Abstract

Rangelands are critical socio-ecological systems, yet they are increasingly threatened by land degradation driven by inadequate grazing management. This study evaluates the effects of livestock management (grazing vs. long-term exclusion), plant community type, and microsite structure (patch vs. inter-patch) on key soil physical properties in the Chilean Magellanic steppe. Five contrasting plant communities were assessed through a factorial design incorporating grazing regime and microsite conditions. Measurements included bulk density, penetration resistance, total porosity, and soil moisture. Our results revealed that soil physical properties are strongly influenced by plant community, management, and microsite. Bulk density and penetration resistance were significantly higher in grazed sites, particularly in Tussock Grass and Small Grasses communities, where values exceeded critical compaction thresholds (>2000 kPa). Conversely, long-term grazing exclusion reduced bulk density by up to 57% in inter-patch areas, suggesting potential for structural recovery. Inter-patch areas consistently retained more moisture than patches, likely due to reduced evapotranspiration. Notably, the degraded state of Small Grasses and Vega soils was corroborated by physical indicators and vegetation composition. These findings underscore the importance of incorporating vegetation heterogeneity and landscape structure into rangeland management. Soil physical properties, particularly under contrasting grazing regimes, serve as reliable indicators for diagnosing degradation and guiding restoration in dryland ecosystems.