autecology of astragalus arpilobus kar. & kir, a promised species for restoration of the winter rangelands in the northeast of iran

studying the autecology of range plants provides the basic information on their ecological requirements, cultivation methods and the interactions with the prevailing environment. such information is necessary for a proper range management. some ecological characteristics of astragalus arpilobus kar. & kir., were studied in the winter rangelands of northern khorasan province. it was naturally growing in jargalan, bojnourd, where the altitudinal range varied 500-600 a.s.l, slope 20-100%, and the average annual rainfall 236.85 mm. soil properties were: loamy texture, average organic matter, low fertility, ph 7.32 and ec 2.30 ds.m-1. a. aripilobus started vegetative growth at the early march, flowering during early may, seed production during june, and terminated its yearly growth at early july. the highest nutritive values and forage quality were at the beginning of growth, which was gradually decreased towards the end of growth season. crude protein (cp), and ash were decreased whereas acid detergent fiber (adf), natural detergent fiber (ndf), and dry matter (dm) increased by the growing season. seeds were easily established within pots; however, seed germination rate was low (24%), which by sand paper scarification was increased up to 51%. in conclusion, feasibility of seedling establishment, high nutritive value, and concurrence of plant phenology with the time of maximum need to fodder, by livestocks, propose a. arpilobus as a promising forage plant species for restoration of the winter rangelands in northern khorasan province.