Effect of fire disturbances on soil respiration of Larix gmelinii Rupr. forest in the Da Xing’an Mountain during growing season

Abstract

The Da Xing’an Mountain is a key distribution area for Chinese boreal forests and is a fire-prone area. Frequent forest fires have influenced on the regional carbon cycle enormously, especially for the influence of soil respiration. Thus, understanding post-fire soil respiration is important in the study of the global carbon balance. This study chose different fire intensities burned area in 2006 and near unburned area as study area. The objectives of this study were to (1) investigate soil respiration and its components after different intensities of fire disturbances; (2) determine the relationship between post-fire soil respiration and soil temperature and soil water content. The results show that heterotrophic respiration is reduced with an increase in fire intensity, whereas autotrophic respiration increases with an increase in fire intensity. The soil respiration does not significantly correlate with fire intensity (P > 0.1). T and W accounted for 56.3 to 77.4% of soil respiration; this percentage increased with an increase in fire intensity. The results provided a foundation for further studies on the effect of forest fires on the soil carbon balance in boreal forests.

Key words: Soil respiration, Larix gmelinii Rupr. forest, fire intensity, heterotrophic respiration, environment factors.