fire consider as a factor and basic management in rangeland in order to reform of composition and biological diversity that use in rangeland ecosystems. this project was established to deal with the effect of fire in the research center for rangeland. zagheh locale where is in 35 km of north eastern of khoramabad with 1960 meters above sea level. the average comparison and analysis show that he...

An elevated concentration of water soluble carbohydrate (WSC) in grasses may increase the availability of readily degradable energy, increase milk production and improve the efficiency of nitrogen utilisation. Two ryegrasses with elevated WSC, a tetraploid Italian (IRG) and a diploid perennial selected for higher WSC (HSG), were compared against a standard diploid perennial (STG) during spring ...

Understanding the relative importance of various functional groups in minimizing invasion by medusahead is central to increasing the resistance of native plant communities. The objective of this study was to determine the relative importance of key functional groups within an intact Wyoming big sagebrush–bluebunch wheatgrass community type on minimizing medusahead invasion. Treatments consisted...

The Columbia root-knot nematode Meloidogyne chitwoodi parasitizes several plant species, including grasses that have been developed for semiarid environments, and substantially reduces the productivity of cereals and the longevity of perennial grasses growing under semiarid conditions throughout the intermountain region. Thirty-two auto- and allotetraploid (2n = 28) taxa in the perennial Tritic...

Biomass crops are being promoted as environmentally favorable alternatives to fossil fuels or ethanol production from maize (Zea mays L.), particularly across the Corn Belt of the United States. However, there are few if any empirical studies on inorganic N leaching losses from perennial grasses that are harvested on an annual basis, nor has there been empirical evaluation of the hydrologic con...

To assess the potential for enhancing an existing stand of native perennial grasses on a California Coast Range Grassland site, we experimentally manipulated the seasonal timing and presence of grazing for 3 years (1994 through 1996) and of autumn burning for 2 years (1994 and 1995) and measured species cover for 6 years (1993 through 1998). We subjected the species matrix to classification (TW...

Changes in species richness and productivity in a Mediterranean dwarf-shrub community were documented during 5 years following treatments intended to improve soil fertility and reduce shrub cover. Five treatments, replicated five times, were tested: (a) shrub cover reduction by selective herbicide application; (b) application of medium levels of phosphorus; (c) application of high doses of phos...