Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Naiman Desertification Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Tongliao 028300, China.
Graduate School of Dairy Science, Rakuno Gakuen University, Hokkaido, 069-8501, Japan.
Sci Total Environ. 2024 May 20;926:172100. doi: 10.1016/j.scitotenv.2024.172100. Epub 2024 Mar 29.
Anthropogenic eutrophication is known to impair the diversity and stability of aboveground community, but its effects on the diversity, composition and stability of belowground ecosystems are not yet fully understood. In this study, we conducted a 9-year nitrogen (N) and phosphorus (P) addition experiment in a semi-arid grassland of Northern China to elucidate the impacts of nutrients addition on soil fungal diversity, functional guilds, and co-occurrence networks. The results showed that N addition significantly decreased soil fungal diversity and altered fungal community composition, whereas P addition had no impact on them. The relative abundance of arbuscular mycorrhizal fungi and leaf_saprotroph were reduced by N and P addition, but P addition enhanced the abundance of saprotrophic fungi. Co-occurrence network analysis revealed that N addition destabilized fungal network complexity and stability, while P addition slightly increased the network complexity. Additionally, the network analysis of N × P interaction revealed that P addition mitigated negative effects of N addition on network complexity and stability. Structural equation modeling (SEM) results suggested that nutrients addition directly or indirectly influenced the fungal community structure through the loss of plant richness and the increase of perennial grass biomass. These findings indicate that in comparison to P addition, N addition exhibits a pronounced negative effect on soil fungal communities. Our findings also suggest that changes in plant functional groups under nutrients deposition are pivotal in shaping soil fungal community structure in semi-arid grassland and highlight the need for a better understanding of the belowground ecosystem dynamics.
人为富营养化被认为会损害地上群落的多样性和稳定性，但它对地下生态系统的多样性、组成和稳定性的影响尚未完全了解。在本研究中，我们在中国北方的半干旱草原进行了为期 9 年的氮（N）和磷（P）添加实验，以阐明养分添加对土壤真菌多样性、功能类群和共生网络的影响。结果表明，N 添加显著降低了土壤真菌多样性并改变了真菌群落组成，而 P 添加对它们没有影响。丛枝菌根真菌和叶腐生真菌的相对丰度被 N 和 P 添加所减少，但 P 添加增强了腐生真菌的丰度。共生网络分析显示，N 添加降低了真菌网络的复杂性和稳定性，而 P 添加略微增加了网络的复杂性。此外，N×P 相互作用的网络分析表明，P 添加减轻了 N 添加对网络复杂性和稳定性的负面影响。结构方程模型（SEM）的结果表明，养分添加通过植物丰富度的丧失和多年生草本生物量的增加，直接或间接影响了真菌群落结构。这些发现表明，与 P 添加相比，N 添加对土壤真菌群落表现出明显的负向影响。我们的研究结果还表明，养分沉积下植物功能群的变化在塑造半干旱草原土壤真菌群落结构方面起着关键作用，并强调了需要更好地理解地下生态系统动态。
