Federal University of Ceará, Soil Science Department, Fortaleza, Ceará, Brazil.
'Luiz de Queiroz' College of Agriculture, University of São Paulo, Piracicaba, Brazil.
Sci Total Environ. 2021 Mar 1;758:143711. doi: 10.1016/j.scitotenv.2020.143711. Epub 2020 Nov 14.
The fungal community plays an important role in forest ecosystems via the provision of resources to plant nutrition and productivity. However, the ecology of the fungal network and its relationship with phosphorus (P) dynamics remain poorly understood in mixed forest plantations. Here, we analyzed the fungal community using the amplicon sequencing in plantations of pure Eucalyptus grandis, with (E + N) and without N fertilization (E), besides pure Acacia mangium (A), and in a consortium of E. grandis and A. mangium (E + A), at 27 and 39 months after planting. We analyzed chemical, physical and biochemical soil and litter attributes related to P cycling, and the fungal community structure to find out if mixed plantations can increase fungal connections and to identify their role in the P dynamics in the soil-litter system. Soil organic fraction (OF), phosphorus in OF, total-P and acid phosphatase activity were significantly higher in E + A and A treatments regardless of the sampling period. Total N and P, richness, and Shannon diversity of the fungi in the litter was significantly higher in the treatments E + A and A. The fungal community structure in litter differed between treatments and sampling periods, and E + A showed an intermediate structure between the two pure treatments (E) and (A). E + A correlated highly with P dynamics when evaluated by both Pearson and redundancy analyses, particularly in the litter layer. Co-occurrence networks of fungal taxa became simpler in pure E. grandis plantations, whereas mixed system (E + A) showed a more connected and complex network. Our findings provide novel evidence that mixed forest plantations promote positive responses in the fungal community connections, which are closely related to P availability in the system, prominently in the litter layer. This indicates that the litter layer represents a specific niche to improve nutrient cycling by fungi in mixed forest ecosystems.
真菌群落通过为植物营养和生产力提供资源，在森林生态系统中发挥着重要作用。然而，混合林种植园中真菌网络的生态学及其与磷（P）动态的关系仍知之甚少。在这里，我们使用扩增子测序分析了纯桉树种植园（E+N 和 E）、纯相思树种植园（A）和桉树和相思树混合种植园（E+A）中的真菌群落，在种植后 27 和 39 个月进行了分析。我们分析了与磷循环有关的土壤和凋落物的化学、物理和生物化学特性，以及真菌群落结构，以确定混合种植园是否可以增加真菌的联系，并确定它们在土壤-凋落物系统中磷动态中的作用。土壤有机部分（OF）、OF 中的磷、总磷和酸性磷酸酶活性在 E+A 和 A 处理中无论采样期如何都显著更高。凋落物中真菌的总 N 和 P、丰富度和 Shannon 多样性在处理 E+A 和 A 中显著更高。凋落物中真菌群落结构在处理和采样期间存在差异，E+A 在两个纯处理（E）和（A）之间表现出中间结构。通过 Pearson 和冗余分析评估时，E+A 与 P 动态高度相关，特别是在凋落物层。纯桉树种植园中真菌分类群的共现网络变得更加简单，而混合系统（E+A）表现出更连接和复杂的网络。我们的研究结果提供了新的证据，表明混合林种植园促进了真菌群落联系的积极反应，这与系统中磷的可用性密切相关，特别是在凋落物层。这表明凋落物层代表了一个特定的生态位，可以通过真菌来改善混合森林生态系统中的养分循环。
