CLAIRO — Urban Forest Living Lab for Cleaner Air

CLAIRO (UIA03-234) was co-financed by the European Regional Development Fund via Urban Innovative Actions (~€2.7M total budget, ~€2.2M EU share), led by the City of Ostrava with the Technical University of Ostrava (VSB-TU) as scientific partner. It targeted Ostrava's most air-polluted residential districts, Radvanice (~12,000 m²) and Bartovice (~8,000 m²), where EU annual-mean PM10/PM2.5 limits had regularly been exceeded.

Deploy a low-cost sensor network for continuous multi-year air-quality monitoring and develop a validated green-infrastructure methodology to capture ozone, SO2, NO2, CO and PM10 under Central European conditions.

From August 2019, a modular network of low-cost optical and electrochemical sensors was installed alongside reference instruments. In spring 2021, 442 trees, 1,867 shrubs and 14,700 m² of lawn were planted at both sites. Palacký University contributed plant-hormone research to improve tree survival in polluted soils. Over 1,200 residents were surveyed on attitudes to air quality and urban greenery.

A peer-reviewed methodology specifying pollution-optimised tree-species mixes was published (MDPI Environments, 2021), validated against reference instruments. Following dissemination workshops, the City of Trinec and the City of Orlova adopted the CLAIRO methodology and updated their strategic planning documents. The scientific monitoring programme runs through 2027.

The project demonstrates a replicable sensor-plus-species-selection methodology, already adopted by two other Czech cities, though city-wide PM10-reduction outcomes are still pending from the ongoing monitoring programme.