Abstract :
: Rangeland is a natural ecosystem involving huge resources of genetic reservoirs and a variety of plant species and this biodiversity always ensures range’s stability against bio-environmental factors. One of the destructive physical pressures posed on the range, which resulted in a decrease in biodiversity and destroys sensitive plant factors, is overgrazing. Range enclosure is one of the methods used to revive vegetation since an increase in the density of plants in enclosed areas enhances on-the-soil shield, and consequently its stabilization and permanency, and reduces soil wastes and sediment production. In order to study the effect of grazing on the rate of rangeland production, considering this point, tow distinct enclosures and grazed areas are selected (in Anablaghi rangeland, located in 50 km from west of Khotbe Sara village, Talesh city). The minimum sample frame area of 1 m2 was achieved, using Spiral Plots method. Based on Dominant Species Collective Average method, 40 frames were specified in each unit, through Systematic – Random method, across 4 transects in 100 m2 and were set up in 50m from each other. The percentage of composition, species diversity, forage production and palatability and their growing form were recorded. Statistical results show that the total annual production of species in the enclosure increased 2.5 times more than those of outside the enclosure and the production percentage of class I and III species markedly differed inside and outside the enclosure but this difference did not exist in class II. As to the species cover, abundance of class I and class II species was greater inside the enclosure and that of class III was greater outside the enclosure. In fact, the main portion of cover outside the enclosure is of class III species. Thus, respecting the significant enclosure effects in terms of increased production of rangeland species, in comparison with increased plant composition, it is proposed to use rangeland enclosure as an administrative tool in identical continents so that more areas of ranges can be devoted to this project. Consequently, increased forage production, encouraging range owners to use enclosure and leading them toward adopting open herding and semi-industrial ranching are among positive effects of such researches.
