Widespread forest fires pose significant challenges to the diverse communities of soil-dwelling organisms and the multiple ecosystem functions they support. However, whether the biodiversity and interactions of various taxonomic groups respond to fire consistently in terms of direction and extent, and their relative role in regulating post-fire soil functioning, remains largely unexplored. In this study, we investigated whether the diversity and co-occurrence networks of soil organisms across various trophic levels (including bacteria, fungi, protists, and invertebrates) in subtropical forests exhibit consistent responses to fire. Furthermore, we investigated their contribution to regulating soil multifunctionality, which is measured by a range of soil extracellular enzyme activities, available nutrients and reduced potential fungal plant pathogens. Our findings revealed that fire led to a decline in the richness of fungi, protists, and invertebrates, without significantly impacting bacterial richness. Fire also simplified the microbial co-occurrence networks while complexifying the invertebrate networks. Interestingly, soil multifunctionality tended to decrease with the richness of lower-trophic communities (i.e., bacteria), whereas it increased with that of high-trophic communities (i.e., protists and invertebrates). Moreover, fire indirectly influenced soil multifunctionality by altering biodiversity and network complexity, particularly pronounced in high-trophic communities. Overall, our results underscored the divergent vulnerability of biodiversity and networks to fires across taxa groups, highlighting the crucial role of biodiversity and interactions of higher trophic taxa groups in shaping the recovery and functionality of fire-affected soils.

中文翻译：

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不同营养级生物多样性和网络复杂性的不同变化推动了受火灾影响的亚热带森林的土壤多功能性


大范围的森林火灾对土壤生物的多样化群落及其支持的多种生态系统功能构成了重大挑战。然而，生物多样性和不同分类群的相互作用是否在方向和范围上对火灾做出一致的反应，以及它们在调节火灾后土壤功能方面的相对作用，在很大程度上仍有待探索。在这项研究中，我们调查了亚热带森林中不同营养级别的土壤生物（包括细菌、真菌、原生生物和无脊椎动物）的多样性和共现网络是否表现出对火灾的一致反应。此外，我们研究了它们对调节土壤多功能性的贡献，这是通过一系列土壤细胞外酶活性、可用养分和减少的潜在真菌植物病原体来衡量的。我们的研究结果表明，火灾导致真菌、原生生物和无脊椎动物的丰富度下降，但没有显着影响细菌的丰富度。火还简化了微生物共现网络，同时使无脊椎动物网络复杂化。有趣的是，土壤多功能性往往随着低营养群落（即细菌）的丰富度而降低，而随着高营养群落（即原生生物和无脊椎动物）的丰富度而增加。此外，火灾通过改变生物多样性和网络复杂性来间接影响土壤的多功能性，在高营养群落中尤其明显。总体而言，我们的结果强调了不同类群的生物多样性和网络对火灾的不同脆弱性，强调了生物多样性和高营养类群的相互作用在塑造受火灾影响的土壤的恢复和功能方面的关键作用。