canonical variation analysis (CVA)–the canonical variant of Fisher's linear discriminant analysis (LDA) was used to construct the model. The CVA enabled the creation of 4 CCA models. The research showed that in general, the soil in all the sites of lime and horse chestnut trees was alkalised–at the same time it was characterised by low salinity. Despite the alkaline soil the statistical analysis showed a positive correlation between the content of manganese in the lime leaves and the deterioration of their health. In spite of that due to the satisfactory health status and condition of trees in most locations temporary guide values of nutrients were proposed for trees growing in urbanised areas. The following temporary guide values of nutrients were proposed for the horse chestnut trees (% d. m.): N 2.38%-4.71%, P 0.24%-0.46%, K 1.13%-2.31%, Ca 1.05%-2.12%, Mg 0.16%-0.42%, S 0.12%-0.23%; Fe 89.8–198.8, Zn 17.6–33.1, Cu 7.36–19.61 (mg kg-1 d. m.). The following temporary guide values were proposed for the small-leaved lime-trees (% d. m.): N 2.45%-3.22%, P 0.27%-0.42%, K 1.52%-2.86%, Ca 1.43%-2.02%, Mg 0.19%-0.35%, S 0.19%-0.25%; Fe 137.6–174.3, Zn 20.2–23.8, Cu 8.36–9.79 (mg kg-1 d. m.).