Meng Wenjing, Chang Lin, Qu Zhaolei, Liu Bing, Liu Kang, Zhang Yuemei, Huang Lin, Sun Hui
Collaborative Innovation Center of Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
Department of Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, 00790 Helsinki, Finland.
J Fungi (Basel). 2024 Oct 3;10(10):690. doi: 10.3390/jof10100690.
Litter decomposition is a crucial biochemical process regulated by microbial activities in the forest ecosystem. However, the dynamic response of the fungal community during litter decomposition to vegetation changes is not well understood. Here, we investigated the litter decomposition rate, extracellular enzyme activities, fungal community, and nutrient cycling-related genes in leaf and twig litters over a three-year decomposition period in a pure forest and a mixed / forest. The result showed that during the three-year decomposition, twig litter in the mixed forest decomposed faster than that in the pure forest. In both leaf litter and twig litter, β-cellobiosidase and N-acetyl-glucosamidase exhibited higher activities in the mixed forest, whereas phosphatase, β-glucosidase, and β-xylosidase were higher in the pure forest. The fungal α-diversity were higher in both litters in the pure forest compared to the mixed forest, with leaf litter showing higher α-diversity than twig litter. Fungal species richness and α-diversity within leaf litter increased as decomposition progressed. Within leaf litter, Basidiomycota dominated in the mixed forest, while Ascomycota dominated in the pure forest. Funguild analysis revealed that Symbiotroph and ectomycorrhizal fungi were more abundant in the mixed forest compared to the pure forest. In the third-year decomposition, genes related to phosphorus cycling were most abundant in both forests, with the pure forest having a higher abundance of and genes. Fungal community structure, predicted functional structure, and gene composition differed between the two forest types and between the two litter types. Notably, the fungal functional community structure during the first-year decomposition was distinct from that in the subsequent two years. These findings suggest that dominant tree species, litter quality, and decomposition time all significantly influence litter decomposition by attracting different fungal communities, thereby affecting the entire decomposition process.
凋落物分解是森林生态系统中由微生物活动调节的关键生物化学过程。然而，凋落物分解过程中真菌群落对植被变化的动态响应尚不清楚。在此，我们研究了在一片纯林和一片混交林中，叶和枝凋落物在三年分解期内的凋落物分解速率、胞外酶活性、真菌群落以及与养分循环相关的基因。结果表明，在三年分解过程中，混交林中的枝凋落物比纯林中的分解得更快。在叶凋落物和枝凋落物中，β - 纤维二糖酶和N - 乙酰 - 葡糖胺酶在混交林中表现出较高的活性，而磷酸酶、β - 葡糖苷酶和β - 木糖苷酶在纯林中较高。与混交林相比，纯林中两种凋落物的真菌α - 多样性更高，且叶凋落物的α - 多样性高于枝凋落物。随着分解的进行，叶凋落物中的真菌物种丰富度和α - 多样性增加。在叶凋落物中，担子菌门在混交林中占主导地位，而子囊菌门在纯林中占主导地位。真菌功能组分析表明，与纯林相比，共生营养型和外生菌根真菌在混交林中更为丰富。在分解的第三年，与磷循环相关的基因在两个森林中最为丰富，纯林中 和 基因的丰度更高。两种森林类型之间以及两种凋落物类型之间的真菌群落结构、预测的功能结构和基因组成存在差异。值得注意的是，第一年分解期间的真菌功能群落结构与随后两年不同。这些发现表明，优势树种、凋落物质量和分解时间都通过吸引不同的真菌群落显著影响凋落物分解，从而影响整个分解过程。
