Data from: Characterization of unexplored deadwood mycobiome in highly diverse subtropical forests using culture-independent molecular technique

The deadwood mycobiome, also known as wood-inhabiting fungi (WIF), are among the key players in wood decomposition, having a large impact on nutrient cycling in forest soils. However, our knowledge of WIF richness and distribution patterns in different forest biomes is limited. Here, we used pyrotag sequencing of the fungal internal transcribed spacer (ITS2) region to characterize the deadwood mycobiome of two tree species with greatly different wood characteristics (Schima superba and Pinus massoniana) in a Chinese subtropical forest ecosystem. Specifically, we tested (i) the effects of tree species and wood quality properties on WIF OTU richness and community composition; (ii) the role of biotic and abiotic factors in shaping the WIF communities; and (iii) the relationship between WIF OTU richness, community composition and decomposition rates. Due to different wood chemical properties, we hypothesized that the WIF communities derived from the two tree species would be correlated differently with biotic and abiotic factors.
Our results show that deadwood in subtropical forests harbors diverse fungal communities comprising six ecological functional groups. We found interesting colonization patterns for this subtropical biome, where Resinicium spp. were highly detected in both broadleaved and coniferous deadwood. In addition, the members of Xylariales were frequently found in Schima. The two deadwood species differed significantly in WIF OTU richness (Pinus > Schima) and community composition (P < 0.001). Variations in WIF community composition of both tree species were significantly explained by wood pH and ecological factors (biotic: deadwood species, basal area and abiotic: soil pH), but the WIF communities derived from each tree species correlated differently with abiotic factors. Interestingly, we found that deadwood decomposition rate significantly correlated with WIF communities and negatively correlated with WIF OTU richness. We conclude that the pattern of WIF OTU richness and community composition are controlled by multiple interacting biotic and abiotic factors. Overall, our study provides an in-depth picture of the deadwood mycobiome in this subtropical forest. Furthermore, by comparing our results to results from temperate and boreal forests we contribute to a better understanding of patterns of WIF communities across different biomes and geographic locations.

枯木真菌群落（deadwood mycobiome），又称栖木真菌（wood-inhabiting fungi, WIF），是木材分解的关键类群之一，对森林土壤的养分循环具有显著影响。然而，当前学界对不同森林生物群区中栖木真菌的物种丰富度与分布模式的认知仍较为有限。本研究通过对真菌内部转录间隔区2（internal transcribed spacer 2, ITS2）区域开展焦磷酸标签测序（pyrotag sequencing），表征了中国亚热带森林生态系统中两种木材特性差异显著的树种——木荷（Schima superba）与马尾松（Pinus massoniana）的枯木真菌群落。具体而言，本研究设置了三项测试内容：（i）树种与木材品质特性对栖木真菌操作分类单元（Operational Taxonomic Unit, OTU）丰富度及群落组成的影响；（ii）生物与非生物因子在塑造栖木真菌群落中的作用；（iii）栖木真菌OTU丰富度、群落组成与木材分解率之间的关联。基于两种木材化学特性的差异，本研究提出假设：源自两种不同树种的栖木真菌群落，其与生物、非生物因子的关联模式存在显著差异。

研究结果显示，亚热带森林的枯木中蕴藏着多样的真菌群落，涵盖六大生态功能类群。本研究在该亚热带生物群区中发现了颇具研究价值的定殖模式：Resinicium属（Resinicium spp.）在阔叶树与针叶树的枯木中均被高频检测到；此外，炭角菌目（Xylariales）类群常在木荷枯木中被检出。两种枯木基质的栖木真菌OTU丰富度（马尾松＞木荷）与群落组成（P < 0.001）均存在显著差异。两种树种枯木的栖木真菌群落组成变异，均可通过木材pH值与生态因子得到显著解释（生物因子：枯木树种、胸高断面积（basal area）；非生物因子：土壤pH值），但源自两种不同树种的栖木真菌群落与非生物因子的关联模式存在明显分化。值得注意的是，本研究发现枯木分解率与栖木真菌群落显著相关，且与栖木真菌OTU丰富度呈负相关关系。本研究得出结论：栖木真菌OTU丰富度与群落组成模式受多种相互作用的生物与非生物因子共同调控。总体而言，本研究深入刻画了该亚热带森林中枯木真菌群落的全貌。此外，通过将本研究结果与温带及寒温带森林的相关研究结果进行对比，本研究有助于进一步深化对不同生物群区与地理区域内栖木真菌群落分布模式的认知。