Speaker
Description
Plant litter decomposition plays a pivotal role in nutrient recycling within soils, especially in ecosystems like grasslands and forests, which together span nearly 70% of the Earth's terrestrial surface. Despite its importance, the variation in microbial genomic capabilities for decomposing litter across these ecosystems remains insufficiently characterized. Through the International Soil Biogeography Consortium (iSBio), we combined insights from soil microbial metagenomics with decomposition measurements across broad environmental gradients. Utilizing data from over 350 sites participating in the TeaComposition initiative and 314 soil metagenomic assemblies, we investigated European grasslands and forest systems. Our analysis revealed 96 carbohydrate-active enzyme (CAZyme) families and 2,628 subfamilies associated with the breakdown of lignin, pectin, cellulose, and hemicelluloses. Among these, 297 subfamilies from Auxiliary Activities (AA), Glycoside Hydrolases (GH), Carbohydrate Esterase (CE), and Polysaccharide Lyases (PL) groups exhibited significant differences (p < 0.05) in relative abundance among grasslands, broadleaf, and coniferous forests. Coniferous forests displayed the highest gene abundances for these pathways, followed by broadleaf forests and grasslands, a trend consistent with CAZyme diversity metrics and observed litter decomposition rates. Taxonomic analyses indicated dominant contributions from Acidobacteriota and Actinomycetota in early-stage degradation, whereas Pseudomonadota were more involved in downstream steps. Basidiomycota were more prominent in forested sites, especially during the initial phases of decomposition. Furthermore, protein sequence analyses revealed signatures of ecosystem-specific genomic adaptations in CAZymes. Variability in microbial functional gene profiles was strongly linked to soil characteristics such as pH and carbon-to-nitrogen ratios, as well as climatic variables like temperature and precipitation, jointly explaining 65% of the observed patterns. Our findings highlight the value of combining microbial genomic data with standardized, global-scale decomposition experiments to better model soil nutrient dynamics across ecosystems.
| Status Group | Postdoctoral Researcher |
|---|---|
| Poster Presentation Option | No, I prefer to present only as a talk. |
