The comparing of plot size in estimating the quantitative characteristics of species in enclosure and non enclosure rangelands of Calpush plain.

Selecting the suitable shape and area of plot is very effective in sampling efficiency in vegetation studies and causes the least variance and time of sampling. to this purpose، for reduction of sampling time and increase of work speed comparing the plot size in estimating the quantitative characteristics of species (containing canopy cover percentage and density of species) in either enclosure and non enclosure area. For do this research، first established 1m2 plots and daubenmire (25*60 cm) plots randomly in the case study in two enclosure and non enclosure area and registered canopy cover percentage and density of species in each plot. Analysed and compared statistically data get of the plots with different size in inside and outside of enclosure. results get showed that vegetation type، plants distribution and measuring variable type have intensive effect on plot size and shape، according as optimum plot size differ for estimating the quantitative characteristics of species in two enclosure and non enclosure area. Therefore seem it is better using 1m2 plots and daubenmire plots for estimating the canopy cover and density in non enclosure and enclosure area respectively.