Li Zixing, Wang Xinghao, Huang Yuan, Yang Xinrong, Wang Ran, Zhang Mengtao
College of Forestry, Shanxi Agriculture University, Jinzhong 030801, China.
Plants (Basel). 2025 May 5;14(9):1392. doi: 10.3390/plants14091392.
Understory vegetation is an important component of forest ecosystems, and the supply of nutrients in the soil is related to the growth and development of soil microorganisms and understory plants. The effects of different tree species composition ratios in the forest on the process of soil microbial community assembly are not clear in the existing studies, and the factors influencing the differences in the abundance of understory plants under different forest canopy compositions and their mechanisms of action have not yet been clearly explained. In this study, two types of pure forests (PFP and PFQ) and two types of mixed forests (MF and MPQ) were selected from the Zhongcun Forestry, and the soil characteristics, soil microbial community assembly process, and understory plant community abundance, composition, and β-diversity were analyzed for the different forest types. The results showed that changes in the proportion of broadleaf and coniferous species in the forest could lead to changes in the community assembly process of soil fungi, and that the fungal assembly process in the mixed forest was mainly related to dispersal limitation. Compared with pure forests that were exclusively coniferous or exclusively broadleaf, mixed coniferous and broadleaf forests had a higher abundance of understory plants and a more stable forest community composition. In mixed forests, forests with a large proportion of broadleaf arbors had more available resources in the soil, soil pH was closer to neutral, and soil C was less likely to be lost compared to forests with a large proportion of conifers.
林下植被是森林生态系统的重要组成部分，土壤中养分的供应与土壤微生物和林下植物的生长发育相关。现有研究中，森林中不同树种组成比例对土壤微生物群落组装过程的影响尚不明确，不同林冠组成下林下植物丰度差异的影响因素及其作用机制也尚未得到清晰阐释。本研究从中村林场选取了两种纯林（PFP和PFQ）和两种混交林（MF和MPQ），对不同森林类型的土壤特性、土壤微生物群落组装过程以及林下植物群落的丰度、组成和β多样性进行了分析。结果表明，森林中阔叶和针叶树种比例的变化会导致土壤真菌群落组装过程的改变，且混交林中真菌的组装过程主要与扩散限制有关。与纯针叶林或纯阔叶林相比，针叶与阔叶混交林具有更高的林下植物丰度和更稳定的森林群落组成。在混交林中，阔叶乔木比例大的森林土壤中有更多的有效资源，土壤pH更接近中性，与针叶比例大的森林相比，土壤碳流失的可能性更小。
