The FREE3 COST Innovators Grant successfully hosted its Training School at the University of Freiburg, Germany, bringing together leading experts and municipal practitioners from Mafra, Málaga, Zurich, Venice, Rome, Poznań, Belgrade, and Chalandri.

The focused three-day training school provided an invaluable hands-on platform to address pressing challenges in urban tree health, biosecurity, and sustainable canopy management across diverse European bioclimatic zones.

The comprehensive programme combined technical validation, knowledge transfer, and field observations, successfully advancing the following core areas:

• Participants conducted rigorous testing and practical training sessions with the newly developed QGIS plugin and Shiny app, evaluating their functionality using real-world urban tree datasets.

• Attendees assessed current and emerging urban tree pests, analysing regional vulnerabilities and the limitations of existing pest mitigation protocols.

• Municipal delegates and researchers evaluated varying management practices across Europe, identifying institutional commonalities, distinct regional challenges, and pathways for harmonised standards.

• The working group generated concrete feature improvements to ensure the tool delivers long-term, accessible value for arborists, urban foresters, and city administrations.

• A specialised technical excursion across Freiburg allowed participants to observe local urban forestry practices, site constraints, and tree health responses directly on the ground.

The successful conclusion of the Training School highlights FREE3’s ongoing dedication to bridging digital innovation and practical urban forestry, empowering European cities with actionable tools to safeguard their urban green infrastructure.