Soil Chemical Patterns under Eastern Oregon Plant Communities Dominated by Big Sagebrush

Abstract

The objectives of this study were (i) to examine soil nutrient patterning in eastern Oregon plant communities dominated by subspecies of Artemisia tridentata Nutt., and (ii) to compare soil nutrient levels between adjacent sites characterized by contrasting amounts of sagebrush and perennial grasses. Horizontal and vertical soil chemical patterns were evident on all sites. Surface concentrations of nutrients were greates tunder shrubs in comparison to interspace and grass influenced soils. Values of total N, organic matter, K, and P tended to decrease with depth, while Mg concentrations generally increased in lower soil horizons. Soil pH was generally lower in upper soil horizons. Soil chemical differences between shrub, interspace and bunchgrass influenced soils became less distinct with increased soil depth. Differences in soil chemical levels between sites with a high proportion of perennial grasses to shrubs and sites with a low proportion of perennial grasses to shrubs were noted. However, no consistent patterns were evident.

Genetic structure of Greater Sage-Grouse (Centrocercus urophasianus) in a declining, peripheral population

“…This creates a heterogeneous distribution of nutrients with resource-rich patches surrounding perennial plants and resource-poor interspaces (Charley and West 1977, Doescher et al 1984, Bolton et al 1993, Jackson and Caldwell 1993, Halvorson et al 1995, Ryel et al 1996.…”

Growth and elemental content of several sagebrush-steppe species in unburned and post-wildfire soil and plant effects on soil attributes

“…In sagebrush ecosystems, nutrients and fuel are heterogeneously distributed; they are concentrated in soil beneath shrub canopies while shrub interspaces are impoverished (Charley and West, 1977;Doescher et al, 1984). The heterogeneous environment dictates that the immediate focus of heat-induced changes, as a consequence of fire, is the soil beneath sagebrush canopies; initially, shrub interspaces are largely unaffected by the fire (Blank et al, 1994).…”

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

“…Calcium also remained homogenous between the microv www.esajournals.org sites in the PLWC and Atherley sites in the Acana soils and, conversely, became patchy within the Druehl site. Even though this suggests that the resource island have not re-established in these sites, Ca does not consistently develop a resource island effect across Artemisia shrublands (Charley and West 1975, Doescher et al 1984, Burke et al 1989, Chambers 2001. Since these were the only differences in soil fertility patterning detected, we suggest that the resource island patterns have Fig.…”

“…Both C and N are often depleted in formerly cultivated soils (Burke et al 1995, McLauchlan 2006. Furthermore, K and bicarbonate-extractable P are typically more concentrated at the soil surface within shrub communities (Doescher et al 1984, West et al 1984, and their content could be diluted through soil mixing. There were no instances in our study in which the overall mean values for C or N were different between cultivated and native conditions, yet there were significant differences between microsites for these soil measures, which is also consistent with other studies (Bolton et al 1993, Robertson et al 1993.…”

“…Plantsoil and ecogeomorphic feedbacks also contribute to the formation and maintenance of resource islands, which may assist in the perpetuation of woody vegetation (Charley and West 1975, Doescher et al 1984, Schlesinger et al 1990, Stavi et al 2009, Ravi et al 2010. 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).…”