Application of statistical indices in selecting appropriate transect length for measurement of vegetation cover (Case Study: semi-steppe rangelands of Ariz, Sanandaj)

Collection of appropriate quantitative data is necessary for proper management and planning in rangelands. One of the ways to access this information is choosing the appropriate methods of sampling and determining the appropriate length of transect for vegetation cover measurement. Therefore, this study was conducted in 2016 in Ariz rangelands located in the northwestern of Sanandaj city. For this purpose, transects with a length of 20, 50, 100, 150, 200, 300 and 400 meters, each with four replications were established perpendicular to slope and parallel to slope in the vegetation type of Bromus tomentellus - Festuca ovina. The 400-m transect was considered as a control for calculations. The obtained data from sampling were compared by ANOVA. The obtained results from different transect lengths were also compared by (E%) 2×T factor. The mean comparisons of vegetation cover percentage of transects were performed using t-student test. According to the results of this study, the transects of 20, 50, 100 and 150m length showed a significant difference with the control transect (400 m) in terms of accuracy index ((E%) 2 × T). However, there was no significant difference among the transects of 200, 300 and 400 meters length for the accuracy index. Therefore, the application of 200-meter transect is recommended regarding the cost and time.