Fire effects on the spatial patterning of soil properties in sagebrush steppe, USA: a meta-analysis

Abstract

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.

Sagebrush steppe recovery on 30–90‐year‐old abandoned oil and gas wells

“…However, today up to 48 percent of these big sagebrush ecosystems have been modified as a result of accidental or intentional fire, conversion to dominance by invasive species, intentional shrub removal to improve perennial grass forage, conversion to cropland, and exurban or energy development (Knick et al 2003, Connelly et al 2004, Sankey et al 2012. Energy development in the form of oil and gas production first occurred early in the 20th century and has recently increased rapidly.…”

“…The type of disturbance (e.g., fire, shrub removal, land use change), the pre-disturbance plant community including subspecies of big sagebrush, soil conditions, and climatic conditions during big sagebrush reestablishment all influence the recovery of big sagebrush plant communities (Anderson and Inouye 2001). For example, disturbances such as fire affect surface soil characteristics of shrub and intershrub microsites and thereby can influence plant community recovery (Sankey et al 2012). Watts and Wambolt (1996) studied recovery in four different types of disturbance treatments, and their results suggested that Wyoming big sagebrush plant communities recover at different rates depending upon disturbance type.…”

Natural recovery of soil organic matter in 30–90‐year‐old abandoned oil and gas wells in sagebrush steppe

“…This fine-scale heterogeneity in soil organic matter, which is concentrated under individual shrubs relative to interspaces, is a well-recognized feature of sagebrush ecosystems, with indications that it is responsive to changes in ecosystem management (Burke et al 1987, Sankey et al 2012b.…”

Long‐term redevelopment of resource islands in shrublands of the Great Basin, USA

“…For example, deposition of soil and litter under shrubs can create more porous conditions that increase infiltration and water availability for shrubs (Stavi et al 2009). Although resource islands are common in many arid and semi-arid ecosystems around the world, their role in either degradation or stability of ecosystems can differ (Stavi et al 2009, Sankey et al 2012. In arid grassland systems, formation of resource islands is recognized as a form of degradation resulting from woody-shrub encroachment into grasslands where soil nutrients were previously more homogenous (Schlesinger et al 1990, Stavi et al 2009, Ravi et al 2010.…”

“…With under-shrub and interspace differences playing such a central part in Artemisia ecosystem functioning, management practices that disturb the soil (e.g., seeding, chaining, and amendments) and possibly alter this heterogeneity need to be explored to determine how they affect ecosystem resilience (Charley and West 1975, Sankey et al 2012. However, little is known about the duration of time necessary for resource islands to reform after soils are homogenized by human disturbance.…”