effect of surface and distribution plot of the estimated species richness in three plans whittaker, stohlgern and a new proposal (ariz), (case study: ghat ranges sanandaj)

vegetation studies measuring the accuracy of the results is important. the purpose of this study is to compare shape and distribution plots on different levels for species richness measurements.thiscomparison was in three design whittaker, stohlgern and a new design (ariz) in ariz, sanandaj.designed proposition (ariz) obtainedon base changes in the size and distribution plotin design stohlgern species richness is designed to measure accurately. this study was conducted with three replications in grassland vegetation type. compare plans were originally wooden and rope was walking in the area, and then proceed to the species in the plots were counted. data analysis and statistical methods in factorial completely randomized design was performed using spss software version 17. the results showed that the three estimates of species richness are having a significant difference in the estimation of species richness and stohlgern plan and whittaker are significantly different in the level 0.01. whittaker plans and proposal (ariz) in this study are the significantly different in the level 0.01 but stohlgern plan and ariz design are significantly different in the level 0.05.