Prescribed burning as a potential regeneration technique for reed stands: a pilot study in the reed belt of Lake Neusiedl, Austria

Nature conservation calls for the management of reed in large stands to support the rejuvenation of reed. Traditional reed management tools at Lake Neusiedl are becoming decreasingly suitable due to insufficient freezing in winter. Therefore, prescribed burning of old Phragmites australis stands is currently being considered as a regeneration measure to promote reed regrowth and maintain invaluable habitats for specialized species in the reed belt. In January 2024 a pilot study was carried out near the municipality of Jois to gain insights into suitability and consequences of controlled burning of old reed mats in the reed belt. Applied methods include pre- and post-fire biomass and carbon content analyses from vegetation, litter and soil, fire behavior and intensity monitoring, moisture content measurements during and after the fire, and area-wide UAV-LiDAR mapping. Mean fire temperature was approx. 700 °C and peaked at 1034 °C. 15.57 ha of the 32 ha study area were affected by the fire, and a total of 57.84 tons of carbon were released (3.72 t C/ha). On burnt areas standing vegetation was removed and litter thickness significantly reduced by approx. 30%, while no biomass loss from soil was detected. Fuel moisture content is negatively correlated to distance from the water table and has mitigating effects on fire spread if above 30%, resulting in unaffected deeper layers and numerous unburnt refugia patches within the fire perimeter. Our results indicate that prescribed fire can be a suitable management tool at Lake Neusiedl for the purpose of reed rejuvenation and wetland habitat regeneration.