Temperature Mainly Determined the Seasonal Variations in Soil Faunal Communities in Semiarid Areas

The implementation of the Grain for Green Project has increased vegetation coverage and provided suitable habitats and food resources for soil fauna, thereby promoting the development of soil faunal communities. Studying seasonal variations in soil fauna communities in different vegetation areas can improve our understanding of the mechanisms that drive soil fauna recovery. We selected five typical artificially restored vegetation habitats, including <i>Populus simonii</i> (POS), <i>Pinus tabulaeformis</i> (PIT), <i>Caragana korshinskii</i> (CAK), <i>Stipa bungeana</i> (STB), and <i>Medicago sativa</i> (MES), and one farmland (<i>Zea mays</i>, FAL) habitat on the Loess Plateau. In this study, soil fauna communities and environmental factors were investigated during spring (May), summer (August), and autumn (November). Among the habitats, the STB habitat had the largest seasonal variation in soil faunal density (from 1173 ind·m⁻² in May to 10,743 ind·m⁻² in August), and the FAL habitat had the smallest (from 2827 ind·m⁻² in August to 5550 ind·m⁻² in November). Among the restored vegetation habitats, Acarina (44.89–88.56%) had the highest relative abundance of all taxa. The redundancy analysis (RDA) results showed that among the factors driving seasonal variation in soil animal communities, temperature (47.41%) was the most important, followed by precipitation (22.60%). In addition, the dominant groups, Acarina and Collembola, played an influential role in seasonal variations in soil faunal density. Temperature mainly determined the seasonal variations in soil faunal communities. Seasonal factors should be considered when conducting soil fauna research, as they contribute to biodiversity conservation and regional ecological management in the Loess Plateau.