in arid and semi-arid ecosystems, shrubs may act as fertility islands but theireffect may vary depending on their morphology and ecological impacts. this research wasaimed to study effect of three shrubs scariola orientalis, astragalus heratensis, and rosapersica on soil properties and on the microclimate conditions (temperature, luminance, andsoil moisture) of their understory in the steppe ra...

Calibrated predictive relationships obtained from simple and multiple regression of thematic mapper or broad-band (BB) and 1.4 nm interval or narrow-band (NB) spectral data were evaluated for quantifying 11 rangeland components (including total vegetation, forb, grass, shrub, litter, and bare soil) and distinguishing among 6 long-term grazing treatments of sagebrush steppe. In general, all 4 da...

Fire is thought to profoundly change the ecology of the sagebrush steppe. The Idaho National Laboratory provides an ideal setting to compare the effects of fire and physical disturbance on plant diversity in high-native-cover sagebrush steppe. Seventy-eight 1-hectare transects were established along paved, green-striped, gravel, and two-track roads, in overgrazed rangeland, and within sagebrush...

annual fires might change many soil physical properties in semi steppe rangeland.the objective of this study was to investigate the impact of fire on soil physical properties and soil water infiltration parameters in semi-steppe rangeland of karsanak region in chaharmahal and bakhtiari province. therefore, several sites were chosen which were affected by fire at three, two and one years prior t...

WILLIAM A. REINERS Department of Botany University of Wyoming PO Box 3165 Laramie, Wyoming 82071-3165, USA ABSTRACT / Carbon sequestration was estimated a northern mixed-grass prairie site and a sagebrush–steppe site in southeastern Wyoming using an approach that integrates remote sensing, CO2 flux measurements, and meteorological data. Net ecosystem exchange (NEE) of CO2 was measured using air...

Prescribed fire in rangeland ecosystems is applied for a variety of management objectives, including enhancing productivity of forage species for domestic livestock. In the big sagebrush (Artemisia tridentata Nutt.) steppe of the western United States, fire has been a natural and prescribed disturbance, temporarily shifting vegetation from shrub–grass codominance to grass dominance. There is li...

al., 1994). Summed to 1-m depth, SOC content was not different between cropland and conservation reserve. Estimates of potential soil organic C (SOC) and total N (TN) In a shortgrass-steppe with 56 yr of grazing in Colorado, sequestration at depths below the traditional plow layer (i.e., 0–0.3 m) in agricultural systems are needed to improve our understanding of SOC was not different between un...

semi-steppe rangelands are a complex, highly dynamic and often multi-layered mosaic of grassland, shrubland, and intermediate communities. a few recent studies have explicitly or implicitly developed synthetic hypotheses about how interactive effects of human made disturbances initiate dynamic changes in plant community composition to cause a shifting mosaic of vegetation pattern across the lan...

Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass invading rangelands in the western United States. Medusahead is a serious management concern because it decreases biodiversity, reduces livestock forage production, and degrades the ecological function of rangelands. Despite the obvious importance of ranchers as partners in preventing and managing medusahead in rangel...