Comparison of Distance Indicators and Quadrate Indicators in Determining Dispersion Pattern of Fritillaria imperialis L. in Ilam

Crown imperial have been distributed in Zagros regions in Ilam according to soil structure and organic matter. This plant has played an important role in the beautification of the environment, tourist attraction, and the supply of plant essential oils used in the production of medicines. The current research was carried out to evaluate the spatial distribution pattern of Fritillaria imperialis in Ilam (Manesht and Ghalarang regions) and to compare distance and quadrate method in 2014. Sampling program was randomsystematic just for transects with the length of 100 meters within the extent of 4300 hectares. Distance methods including t2, Hopkins, Holgate, Johnson and Zimmer and Pielou; and quadrate methods including Taylor, Iwao, Morisita, K and CV were used to determine the spatial distribution pattern of crown imperial. Results showed that the quadrate method (Morisita and CV) and distance method (Holgate and Peilou) evaluated the spatial distribution pattern of crown imperial to be a random pattern. But, the results of quadrate methods (Taylor, Iwao, and K) and distance methods (Hopkins, t2 and Johnson and Zimmer) evaluated a clumped pattern for this species in the study area. It was shown that the distance methods outperformed quadrate methods in accuracy. Also, t2 and Hopkins indexes were the best distance methods to identify the pattern. Iwao and K indexes were the best ones among quadrate methods. Overall, it was revealed that Iwao, K, t2, and Hopkins had the highest and CV, Morisita, Holgate and Pielou had the lowest accuracy.