首页 > 分享 > 林龄和生态位对樟子松人工林地下真菌群落构建的影响

林龄和生态位对樟子松人工林地下真菌群落构建的影响

花匠小妙招
2025-09-30 10:14

摘要： 樟子松(Pinus sylvestris var. mongolica)是北方风沙区生态环境建设中重要常绿乔木树种。该研究旨在揭示樟子松人工林地下真菌群落构建模式, 以期深化对“樟子松-真菌”互馈调节关系的理解, 并为樟子松人工林可持续经营管理提供微生物视角下的理论基础。该研究以呼伦贝尔沙地不同林龄(26 a、37 a和46 a)樟子松人工林为研究对象, 探究其不同生态位(根系、根际土壤和非根际土壤)下真菌多样性和群落组成时空动态特征, 并阐明其构建模式。主要结果有: (1)林龄和生态位对樟子松人工林地下真菌多样性有显著影响。地下真菌群落丰富度和多样性指数均值排序为46 a > 26 a > 37 a, 随林龄增加群落间相异性逐渐增加; 地下真菌群落丰富度、多样性指数和相异性指数均呈现非根际土壤真菌(NRhSF) >根际土壤真菌(RhSF) >根内真菌(RAF)。(2)樟子松人工林地下真菌属于14门592属。26 a、37 a和46 a人工林地下真菌分别包含3、1和5个丰富属, 均具有内生真菌或外生菌根真菌的共生能力; RAF、RhSF和NRhSF分别包含3、8和5个丰富属, 被孢霉门(Mortierellomycota)和腐生营养型真菌占比逐渐增加。(3)樟子松人工林地下真菌主要构建过程为扩散限制(63.54%), 其次是生态漂变(22.06%)和同质选择(12.90%)。林龄与地下真菌群落呈显著正相关关系; 影响RAF、RhSF和NRhSF的主要土壤因子分别为土壤全磷含量(RAF)、全氮含量和全磷含量(RhSF)以及土壤有机质含量(NRhSF)。研究结果表明, 樟子松人工林地下真菌多样性和群落组成在不同林龄和不同生态位存在时空异质性, 随机性过程主要由扩散限制主导, 确定性过程是宿主选择和环境过滤共同作用的结果。

关键词: 樟子松, “植物-微生物”互作, 林龄, 生态位, 真菌功能

Abstract:

Aims Pinus sylvestris var. mongolica, an evergreen coniferous tree species, plays a pivotal role in ecological restoration efforts in the deserts of northern China. This study aimed to elucidate the community assembly of belowground fungi and the intricate relationships between P. sylvestris var. mongolica and fungi in P. sylvestris var. mongolica plantations. The findings would provide the novel microbial perspectives for sustainable management strategies of P. sylvestris var. mongolica plantations.

Methods Pinus sylvestris var. mongolica plantations of different stand ages (26 a, 37 a, and 46 a) in the Hulun Buir Sandy Land were selected to examine the diversity, composition and assembly pattern of root-associated fungi (RAF), rhizosphere soil fungi (RhSF) and non-rhizosphere soil fungi (NRhSF).

Important findings (1) Stand ages and niches significantly influenced fungal diversity. The fungal community richness and diversity indices ranked as follows: 46 a > 26 a > 37 a, and the dissimilarity gradually increased with the increase of the stand age. Among the different niches, the richness, diversity indexes, and dissimilarity were the highest in NRhSF, the middle in RhSF and the lowest in RAF. (2) The belowground fungi were assigned to 14 phyla and 592 genera. The belowground fungal communities of 26 a, 37 a, and 46 a plantations had 3, 1, and 5 abundant genera respectively, and they had symbiotic capability of endophytic or ectomycorrhizal fungi. RAF, RhSF, and NRhSF had 3, 8, and 5 abundant genera, respectively, and the proportions of Mortierellomycota and saprotrophic fungi increased from root to soil. (3) The primary assembly processes of belowground fungal communities were the dispersal limitation (63.54%), drift (22.06%) and homogeneous selection (12.90%). Stand age significantly correlated with structure of belowground fungi. Soil total nitrogen content, soil total nitrogen and phosphorus content, and soil organic matter content were the main factors influencing RAF, RhSF, and NRhSF, respectively. This study highlights temporal and spatial heterogeneity of fungal community diversity and composition in P. sylvestris var. mongolica plantations. Stochastic processes mainly were dispersal limitations, shaping these communities, while the deterministic processes were influenced by host selection and environmental filtering.

Key words: Pinus syivestris var. mongolica, Plant–microbiome interactions, Stand age, Niche, Fungal function