Project description:Fire is a crucial event regulating the structure and functioning of many ecosystems. Yet few studies focused on how fire affects both the taxonomic and functional diversity of soil microbial communities, along with plant diversity and soil carbon (C) and nitrogen (N) dynamics. Here, we analyze these effects for a grassland ecosystem 9-months after an experimental fire at the Jasper Ridge Global Change Experiment (JRGCE) site in California, USA. Fire altered soil microbial communities considerably, with community assembly process analysis indicating that environmental selection pressure was higher in burned sites. However, a small subset of highly connected taxa were able to withstand the disturbance. In addition, fire decreased the relative abundances of most genes associated with C degradation and N cycling, implicating a slow-down of microbial processes linked to soil C and N dynamics. In contrast, fire stimulated plant growth, likely enhancing plant-microbe competition for soil inorganic N. To synthesize our findings, we performed structural equation modeling, which showed that plants but not microbial communities were responsible for the significantly higher soil respiration rates in burned sites. In conclusion, fire is well-documented to considerable alter the taxonomic and functional composition of soil microorganisms, along with the ecosystem functioning, thus arousing feedback of ecosystem responses to affect global climate.
Project description:Fire disturbances are becoming more common, more intense, and further-reaching across the globe, with consequences for ecosystem functioning. Importantly, fire can have strong effects on the soil microbiome, including community and functional changes after fire, but surprisingly little is known regarding the role of soil fire legacy in shaping responses to recent fire. To address this gap, we conducted a manipulative field experiment administering fire across 32 soils with varying fire legacies, including combinations of 1-7 historic fires and 1-33 years since most recent fire. We analyzed soil metatranscriptomes, determining for the first time how fire and fire legacy interactively affect metabolically-active soil taxa, the microbial regulation of important carbon (C), nitrogen (N) and phosphorus (P) cycling, expression of carbohydrate-cycling enzyme pathways, and functional gene co-expression networks. Experimental fire strongly downregulated fungal activity while upregulating many bacterial and archaeal phyla. Further, fire decreased soil capacity for microbial C and N cycling and P transport, and drastically rewired functional gene co-expression. Perhaps most importantly, we highlight a novel role of soil fire legacy in regulation of microbial C, N, and P responses to recent fire. We observed a greater number of functional genes responsive to the interactive effects of fire and fire legacy than those affected solely by recent fire, indicating that many functional genes respond to fire only under certain fire legacy contexts. Therefore, without incorporating fire legacy of soils, studies will miss important ways that fire shapes microbial roles in ecosystem functioning. Finally, we showed that fire caused significant downregulation of carbon metabolism and nutrient cycling genes in microbiomes under abnormal soil fire histories, producing a novel warning for the future: human manipulation of fire legacies, either indirectly through global change-induced fire intensification or directly through fire suppression, can negatively impact soil microbiome functional responses to new fires.
2024-08-12 | GSE274211 | GEO
Project description:Effect of fire on diversity of soil fungi
| PRJNA1025120 | ENA
Project description:LongTerm Prescribed Fire Soil Bacteria
| PRJNA847616 | ENA
Project description:Soil bacteria after the fire
| PRJNA1140733 | ENA
Project description:Effect of fire on diversity of soil arbuscular mycorrhizal fungi
Project description:Sensing environmental cues is essential for plants in order to respond properly to, adapt to and survive changes in the environment and disturbances. Smoke-derived germination active compounds are important cues which provide a strong chemical signal to seeds in the soil seed bank about the available germination niche created by the passage of fire. The germination stimulatory activity can largely be attributed to the presence of the butenolide, 3-methyl-2H-furo[2,3-c]pyran-2-one (karrikinolide; KAR1). More recently, a related fire-borne butenolide, 3,4,5-trimethylfuran-2(5H)-one (inhibenolide A; InhA), was shown to have an inhibitory effect on germination. The aim of this study was to extensively characterize the interaction of these potent smoke-derived compounds in the highly KAR1-sensitive Lactuca sativa cv. ‘Grand Rapids’ achenes.
Project description:Soil transplant serves as a proxy to simulate climate change in realistic climate regimes. Here, we assessed the effects of climate warming and cooling on soil microbial communities, which are key drivers in Earth’s biogeochemical cycles, four years after soil transplant over large transects from northern (N site) to central (NC site) and southern China (NS site) and vice versa. Four years after soil transplant, soil nitrogen components, microbial biomass, community phylogenetic and functional structures were altered. Microbial functional diversity, measured by a metagenomic tool named GeoChip, and phylogenetic diversity are increased with temperature, while microbial biomass were similar or decreased. Nevertheless, the effects of climate change was overridden by maize cropping, underscoring the need to disentangle them in research. Mantel tests and canonical correspondence analysis (CCA) demonstrated that vegetation, climatic factors (e.g., temperature and precipitation), soil nitrogen components and CO2 efflux were significantly correlated to the microbial community composition. Further investigation unveiled strong correlations between carbon cycling genes and CO2 efflux in bare soil but not cropped soil, and between nitrogen cycling genes and nitrification, which provides mechanistic understanding of these microbe-mediated processes and empowers an interesting possibility of incorporating bacterial gene abundance in greenhouse gas emission modeling.
Project description:Analysis of aquatic microbial communities revealed that parts of its diversity consist of bacteria with cell sizes of ~0.1 μm. Such bacteria can show genomic reductions and metabolic dependencies with other bacteria. So far, no study investigated if such bacteria exist in terrestrial environments e.g. soil. Here, we show that such bacteria also exist in soil. The isolated bacteria was identified as Hylemonella gracilis.Co-culture assays with phylogenetically different soil bacteria revealed that H. gracilis grows better when co-cultured with other soil bacteria. Transcriptomics and metabolomics showed that H. gracilis was able to change gene expression, behavior, and biochemistry of the interacting bacteria without direct contact. Our study revealed that bacteria are present in soil that can pass through 0.1 µm filters. Such bacteria may have been overlooked in previous research on soil microbial communities and may contribute to the symbiosis of soil bacterial communities.
2022-12-14 | MTBLS5841 | MetaboLights
Project description:soil bacteria community diversity