Soil storage temperature and air-drying did not significantly change bacterial taxa in the short-term

Analysing soil microbial communities is vital for understanding ecosystem health, but samples from remote locations often require preservation before DNA can be extracted. In this study, we used the 16S rRNA amplicon sequencing to investigate how different storage methods affect soil microbial diversity over 4 weeks. We implemented storage temperature and moisture as two experimental factors. Three topsoils (sandy, silty loam, and clay loam) were collected and stored under four conditions: frozen at -20 °C, refrigerated at 4 °C, room temperature, and air-dried. DNA extractions and sequencing were performed at 1, 3, 7, 14, and 28 days. Our results revealed that storage temperature and moisture did not substantially change bacterial diversity and composition across all three soil types. Rare taxa showed a similar pattern to abundant taxa but were more variable in beta diversity. Overall, all tested methods effectively preserved both abundant and rare taxa in the short term. However, the long-term impacts of the sample storage, particularly on rare taxa, need further exploration.