森林地表可燃物是林火传播的重要因素之一，而热值又是表征可燃物燃烧性的重要指标。以新疆天山东部4种典型植被类型下地表可燃物为研究对象，分析地表可燃物热值特征及其与燃点、绝对含水率之间的关系。结果表明：针叶林和阔叶林中，草本与凋落物组分之间差异显著，灌木林中，灌木与凋落物组分之间差异显著；天山东部林区同一林型不同组分热值大小顺序为：凋落物>草本>灌木>腐殖质；草本可燃物组分中针叶林的热值最高（19.38±0.08 kJ·g^-1），凋落物可燃物组分中同样是针叶林的热值最高（19.55±0.05 kJ·g^-1）；不同组分地表可燃物热值与燃点间的关系存在差异：灌木可燃物组分燃点与热值存在极显著关系（R²=0.81，P<0.01）,凋落物可燃物组分燃点与热值存在显著相关性（R²=0.38，P<0.05），然而草本和腐殖质可燃物组分燃点与热值间无显著相关（P>0.05）；另外，所有林型的地表可燃物热值与绝对含水率之间均无显著相关关系。可见，林型、树种以及理化性质等条件综合影响着可燃物的热值含量。研究结果旨在为天山东部森林管理人员准确预测林内可燃物热值能量和潜在森林火险提供理论依据，为区域地表可燃物深入研究提供数据支撑。

Forest surface combustibles are one of the important factors in forest fire propagation, and their calorific values are an important index by which to assess combustibility. This study has aimed to assess the surface fuels available in four typical vegetation types in the eastern Tianshan Mountains of Xinjiang, China. The characteristics of the surface fuel calorific values and relationship with ignition point and absolute moisture content were analyzed. The results show that in coniferous and broad-leaved forests, there were significant differences between herb and litter components, while in shrub forest, there were significant differences between shrub and litter components. Within the same forest the calorific values were litter > herb > shrub > humus. The calorific values in the coniferous forests were the highest among the herbaceous fuel components (19.38 ± 0.08 kJ·g^-1), while those in the coniferous forests were highest among the litter fuel components (19.55 ± 0.05 kJ·g^-1). Differences were identified in the relationship between the calorific value and the ignition point of the surface combustibles for the different components. There was a significant correlation between the burning point of the shrub fuel components and the calorific value (R² = 0.81, P < 0.01), and between the burning point of litter fuel components and the calorific value (R² = 0.38, P < 0.05). However, there was no significant correlation between the burning point and calorific value of the herbs and humus (P > 0.05). In addition, there was no significant correlation between the calorific values of the surface fuel and the absolute moisture content of all forest types. Forest type, tree species, physical and chemical properties, and other conditions were thus found to have a comprehensive effect on the calorific values of the different fuels. The results of this study provide a theoretical basis for forest fire management in the eastern Tianshan Mountains as they will help to accurately predict the calorific energy and potential forest fire risks and provide data support for in-depth research on regional surface fuels.