Natural Hazards Research (Sep 2021)
The characteristics of seedling regeneration and its influencing factors of Pinus tabuliformis under different wildfire severity of Liaoheyuan Nature Reserve
Abstract
Purpose: This paper studies the characteristics of the seedling regeneration, stand structures, undergrowth biomasses, litter amounts and soil water contents of planted forests of Pinus tabuliformis in the Liaoheyuan Nature Reserve after a fire disturbance in 2014 and analyzes the significant factors affecting seedling regeneration to offer a scientific basis for the ecological restoration of vegetation in burned areas. Methods: Plots of forest stands that experienced different fire severities (high severity, moderate severity, low severity) and control sample plots were used to study the significance of differences in seedling regeneration, stand structure, undergrowth biomass, litter amount and soil water content characteristics among stands under the effects of different fire severities by using single element variance analysis. The major factors affecting seedling regeneration characteristics were also analyzed here by using correlation and principal component analyses. Results: (1) There was no significant difference in the density and growth characteristics (base diameter, plant height and crown diameter) of regenerated seedlings of Pinus tabuliformis under the different fire severities (P > 0.05), and the spatial distribution of regenerated seedlings fit the aggregated distribution pattern. (2) There was no significant difference in diameter at breast height (DBH), plant height or crown diameter of Pinus tabuliformis under different fire severities (P > 0.05), but there were highly significant differences in scorch height, biomass of undergrowth woody plants, biomass of undergrowth herbs, undecomposed litter amount, semidecomposed litter amount and soil water content under different the fire severities (P < 0.01). (3) According to the correlation and principal component analyses, the results indicate that the characteristics of regenerated seedlings of Pinus tabuliformis are significantly affected by stand structure, undergrowth plants and litter and soil factors in burned areas but not by stand density. Conclusion: In the 5th year after a fire disturbance, the seedling regeneration of Pinus tabuliformis in a burned area was influenced by factors such as the stand structure, undergrowth plants, litter and soil. Low- and moderate-severity fires promote the natural regeneration of stands and are conducive to the stable balance of ecosystems.
