Abstract: Pinus yunnanensis is a typical flammable coniferous species in forest areas of southwest China. Understanding the effects of forest fire on surface fuel loading and post-fire carbon emissions in P. yunnanensis forests can provide a scientific basis for fire fuel management and the maintenance of regional carbon balance. A forest fire occurred in Xichang, Sichuan Province on March 30, 2020. We established plots with different fire intensities (light, moderate, high) and control (unburned) in a P. yunnanensis forest area. We analyzed the variations of surface fuel loadings under different fire intensities and the correlation between surface fuel loadings and environmental factors. The carbon emissions of different components of fuels were obtained by calculating the combustion efficiency of fuels by the degree of loss of fuel loadings in the arbor layer, litter layer, and surface organic matter layer. The results showed that: (1) There were significant differences in the surface fuel loadings of different types under different fire intensities (P<0.05), and the total surface fuel loadings were as follows: high fire intensity (50.94 t·hm^-2) > control plot (41.08 t·hm^-2) > moderate fire intensity (37.40 t·hm^-2) > light fire intensity (28.83 t·hm^-2). (2) The results of redundancy analysis showed that among the stand factors, burned wood percentage and the ratio of blackened height to tree height had a greater explanation of the shrub and herb loadings. Among the topographic factors, slope direction explained more variations of the surface fuel loadings than slope and altitude. (3) There were significant differences in carbon emissions from arbor layer, litter layer, and surface organic matter layer among different fire intensity plots (P<0.05), and the carbon emissions were 23451.30, 8322.86, and 5244.74 t, respectively. The total carbon emissions of this forest fire were 37018.90 t.

Key words: fire intensity, Pinus yunnanensis, fuel loading, carbon emission, redundancy analysis