State Key Laboratory of Subtropical Silviculture, College of Forestry & Bio-technology, Zhejiang A&F University, Lin'an, Hangzhou, Zhejiang 311300, PR China.
Agricultural and Rural Bureau of Lin'an District, Hangzhou, Zhejiang 311300, PR China.
Microbiol Res. 2024 Dec;289:127931. doi: 10.1016/j.micres.2024.127931. Epub 2024 Oct 20.
Soil microbes are critical to the maintenance of forest ecosystem function and stability. Forest diversification, such as monocultures versus mixed forests stands, can strongly influence microbial community patterns and processes, as well as their role in soil ecosystem multifunctionality, such as in subtropical forest ecosystems. However, less is known about these patterns and processes vary with soil depth. Here, we investigated the results of an eight-year forest diversification field experiment comparing the soil ecosystem multifunctionality, bacterial and fungal community assembly, and network patterns in mixed versus monoculture plantations along vertical profiles (0-80 cm depth) in a subtropical region. We found that the introduction of broadleaf trees in coniferous monocultures led to enhanced synergies between multiple functions, thus improving soil multifunctionality. The effects of mixed plantations on the functional potential in top soils were greater than in deep soils, especially for carbon degradation genes (apu, xylA, cex, and glx). Microbial community assembly in the top layer, particularly in mixed plantations, was dominated by stochastic processes, whereas deterministic were more important in the deep layer. Soil microbial network complexity and stability were higher in the top layer of mixed plantations, but in the deep layer was monoculture. Interestingly, the changes in microbial communities and multifunctionality in the top layer were mainly related to variation in nutrients, whereas those in the deep were more influenced by soil moisture. Overall, we reveal positive effects of mixed forest stands on soil microbial characteristics and functionality compared to that of monocultures. Our findings highlighted the importance of enhancing functional diversity through the promotion of tree species diversity, and managers can better develop forest management strategies to promote soil health under global change scenarios.
土壤微生物对于维持森林生态系统功能和稳定性至关重要。森林多样化，例如混交林与单一树种林分，强烈影响微生物群落的格局和过程，以及它们在土壤生态系统多功能性中的作用，如在亚热带森林生态系统中。然而，对于这些格局和过程随土壤深度而变化的了解较少。在这里，我们调查了一项为期八年的森林多样化野外实验的结果，该实验比较了亚热带地区沿垂直剖面（0-80cm 深度）的混交林与单一树种林分中土壤生态系统多功能性、细菌和真菌群落组装以及网络模式的差异。我们发现，在针叶树单一树种林中引入阔叶树种导致多种功能之间的协同作用增强，从而提高了土壤多功能性。混交林对表土功能潜力的影响大于对深层土壤的影响，特别是对于碳降解基因（apu、xylA、cex 和 glx）。在表层土壤中，微生物群落组装主要受随机过程的控制，而在深层土壤中则更受确定性过程的控制。在混交林的表层土壤中，土壤微生物网络的复杂性和稳定性较高，但在深层土壤中则是单一树种林。有趣的是，微生物群落和多功能性的变化在表层主要与养分的变化有关，而在深层则更多地受到土壤水分的影响。总体而言，与单一树种林相比，混交林对土壤微生物特性和功能具有积极影响。我们的研究结果强调了通过促进树种多样性来增强功能多样性的重要性，管理者可以更好地制定森林管理策略，以在全球变化情景下促进土壤健康。
