in natural ecosystems, biological relationships have serious effects on system stability. allelopathic is negative or positive effect of a plant on other plant growth. today this word is used for rangelands, same as agricultural areas. because of good herbage production, medicago is most common plant in agricultural rotations and rangelands. therefore investigation of its allelopathic qualities...

West Nile virus has undergone an unprecedented rate of infection in North America, sweeping from New York to California in four years. It attacked an exceptionally broad range of hosts/vectors over a broad geographic area. In 2004, the California Department of Health Services received approximately 98,000 reports of dead birds, representing tens of millions of birds killed by West Nile virus in...

In this review, the author discusses how pastoralism, and its many constituent components, is increasingly being recognised as in tune with the changing political and ecological nature of rangelands. He describes ways in which the literature reflects this changing attitude, outlines how rangelands respond to changes in climate and explores the evolving use of livestock resources. In addition, h...

Article history: Received 6 July 2005 Received in revised form 11 October 2005 Accepted 21 October 2005 Available online 4 January 2006 Global Climate Change (GCC) can bring about changes in ecosystems and consequently in their services value. Here we show that the urban population in Israel values the green landscape of rangelands in the mesic Mediterranean climate region and is willing to pay...

PURPOSE: Yellow starthistle is one of most problematic invasive species in grass and rangelands in the western United States. It has expanded its distribution since the 1950’s threatening native species’ diversity and reducing the utility of rangelands for livestock. Control of yellow starthistle has relied heavily on the use of picloram and clopyralid. Although these herbicides have been widel...

Rangelands are known as one of the main income resources for their exploiters.In the recent century, management of Iran rangeland has undergone vast transformationsbecause of vulnerable socio-economic conditions of pastoralists. A study was done toprovide a clear picture of the status and utilization of Aq Qala rangelands via assessinginternal and external environmental factors affecting the ut...

sepals and petals are byproducts from saffron production process that waste without any use in iran. these byproducts containing a lot of anthocyanin and natural antioxidants.the aim of this study is determine efficiency of extraction and measurement of antioxidant activity and anthocyanin pigments of pollen and anther of saffron flower ,using mixed solvent of ethanol and hydrochloridic acid 1....

Biomass, one of the most important renewable energies, is playing and will continue to play an important role in the future energy structure of the world. This article aims to analyze the position and role, assess the resource availability, discuss the geographic distribution, market scale and industry development, and present the policy options of biomass in China. The resource availability an...