ABSTRACT Understanding how soil mesofauna respond to altered precipitation and warming is essential for assessing dryland ecosystem vulnerability under climate change. We used two decade‐scale field experiments in a Stipa breviflora desert steppe of Inner Mongolia: continuous infrared warming (+1.5°C since 2006) and precipitation manipulation (±30% since 2008). Rainfall addition increased mesofaunal abundance and genus richness in the surface layer (0–5 cm) and increased total community biomass when pooled across 0–15 cm, whereas rainfall reduction caused limited changes relative to the rainfall control. Warming reduced total biomass at the pooled 0–15 cm scale and lowered mean body weight without changing mean body length, while abundance remained unchanged across soil layers. Genus richness responded in a depth‐dependent manner under warming, decreasing in 0–5 cm but increasing in 10–15 cm. Order‐level analyses showed selective responses to rainfall addition (increased Prostigmata in surface soil and pooled 0–15 cm, and increased Oribatida in 5–10 cm), whereas warming effects were not significant at the order level. Co‐occurrence network analysis revealed pronounced structural contrasts among treatments: rainfall addition greatly expanded network size and connectivity, whereas warming reduced network size and connectivity and increased the proportion of negative links. Together, these results indicate that biomass‐ and trait‐based metrics, as well as network structure, can reveal climate‐driven changes in soil mesofauna even when abundance responses are weak, highlighting potential implications for belowground functioning in desert steppe ecosystems.
Hu et al. (Sun,) studied this question.