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Abstract

Disturbance-induced dieback of mountain Norway spruce forests alters stand-level fire climate by weakening canopy buffering and creating a gradient from intact forest interiors to highly exposed open areas. This study quantified differences in meteorological conditions (global radiation, air temperature, relative humidity, and potential evapotranspiration), Angström Index-based fire danger (including fire-danger class frequencies), and fine dead fuel moisture (grass, spruce litter, and lichens) across three plot types – an open area, a dying spruce forest, and a living spruce forest – in the Western Tatra Mountains during the 2024 fire season (1 May – 23 October). Open area exhibited the most fireconducive microclimatic conditions, characterized by higher global radiation, warmer and drier air, and the greatest evaporative demand. Fire danger followed a comparable gradient: open areas exhibited the highest proportion of days within elevated fire-danger classes, while living and dying forests were dominated by lower to moderate danger. The moisture content of fine dead fuels was higher in the living forest than in the dying forest, consistent with stronger microclimatic canopy buffering. Overall, canopy loss associated with dieback may substantially increase wildfire susceptibility, especially in open and structurally degraded stands, underscoring the need for targeted fuel and restoration-focused management.