Objective Burning probability model was used to simulate fire burning on the landscape scale and the impacts of prescribed burning on forest flammability were assessed quantitatively.

Method The data about fuel conditions of some areas of Daxing’anling after prescribed burning before the fire season of 2016 were extracted from SPOT6 satellite data. The daily weather indices in the fire season were calculated with the weather observation data near the study area by using R-software. The burning probability and fire behavior indices of the forest were simulated with BURN-P3 model for the scenarios with and without prescribed burning.

Result The areas treated with prescribed burning in 2016 were 44,931 hm², accounting for 20.8% of the total area. The average burning probability was 0.0164 and 0.0124 for the scenarios with and without prescribed burning. The average burning probability for each fuel type respectively decreased by 4.2% for deciduous coniferous forest, 3.5% for evergreen coniferous forest, 5.9% for coniferous and broad-leaved mixed forest, 2.3%for grass, and 0.6% for broad-leaved forest after prescribed burning. The average fire intensity and spread speed were 548.9 kW/m² and 2.2 m/min under the scenario with prescribed burning. The average fire intensity and spread rate decreased by 17.9% and 24.3% due to prescribed burning. Deciduous coniferous forests and mixed forest showed high fire intensity and spread speed, and are easy to occur crown fires. The proportion of crown fire reduced by 11.7% after prescribed burning.

Conclusion The prescribed burning could decrease the distribution areas of grass fuel and fuel loadings. The burn probability, fire intensity, rate of spread and crown fire fraction of the region decrease after prescribed burning. The burning probability will drop obviously in the buffer areas with 2500 m wide around the prescribed burning regions.