Introduction: Coarse woody debris (CWD) plays a vital role in forest ecosystems, serving as a reservoir for carbon sequestration. While global climate change is expected to exacerbate forest disturbances and lead to a significant accumulation of CWD, the effect of CWD decomposition on the composition, diversity and functional traits of soil fungal communities remains unclear, especially for subtropical forests with high tree species diversity.Methods: Here, we conducted a 6-year in situ field experiment (2018–2024) in a subtropical evergreen broad-leaved forest in southern China. We used high-throughput sequencing and qPCR to examine how decomposition of three dominant tree species (conifer, broadleaved, and woody monocot moso bamboo) influences soil fungal composition, and applied the FUNGuild tool to infer fungal trophic modes and functional groups from sequencing data. We found that 6 years of CWD decomposition significantly increased soil organic carbon (SOC), dissolved organic carbon (DOC), and microbial biomass carbon (MBC) while reducing soil pH. Bamboo CWD showed the highest SOC and MBC accumulation.Results: High-throughput sequencing of the ITS1 region indicated a statistically significant increase in α-diversity and a marked differentiation in β-diversity of fungal communities following decomposition. Taxonomic analysis identified Ascomycota and Basidiomycota as the dominant fungal phyla. CWD decomposition was associated with observable differences in taxonomic composition, specifically an increase in the Basidiomycota-to-Ascomycota ratio. Key gener as such as Geminibasidium, Trichoderma, and Trechispora exhibited species-specific responses to both CWD decomposition and tree species identity. Functional analysis via FUNGuild revealed an increased relative abundance of taxa predicted to be saprotrophic, alongside a decreased relative abundance of taxa inferred to be symbiotrophic. Soil pH and SOC emerged as the primary factors influencing fungal community structure.Discussion: These findings highlight the critical role of CWD in shaping soil fungal communities and their inferred functional traits, underscore the influence of tree species identity on fungal assembly, and provide insights into stable carbon sequestration stability in subtropical forests.

Coarse woody debris (CWD) is crucial for carbon and nutrient cycling in forest ecosystems, with decomposition rates influenced by species-specific wood traits. This five-year study in a subtropical Chinese forest evaluated the CWD decomposition of five dominant species. Results showed that broadleaved species decomposed fastest (k = 0.230 years⁻¹), followed by moso bamboo (0.168 years⁻¹), and conifers slowest (0.022 years⁻¹). Fast-decaying species were characterized by high hemicellulose, cellulose, and phosphorus (P) content, with rapid P release within the first decay year and nitrogen (N) accumulation over time. Tannin initially inhibited decay in fast-decaying species, but defensive compounds (tannins and phenolics) showed no sustained effect on decomposition rates. These findings indicate active CWD decomposition in subtropical forests, where P limitation outweighs N for broadleaves and bamboo. Defensive compounds only weakly influenced early-stage decay. Our results enhance the understanding of deadwood decomposition and carbon sink dynamics in subtropical ecosystems.

Coating materials extend fruit shelf life by forming protective barriers against microbial growth and preserving freshness. Herein, three chitooligosaccharide (COS) derivatives were synthesized via grafting protocatechuic acid, caffeic acid, and gallic acid onto COS, with their structures characterized. Fourier transform infrared spectroscopy confirmed successful grafting via amide linkages. ¹H NMR analysis revealed new absorption peaks between 6.5 and 7.5 ppm, attributable to the grafted phenolic acids. Compared to ungrafted COS, the derivatives exhibited enhanced antioxidant activity and superior bacteriostatic activity. Spraying 2 mg L⁻¹ derivatives on cherry tomatoes significantly reduced decay (33.7%–44.7%), browning (14.3%–23.6%), and the accumulation of reducing sugars (41.9%–49.6%) and soluble solids (13.3%–22.3%) during storage. These derivatives alleviated oxidative stress by enhancing catalase activity and reducing malondialdehyde levels, while inhibiting polyphenol oxidase to slow phenolic degradation and delay senescence. This grafted COS derivative coating offers enhanced biocompatibility for cherry tomato preservation systems.