Post-fire forest regeneration under different restoration treatments in the Greater Hinggan Mountain area of China

Abstract

Forest fire is one of the dominant disturbance factors in boreal forests. Post-fire forest regeneration is crucial to both ecological research and forest management. Three different restoration treatments, namely natural regeneration, artificial regeneration, and artificial promotion, were adopted in the Greater Hinggan Mountain area of China after a serious forest fire occurred on May 6, 1987. Natural regeneration means recovering naturally without any intervention, artificial regeneration comprises salvage logging followed by complete planting, while artificial promotion refers to regeneration by removing dead trees, weeding, and digging some pits to promote seed germination. The objectives of this study were to evaluate and compare the effects of the three restoration treatments and determine which approach is the most suitable for local forest recovery. A field survey was conducted to collect the attribute data, specifically species composition, structural parameters, and leaf area index (LAI), which were analyzed through the analysis of variance and a post hoc test. The broad-leaved species occupied the main component of the forest under natural regeneration while the coniferous species dominated those under the other two treatments. Tree height and diameter at breast height (DBH) were significantly highest for the forest under artificial regeneration, but an insignificant difference was found for crown widths among the three treatments. Significantly highest LAI was observed in forest under natural regeneration. The results suggest artificial regeneration to be adopted in post-fire recovery if the goal is timber production, while natural regeneration to be utilized when focusing on canopy vertical density and species richness. The artificial promotion treatment showed no advantage. This study demonstrated the advantages of limited strategies that can be helpful for local post-fire forest management.