Li Zizhen, Wei Jia, Zhou Xiaolei, Tian Qing, He Wanpeng, Cao Xueping
College of Forestry, Gansu Agricultural University, Lanzhou, China.
Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Front Plant Sci. 2024 Jul 25;15:1368814. doi: 10.3389/fpls.2024.1368814. eCollection 2024.
Forest fires play a pivotal role in influencing ecosystem evolution, exerting a profound impact on plant diversity and community stability. Understanding post-fire recovery strategies holds significant scientific importance for the ecological succession and restoration of forest ecosystems. This study utilized Partial Least Squares Path Modeling (PLS-PM) to investigate dynamic relationships among plant species diversity, phylogenetic diversity, soil properties, and community stability during various recovery stages (5-year, 15-year, and 23-year) following wildfires on the northeastern margin of the Qinghai-Tibet Plateau. The findings revealed: (1) Over time, species richness significantly decreased (< 0.05 or < 0.01), while species diversity and dominance increased, resulting in uniform species distribution. Community stability progressively improved, with increased species compositional similarity. (2) Throughout succession, phylogenetic diversity (PD) significantly decreased (< 0.01), accompanied by rising Mean Pairwise Distance (MPD) and Mean Nearest Taxon Distance (MNTD). Net Relatedness Index (NRI) shifted from positive to negative, indicating an increasing aggregation and dominance of plants with similar evolutionary traits in burned areas. Early succession witnessed simultaneous environmental filtering and competitive exclusion, shifting predominantly to competitive exclusion in later stages. (3) PLS-PM revealed that in the early recovery stage, soil properties mainly affected community stability, while species diversity metamorphosed into the primary factor in the mid-to-late stages. In summary, this study showed that plant diversity and phylogenetic variation were successful in revealing changes in community structure during the succession process. Soil characteristics functioned as selective barriers for plant communities during succession, and community stability underwent a multi-faceted and dynamic process. The soil-plant dynamic feedback continuously enhanced soil conditions and community vegetation structure thereby augmenting stability. Post-fire vegetation gradually transitioned towards the original native state, demonstrating inherent ecological self-recovery capabilities in the absence of secondary disturbances.
森林火灾在影响生态系统演化方面起着关键作用，对植物多样性和群落稳定性产生深远影响。了解火灾后的恢复策略对于森林生态系统的生态演替和恢复具有重要的科学意义。本研究利用偏最小二乘路径模型（PLS-PM），调查了青藏高原东北边缘野火后不同恢复阶段（5年、15年和23年）植物物种多样性、系统发育多样性、土壤性质和群落稳定性之间的动态关系。研究结果表明：（1）随着时间的推移，物种丰富度显著下降（<0.05或<0.01），而物种多样性和优势度增加，导致物种分布均匀。群落稳定性逐渐提高，物种组成相似性增加。（2）在整个演替过程中，系统发育多样性（PD）显著下降（<0.01），同时平均成对距离（MPD）和平均最近分类单元距离（MNTD）上升。净亲缘关系指数（NRI）从正值变为负值，表明火烧区域内具有相似进化特征的植物聚集性和优势度增加。早期演替同时存在环境过滤和竞争排斥，后期主要转变为竞争排斥。（3）PLS-PM显示，在早期恢复阶段，土壤性质主要影响群落稳定性，而物种多样性在中后期转变为主要因素。总之，本研究表明植物多样性和系统发育变异成功揭示了演替过程中群落结构的变化。土壤特征在演替过程中作为植物群落的选择屏障，群落稳定性经历了多方面的动态过程。土壤-植物动态反馈不断改善土壤条件和群落植被结构，从而增强稳定性。火灾后的植被逐渐向原始自然状态转变，表明在没有二次干扰的情况下具有内在的生态自我恢复能力。
