High-mountain agro-pastoral ecosystems are threatened by climate change, which alters plant–soil interactions. Soil mites are key bioindicators of soil functional integrity. This study investigates the ecological niches and temporal dynamics of mite assemblages in Maiella National Park (central Apennines, Italy), focusing on how the soil physical and hydrological properties (porosphere), floristic diversity and micro-refugia sustain community resistance to climatic stress. From 2021 to 2024, a porosphere-centered monitoring program was conducted in autumn at two high-altitude sites (CDX, CSX). We integrated climatic, pedological, and botanical data with taxonomical and functional Acari profiling. In 2024, the protocol included soil functional indicators, such as key enzymatic activities (C, P, and N cycles), microbial biomass (dsDNA), and advanced physical parameters including pore-size distribution and water retention properties. All abundance data were ln(N+1)-transformed prior to analysis. A community of 49,299 edaphic arthropods was recorded, dominated by Acari (76%). Linear mixed models showed no significant site or year effects, but Pearson correlations revealed a strong relationship between small-bodied mites (e.g., Nanorchestidae) and storage pore volume (0.5–50 µm). This highlights a niche-filtering process where the porosphere serves a dual function: as a hydrological reservoir sustaining microbial activity during dry periods, and as a trophic ‘larder’. Although these mites are too large to enter the smallest pores, they use specialized mouthparts to graze on fungal and bacterial biofilms hosted within, ensuring a stable food supply and physical protection. Larger-bodied Oribatida (e.g., Galumnidae, Nothridae)— K-strategists and soil engineers— are correlated to total organic carbon (TOC), playing role as indicators of functional soil maturity, porosphere integrity, and ecosystem resilience in carbon-rich mountain matrices. Notably, Astigmata related positively with cover grass and negatively to microbial activity (FDA), suggesting a role as opportunistic colonizers that bypass the microbial decomposition chain to feed directly on fresh plant detritus or exudates. This inverse relationship may also reflect local niche exclusion where high microbial metabolism or root competition creates conditions less favorable for Astigmata compared to other groups. Predator mites were correlated with other functional mite groups, indicating that the diversity of prey guilds– rather than prey abundance alone – supports predator establishment and shapes trophic structure within the soil food webs. Overall, mite communities maintained high functional integrity, demonstrating that soil architectural complexity acts as a critical biophysical buffer, sustaining ecosystem resilience and nutrient cycling against environmental stress.