Effect of Vegetation Structure on Urban Climate Mitigation

Vegetation formations are an important component in the urban structure, as they perform a wide range of ecosystem services there. The climate modification to improve the environmental and residential quality of the city is one of the important functions. The paper presents the results of the microclimate assessment in the chosen localities of Nitra town, Slovakia, with an emphasis on the stage and differences in air temperature and relative humidity. The climate elements were measured at 7 spatially different sites (sites A to G), each of them at two comparative sites, vegetation stand and open area. The largest average air temperature difference between the vegetation stand and the non-vegetation area was 1.2 °C at the locality D. The largest air temperature difference in the vegetation stands was measured between the street space (site E) and the city park (F), reaching 2.3–2.5 °C. The relative air humidity reached the highest differences between the park (locality F) and the street space (G) measured at 3:00–8:00. These reached 19.6% to 24.4% with higher relative humidity in the popular city park. The highest differences between the compared habitats were measured at locality G and averaged 9.6% at 04:00 – 07:00 in a preference to a tree canopy. The research results confirmed the importance of the vegetation structures in the process of mitigating the urban climate extremes and the environmental quality improving.