As one of the most relevant acts of CLAIRO, an area of over 20,000 m² in total have been planted with greenery in Ostrava in 2021 from mid-March to early May. Altogether 442 new trees and 1867 shrubs have been planted and almost 15,000 m2 of lawn have been installed in the two target areas of the project located in the Radvanice and Bartovice neighbourhoods of the city.
The design of the composition and structure of the greenery at the two plots was supported by a model of capture of air pollutants, which was developed based on measurements of air pollutants and climatic conditions.
This green infrastructure intervention is meant to function as a testbed, a living vegetation lab encouraging the smart use of nature-based solutions aiming at air quality improvements in urban areas elsewhere in the Moravian-Silesian Region and in Europe.
The selection of the target sites was carefully planned to be able to effectively demonstrate the capture of air pollutants. A number of factors were considered during the selection process. First of all, plots located in the most polluted areas of Ostrava were sought in the direct vicinity of a metallurgical plant operated by Liberty Ostrava. The prevailing wind direction was also taken into account, the plots being east of the facility in the downwind side of the smelting plant, so that the pollution plume usually moves towards the plots. It was also an important consideration to pick locations with different soil types that favour differing plant species.
A multi-level plant cover was created to filter as much as possible the quantity of air pollutants. Species with large mature size, high canopy density and well-developed crowns were used. An additional vegetation layer was provided by shrubs.
A specific treatment method developed by the Palacky University Olomouc have been applied on the newly planted greenery. The soil and the plants have been treated with specific preparations that contain plant hormones and biostimulants.
The vegetation at the two target sites is exposed to multiple abiotic stressors such as poor air quality, soils lacking nutrients or heavy metal contamination. It is expected that the innovative treatment will increase the resistance of the greenery to these stressors. It is also foreseen that the health of plants will improve in general, trees and shrubs growing denser foliage, resulting in longevity. All these positive changes will enhance the ability of the new greenery to capture air pollutants.
The first treatment took place following the planting of the trees in June, and the second one in September 2021. The physiological effects of the preparations are monitored regularly by the Palacky University by measuring photosynthetic parameters and gas exchange characteristics of the plants.