Fire Effects on the Spatial Patterning of Soil Properties in Sagebrush Steppe, USA: A Meta-Analysis

Understanding effects of changes in ecological disturbance regimes on soil properties, and capacity of soil properties to resist disturbance, is important for assessing ecological condition. In this meta-analysis, we examined the resilience of surface soil properties and their spatial patterning to disturbance by fire in sagebrush steppe of North America – a biome currently experiencing increases in wildfire due to climate change. We reviewed 39 studies that reported on soil properties for sagebrush steppe with distinct microsite (undershrub and interspace) patterning that was or was not recently burned. We estimated microsite effects for 21 soil properties and examined the effect of burning on microsite effects during the first year post-fire, before the re-establishment of vegetation. Results indicated that the spatial patterning of biogeochemical resources, in which soil surfaces beneath shrubs are enriched, is resilient to burning. However, microsite effects for soil-surface hydrologic, temperature and erosion characteristics appeared to shift following burning. These shifts appear to create a negative feedback for the spatial patterning of soil properties before vegetation recovery. Relatively long (decades–centuries) historic fire intervals in sagebrush steppe ecosystems likely reinforce spatial patterning of soil resources. However, increased fire frequency might affect the ability for soil resources to withstand change.